Engine Management – HSV - Gen IV V8 Page 6C4–1

Page 6C4–1

Section 6C4

Engine Management – HSV - Gen IV V8

1 Component Replacement......................................................................................................................3

1.1 Accelerator Pedal Position (APP) Sensor............................................................................................................ 3

Remove................................................................................................................................................................... 3

Reinstall.................................................................................................................................................................. 4

1.2 Accelerator Pedal Position (APP) Sensor Support Bracket............................................................................... 5

1.3 Air Cleaner Assembly............................................................................................................................................ 6

Air Cleaner Upper Housing................................................................................................................................... 6

Remove.............................................................................................................................................................. 6

Reinstall ............................................................................................................................................................. 6

Air Cleaner Lower Housing................................................................................................................................... 7

Remove.............................................................................................................................................................. 7

Reinstall ............................................................................................................................................................. 7

1.4 Engine Control Module (ECM) .............................................................................................................................. 8

Remove................................................................................................................................................................... 8

Reinstall.................................................................................................................................................................. 9

1.5 Engine Control Module (ECM) Bracket Assembly ............................................................................................ 10

Remove................................................................................................................................................................. 10

Reinstall................................................................................................................................................................ 10

1.6 EVAP Canister Purge Solenoid Valve ................................................................................................................ 11

Remove................................................................................................................................................................. 11

Reinstall................................................................................................................................................................ 11

1.7 Heated Oxygen Sensors (HO2S)......................................................................................................................... 12

Service Precautions............................................................................................................................................. 12

Remove................................................................................................................................................................. 12

Reinstall................................................................................................................................................................ 13

Test ....................................................................................................................................................................... 13

Front Sensors................................................................................................................................................... 13

Rear Sensors ................................................................................................................................................... 14

1.8 Intake Air Temperature (IAT) Sensor.................................................................................................................. 15

Test ....................................................................................................................................................................... 15

Resistance Check ............................................................................................................................................ 15

1.9 Mass Air Flow (MAF) Sensor and Intake Air Duct............................................................................................. 16

Remove................................................................................................................................................................. 16

Reinstall................................................................................................................................................................ 17

1.10 Throttle Body........................................................................................................................................................ 18

Handling Precautions.......................................................................................................................................... 18

Remove................................................................................................................................................................. 18

Inspect .................................................................................................................................................................. 19

Reinstall................................................................................................................................................................ 20

1.11 Camshaft Position (CMP) Sensor Replacement................................................................................................ 21

Removal Procedure............................................................................................................................................. 21

Installation Procedure ......................................................................................................................................... 22

Techline

Engine Management – HSV - Gen IV V8 Page 6C4–2

Page 6C4–2

2 Fastener Tightening Specifications ...................................................................................................23

3 MY2004 HSV VZ LS2 Diagnostic Trouble Codes...............................................................................24

4 Diagnostics...........................................................................................................................................30

4.1 DTC P0513, P0633, P1629, P1632, P1648, P1677, P1678, and P1679 – Immobiliser Signal........................... 30

DTC Description................................................................................................................................................... 30

Circuit Description............................................................................................................................................... 30

Condition for Running the DTCs........................................................................................................................ 31

Condition for Setting the DTCs........................................................................................................................... 31

Conditions for Clearing the DTCs ...................................................................................................................... 31

Additional Information......................................................................................................................................... 31

Test Description................................................................................................................................................... 31

Diagnostic Table for DTC P0513, P0633, P1629, P1632, P1648, P1677, P1678, and P1679 ........................... 32

4.2 DTC P1575 – Extended Travel Brake Switch Failure ........................................................................................ 33

Circuit Description............................................................................................................................................... 33

DTC Descriptor..................................................................................................................................................... 33

Conditions for running the DTC ......................................................................................................................... 33

Conditions for setting the DTC........................................................................................................................... 33

Action taken when the DTC sets ........................................................................................................................ 33

Conditions for clearing the MIL/DTC.................................................................................................................. 33

Diagnostic Aids.................................................................................................................................................... 33

Test Description................................................................................................................................................... 33

Diagnostic Table for DTC P1575......................................................................................................................... 34

4.3 DTC P0719 – Brake Switch Failure..................................................................................................................... 35

Circuit Description............................................................................................................................................... 35

DTC Descriptor..................................................................................................................................................... 35

Conditions for Running the DTC........................................................................................................................ 35

Conditions for Setting the DTC........................................................................................................................... 35

Action Taken When the DTC Sets ...................................................................................................................... 35

Conditions for Clearing the DTC ........................................................................................................................ 35

Diagnostic Aids.................................................................................................................................................... 35

Test Description................................................................................................................................................... 35

Diagnostic Table for DTC P0719......................................................................................................................... 36

4.4 DTC P0724 – Brake Switch Failure..................................................................................................................... 38

Circuit Description............................................................................................................................................... 38

DTC Descriptor..................................................................................................................................................... 38

Conditions for Running the DTC........................................................................................................................ 38

Conditions for Setting the DTC........................................................................................................................... 38

Action Taken When the DTC Sets ...................................................................................................................... 38

Conditions for Clearing the DTC ........................................................................................................................ 38

Diagnostic Aids.................................................................................................................................................... 38

Test Description................................................................................................................................................... 38

Diagnostic Table for DTC P0724......................................................................................................................... 39

Engine Management – HSV - Gen IV V8 Page 6C4–3

Page 6C4–3

1 Component Replacement

1.1 Accelerator Pedal Position (APP) Sensor

Remove

1 Turn the ignition switch off.

2 Remove the screw (1) retaining the vacuum tank (2).

Take care not to damage the hose connected

to the vacuum tank.

3 Manoeuvre the vacuum tank out from under the

instrument panel and place to one side.

Figure 6C4 – 1

NOTE

If difficulty is experienced in disconnecting the

harness connector from the A PP sensor, remove

the sensor from the APP support bracket and

then disconnect the harness c onnector.

4 Disconnect the wiring harness connector (1) from the

Accelerator Pedal Position (APP) sensor (2) by

depressing the latch in the direction of the ar row.

Figure 6C4 – 2

Engine Management – HSV - Gen IV V8 Page 6C4–4

Page 6C4–4

5 Remove the bolt (1) in two places, attaching the APP

sensor (2) to the Accelerator Pedal Position (APP)

sensor support bracket (3).

6 Slide the APP sensor upwards in the direction of the

arrow, to disengage the sensor from the support

bracket.

Figure 6C4 – 3

Reinstall

Reinstallation of the APP sensor is the reverse of the removal procedure, noting the following:

Make sure that the APP sensor engages the

APP support bracket, refer to Figure 6C4 – 3.

1 Reinstall the bolt, two places, attaching th e APP sensor to the supp ort bracket and tighten to the correct torque

specification.

APP sensor attaching bolt

torque specification...................................7.0 – 12.0 Nm

2 Road test the vehicle and check for correct operation.

Engine Management – HSV - Gen IV V8 Page 6C4–5

Page 6C4–5

1.2 Accelerator Pedal Position (APP) Sensor

Support Bracket

The Accelerator Pedal Position (APP) Sensor Support Bracket is integral with the brake pedal support bracket assem bl y,

refer to Section 5A Service and Park Braking System.

Engine Management – HSV - Gen IV V8 Page 6C4–6

Page 6C4–6

1.3 Air Cleaner Assembly

Air Cleaner Upper Housing

Remove

1 Turn the ignition switch off.

2 Remove the upper radiator shroud, refer to Section 6B4 Eng ine Cooling – Gen IV V8 Engine.

3 Remove the air duct, refer to 1.9 Mass Air Flow (MAF) Sensor and Intake Air Duct.

4 Remove the screw (1), three places, attaching the air

cleaner upper housing (2) to the air cleaner lower

housing (3).

5 Remove the upper housing and air cleaner

element (4).

Figure 6C4 – 4

Reinstall

Reinstallation of the air cleaner upper housing is the reverse of the remo val procedure, noting the foll owing:

1 Reinstall the air cleaner element.

Make sure that the air cleaner sealing rubber

is correctly located in the air cleaner lower

housing during installation. Failure to do this

may result in engine damage due to unfiltered

air entering the engin e air intake s ystem.

2 Reinstall the screw, in three places, attaching the air cleaner upper hous ing to the air cleaner lower housing an d

tighten to the correct torque specification.

Air cleaner upper housing attaching

screw torque specification...........................2.0 – 3.0 Nm

3 Road test the vehicle and check for correct operation, taking particular note that no air leaks are evident.

Engine Management – HSV - Gen IV V8 Page 6C4–7

Page 6C4–7

Air Cleaner Lower Housing

Remove

1 Turn the ignition switch off.

2 Remove the air cleaner upper housing as described previously.

3 Fully loosen the stud (1), three places, attaching the

air cleaner lower housing (2) to the fender inner panel.

NOTE

The stud and air cleaner housing insulator are

removed with the air cleaner housing.

4 Disengage the air cleaner air inlet duct (3) from the

lower housing. Remove the lo wer ho using.

Figure 6C4 – 5

5 If required, remove the stud (1) and air cleaner

housing insulator (2) from the air cleaner lower

housing.

Figure 6C4 – 6

Reinstall

Reinstallation of the air cleaner assembly is the reverse of the removal procedure, noting the following:

1 Reinstall the stud, three places, attaching the air cleaner lo wer housing to the fender inner panel and tighten to the

correct torque specification.

Air cleaner lower housing attaching

stud torque specification ...........................7.5 – 12.5 Nm

2 Road test the vehicle and check for correct operation, taking particular note that no air leaks are evident.

Engine Management – HSV - Gen IV V8 Page 6C4–8

Page 6C4–8

1.4 Engine Control Module (ECM)

Service of the Engine Control Module (ECM) should normally consist of either replacement of the ECM, or ECM

programming. If the diagnostic proced ures call for the ECM to be replaced, the ECM should be first checked to ensure it

is the correct part. If it is, replace the faulty ECM.

• Do not touch the ECM connector pins as

Electrostatic Discharge (ESD) d amage may

result. For further information on ESD,

refer to Section 00 Warnings, Cautions and

Notes.

• When removing or reinstalling the ECM

harness connector/s, ensure that the

ignition switch is in the OFF position and

that the battery has been disconnected.

Failure to do so may result in damage to

the ECM and/or associated components.

• Disconnection of the battery affects

certain vehicle electronic systems. Refer

to Section 00 Warnings, Cautions and

Notes before disconnecting the battery.

Remove

1 Turn the ignition switch off.

2 Disconnect the battery, refer to Section 00 Warnings, Cautions and Notes.

3 Remove the Connector Protection Assura nce (CPA)

locks on each ECM electrical connector, then move

the connector lock levers to the unlock position.

4 Disconnect the wiring harness connectors.

Figure 6C4 – 7

Engine Management – HSV - Gen IV V8 Page 6C4–9

Page 6C4–9

5 Remove the two screws (1) securing the ECM to the

mounting bracket

6 Remove the ECM.

Figure 6C4 – 8

Reinstall

Reinstallation is the reverse of the removal procedure, noting the following:

1 Reinstall the ECM scre ws, and tighten to the correct torque specification.

ECM retaining screw torque specification.........1 – 3 Nm

2 If the ECM has been replaced, perform the following proced ures:

• ECM service programming, refer to Section 0C Tech 2.

• ECM/PIM/BCM security link, refer to Section 0C Tech 2.

• Main diagnostic functional check.

3 If the ECM has been removed, but not replaced, perform the main diagnostic table functional check.

Engine Management – HSV - Gen IV V8 Page 6C4–10

Page 6C4–10

1.5 Engine Control Module (ECM) Bracket

Assembly

Remove

1 Remove the ECM, refer to 1.4 Engine Control Module (ECM).

2 Remove nut (2) securing the ECM bracket (1) to the

body.

3 Remove the ECM mounting bracket by lifting up and

away from the body.

Figure 6C4 – 9

Reinstall

Reinstallation of the ECM mounting bracket is the reverse of the removal procedure, notin g the following:

Tighten the nuts attaching the ECM mounti ng bracket to the bod y to the correct torque specification.

ECM mounting bracket attaching

nut torque specification.................................15 – 20 Nm

Engine Management – HSV - Gen IV V8 Page 6C4–11

Page 6C4–11

1.6 EVAP Canister Purge Solenoid Valve

Remove

1 Disconnect the electrical connector from the EVAP

purge solenoid (1).

2 Disconnect the inlet hose (2) by squeezing the

retaining clip and pulling the hose from the solenoid.

3 Disconnect the outlet hose (3) from the purge solenoid

using tool AU533, refer to Section 8A Fuel System.

Figure 6C4 – 10

4 Remove the bolt (1) from the EVAP purge solenoid

mounting bracket and remove the EVAP purge

solenoid valve (2) and bracket.

Figure 6C4 – 11

Reinstall

Reinstallation of the EVAP canister pur ge solenoid valve is the reverse of the removal procedure, noting the follo wing:

Tighten the bolt attaching the EVAP canister purge solenoid valve to the engin e to the corr ect torque specification.

EVAP canister purge solenoid valve attaching

bolt torque specification....................................4 – 6 Nm

Engine Management – HSV - Gen IV V8 Page 6C4–12

Page 6C4–12

1.7 Heated Oxygen Sensors (HO2S)

To avoid the possibility of personal injury,

allow the exhaust pipe to cool to ambient

temperature (less than 50° C) before

attempting to remove the oxygen sensor.

Service Precautions

• Handle the oxygen sensor carefull y. Do not drop it, and keep it free of grease, dirt and other contaminants. Do not

use cleaning solvents of any type on the sen s or.

• Do not repair the sensor or any of its parts, including the wiring and connector. Replace the oxygen sens or if any

damage is evident.

• The oxygen sensor may be di fficult to remove when the engine is cold. Excessive force may damage the threads in

the exhaust manifold or exhaust pipe.

• If the oxygen sensor has been removed, but not replaced, then anti-seize compound must be appl ied to the

threads prior to installation. New oxygen sensors will already have the a nti-seize compound appli ed.

Remove

NOTE

It may be necessary to lower the exhaust system

to gain sufficient access to the front HO2S (1)

and/or its connector, refer to

Section 8B Exhaust System.

1 Raise the front of vehicle and support on safety

stands, refer to Section 0A General Information for the

location of jacking and support points.

138-48Nm

Figure 6C4 – 12

2 Disconnect the electrical connector from the HO2S (1)

to be removed.

3 Loosen and carefully remove the HO2S from the

exhaust pipe.

Figure 6C4 – 13

Engine Management – HSV - Gen IV V8 Page 6C4–13

Page 6C4–13

Reinstall

Reinstallation is the reverse of the removal procedure, noting the following:

A special anti-seize compound is used on the

heated oxygen sensor threads. New oxygen

sensors will already have the anti-seize

compound applied to the threads.

If an oxygen sensor has been removed, but

not replaced, then anti-seize compound must

be applied to the threads prior to installation.

1 Coat the cleaned threads of the sensor with anti-seize compound, part number 1237 7953. Specified anti-seize

compound is availabl e from authorised retailer parts outlets as part number 5613695.

2 Tighten the HO2S to the correct torque specificatio n.

HO2S torque specification ......................38.0 – 48.0 Nm

3 Road test the vehicle and check for correct operation, taking particular note that no exhaust leakage is evident.

Test

Front Sensors

• Under no circumstances should battery

voltage be applied to the HO2S heater.

• To prevent component damage use

connector test adaptor kit J 35616-A.

Heater Resistance Check

1 Using a digital ohmmeter and connector test adaptor

kit J 35616-A, measure the resistance acr oss

terminals C and D.

2 Compare the reading against the specification.

HO2S heater resistance @ 20° C........................ TBA Ω

3 If the resistance is not within specification, replace the

HO2S.

Figure 6C4 – 14

Engine Management – HSV - Gen IV V8 Page 6C4–14

Page 6C4–14

Rear Sensors

• Under no circumstances should battery

voltage be applied to the HO2S heater.

• To prevent component damage use

connector test adaptor kit J 35616-A.

Heater Resistance Check

1 Using a digital ohmmeter and connector test adaptor

kit J 35616-A, measure the resistance acr oss

terminals C and D.

2 Compare the reading against the specification.

HO2S heater resistance @ 20° C........................ TBA Ω

3 If the resistance is not within specification, replace the

HO2S.

Figure 6C4 – 15

Engine Management – HSV - Gen IV V8 Page 6C4–15

Page 6C4–15

1.8 Intake Air Temperature (IAT) Sensor

The Intake Air Temperature (IAT) sensor is part of the MAF sensor assembly, refer to

1.9 Mass Air Flow (MAF) Sensor and Intake Air Duct for the replacement procedure.

Test

To prevent component damage use connector

test adaptor kit J 35616-A.

Resistance Check

1 Connect a digital ohmmeter using connector test

adaptor kit J 35616-A to the Mass Air Flow (MAF)

sensor across terminals (A) and (B).

Do not use a high temperature heat gun as

damage to the MAF sensor will result.

2 Whilst holding a thermometer (1), use a commercially

available hair dryer (2) to blow warm air through the

MAF sensor.

Figure 6C4 – 16

3 Observe the resistance values as the temperature

increases and compare t he temperature/resistance

change to the specifications.

4 If the resistance is not within specifications, replace

the MAF sensor.

Intake Air Temperature Vs Resistance

Temperature °C Resistance – Ohms (Ω)

-10 16180

0 9420

20 3520

25 2796

40 1459

60 667

80 332

100 177

120 100

140 60

Engine Management – HSV - Gen IV V8 Page 6C4–16

Page 6C4–16

1.9 Mass Air Flow (MAF) Sensor and Intake

Air Duct

Remove

1 Remove the upper radiator shroud, refer to Section 6B4 Eng ine Cooling.

2 Remove the intake air duct:

a Lift up the security tang on the MAF sensor wiring harness conn ector (1) and remove the connector from

sensor (2), refer to Figure 6C4 – 17.

b Disconnect the PCV hose (3) from the intake air duct.

c Loosen the clamps (4) at eac h end securing the intake air duct to the throttle body and the air cleaner upper

housing. Remove the duct.

Figure 6C4 – 17

3 Loosen the two clamps (1) securing the air intake duct

and the air duct adaptor to the MAF sensor (2).

Figure 6C4 – 18

Engine Management – HSV - Gen IV V8 Page 6C4–17

Page 6C4–17

Reinstall

Reinstallation of the MAF sensor is the reverse of the removal procedure, noting the following:

NOTE

• The embossed arrows on the MAF sensor

indicate the correct air flow direction. The

arrows must point towards the engine.

• The air duct adaptor (between air cleaner and

MAF sensor), retaining clamps, air duct and

MAF sensor, all have locating notches.

Ensure all notches are aligned.

1 Reinstall the retaining clamps, aligning notches, tighten cla m ps to the specified torque.

Intake Air Duct Clamp

Torque Specification ...................................1.5 – 2.5 Nm

2 Start vehicle and check for air leaks.

Engine Management – HSV - Gen IV V8 Page 6C4–18

Page 6C4–18

1.10 Throttle Body

Handling Precautions

Under no circumstances should the throttle

body be disassembled. If the throttle body is

disassembled, the vacuum seal between the

cover plate and the throttle body will be

broken. This will allow the ingress of foreign

particles and or moisture and render the

throttle body unserviceable.

The throttle body must not be subjected to

any form of shock such as dropping it. If the

throttle body is subjected to shock, damage

may result to the fragile motor magnets within

the throttle body.

Remove

1 Turn the ignition switch off.

2 Remove the intake air duct, refer to 1.9 Mass Air Flow (MAF) Sensor and Intake Air Duct.

3 Disconnect the throttle body electrical connector (1)

from the throttle body (2).

Figure 6C4 – 19

Engine Management – HSV - Gen IV V8 Page 6C4–19

Page 6C4–19

4 Remove the bolts (1), four places, attaching the

throttle body (2) to the inlet manifold.

5 Remove the throttle body and the seal (3).

6 Discard the removed seal.

• To prevent damage to the sealing

surfaces, it is preferred that only plastic

scrapers are used for cleaning deposits

from machined alloy surfaces.

• Do not soak the throttle body in cold

immersion type cleaner. To clean the

throttle body following disassembly, use

a spray type cleaner such as GM 1052626

or equivalent. Use a shop towel to remove

heavy deposits.

• The throttle body contains electrical

components that should not come in

contact with solvent or cleaner, as

damage may result.

7 Clean both of the sealing surfaces.

Figure 6C4 – 20

Inspect

To avoid serious personal injury, never

attempt to rotate the throttle plate manually

whilst the throttle body harness connector is

connected to the throttle bod y.

The following throttle body inspection procedure may be carried o u t with the throttle body installed on the vehicle. Prior to

performing a throttle body on-v ehicle inspection, perform the following:

1 Switch the ignition off.

2 Disconnect the throttle body harness conn ector.

3 Remove the air cleaner intake duct, refer to 1.9 Mass Air Flow (MAF) Sensor and Intake Air Duct.

4 Fully open the throttle plate by hand in order to inspect the throttle body bore and the thr ottle plate for a ny deposits.

When cleaning / inspecting the throttle body:

• Do not subject the throttle body assembly

to an immersion cleaner or a strong

solvent. Damage to the throttle position

sensor and / or sealed throttle shaft

bearings will result.

• Never use a wire brush or scraper to clean

the throttle body. A wire brush or sharp

tool may damage the throttle body

components.

5 Use a clean shop towel and GM cleaner 105 2626 or equivalent product to clean the throttle body bore and throttle

plate. If necessary, use a parts cleaning brush in order to remove heavy deposits.

6 To inspect the throttle body for a binding throttle plate, fully open and close the throttle plate by hand. The throttle

plate should open and close smoothly.

Engine Management – HSV - Gen IV V8 Page 6C4–20

Page 6C4–20

7 Inspect the throttle body for a bent or damaged throttle plate, and cracks, corrosion, or distortion in the throttle body

housing.

NOTE

The throttle body contains no serviceable parts

and should not be disassembled. If the throttle

body is damaged it must be replaced as an

assembly.

8 If the throttle body is affected by any of the above conditions, the throttle body must be re placed.

9 If an on-vehicle throttle body inspection was performed, reinstall the air cleaner intake d uct, refer to

1.9 Mass Air Flow (MAF) Sensor and Intake Air Duct.

10 Road test the vehicle and check for correct operation, taking particular note that no air leaks are evide nt.

Reinstall

Reinstallation of the throttle bod y is the reverse of the removal procedure, noting the foll owing:

1 Install a new throttle body seal .

2 Reinstall the throttle body attaching bolts and tighten to the correct torque specification.

Throttle body attaching bolt

torque specification...................................8.0 – 12.0 Nm

3 Road test the vehicle and check for correct operation, taking particular note that no air leaks are evident.

Engine Management – HSV - Gen IV V8 Page 6C4–21

Page 6C4–21

1.11 Camshaft Position (CMP) Sensor

Replacement

Removal Procedure

1 Remove the generator bracket assembly. Refer to

Generator Bracket Replacement in Engine Electrical.

2 Disconnect the camshaft position sensor electrical

connector (1).

Figure 6C4 – 21

3 Remove the camshaft position sensor mounti ng bolt

(1).

4 Remove the camshaft position sensor assembl y (2, 3)

from the engine front cover.

Figure 6C4 – 22

Engine Management – HSV - Gen IV V8 Page 6C4–22

Page 6C4–22

Installation Procedure

Important: Before installing the camshaft sensor assembly,

apply a small amount of clean motor oil to the O-ring (3).

1 If removed, install the O-ring onto the camshaft positio n

sensor.

2 Install the camshaft position sensor assembly into the

engine front cover.

Notice: Refer to Fastener Notice in Section 00 Cautions and

Notices.

3 Install the camshaft position sensor mounting bolts.

Tighten

Tighten the camshaft position mountin g bolts to 25 N·m

(18 lb ft).

Figure 6C4 – 23

4 Reconnect the camshaft sensor electric al connector

(1).

5 Install the generator bracket assembly. Refer to

Generator Bracket Replacement in Engine Electrical.

Figure 6C4 – 24

Engine Management – HSV - Gen IV V8 Page 6C4–23

Page 6C4–23

2 Fastener Tightening

Specifications

Application Metric English

Accelerator Pedal Position Sensor Attaching Bolts 7 - 12 Nm 62 - 106 lb in

Air Cleaner Lower Housing Securing Bolts 7.5 - 12.5 Nm 66 - 111 lb in

Air Cleaner Upper Housing Securing Screws 2 - 3 Nm 17 - 22 lb in

A/C Refrigerant Pressure Sensor 6 Nm 53 lb in

Camshaft Position (CMP) Sensor Bolt 25 Nm 18 lb ft

Crankshaft Position (CKP) Sensor Bolt 25 Nm 18 lb ft

Engine Coolant Temperature (ECT) Sensor 20 Nm 15 lb ft

Evaporative Emissions (EVAP) Canister Retaining Nut 6 Nm 53 lb in

Evaporative Emissions (EVAP) Purge Solenoid Retaining Bolt 4 - 6 Nm 35 - 53 lb in

Fuel Pump And Sender Assembly Ground Terminal Nut 7 Nm 62 lb in

Fuel Filler Pocket Fastening Nut 5 Nm 44 lb in

Fuel Fill Hose Clamps 2.5 Nm 20 lb in

Fuel Pipe Shield Nuts and Bolts 5 Nm 44 lb in

Fuel Rail Attaching Bolts 10 Nm 89 lb in

Fuel Tank Strap Upper Fastening Nut 20 Nm 15 lb ft

Fuel Tank Strap Lower Fastening Nut 40 Nm 30 lb ft

Heated Oxygen Sensor (HO2S) 38 - 48 Nm 28 - 35 lb ft

Ignition Coil Mounting Bolt 12 Nm 106 lb in

Knock Sensor (KS) Attaching Bolt 20 Nm 15 lb ft

Intake Air Duct Clamp 1.5 - 2.5 Nm 13 - 20 lb in

Engine Control Module (ECM) Mounting Fastener 1 - 3 Nm 9 - 22 lb in

Engine Control Module (ECM) Mounting Bracket Assembly Fastener 15 - 20 Nm 11 - 15 lb ft

Spark Plug New Cylinder Head 20 Nm 15 lb ft

Spark Plug Old Cylinder Head 15 Nm 11 lb ft

Throttle Body Attaching Bolts 8 - 12 Nm 70 - 106 lb in

Engine Management – HSV - Gen IV V8 Page 6C4–24

Page 6C4–24

3 MY2004 HSV VZ LS2 Diagnostic

Trouble Codes

Automatic Manual

Index P-Code P-Code Description Software Identifier Type Light Type Light

1 P0016

Crankshaft Position (CKP)-Camshaft

Position (CMP) Correlation Bank 1

Sensor A CeDFIR_e_CKP_ToCMP_A_CorrB1 B 1 B 1

5 P0030 Heater Control Bank 1 Sensor 1 CeDFIR_e_O2S_HtrCktB1S1 B 1 B 1

6 P0036 Heater Control Bank 1 Sensor 2 CeDFIR_e_O2S_HtrCktB1S2 B 1 B 1

7 P0050 Heater Control Bank 2 Sensor 1 CeDFIR_e_O2S_HtrCktB2S1 B 1 B 1

8 P0056 Heater Control Bank 2 Sensor 2 CeDFIR_e_O2S_HtrCktB2S2 B 1 B 1

9 P0068

MAP/MAF - Throttle Position

Correlation - Type "a" per Colin

Roberts CeDFIR_e_MAP_MAF_TP_Corr A 1 A 1

10 P0101 Air Flow Circuit Range/Performance

Problem CeDFIR_e_MAF_SnsrPerf B 1 B 1

11 P0102 Air Flow Circuit Low Input CeDFIR_e_MAF_SnsrCktLo B 1 B 1

12 P0103 Air Flow Circuit High Input CeDFIR_e_MAF_SnsrCktHi B 1 B 1

13 P0106 MAP/Barometric Pressure

Range/Perform CeDFIR_e_MAP_SnsrPerf B 1 B 1

14 P0107 MAP/Barometric Pressure Circuit Low

Input CeDFIR_e_MAP_SnsrCktLo B 1 B 1

15 P0108 MAP/Barometric Pressure Circuit

High Input CeDFIR_e_MAP_SnsrCktHi B 1 B 1

16 P0112 Intake Air Temperature Circu it Low

Input CeDFIR_e_IAT_SnsrCktLo B 1 B 1

17 P0113 Intake Air Temperature Circu it High

Input CeDFIR_e_IAT_SnsrCktHi B 1 B 1

18 P0116 CTS Rationalit y Fault CeDFIR_e_ECT_SnsrPerf B 1 B 1

19 P0117 Engine Coolant Temperature Low

Input CeDFIR_e_ECT_SnsrCktLo B 1 B 1

20 P0118 Engine Coolant Temperature High

Input CeDFIR_e_ECT_SnsrCktHi B 1 B 1

21 P0120 Throttle Position (TP) Sensor 1 Circuit CeDFIR_e_TP_Snsr1Ckt A 1 A 1

22 P0121 TPS Sensor Ration ality Fault ID CeDFIR_e_TP_Snsr1Perf B 1 B 1

23 P0122 Throttle Position (TP) Sensor 1 Circuit

Low CeDFIR_e_TP_Snsr1CktLo A 1 A 1

24 P0123 Throttle Position (TP) Sensor 1 Circuit

High CeDFIR_e_TP_Snsr1CktHi A 1 A 1

26 P0128 CTS_Below_Stat_Reg_Temp CeDFIR_e_ECT_BelowThstRegTemp B 1 B 1

27 P0130 O2 Sensor Circuit Bank 1 Sensor 1 CeDFIR_e_O2S_CktB1S1 X 0 X 0

28 P0131 O2 Sensor Circuit Grounded Bank 1

Sensor 1 CeDFIR_e_O2S_CktLoB1S1 B 1 B 1

29 P0132 O2 Sensor Circuit High Volt CeDFIR_e_O2S_CktHiB1S1 B 1 B 1

30 P0133 O2 Sensor Slow Response CeDFIR_e_O2S_SlowRespB1S1 B 1 B 1

Engine Management – HSV - Gen IV V8 Page 6C4–25

Page 6C4–25

Automatic Manual

Index P-Code P-Code Description Software Identifier Type Light Type Light

31 P0134 O2 Sensor Circuit Inactive CeDFIR_e_O2S_CktInsufActyB1S1 B 1 B 1

32 P0135 O2 Sensor Heater Circuit CeDFIR_e_O2S_HtrPerfB1S1 B 1 B 1

33 P0136 O2S POSD Bank 1 Sensor 2 CeDFIR_e_O2S_CktB1S2 B 1 B 1

34 P0137 O2 Sensor Circuit Grounded Bank 1

Sensor 2 CeDFIR_e_O2S_CktLoB1S2 B 1 B 1

35 P0138 O2 Sensor Circuit High Volt CeDFIR_e_O2S_CktHiB1S2 B 1 B 1

36 P0140 O2 Sensor Circuit Inactive CeDFIR_e_O2S_CktInsufActyB1S2 B 1 B 1

37 P0141 O2 Sensor Heater Circuit CeDFIR_e_O2S_HtrPerfB1S2 B 1 B 1

39 P0151 O2 Sensor Circuit Grounded Bank 2

Sensor 1 CeDFIR_e_O2S_CktLoB2S1 B 1 B 1

40 P0152 O2 Sensor Circuit High Volt CeDFIR_e_O2S_CktHiB2S1 B 1 B 1

41 P0153 O2 Sensor Slow Response CeDFIR_e_O2S_SlowRespB2S1 B 1 B 1

42 P0154 O2 Sensor Circuit Inactive CeDFIR_e_O2S_CktInsufActyB2S1 B 1 B 1

43 P0155 O2 Sensor Heater Circuit CeDFIR_e_O2S_HtrPerfB2S1 B 1 B 1

44 P0156 O2S POSD Bank 2 Sensor 2 CeDFIR_e_O2S_CktB2S2 B 1 B 1

45 P0157 O2 Sensor Circuit Grounded Bank 2

Sensor 2 CeDFIR_e_O2S_CktLoB2S2 B 1 B 1

46 P0158 O2 Sensor Circuit High Volt CeDFIR_e_O2S_CktHiB2S2 B 1 B 1

47 P0160 O2 Sensor Circuit Inactive CeDFIR_e_O2S_CktInsufActyB2S2 B 1 B 1

48 P0161 O2 Sensor Heater Circuit CeDFIR_e_O2S_HtrPerfB2S2 B 1 B 1

50 P0171 Fuel System Too Lean CeDFIR_e_FuelTrimSysLeanB1 B 1 B 1

51 P0172 Fuel System Too Ric h CeDFIR_e_FuelTrimSysRichB1 B 1 B 1

52 P0174 Fuel System Too Lean CeDFIR_e_FuelTrimSysLeanB2 B 1 B 1

53 P0175 Fuel System Too Ric h CeDFIR_e_FuelTrimSysRichB2 B 1 B 1

56 P0201 Injector Circuit Fault CeDFIR_e_Cyl1InjCkt B 1 B 1

57 P0202 Injector Circuit Fault CeDFIR_e_Cyl2InjCkt B 1 B 1

58 P0203 Injector Circuit Fault CeDFIR_e_Cyl3InjCkt B 1 B 1

59 P0204 Injector Circuit Fault CeDFIR_e_Cyl4InjCkt B 1 B 1

60 P0205 Injector Circuit Fault CeDFIR_e_Cyl5InjCkt B 1 B 1

61 P0206 Injector Circuit Fault CeDFIR_e_Cyl6InjCkt B 1 B 1

62 P0207 Injector Circuit Fault CeDFIR_e_Cyl7InjCkt B 1 B 1

63 P0208 Injector Circuit Fault CeDFIR_e_Cyl8InjCkt B 1 B 1

64 P0220 Throttle Position (TP) Sensor 2 Circuit CeDFIR_e_TP_Snsr2Ckt A 1 A 1

65 P0222 Throttle Position (TP) Sensor 2 Circuit

Low Voltage CeDFIR_e_TP_Snsr2CktLo A 1 A 1

66 P0223 Throttle Position (TP) Sensor 2 Circuit

High Voltage CeDFIR_e_TP_Snsr2CktHi A 1 A 1

67 P0230 MFD1_Output_FUELPMP CeDFIR_e_FuelPmpPriCkt B 1 B 1

68 P0300 Random Misfire Detected CeDFIR_e_EngMisfDtctd B 1 B 1

Engine Management – HSV - Gen IV V8 Page 6C4–26

Page 6C4–26

Automatic Manual

Index P-Code P-Code Description Software Identifier Type Light Type Light

69 P0315 Crankshaft Position System Variati on

Not Learned CeDFIR_e_CKP_VariationNotLrnd A 1 A 1

70 P0325 Knock Sensor 1 Circuit Malfu nction CeDFIR_e_KS_CktB1 B 1 B 1

71 P0326 Knock Sensor Performance - on per

Shepherd CeDFIR_e_KS_PerfB1 B 1 B 1

72 P0327 Knock Sensor 1 Circuit Low Input CeDFIR_e_KS_CktLoFreqB1 B 1 B 1

73 P0332 Knock Sensor 2 Circuit Low Input CeDFIR_e_KS_CktLoFreqB2 B 1 B 1

74 P0335 Crank Sensor Not Valid CeDFIR_e_CKP_SnsrA_Ckt B 1 B 1

75 P0336 Loss Of Match CeDFIR_e_CKP_SnsrA_Perf B 1 B 1

76 P0340 Intake Cam Sensor Circuit - Bank 1 CeDFIR_e_CMP_SnsrA_CktB1 B 1 B 1

77 P0341 Intake Cam Sensor Performance -

Bank 1 CeDFIR_e_CMP_SnsrA_PerfB1 B 1 B 1

80 P0351 Ignition_Control_A_Fault_ID CeDFIR_e_IgnCoil1Ckt B 1 B 1

81 P0352 Ignition_Control_B_Fault_ID CeDFIR_e_IgnCoil2Ckt B 1 B 1

82 P0353 Ignition_Control_C_Fault_ID CeDFIR_e_IgnCoil3Ckt B 1 B 1

83 P0354 Ignition_Control_D_Fault_ID CeDFIR_e_IgnCoil4Ckt B 1 B 1

84 P0355 Ignition_Control_E_Fault_ID CeDFIR_e_IgnCoil5Ckt B 1 B 1

85 P0356 Ignition_Control_F_Fault_ID CeDFIR_e_IgnCoil6Ckt B 1 B 1

86 P0357 Ignition_Control_G_Fault_ID CeDFIR_e_IgnCoil7Ckt B 1 B 1

87 P0358 Ignition_Control_H_Fault_ID CeDFIR_e_IgnCoil8Ckt B 1 B 1

103 P0420 Catalyst Sys Efficiency Low Bank 1 CeDFIR_e_CatSysEffLoB1 A 1 A 1

104 P0430 Catalyst Sys Efficiency Low Bank 2 CeDFIR_e_CatSysEffLoB2 A 1 A 1

105 P0442 EVAP System Small Leak CeDFIR_e_EVAP_SmallLeak A 1 A 1

106 P0443 SIDM_1_Output_CCP CeDFIR_e_EVAP_Purg1SlndCkt B 1 B 1

107 P0446 EVAP System Excess Vac CeDFIR_e_EVAP_VentSysPerf B 1 B 1

108 P0449 SIDM_3_Output_FUELTANK_VENT CeDFIR_e_EVAP_VentSlndCkt B 1 B 1

110 P0452 Fuel Tank Pressure (FTP) Sensor

Circuit Low Voltage CeDFIR_e_FTP_SnsrCktLo B 1 B 1

111 P0453 Fuel Tank Pressure (FTP) Sensor

Circuit High Voltage CeDFIR_e_FTP_SnsrCktHi B 1 B 1

113 P0455 EVAP System Large Leak (Weak

Vac) CeDFIR_e_EVAP_LargeLeak B 1 B 1

114 P0461 Fuel Level No change Primary CeDFIR_e_FuelLvlSnsr1Perf B 1 B 1

115 P0462 Fuel Level Low Primary CeDFIR_e_FuelLvlSnsr1CktLo B 1 B 1

116 P0463 Fuel Level High Primary CeDFIR_e_FuelLvlSnsr1CktHi B 1 B 1

118 P0480 SIDM_1_Output_FAN1 CeDFIR_e_Fan1CntrlCkt B 1 B 1

119 P0481 SIDM_1_Output_FAN2 CeDFIR_e_Fan2CntrlCkt B 1 B 1

Engine Management – HSV - Gen IV V8 Page 6C4–27

Page 6C4–27

Automatic Manual

Index P-Code P-Code Description Software Identifier Type Light Type Light

126 P0496 (EVAP) System Flow During Non-

Purge CeDFIR_e_EVAP_FlowDurNonPurg B 1 B 1

127 P0502 Vehicle_Speed_Sens_Ckt_Low_Input CeDFIR_e_VSS_A_CktLo X 0 B 1

128 P0503 Output Speed Lost CeDFIR_e_VSS_A_CktInt X 0 B 1

129 P0506 Idle Control Underspeed Problem CeDFIR_e_IAC_SysRPM_TooLo B 1 B 1

130 P0507 Idle Control Overspeed Problem CeDFIR_e_IAC_SysRPM_TooHi B 1 B 1

131 P0513 Incorrect Immobilizer Key CeDFIR_e_ImmobKeyIncrt C 0 C 0

134 P0522 Engine_Oil_Pressure _Sensor_LOW -

Type as B for DOD ? CeDFIR_e_EOP_SnsrCktLo C 0 C 0

135 P0523 Engine_Oil_Pressure_Sensor_HIGH CeDFIR_e_EOP_SnsrCktHi C 0 C 0

137 P0532 A/C Pressure Sensor Low CeDFIR_e_AC_RefrigPresSnsrALo C 0 C 0

138 P0533 A/C Pressure Sensor High CeDFIR_e_AC_RefrigPresSnsrAHi C 0 C 0

142 P0562 System Voltage Low CeDFIR_e_SysVoltLo C 0 C 0

143 P0563 System Voltage High CeDFIR_e_SysVoltHi C 0 C 0

150 P0601 ROM Checksum Error CeDFIR_e_CM_ROM_Err A 1 A 1

151 P0602 Programming Error CeDFIR_e_CM_NotProgd A 1 A 1

152 P0603 P/U NVM Integrity Check CeDFIR_e_CM_LongTermMemReset A 1 A 1

153 P0604 PCM RAM Failure CeDFIR_e_CM_RAM_Err A 1 A 1

154 P0606 PCM_Integrity CeDFIR_e_ECM_PCM_ProcessorPerf A 1 A 1

155 P0607 Main Processor Fault CeDFIR_e_CM_Perf C 0 C 0

156 P0608 Vehicle Speed Output Circuit 1 CeDFIR_e_VehSpdOut1_Ckt C 0 C 0

158 P060D Pedal Position Sensors 1/2 Short CeDFIR_e_CM_APP_SysPerf A 1 A 1

159 P060E Throttle Position State of health CeDFIR_e_CM_TP_SysPerf A 1 A 1

161 P0621 Gen L-Term Diag (Key on) CeDFIR_e_Genr1_L_TermCkt C 0 C 0

162 P0622 Gen F-Term Diag (Key on) CeDFIR_e_Genr1_F_TermCkt C 0 C 0

163 P0633 Immobilizer Key Not Programmed -

ECM/PCM CeDFIR_e_ImmobKeyNotProgd C 0 C 0

164 P0641 5 Volt Reference 1 Circuit CeDFIR_e_SnsrRefVolt1Ckt A 1 A 1

165 P0645 Air Conditioning (A/C) Clutch Relay

Control Circuit CeDFIR_e_AC_ClchRlyCkt C 0 C 0

166 P0650 ODM_Output_MIL CeDFIR_e_MIL_LmpCkt B 0 B 0

167 P0651 5 Volt Reference 2 Circuit CeDFIR_e_SnsrRefVolt2Ckt A 1 A 1

168 P0654 Engine Speed Output Circuit CeDFIR_e_EngSpdOutCkt C 0 C 0

169 P0685 ECM Power Relay Control - Type B

per Grenn's Sheet CeDFIR_e_CM_PwrRlyCkt B 1 B 1

170 P0689 Control Module Power Rela y

Feedback Circuit Low Voltage CeDFIR_e_CM_PwrRlyFdbckCktLo B 1 B 1

171 P0690 Control Module Power Rela y

Feedback Circuit High Voltage CeDFIR_e_CM_PwrRlyFdbckCktHi B 1 B 1

172 P0700 ATD_General_Trans_Failure CeDFIR_e_TCM_MIL_Req A 0 X 0

Engine Management – HSV - Gen IV V8 Page 6C4–28

Page 6C4–28

Automatic Manual

Index P-Code P-Code Description Software Identifier Type Light Type Light

178 P0719 Brake Switch Circuit Lo w - TCC Brake

Switch CeDFIR_e_TransBrkSwCktLo C 0 C 0

181 P0724 Brake Switch Circuit High - TCC

Brake Switch CeDFIR_e_TransBrkSwCktHi C 0 C 0

183 P0801 Reverse Inhibit Solenoid C ontrol

Circuit CeDFIR_e_RvrsInhbSlndCkt X 0 C 0

184 P0803 Skip Shift Solenoid Control Ci rcuit CeDFIR_e_SkipShfSlndCkt X 0 B 1

187 P0833 Clutch Pedal Switch B Circuit CeDFIR_e_ClchPedSwB_Ckt X 0 B 1

189 P0852 Park/Neutral Position (PNP) Switch

Circuit High Voltage CeDFIR_e_ParkNeutPstnSwCktHi C 0 X 0

190 P0856 Traction Control Torque Request

Circuit CeDFIR_e_TCS_TorqReqCkt C 0 C 0

192 P1101 Intake Airflow System Performance CeDFIR_e_IntkFlowSysPerf B 1 B 1

199 P1133 O2 Sensor Switch Bank 1 Sensor 1 CeDFIR_e_O2S_InsufSwitchingB1S1 B 1 B 1

200 P1134 O2 Sensor Ratio invali d Bank 1

Sensor 1 CeDFIR_e_O2S_TrnstnTmRatB1S1 B 1 B 1

201 P1153 O2 Sensor Switch Bank 2 Sensor 1 CeDFIR_e_O2S_InsufSwitchingB2S1 B 1 B 1

202 P1154 O2 Sensor Ratio invali d Bank 2

Sensor 1 CeDFIR_e_O2S_TrnstnTmRatB2S1 B 1 B 1

203 P1258 Engine Protection Mode Active CeDFIR_e_ECT_TooHiPrtctModeActv A 1 A 1

205 P1380 ABS Rough Road Detection Fault CeDFIR_e_MisfDtctdRghRdNotAvail C 0 C 0

206 P1381 ABS Rough Road Serial Data Fault CeDFIR_e_MisfDtctdRghRdNoComm C 0 C 0

209 P1516

Throttle Actuator Control (TAC)

Module Throttle Actuator Position

Performance CeDFIR_e_TACM_ThrotActPstnPerf A 1 A 1

211 P1575 Extended T r avel Brake Switch Failure CeDFIR_e_ExtnddTrvlBrkSwCkt C 0 X 0

213 P1621 Powerdown NVM Integrity CeDFIR_e_CM_LongTermMemPerf A 1 A 1

214 P1629 Theft Deterrent Start Enable Signal

Not Received CeDFIR_e_VTD_EnblSigNotRx C 0 C 0

217 P1632 Theft Deterrent Start Disable Signal

Received CeDFIR_e_VTD_DsblSigRx C 0 C 0

218 P1648 Anti-Theft Device - Wrong Security

Code CeDFIR_e_ImmobSecurityCodeIncrt C 0 C 0

221 P1677 ECM Immobilizer Function

Deactivated CeDFIR_e_ImmobDeactivated C 0 C 0

222 P1678 Immobilizer Powertrain Identification

Failed CeDFIR_e_ImmobPwrTrnID_Failed C 0 C 0

223 P1679 Immobilizer Environment Iden tification

Failed CeDFIR_e_ImmobEnvironID_Failed C 0 C 0

224 P1682 Ignition out of correlation fault (Should

be type "a" per ETC PDT) CeDFIR_e_Ign1SwCkt2 A 1 A 1

237 P2101 Control Module Throttle Actuator

Position Performance CeDFIR_e_CM_ThrotActPstnPerf A 1 A 1

238 P2119 Throttle Closed Position Performance CeDFIR_e_ThrotClsdPstnPerf C 0 C 0

Engine Management – HSV - Gen IV V8 Page 6C4–29

Page 6C4–29

Automatic Manual

Index P-Code P-Code Description Software Identifier Type Light Type Light

239 P2120 Accelerator Pedal Position (APP)

Sensor 1 Circuit CeDFIR_e_APP_Snsr1Ckt A 1 A 1

240 P2122 Accelerator Pedal Position (APP)

Sensor 1 Circuit Low Voltage CeDFIR_e_APP_Snsr1CktLo A 1 A 1

241 P2123 Accelerator Pedal Position (APP)

Sensor 1 Circuit High Voltage CeDFIR_e_APP_Snsr1CktHi A 1 A 1

242 P2125 Accelerator Pedal Position (APP)

Sensor 2 Circuit CeDFIR_e_APP_Snsr2Ckt A 1 A 1

243 P2127 Accelerator Pedal Position (APP)

Sensor 2 Circuit Low Voltage CeDFIR_e_APP_Snsr2CktLo A 1 A 1

244 P2128 Accelerator Pedal Position (APP)

Sensor 2 Circuit High Voltage CeDFIR_e_APP_Snsr2CktHi A 1 A 1

245 P2135 Throttle Position (TP) Sensor 1-2

Correlation CeDFIR_e_TP_Snsr12_Corr A 1 A 1

246 P2138 Accelerator Pedal Position (APP)

Sensor 1-2 Correlation CeDFIR_e_APP_Snsr12_Corr A 1 A 1

248 P2176 Minimum Throttle Position Not

Learned CeDFIR_e_MinThrotPstnNotLrnd A 1 A 1

260 P2610 ECM/PCM Internal Engine Off Timer

Performance CeDFIR_e_ECM_EngOffTmrPerf B 1 B 1

286 U0001 High Speed CA N Communication Bus CeDFIR_e_HiSpdCANCommBus C 0 C 0

288 U0101 Loss of CAN Communication with

TCM CeDFIR_e_LostCommTrans B 1 X 0

289 U0121 Loss of CAN Communication with

ABS/TCS CeDFIR_e_LostCommABSCM C 0 C 0

Engine Management – HSV - Gen IV V8 Page 6C4–30

Page 6C4–30

4 Diagnostics

4.1 DTC P0513, P0633, P1629, P1632, P1648,

P1677, P1678, and P1679 – Immobiliser

Signal

DTC Description

This diagnostic procedure cov ers the following DTCs:

• DTC P0513 – Incorrect Immobiliser Key

• DTC P0633 – Immobiliser Key Not Programmed

• DTC P1629 – Theft Deterrent Start Enable Signal Not Recei v ed

• DTC P1632 – Theft Deterrent Start Disable Signal Received

• DTC P1648 – Anti-theft Device Wrong Security Code

• DTC P1677 – Immobiliser Function Deactivated

• DTC P1678 – Immobiliser Powertrain Identifi cation Failed

• DTC P1679 – Immobiliser Environment Iden tification F ailed

Circuit Description

The Engine Control Module (ECM), the Powertrain Interface Module (PIM), and the Body Control Module (BCM) are

integral part of the vehicle theft deterrent system. The theft deterrent system authenticates the security code

programmed into each of these modules to prevent unauthorised vehicle operation. This authentication process includes

the following steps:

1 When the ignition is turned on or the door is unlocked by remote key the BCM and the key e xc hange security data

to verify the correct key is used.

2 Once the correct key has been confirmed and the ignition is turned on, the PIM and BCM exchange data to confirm

the correct BCM and PIM is being used.

3 Once the correct key, BCM, and PIM is confirmed, the PIM and ECM exchange data to allow the vehicle to start.

4 The data exchange processes conducted use various encrypted data exchanges between each of the devices.

NOTE

If any of these authentication processes fail, the

vehicle will not start and DT Cs will set. For further

information on the theft deterrent system, refer to

Section 12J Body Control Module.

An immobiliser signal DTC sets if the theft deterrent system authentication process fails.

Engine Management – HSV - Gen IV V8 Page 6C4–31

Page 6C4–31

Condition for Running the DTCs

The ignition is on. T he DTC runs in conjunction with the authentication process.

Condition for Setting the DTCs

• If the key is not programmed to the BCM, then the key authentication will fail (and the vehicle will be immobil ised)

• If the BCM is not linked to the PIM, then PIM to BCM Authentication will fail (and the vehicle will be immo bilised)

• If the PIM is not linked to the ECM then the ECM to PIM authentication will fail (and the vehicle will be immobilised)

• If the PIM, BCM, Key or ECM have corrupt memory, then the authentication will fail (and the vehicl e will be

immobilised)

• If there is a fault with the GMLAN or UART bus, no authentication will occur (and the vehicle will be immobilised)

Conditions for Clearing the DTCs

The Immobiliser signal DTCs are Type C DTCs. Refer to # for action taken when a Type C DTC sets and conditions for

clearing Type C DT Cs.

Additional Information

• Since a fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic

procedure for shorted terminals or poor wiring connection before replacing an y compone nt.

Refer to Section 12P Wiring Diagrams for information on electrical fault diagnosis.

• For an intermittent fault condition, refer to Intermittent Fault Conditions.

• The vehicle will allow engine cranking for up to 5 seconds. If the ignition key, BCM, and PIM do not authenticate

the ECM will cease engine cranki ng, or if the engine has started it will stall. Subsequent engine cranking will not

initiate unless the ignition is switched off for more than 5 seconds.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

2 Tests the integrity of the GM LAN serial dat a communication circuit.

3 Tests for fault conditions on the vehicle th eft deterrent system stored in the PIM.

4 Tests for fault conditions on the vehicle th eft deterrent system stored in the BCM.

Engine Management – HSV - Gen IV V8 Page 6C4–32

Page 6C4–32

Diagnostic Table for DTC P0513, P0633, P1629, P1632, P1648, P1677, P1678, and P1679

Step Action Yes No

1 Did you perform the Diag nostic System Check – Vehicle?

Go to Step 2

Refer to Diagnostic

System Check –

Vehicle in Vehicle

DTC Information

2 Using Tech 2, attempt to communicate with the PIM, the ECM, and

the BCM.

Did the PIM, the ECM, or the BCM fail to communicate?

Refer to Section

6E4 Powertrain

Interface Module –

Main Diagnostic

Table Go to Step 3

3 Does DTC U1304, U2100, U2105, U2106, U2108, B1000, B1009,

B1013, B1014, B3057, B3924, P0633, P1611 or P1678 als o set in the

PIM?

Refer to Section

6E4 Powertrain

Interface Module –

Main Diagnostic

Table Go to Step 4

4 Does DTC 2, DTC 17, DTC 19, DTC 20, DTC 24 DTC 25 also set in

the BCM? Refer to Section 12J

Body Control

Module for the

appropriate BCM

DTC table. Go to Step 5

5 Does Tech 2 display any serial data communication circuit DTC? Refer to the

appropriate serial

data communication

circuit DTC table. Go to Step 6

6 1 Switch Off the ignition for 30 seconds.

2 Operate the vehicle within the conditions for running the DTC.

3 Using Tech 2, select the DTC displa y function.

Does DTC P0423, U0121, U0155, or U0423 fail this ignition cycle? Go to Step 7 Go to Step 10

7 Attempt to program the ECM. Refer to Section 0C Tech 2.

Was the programming successful? Go to Step 9 Go to Step 8

8 Replace the ECM. Refer to Section 6C1-3 Engi ne Management V6 –

Service Information.

Was the repair completed? Go to Step 9 –

9 1 Using Tech 2, clear the DTCs.

2 Switch Off the ignition for 30 seconds.

3 Start the engine.

4 Operate the vehicle within the conditions for running the DTC.

Does any of the immobiliser signal DTCs fail this ignition cycle? Go to Step 2 Go to Step 10

10 Using Tech 2, select the DTC displa y function.

Are there any DTCs displayed?

Go to the

appropriate DTC

Table System OK

When all diagno sis an d repairs are completed, ch eck the engine management system for corre ct operation.

Engine Management – HSV - Gen IV V8 Page 6C4–33

Page 6C4–33

4.2 DTC P1575 – Extended Travel Brake

Switch Failure

Circuit Description

When the brake pedal is pr essed past the extended travel brake switch point, the BTM (Brake Torque Manag ement)

function is enabled. This function limits the torque o utput of the engine whilst traction control is enabled.

The extended tr avel brake switch is a normall y closed switch that supplies igniti on voltage, via the engine control relay

and fuse 33, to the ECM at connector A43 – X1 pin 38. When the brake pedal is pressed past the extended travel switch

point the switch opens, interrupting the voltage suppl y.

If the ECM detects deceleration great enough to indicate that the extended travel brake switch should have operated, but

does not detect an open extended travel brake switch circuit (0 volts / low input), DTC P1575 sets. DTC P01575 is a

type C DTC.

DTC Descriptor

This diagnostic procedure su pports the following DTC :

DTC P1575 Extended Tr avel Brake Switch Failure

Conditions for running the DTC

• Engine RPM is greater than 500rpm.

• Auto transmission is in 4th Gear.

• DTCs P0502, P0503, P0719, P0724 ar e not set.

• Vehicle speed is above 32 km/hr for more than 3 secon ds.

• Vehicle deceleration is greater than 10 km/hr over 0.5 sec.

• Vehicle speed needs to be less than 10 km/hr after the test has run before re-enabling the test.

Conditions for setting the DTC

When the diagnostic is enabled as per the above conditions, the ECM checks the status of the extended travel brake

switch. If the ECM detects that the extended travel brake s witch is closed on five consecut ive tests, the DTC is set.

Action taken when the DTC sets

The control module records the oper ating conditions at the time the diagnostic fails. The control module stores the

information in the Freeze Frame/Failure Records.

Conditions for clearing the MIL/DTC

• A current DTC last test failed clears when the diagnostic ru ns and passes.

• A history DTC clears after 40 consecutive warm-up cycles if no failures ar e reported by this diagnostic.

• Clear the DTC with a SCAN tool.

Diagnostic Aids

• Inspect the brake switch for proper mounting, adjustment, and operation.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

2 This step isolates the brake switch as a source for setting the DTC.

Engine Management – HSV - Gen IV V8 Page 6C4–34

Page 6C4–34

Diagnostic Table for DTC P1575

Step Action Yes No

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic

System Check -

Vehicle in Vehicle

DTC Information

1 Install a scan tool.

2 Turn ON the ignition, with the engine OFF .

Before clearing the DTC, use the scan tool in order to

record the Failure Records. Using the Clear Info

function erases the Failure Records from the ECM.

3 Record the DTC Failure Records.

4 Clear the DTC.

5 Select Extended Travel Brake Switch on the scan tool.

Refer to SIR Caution in Cautions and Notices.

6 Disconnect the extended trav el brake switch connector from the

brake switch.

Did the Extended Travel Brake Switch status on the scan tool

change from Closed to Open?

Go to Step 3 Go to Step 4

3 Replace the extended travel brake switch.

Refer to Stop Lamp Switch Replacement in Lighting S ystems.

Did you complete the replacement? Go to Step 6 --

The condition that affects this circuit may exist in other

connecting branches of the circuit. Refer to Power

Distribution Schematics in Wiring Systems for

complete circuit distribution.

Test the signal circuit of the extended travel brake switch for a short to

voltage. Refer to Testing for a Short to Voltage and Wiring Repairs in

Wiring Systems.

Did you find and correct the condition?

Go to Step 6 Go to Step 5

Replace the ECM.

Refer to Control Module References in Com puter/Integrating Systems

for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 6 --

Perform the following procedure in order to verify the repair:

1 Select DTC.

2 Select Clear Info.

3 Turn ON the ignition, with the engine OFF .

4 Apply the brake ped al to full travel and relea s e.

5 Verify that the scan tool Extended Tra vel Brake Switch status

indicates Open / 0 volts, for 2 seconds.

6 Select Specific DTC.

7 Enter DTC P1575.

Has the test run and passed?

Go to Step 7 Go to Step 2

With the scan tool, observe the stored information, capt ure info, and

DTC Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic

Trouble Code (DT C)

List - Vehicle in

Vehicle DTC

Information

System OK

Engine Management – HSV - Gen IV V8 Page 6C4–35

Page 6C4–35

4.3 DTC P0719 – Brake Switch Failure

Circuit Description

The brake switch indicates the brake p ed al status to the engine control module (ECM). The brake switch is a normally-

closed switch that supplies battery voltage on the brake swit ch supply voltage circuit to the ECM at connector A43 – X1

pin 46. Applying the brake opens the brake s witch, interrup t ing voltage to the ECM. When the brake is releas ed, the

ECM receives a constant voltage signal in put.

If the ECM receives a zero voltage signal input at the brake switch supply voltage circuit, and the cruise control is

engaged, the ECM disengages the cruise control. The ECM disregards the brake switch input if there is a brake switch

circuit fault, and the cruise control will not operate.

When the ECM detects an open brake switch circuit (0-volts / low input) during accelerations, then DTC P071 9 sets.

DTC P0719 is a type C DTC.

DTC Descriptor

This diagnostic procedure su pports the following DTC:

DTC P0719 Brake Switch Circuit Low Voltage

Conditions for Running the DTC

No Brake Switch DTC P0724.

Conditions for Setting the DTC

The ECM detects that vehicle speed has increased from below 8 kph to within 8-30 kph for 2-4 seconds then is greater

than 30kph for 6 seconds (an acceleration) while the brake switch in put to the ECM is low. The ECM must fail the

diagnostic on eight consecutive tests for the DTC to set.

Action Taken When the DTC Sets

• The ECM does not illuminate the malfunction indicator lamp (MIL).

• The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM records this

information as a Failure Record.

• The ECM stores DTC P0719 in ECM history.

Conditions for Clearing the DTC

• The ECM clears the DTC from ECM history if the vehicle completes 40 warm-up cycles without a non-emission

related diagnostic fault occurring.

• A scan tool can clear the DTC.

Diagnostic Aids

• Inspect the brake switch for proper mounting and operation.

• Inspect for ABS DTCs. A faulty ABS condition may contribute to setting DTC P0719.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

3 This step isolates the brake switch as a source for setting the DTC.

Engine Management – HSV - Gen IV V8 Page 6C4–36

Page 6C4–36

Diagnostic Table for DTC P0719

Step Action Yes No

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic

System Check -

Vehicle in Vehicle

DTC Information

1 Install a scan tool.

2 Turn ON the ignition, with the engine OFF .

Before clearing the DTC, use the scan tool in order to

record the Failure Records. Using the Clear Info

function erases the Failure Records from the ECM.

3 Record the DTC Failure Records.

4 Clear the DTC.

5 Select Brake Switch on the scan tool.

Refer to SIR Caution in Cautions and Notices.

6 Disconnect the brake switch connector from the brake switch.

7 Connect a test lamp from the ignition voltage supply circuit of the

brake switch connector to ground.

Does the test lamp illuminate?

Go to Step 3 Go to Step 4

Connect a fused jumper wire between the ignition voltage supply and

signal circuits of the brake switch connector.

Did the TCC/Cruise Brake P ed al Switch status on the scan tool

change from Applied to Released?

Go to Step 7 Go to Step 9

4 Inspect the ignition voltage supply fuse for an open.

Refer to Circuit Protection - Fuses in Wiring Systems.

Is the fuse open? Go to Step 5 Go to Step 8

The condition that affects this circuit may exist in other

connecting branches of the circuit. Refer to Power

Distribution Schematics in Wiring Systems for

complete circuit distribution.

Test the ignition voltage circuit of the brake switch for a short to

ground. Refer to Testing for Short to Ground and W iring Repairs in

Wiring Systems.

Did you find and correct the condition?

Go to Step 11 Go to Step 6

The condition that affects this circuit may exist in other

connecting branches of the circuit. Refer to Power

Distribution Schematics in Wiring Systems for

complete circuit distribution.

Test the signal circuit of the brake switch for a short to ground. Refer to

Testing for Short to Ground and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11 Go to Step 10

7 Replace the brake switch.

Refer to Stop Lamp Switch Replacement in Lighting S ystems.

Did you complete the replacement? Go to Step 11 --

Engine Management – HSV - Gen IV V8 Page 6C4–37

Page 6C4–37

Step Action Yes No

The condition that affects this circuit may exist in other

connecting branches of the circuit. Refer to Power

Distribution Schematics in Wiring Systems for

complete circuit distribution.

Test the ignition voltage circuit of the brake switch for an open.

Refer to Testing for Continuity and W irin g Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11 --

The condition that affects this circuit may exist in other

connecting branches of the circuit. Refer to Power

Distribution Schematics in Wiring Systems for

complete circuit distribution.

Test the signal circuit of the brake switch for an open. Refer to Testing

for Continuity and Wiring Repairs in W irin g Systems.

Did you find and correct the condition?

Go to Step 11 Go to Step 10

Replace the ECM.

Refer to Control Module References in Com puter/Integrating Systems

for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 11 --

Perform the following procedure in order to verify the repair:

1 Select DTC.

2 Select Clear Info.

3 Turn ON the ignition, with the engine OFF .

4 Apply and release the brake pedal.

5 Verify that the scan tool TCC/Cruise Brake Pedal Switch status

indicates Applied / 0 volts, for 2 seconds.

6 Select Specific DTC.

7 Enter DTC P0719.

Has the test run and passed?

Go to Step 12 Go to Step 2

With the scan tool, observe the stored information, capt ure info, and

DTC Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic

Trouble Code (DT C)

List - Vehicle in

Vehicle DTC

Information

System OK

Engine Management – HSV - Gen IV V8 Page 6C4–38

Page 6C4–38

4.4 DTC P0724 – Brake Switch Failure

Circuit Description

The brake switch indicates the brake p ed al status to the engine control module (ECM). The brake switch is a normally-

closed switch that supplies battery voltage on the brake swit ch supply voltage circuit to the ECM at connector A43 – X1

pin 46. Applying the brake opens the brake s witch, interrup t ing voltage to the ECM. When the brake is releas ed, the

ECM receives a constant voltage signal in put.

If the ECM receives a zero voltage signal input at the brake switch supply voltage circuit, and the cruise control is

engaged, the ECM disengages the cruise control. The ECM disregards the brake switch input if there is a brake switch

circuit fault, and the cruise control will not operate.

When the ECM detects a closed brak e switch circuit (battery voltage / high input) during decelerations, then DTC P0724

sets. DTC P0724 is a type C DTC.

DTC Descriptor

This diagnostic procedure su pports the following DTC:

DTC P0724 Brake Switch Circuit High Voltage

Conditions for Running the DTC

No Brake Switch DTC P0719.

Conditions for Setting the DTC

The ECM detects that vehicle speed has decreased from above 30 kph to within 30-8 kph for 2-4 secon ds then is below

8 kph for 6 seconds (a deceleration) while the brake switch input to the ECM is high. The ECM must fail the di agnostic on

eight consecutive tests for the DTC to set.

Action Taken When the DTC Sets

• The ECM does not illuminate the malfunction indicator lamp (MIL).

• The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM records this

information as a Failure Record.

• The ECM stores DTC P0724 in ECM history.

Conditions for Clearing the DTC

• The ECM clears the DTC from ECM history if the vehicle completes 40 warm-up cycles without a non-emission

related diagnostic fault occurring.

• A scan tool can clear the DTC.

Diagnostic Aids

• Inspect the brake switch for proper mounting and operation.

• Inspect for ABS DTCs. A faulty ABS condition may contribute to setting DTC P0724.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

2 This step isolates the brake switch as a source for setting the DTC.

Engine Management – HSV - Gen IV V8 Page 6C4–39

Page 6C4–39

Diagnostic Table for DTC P0724

Step Action Yes No

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic

System Check -

Vehicle in Vehicle

DTC Information

1 Install a scan tool.

2 Turn ON the ignition, with the engine OFF .

Before clearing the DTC, use the scan tool in order to

record the Failure Records. Using the Clear Info

function erases the Failure Records from the ECM.

3 Record the DTC Failure Records.

4 Clear the DTC.

5 Select TCC/Cruise Brake Pedal Switch on the scan tool.

Refer to SIR Caution in Cautions and Notices.

6 Disconnect the brake switch connector from the brake switch.

Did the TCC/Cruise Brake P ed al Switch status on the scan tool

change from Released to Applied? Go to Step 3 Go to Step 4

3 Replace the brake switch.

Refer to Stop Lamp Switch Replacement in Lighting S ystems.

Did you complete the replace m ent? Go to Step 6 --

The condition that affects this circuit may exist in

other connecting branches of the circuit. Refer to

Power Distribution Schematics in Wiring Systems for

complete circuit distribution.

Test the signal circuit of the brake switch for a short to voltage. Refer

to Testing for a Short to Voltage and Wiring Repairs in Wiri ng

Systems.

Did you find and correct the condition? Go to Step 6 Go to Step 5

Replace the ECM.

Refer to Control Module References in Com puter/Integrating

Systems for replacement, setup, and progra mming.

Did you complete the replacement? Go to Step 6 --

Perform the following procedure in order to verify the repair:

1 Select DTC.

2 Select Clear Info.

3 Turn ON the ignition, with the engine OFF .

4 Apply and release the brake pedal.

5 Verify that the scan tool TCC/Cruise Brake Pedal Switch

status indicates Applied / 0 volts, for 2 seconds.

6 Select Specific DTC.

7 Enter DTC P0724.

Has the test run and passed? Go to Step 7 Go to Step 2

With the scan tool, observe the stored information, capt ure info, and

DTC Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic

Trouble Code (DT C)

List - Vehicle in

Vehicle DTC

Information System OK

Engine Controls - 6.0L

Speciﬁcations

Temperature vs Resistance

°C °F OHMS

Temperature vs Resistance Values (Approximate)

150 302 47

140 284 60

130 266 77

120 248 100

110 230 132

100 212 177

90 194 241

80 176 332

70 158 467

60 140 667

50 122 973

45 113 1188

40 104 1459

35 95 1802

30 86 2238

25 77 2796

20 68 3520

15 59 4450

10 50 5670

5 41 7280

0 32 9420

−5 23 12300

−10 14 16180

−15 5 21450

−20 −4 28680

Temperature vs Resistance (cont’d)

°C °F OHMS

−30 −22 52700

−40 −40 100700

Altitude vs Barometric Pressure

Altitude

Measured in

Meters (m)

Altitude

Measured in

Feet (ft)

Barometric

Pressure

Measured in

Kilopascals

(kPa)

Determine your altitude by contacting a local weather

station or by using another reference source.

4 267 14,000 56–64

3 962 13,000 58–66

3 658 12,000 61–69

3 353 11,000 64–72

3 048 10,000 66–74

2 743 9,000 69–77

2 438 8,000 71–79

2 134 7,000 74–82

1 829 6,000 77–85

1 524 5,000 80–88

1 219 4,000 83–91

914 3,000 87–95

610 2,000 90–98

305 1,000 94–102

0 0 Sea Level 96–104

−305 −1,000 101–105

Ignition System Speciﬁcations

Application Speciﬁcation

Metric English

Firing Order 1-8-7-2-6-5-4-3

Spark Plug Wire Resistance 188–312 ohms

Spark Plug Torque 15 N·m 11 lb ft

Spark Plug Gap 1.02 mm 0.040 in

Spark Plug Type GM P/N 12571164

AC Spark Plug P/N 41-985

EngineEngineControls-6.0L

Fastener Tightening Speciﬁcations

Application Speciﬁcations

Metric English

Accelerator Control Assembly to Floor Fasteners 20 N·m 15 lb ft

Camshaft Position (CMP) Sensor Bolt 25 N·m 18 lb ft

Crankshaft Position (CKP) Sensor Bolt 25 N·m 18 lb ft

Engine Coolant Temperature (ECT) Sensor 20 N·m 15 lb ft

EVAP Canister Bracket Bolt 7 N·m 62 lb in

Fuel and EVAP Pipe Retainer Nut 6 N·m 53 lb in

Fuel Crossover Hose Clamps 4 N·m 35 lb in

Fuel Filter and Fuel Pressure Regulator Bracket Nut 5 N·m 44 lb in

Fuel Pipe Assembly Clip Nuts 3 N·m 27 lb in

Fuel Rail Attaching Bolts 10 N·m 89 lb in

Fuel Tank Fill and Vent Pipe Bolts 3 N·m 22 lb in

Fuel Tank Fill Hose Clamp 4 N·m 35 lb in

Fuel Tank Fill Pipe Ground Strap Bolt 8 N·m 71 lb in

Fuel Tank Shield Mount Bolt 25 N·m 18 lb in

Fuel Tank Shield Nut 12 N·m 106 lb in

Fuel Tank Strap and Shield Bolts 25 N·m 18 lb ft

Heated Oxygen Sensor (HO2S) 41 N·m 30 lb ft

Ignition Coil Harness Mounting Bolt 12 N·m 106 lb in

Ignition Coil Mounting Bolts 12 N·m 106 lb in

Knock Sensor (KS) 20 N·m 15 lb ft

PCV Hose Assembly Mounting Cable Nut 12 N·m 106 lb in

Powertrain Control Module (PCM) Electrical Connector Fasteners 8 N·m 70 lb in

Powertrain Control Module (PCM) Retaining Fastener 2 N·m 17 lb in

Secondary Air Injection (AIR) Check Valves 23 N·m 17 lb ft

Secondary Air Injection (AIR) Check Valve to the AIR Pipe 23 N·m 17 lb ft

Secondary Air Injection (AIR) Pipe To Exhaust Manifold Bolts 20 N·m 15 lb ft

Secondary Air Injection (AIR) Pump to Bracket 9 N·m 80 lb in

Secondary Air Injection (AIR) Solenoid Valve Retaining Nut 7 N·m 62 lb in

Spark Plug 15 N·m 11 lb ft

Spark Plug in New Cylinder Head 20 N·m 15 lb ft

Tank Crossover Hose Clamp 4 N·m 35 lb in

Throttle Actuator Control (TAC) Module to PCM Bracket 2 N·m 17 lb in

Throttle Actuator Control (TAC) Module to PCM Bracket Fasteners 2 N·m 17 lb in

Throttle Body Attaching Bolts 10 N·m 189 lb in

Diagnostic Trouble Code (DTC) Type

Deﬁnitions

Emissions Related DTCs

Action Taken When the DTC Sets – Type A

The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs and fails.

Action Taken When the DTC Sets – Type B

The control module illuminates the MIL on the

second consecutive ignition cycle that the diagnostic

runs and fails.

Conditions for Clearing the MIL/DTC – Type A or

Type B

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC Last Test Failed clears when the

diagnostic runs and passes.

•UseaTech 2 inordertocleartheMILand

the DTC.

Non-Emissions Related DTCs

Action Taken When the DTC Sets – Type C

• The control module stores the DTC information

into memory when the diagnostic runs and fails.

EngineControls-6.0LEngine

• The MIL will not illuminate.

• The driver information center, if equipped, may

display a message.

Conditions for Clearing the DTC – Type C

• A last test failed, or current DTC, clears when the

diagnostic runs and passes.

•UseaTech 2 inordertocleartheDTC.

Conditions for Clearing the DTC – Type X

This DTC is available in the PCM software, but has

been disabled, or turned OFF. In this case, the

diagnostic does not run, the DTCs are stored, and the

MIL does not illuminate. Type X DTCs are used

primarily for export vehicles that do not require MIL

illumination or DTC storing.

Diagnostic Trouble Code (DTC) Type(s)

DTC Description Domestic

DTCP0016B

DTCP0030B

DTCP0036B

DTCP0050B

DTCP0056B

DTCP0068A

DTCP0101B

DTCP0102B

DTCP0103B

DTCP0106B

DTCP0107B

DTCP0108B

DTCP0112B

DTCP0113B

DTCP0116B

DTCP0117B

DTCP0118B

DTCP0120A

DTCP0121B

DTCP0122A

DTCP0123A

DTCP0128B

DTCP0131B

DTCP0132B

DTCP0133B

DTCP0134B

DTCP0135B

DTCP0136B

DTCP0137B

DTCP0138B

DTCP0140B

DTCP0141B

DTCP0151B

DTCP0152B

DTCP0153B

DTCP0154B

DTCP0155B

DTCP0156B

DTCP0157B

EngineEngineControls-6.0L

Diagnostic Trouble Code (DTC) Type(s) (cont’d)

DTC Description Domestic

DTCP0158B

DTCP0160B

DTCP0161B

DTCP0171B

DTCP0172B

DTCP0174B

DTCP0175B

DTCP0201-P0208B

DTCP0220A

DTCP0222A

DTCP0223A

DTCP0230B

DTCP0300B

DTCP0315A

DTCP0325C

DTCP0326C

DTCP0327C

DTCP0332C

DTCP0335B

DTCP0336B

DTCP0340B

DTCP0341B

DTCP0351-P0358B

DTCP0420A

DTCP0430A

DTCP0442A

DTCP0443B

DTCP0446B

DTCP0449B

DTCP0451A

DTCP0452B

DTCP0453B

DTCP0454A

DTCP0455B

DTCP0461B

DTCP0462B

DTCP0463B

DTCP0464A

DTCP0496B

DTCP0506B

DTCP0507B

DTCP0522C

DTCP0523C

DTCP0532C

DTCP0533C

DTCP0562C

EngineControls-6.0LEngine

Diagnostic Trouble Code (DTC) Type(s) (cont’d)

DTC Description Domestic

DTCP0563C

DTCP0572C

DTCP0573C

DTCP0601A

DTCP0602A

DTCP0603A

DTCP0604A

DTCP0606A

DTCP0607C

DTCP0608C

DTCP060DA

DTCP060EA

DTCP0621C

DTCP0622C

DTCP0641A

DTCP0645C

DTCP0650B

DTCP0651A

DTCP0654C

DTCP0685B

DTCP0689B

DTCP0690B

DTCP0703C

DTCP1101B

DTCP1133B

DTCP1134B

DTCP1153B

DTCP1154B

DTCP1258A

DTCP1380C

DTCP1381C

DTCP1482B

DTCP1516A

DTCP1621A

DTCP1630C

DTCP1631C

DTCP1682A

DTCP2066B

DTCP2067B

DTCP2068B

DTCP2101A

DTCP2119C

DTCP2120A

DTCP2122A

DTCP2123A

DTCP2125A

EngineEngineControls-6.0L

Diagnostic Trouble Code (DTC) Type(s) (cont’d)

DTC Description Domestic

DTCP2127A

DTCP2128A

DTCP2135A

DTCP2138A

DTCP2172A

DTCP2176A

DTCP2610B

DTCP2636C

EngineControls-6.0LEngine

Schematic and Routing Diagrams

Emission Hose Routing Diagram

Legend

(1) To HVAC

(2) To Power Brake Vacuum Assist

(3) To EVAP Canister

(4) EVAP Canister Purge Solenoid Valve

(5) Throttle Body

(6) Engine Coolant Hoses

(7) Positive Crankcase Ventilation (PCV) Valve

(8) Crankcase Ventilation Hose

(9) Crankcase Ventilation Hose

344988

EngineEngineControls-6.0L

Legend

(1) EVAP Canister Purge Solenoid Valve

(2) EVAP Canister

(3) Fuel Fill Neck/Fill Cap

(4) Rollover Valve/Fuel Tank Pressure (FTP)

Sensor

(5) Fuel Tank

(6) EVAP Canister Vent Solenoid Valve

(7) Vent Hose/Pipe

(8) EVAP Vapor Pipe

(9) EVAP Purge Pipe

(10) EVAP Service Port

EvaporativeEmissions(EVAP)HoseRoutingDiagram(EVAPSystemOverview)

678941

EngineControls-6.0LEngine

Fuel Hose/Pipes Routing Diagram

Legend

(1) Fuel Fill Hose

(2) Left Fuel Tank Grade Vent Valve

(3) Fuel Feed Pipe to Engine

(4) 5/16 Inch Auxiliary Fuel Feed Pipe

(5) 3/8 Inch Auxiliary Fuel Return Pipe

(6) Right Fuel Tank Grade Vent Valve

(7) Fill Limiter Vent Valve (FLVV)

(8) Secondary Fuel Pressure Regulator

(9) Siphon Jet Pump

(10) Convoluted Crossover Hose

(11) Anti-siphon Hole

(12) Fuel Sender Reservoir

(13) Turbine Fuel Pump

(14) Venturi Pump

(15) Primary Fuel Pressure Regulator

(16) Reverse Flow Check Valve

(17) Fuel Filter

877203

EngineEngineControls-6.0L

Diagnostic Information and Procedures

Diagnostic Starting Point - Engine

Controls

Begin the system diagnosis with

Diagnostic System

Check - Vehicle

in Vehicle DTC Information. The

Diagnostic System Check–Vehicle will provide

the following information:

• The identiﬁcation of the control modules which

command the system

• The ability of the control modules to communicate

through the serial data circuit

• The identiﬁcation of any stored diagnostic trouble

codes (DTCs) and the codes’ statuses

The use of the Diagnostic System Check–Vehicle will

identify the correct procedure for diagnosing the

system and where the procedure is located.

Tech 2 DataList

TheTech 2 DataListcontainsallengine

relatedparametersthatareavailableontheTech 2 .

The list is arranged in alphabetical order. A given

parameter may appear in any one of the data lists, and

in some cases may appear more than once, or in

more than one data list in order to group certain related

parameters together.

UsetheTech 2 DataListonlyafterthe

following is determined:

• The Diagnostic System Check – Vehicle is

completed.

• No diagnostic trouble codes (DTCs)

• On-board diagnostics are functioning properly.

Tech 2 valuesfromaproperlyrunningenginemay

be used for comparison with the engine you are

diagnosing.TheTech 2 DataList

represents values that would be seen on a normal

running engine.

Important:ATech 2 thatdisplaysfaultydatashould

notbeused.TheTech 2 problemshouldbe

reportedtothemanufacturer.UseofafaultyTech 2

can result in misdiagnosis and unnecessary parts

replacement.

Only the parameters listed below are referenced in

this service manual for use in diagnosis. If all values

are within the typical range described below, refer

Symptoms - Engine Controls

for diagnosis.

The column labeled Data List indicates where a

parametercanbelocatedontheTech 2 .Referto

theTech 2 operatingmanualfortheexactlocations

of the data lists. The following is a description of

each term listed:

All: The Parameter is in all of the data lists

indicated below.

Eng 1: Engine Data 1 List

Eng 2: Engine Data 2 List

EGR: Exhaust Gas Recirculation (EGR) Data

EE: Enhanced Evaporative Emission (EVAP) Data

FF/FR: Freeze Frame/Failure Records

FT: Fuel Trim Data List

MF: Misﬁre Data List

TAC: Throttle Actuator Control (TAC) Data List

CC: Cruise Control Data List

Tech 2 DataList

Tech 2 ParameterDataListParameterRange/UnitsTypicalDataValues

Engine Idling/Radiator Hose Hot/Closed Throttle/Park or Neutral/Closed Loop/Accessories Off

A/C Clutch Feedback Signal Eng 2 Yes/No No

A/C Relay Command Eng 1, 2, EGR, MF On/Off Off

A/C Compressor Cycling

Switch Eng 2 Normal/High Pressure Normal

A/C Request Signal Eng 2 Yes/No No

A/C High Pressure

Recirculation Switch Eng 2 Normal/Closed Normal

Air Fuel Ratio FF, FR Ratio 14.7:1

AIR Pump Relay Command

(w/NC1) Eng 1, FT On/Off Off

APP Average TAC 0–100% 0%

APP Indicated Angle Eng 1, Eng 2, EE, EGR,

FT, TAC 0–100% 0%

APP Sensor 1 TAC 0–5.0 Volts 0.4–0.9 Volts

EngineEngineControls-6.0L

Tech 2 DataList(cont’d)

Tech 2 ParameterDataListParameterRange/UnitsTypicalDataValues

Engine Idling/Radiator Hose Hot/Closed Throttle/Park or Neutral/Closed Loop/Accessories Off

APP Sensor 2 TAC 5.0–0 Volts 4.5–4.1 Volts

APP Sensor 3 TAC 5.0–0 Volts 4.2–3.7 Volts

APP Sensor 1 Angle TAC 0–100% 0%

APP Sensor 2 Angle TAC 0–100% 0%

APP Sensor 3 Angle TAC 0–100% 0%

APP Sensor 1 and 2

Disagree TAC Yes/No No

APP Sensor 1 and 3

Disagree TAC Yes/No No

APP Sensor 2 and 3

Disagree TAC Yes/No No

APP Sensor 1 Out of Range TAC Yes/No No

APP Sensor 2 Out of Range TAC Yes/No No

APP Sensor 3 Out of Range TAC Yes/No No

BARO Eng 1, EE, EGR, FT, FF/FR kPa/volts 65–104 kPa/3.5–4.9 Volts

Varies w/Altitude

Clutch Pedal Switch

(Manual Transmission only) Eng 1, EGR Depressed/Released Released

CMP Sensor–High to Low Eng 2 Counts Varies

CMP Sensor–Low to High Eng 2 Counts Varies

Coolant Level Switch Eng 2 OK/Low OK

Cruise Control Active Eng 1, TAC Yes/No No

Cruise Disengage 1 History CC Varies Varies

Cruise Disengage 2 History CC Varies Varies

Cruise Disengage 3 History CC Varies Varies

Cruise Disengage 4 History CC Varies Varies

Cruise Disengage 5 History CC Varies Varies

Cruise Disengage 6 History CC Varies Varies

Cruise Disengage 7 History CC Varies Varies

Cruise Disengage 8 History CC Varies Varies

Cruise Inhibit Signal

Command Eng 1 Varies Varies

Cruise On/Off Switch CC, TAC On/Off Off

Cruise Control Release Brake

Pedal Switch CC On/Off Off

Cruise Resume/Accel Switch CC, TAC Resume/Accel Resume

Cruise Set/Coast Switch CC, TAC Set/Coast Coast

Current Gear Eng 1, 2, EGR, FT, FF/FR 0–4 1

Cycles of Misﬁre Data MF 0–100 Counts Varies

Desired EGR Position Eng 1, EGR, MF, FF/FR 0–100% 0%

Desired EGR Position EGR 0–5 volts Less than 1.3 volts

Desired IAC Airﬂow Eng 1 0–64 g/s Varies

Desired IAC Position Eng 1 Counts Varies

Desired Idle Speed Eng 1, Eng 2, TAC,

EE, FF/FR RPM PCM Controlled

DTC Set This Ignition Eng 1, 2, CC, EE, FT Yes/No No

ECT Sensor Eng 1, Eng 2, EE, EGR, FT,

MF, FF/FR −39 to +140°C (−38 to

+284°F) 88–105°C (190–221°F)

EGR Learned Minimum POS EGR 0–5.0 volts Less than 1.3 volts

EngineControls-6.0LEngine

Tech 2 DataList(cont’d)

Tech 2 ParameterDataListParameterRange/UnitsTypicalDataValues

Engine Idling/Radiator Hose Hot/Closed Throttle/Park or Neutral/Closed Loop/Accessories Off

EGR Position Sensor Eng 1, EGR, FF/FR, MF 0–5.0 volts Less than 1.3 volts

Engine Load All 0–100% 1–4% Idle

7–9% 2500 RPM

Engine Oil Level Switch Eng 2 OK/Low OK

Engine Oil Life Remaining Eng 2 0–100% Varies

Engine Run Time All Hrs, Min, Sec Varies

Engine Speed All 0–10,000 RPM 500–700 RPM

EVAP Purge Solenoid

Command Eng 1, EE, FT 0–100% 10–25%

EVAP Test Result EE Test Result Varies

EVAP Test State EE Test State Varies

EVAP Vent Solenoid

Command Eng 1, EE, FT Not Venting/Venting Venting

Fail Counter FF, FR Counts Varies

Fuel Alcohol Content Eng 2 % Varies

Fuel Comp. Sensor

Frequency Eng 2 Hz Varies

Fuel Comp. Sensor On Time Eng 2 mS Varies

Fuel Level Sensor Eng 1, EE 0–5 volts 0.7–2.5 volts

Fuel Level Sensor Rear Tank Eng 1, EE 0–5 volts 0.7–2.5 volts

Fuel Tank Level Remaining EE Gallon/Liter Varies

Fuel Tank Level Remaining EE 0–100% Varies

Fuel Tank Pressure Sensor Eng 1, EE −32.7 to +14.0 mm/Hg (−17.5

to +7.5 in/H2O) Varies

Fuel Tank Pressure Sensor EE 0–5.0 volts Varies

Fuel Tank Rated Capacity EE 98 Liters (25.9 Gallons) or

128 Liters (34 Gallons) Varies with fuel tank option

Fuel Temperature Eng 2 °C/°F Varies

Fuel Trim Cell Eng 1, EE, FT 0–23 16, 17

Fuel Trim Learn Eng 1, EE, FT Enabled/Disabled Enabled, May Toggle

Generator F Terminal Signal Eng 2 Percent Varies

Generator L Terminal Signal

Command Eng 2 On/Off On

HO2S Bank 1 Sensor 1 Eng 1, EE, FT Millivolts 10–1,000 mV and Varying

HO2S Bank 1 Sensor 2 Eng 1, FT Millivolts 10–1,000 mV and Varying

HO2S Bank 2 Sensor 1 Eng 1, EE, FT Millivolts 10–1,000 mV and Varying

HO2S Bank 2 Sensor 2 Eng 1, FT Millivolts 10–1,000 mV and Varying

Fuel Level Sensor Eng 1, 2, EE 0–5 volts 0.7–2.5 volts

IAC Position Eng 1, EGR FT Counts Varies

IAT Sensor Eng 1, Eng 2, EE, EGR, FT −39 to +140°C (−38 to

+284°F) 35°C (91°F) Depends on

ambient temperature

Ignition 1 Signal Eng 1, Eng 2, CC, EE, EGR,

FT, TAC 0–25 Volts 11.5–14.5 Volts

Inj. PWM Bank 1 Average Eng 2, FT, FF/FR, MF Milliseconds 2–6

Inj. PWM Bank 2 Average Eng 2, FT, FF/FR, MF Milliseconds 2–6

Knock Retard Eng 1, EGR 0.0–16° 0°

Long Term FT Avg. Bn1 FT Percentage Near 0%

Long Term FT Avg. Bn2 FT Percentage Near 0%

Long Term FT Bank 1 Eng 1, Eng 2, EE, FT, FF/FR Percentage Near 0%

EngineEngineControls-6.0L

Tech 2 DataList(cont’d)

Tech 2 ParameterDataListParameterRange/UnitsTypicalDataValues

Engine Idling/Radiator Hose Hot/Closed Throttle/Park or Neutral/Closed Loop/Accessories Off

Long Term FT Bank 2 Eng 1, Eng 2, EE, FT, FF/FR Percentage Near 0%

Loop Status Eng 1, 2, EE, EGR,

FT, FF/FR Open/Closed Closed

Low Oil Lamp Command Eng 2 On/Off Off

MAF Sensor EGR, Eng 1, 2, FT, MF,

EE, TAC Grams Per Seconds (g/s)

1–9 g/s Idle, depends on

altitude

15–26 g/s 2,500 RPM,

depends on altitude

MAF Sensor Eng 2 0–31,999 Hz 2,000–3,000 Hz

MAP Sensor EGR, Eng 1, 2, FT, MF,

EE, TAC kPa 20–48 kPa

MAP Sensor Eng 1, Eng 2 Volts 1.0–2.0 volts

Varies with altitude

MIL Command Eng 2 Off/On Off

Mileage Since DTC Cleared Eng 2 kilometers/miles Varies

Misﬁre Counter Status MF Counts NormalKOEO

Misﬁre Current Cyl. 1–8 MF 0–200 Counts 0

Misﬁre History Cyl. 1–8 MF 0–65,535 Counts 0

Not Run Counter FF, FR Counts Varies

Pass Counter FF, FR Counts Varies

PCM Reset Eng 1, Eng 2, EGR, EE, FT Yes/No No

PCM/VCM in VTD Fail

Enable Eng 1 Yes/No No

Power Enrichment Eng 1 Active/Inactive Inactive

Reduced Engine Power Eng 1, EGR, TAC Yes/No No

Short Term FT Bn1 Average FT Percentage Near 0%

Short Term FT Bn2 Average FT Percentage Near 0%

Short Term FT Bank 1 Eng 1, Eng 2, EE, FT Percentage Near 0%

Short Term FT Bank 2 Eng 1, Eng 2, EE, FT Percentage Near 0%

Spark Eng 1, Eng 2, FT, MF Degrees 15°–20°

Start Up ECT Eng 2, EE, FT F°/C° Varies

Stop Lamp Pedal Switch Eng 1, 2, TAC, FF/FR Applied/Released Released

TAC/PCM Comm Signal Eng 1, TAC Yes/No Yes

TCC Enable Solenoid

Command Eng 1, Eng 2, MF On/Off Off

TCC PWM Solenoid

Command Eng 2 On/Off Off

TFP Switch Eng 2, EGR, FT Transmission Gear Position Varies

TP Desired Angle Eng 1, Eng 2, EE, EGR,

TAC, CC 0–100% 0%

TP Indicated Angle All 0–100% 0%

TP Sensor Eng 1, 2 volts 0.4–0.9 volts

TP Sensor TA, Eng 1, 2, EGR, FT,

MF, EE % Varies

TP Sensor 1 TAC 0–5.0 volts 0.4–0.9 volts

TP Sensor 2 TAC 5.0–0 volts 4.8–4.3 volts

TP Sensor 1 Angle TAC 0–100% 0%

TP Sensor 2 Angle TAC 100–0% 100%

TP Sensors Disagree TAC Yes/No No

TP Sensor 1 Out of Range TAC Yes/No No

EngineControls-6.0LEngine

2005 - Y Car GMX245 (June 22, 2004)

Tech 2 DataList(cont’d)

Tech 2 ParameterDataListParameterRange/UnitsTypicalDataValues

Engine Idling/Radiator Hose Hot/Closed Throttle/Park or Neutral/Closed Loop/Accessories Off

TP Sensor 2 Out of Range TAC Yes/No No

Torque Delivered Signal Eng 2 ft lbs/N·m 0 ft lbsKOEO

Torque Request Signal Eng 2 ft lbs/N·m 349 ft lbsKOEO

TR Sw Eng 2, EGR, FT Transmission Gear Position Varies

Vehicle Speed Sensor Eng 1, 2, FT km/h

mph 0

VTD Auto Learn Timer Eng 1 Active/Inactive Inactive

VTD Fuel Disable Eng 1 Active/Inactive Inactive

VTD Fuel Disable Until

Ign. Off Eng 1 Yes/No No

Warm-Ups w/o Emission

Faults Eng 2 0–255 Counts Varies

Warm-Ups w/o Non-Emission

Faults Eng 2 0–255 Counts Varies

Tech 2 DataDeﬁnitions

TheEngineTech 2 DataDeﬁnitionscontainsabrief

description of all engine related parameters available

ontheTech 2 .Thelistisinalphabeticalorder.

A given parameter may appear in any one of the data

lists. In some cases, the parameter may appear

more than once or in more than one data list in order

to group certain related parameters together.

A/C Compressor Cycling Switch: This parameter

displays the state of the air conditioning (A/C)

compressor cycling switch as determined by the

controlmodule.TheTech 2 willdisplayNormalor

Low Pressure. Normal indicates the A/C system

has enough refrigerant to close the A/C compressor

cycling switch, allowing the A/C compressor to engage.

Low Pressure indicates the A/C refrigerant system

has low pressure and the A/C compressor cycling

switch is open.

A/C Relay Command: This parameter displays the

commanded state of the air conditioning (A/C)

clutchrelaycontrolcircuit.TheTech 2 willdisplay

ON or OFF. ON indicates the A/C clutch relay

control circuit is being grounded by the control module,

allowing voltage to the A/C compressor clutch. OFF

indicates the A/C clutch relay is not being commanded

on by the control module.

A/C Request Signal: This parameter displays the

state of the air conditioning (A/C) request input to

the control module from the heating, ventilation, and

airconditioning(HVAC)controls.TheTech 2

will display Yes or No. Yes indicates the control

module is receiving a request from the HVAC system

to ground the A/C clutch relay control circuit,

engaging the A/C compressor clutch. No indicates the

control module is not receiving a request from the

HVAC system to ground the A/C clutch relay control

circuit.

Air Fuel Ratio: This parameter displays the ratio of

air to fuel as calculated by the control module

basedonvarioussensorinputs.TheTech 2 will

display a lower air fuel ratio when a richer air to fuel

mixtureiscommanded.TheTech 2 willdisplay

a higher air fuel ratio when a leaner air to fuel mixture

is commanded. In closed loop operation the air fuel

ratio should normally be around 14.2–14.7 to 1.

AIR Pump Relay Command: This parameter

displays the commanded state of the secondary air

injection(AIR)pumprelaycontrolcircuit.TheTech 2

will display ON or OFF. ON indicates the AIR pump

relay control circuit is being grounded by the

control module, allowing voltage to the AIR pump.

OFF indicates the AIR pump relay is not being

commanded on by the control module.

BARO (Gasoline): This parameter displays the

barometric pressure as calculated by the control

module using the signal from the manifold absolute

pressure (MAP) sensor measured when the ignition is

turned on with the engine not running. The control

module will update the barometric pressure during

wide-openthrottle(WOT)conditions.TheTech 2 will

display a low value when the barometric pressure is

low, and a high value when the barometric pressure

is high.

BARO (Gasoline): This parameter displays the

EngineEngineControls-6.0L

voltage signal received by the control module from the

manifold absolute pressure (MAP) sensor measured

when the ignition is turned on with the engine not

running. The control module will update the barometric

pressure during wide-open throttle (WOT) conditions.

TheTech 2 willdisplayalowvaluewhenthe

barometric pressure is low, and a high value when the

barometric pressure is high.

Clutch Pedal Switch: This parameter displays the

current state of the clutch pedal as determined by

the control module.

CMP Sensor - High To Low: This parameter

displays the number of times the signal voltage from

the camshaft position (CMP) sensor changes from high

tolow.TheTech 2 willdisplaythesetransitions

as counts.

CMP Sensor - Low To High: This parameter

displays the number of times the signal voltage from

the camshaft position (CMP) sensor changes from low

tohigh.TheTech 2 willdisplaythesetransitions

as counts.

Coolant Level Switch: This parameter displays the

level of engine coolant as determined by the control

module. The control module determines the level of the

coolant using the signal from a switch used to

monitortheenginecoolantlevel.TheTech 2 will

display low when the engine coolant level is low. The

Tech 2 willdisplayOKwhenthecoolantlevelis

correct.

Cruise Control Active: This parameter displays the

status of the cruise control system as determined

bythecontrolmodule.TheTech 2 willdisplayYes

when the cruise control system is in control of

vehiclespeed.TheTech 2 willdisplayNowhenthe

cruise control system is not operating.

Cruise Inhibit Signal Command: This parameter

displays the commanded state of the cruise inhibit

signalcircuit.TheTech 2 willdisplayOnwhenthe

control module is inhibiting cruise control operation.

TheTech 2 willdisplayOffwhenthecontrolmodule

is allowing cruise control operation.

Current Gear: This parameter displays the

transmission gear commanded by the control module.

TheTech 2 willdisplay1whenthecontrolmodule

has commanded ﬁrst gear regardless of the gear

selectorposition.TheTech 2 willdisplayupto6

depending upon which gear is commanded and what

transmissionisinthevehicle.TheTech 2 will

display 9 if the transmission gear is not known.

Cycles Of Misﬁre Data: This parameter displays

the number of cylinder ﬁring events that were recorded

as misﬁres as determined by the control module.

Desired EGR Position: This parameter displays the

position of the exhaust gas recirculation (EGR)

valvecommandedbythecontrolmodule.TheTech 2

tool will display 0 percent when the control module is

commanding the EGR valve closed.

Desired IAC Airﬂow: This parameter displays the

desired airﬂow in the idle air control (IAC) passage as

calculated by the control module.

Desired Idle Speed: This parameter displays the

engine idle speed in RPM commanded by the control

module. The control module compensates for

various engine loads in order to maintain the desired

engine RPM at idle. This parameter is not valid

unless the engine is running.

DTC Set This Ignition: This parameter displays if a

diagnostic trouble code (DTC) set during the current

ignitioncycle.TheTech 2 willdisplayYESifaDTC

is stored this ignition cycle.

ECT Sensor: This parameter displays the

temperature of the engine coolant based on a voltage

input from the engine coolant temperature (ECT)

sensortothecontrolmodule.TheTech 2 willdisplay

a low value when the coolant temperature is low,

and a high value when the coolant temperature is high.

EGR Learned Minimum Position: This parameter

displays the voltage from the EGR valve that the

control module uses to determine that the EGR valve

is closed. The voltage displayed will be the closed

position of the EGR pintle learned by the control

module.

Engine Load: This parameter displays the engine

load in percent based on inputs to the control module

fromvariousenginesensors.TheTech 2 will

display a low percentage when the engine is at idle

withlittleornoload.TheTech 2 willdisplayahigh

percentage when the engine is running at a high

RPM under a heavy load.

Engine Oil Level Switch: This parameter displays

the state of the engine oil level switch as determined

bythecontrolmodule.TheTech 2 willdisplayOKor

Low. OK indicates that the engine oil level is not too

low for safe operation of the engine. Low indicates the

engine oil level is abnormally low and has closed

the engine oil level switch.

Engine Oil Life Remaining: This parameter

displays the amount of engine oil life remaining before

requiring an oil change. This number is calculated

by the control module based on many inputs and is

displayed as a percent. The lower the percentage, the

sooner the next oil change will be required.

Engine Run Time: This parameter displays the time

elapsedsincetheenginewasstarted.TheTech 2

tool will display the time in hours, minutes and

seconds. The engine run time will reset to zero as

soon as the engine stops running.

Engine Speed: This parameter displays the speed

of the crankshaft as calculated by the control

module based on inputs from the Crankshaft

Position(CKP)Sensor.TheTech 2 willdisplaythe

engine speed in revolutions per minute (RPM).

EVAP Purge Solenoid Command: This parameter

displays the commanded state of the EVAP purge

solenoidcontrolcircuit.TheTech 2 willdisplay

0-100%. A high value indicates the purge solenoid

control circuit is being commanded more by the control

module, opening the EVAP purge solenoid. A low

value indicates the purge solenoid is being

commanded on less by the control module.

EVAPTestResult:TheTech 2 displaysNo

Result, Passed, Aborted, Fail-DTC P0440,

EngineControls-6.0LEngine

Fail-DTC P0442, Fail-DTC P0446, or Fail-DTC P1441.

TheTech 2 displaysPASSifthecontrolmodule

determines that the EVAP test has passed.

EVAPTestState:TheTech 2 displaysWaiting

For Purge, Test Running, or Test Completed.

This parameter indicates the state of the EVAP service

bay test.

EVAP Vent Solenoid Command: This parameter

displays the commanded state of the EVAP vent

solenoidcontrolcircuit.TheTech 2 willdisplay

venting or not venting. Not venting indicates the purge

solenoid control circuit is being commanded ON by

the control module, closing the EVAP vent solenoid.

Venting indicates the vent solenoid is not being

commanded by the control module, allowing the

solenoid to remain open.

FailCounter:TheTech 2 displaysthenumberof

times that a diagnostic has failed.

Fuel Alcohol Content: This parameter displays the

percentage of alcohol in the fuel. This value is

calculated by the control module using the frequency

signalfromthefuelcompositionsensor.TheTech 2

tool will display a low percentage when there is very

littlealcoholinthefuel.TheTech 2 willdisplay

a high percentage when the alcohol content of the fuel

is high.

Fuel Composition Sensor Frequency: This

parameter displays the frequency from the sensor

used to monitor the concentration of alcohol in the fuel.

The fuel composition sensor measures the fuel

capacitance, temperature, and fuel conductance to

determine the amount of alcohol contained in the fuel.

TheTech 2 willdisplayalowfrequencyreading

when the alcohol concentration of the fuel is low. The

Tech 2 willdisplayahighfrequencyreading

when the alcohol concentration of the fuel is high.

Fuel Composition Sensor On Time: This

parameter displays the pulse width signal of the fuel

composition sensor as received by the control module.

TheTech 2 willdisplayalowervalueatcolder

fueltemperatures.TheTech 2 willdisplayahigher

value at higher fuel temperatures.

Fuel Level Sensor: This parameter displays the

voltage from the signal produced by the sensor used

to monitor the fuel level inside the fuel tank. The

Tech 2 willdisplayalowvoltagereadingwhenthe

fuel level in the tank is low or near empty. The

Tech 2 willdisplayahighvoltagereadingwhenthe

fuel level in the tank is high or near full.

Fuel Level Sensor Rear Tank: This parameter

displays the voltage from the signal produced by the

sensor used to monitor the fuel level inside the

rearfueltank.TheTech 2 willdisplayalowvoltage

reading when the fuel level in the rear tank is low

ornearempty.TheTech 2 willdisplayahighvoltage

reading when the fuel level in the tank is high or

near full.

Fuel Tank Level Remaining: This parameter

displays the amount of fuel remaining in all fuel tanks

of the vehicle as measured in liters or gallons. The

control module calculates the amount of fuel remaining

in the tank by using information from the fuel level

sensors.

Fuel Tank Level Remaining: This parameter

displays the amount of fuel remaining in tall of the fuel

tanks of the vehicle as a percentage. The control

module calculates this level using the signals from the

sensors used to monitor the fuel level in the fuel

tanks.TheTech 2 willdisplayalowreadingwhen

the total fuel level in the vehicle is low or near

empty.TheTech 2 willdisplayahighreadingwhen

the fuel level in the tank is high or near full.

FuelTankRatedCapacity:TheTech 2 displays

Liters or gallons. This parameter displays the fuel

tank capacity as determined by the calibrations of the

vehicle.

Fuel Temperature: This parameter displays the

current fuel temperature as calculated by the control

module based on input from the fuel composition

sensor.TheTech 2 willdisplayahighervalueat

higherfueltemperatures.TheTech 2 willdisplaya

lower value at lower fuel temperatures.

Fuel Trim Cell: This parameter displays the fuel trim

cell as calculated by the control module based on

many sensor inputs. The fuel trim cell indicates which

cell is currently active.

FuelTrimLearn:TheTech 2 displaysEnabledor

Disabled. When conditions are appropriate for

enablinglongtermfueltrimcorrections,theTech 2

displaysEnabled.IftheTech 2 displaysDisabled,

then long term fuel trim will not respond to changes in

short term fuel trim.

Generator F-Terminal Signal: This parameter

displays the commanded state of the generator by the

control module. A High value indicates a high

charging command, and a low value indicates a low

charging command.

Generator L-Terminal Signal Command: This

parameter displays if the control module is allowing the

generatortooperate.TheTech 2 displaysONif

thegeneratorisallowedtooperate.TheTech 2

tool displays OFF if the control module is disabling the

generator.

HO2S Bank 1 Sensor 1: This parameter displays

the voltage from the signal produced by the heated

oxygen sensor used to monitor fuel trim for cylinder

bank1.TheTech 2 willdisplayalowvoltagereading

whenthatcylinderbankisrunninglean.TheTech 2

willdisplayahighvoltagereadingwhenthat

cylinder bank is running rich.

HO2S Bank 1 Sensor 2: This parameter displays

the voltage from the signal produced by the heated

oxygen sensor used to monitor catalyst efficiency for

cylinderbank1.TheTech 2 willdisplayalow

voltage reading when that cylinder bank is running

lean.TheTech 2 willdisplayahighvoltagereading

when that cylinder bank is running rich.

HO2S Bank 2 Sensor 1: This parameter displays

the voltage from the signal produced by the heated

oxygen sensor used to monitor fuel trim for cylinder

bank2.TheTech 2 willdisplayalowvoltagereading

whenthatcylinderbankisrunninglean.TheTech 2

EngineEngineControls-6.0L

willdisplayahighvoltagereadingwhenthat

cylinder bank is running rich.

HO2S Bank 2 Sensor 2: This parameter displays

the voltage from the signal produced by the heated

oxygen sensor used to catalyst efficiency for cylinder

bank2.TheTech 2 willdisplayalowvoltage

reading when that cylinder bank is running lean. The

Tech 2 willdisplayahighvoltagereadingwhen

that cylinder bank is running rich.

HO2S Heater Bn 1 Sen. 1: This parameter displays

the current through the control module when the

bank 1 sensor 1 HO2S heater is commanded ON by

the control module. HO2S Heater Bn 1 Sen. 1 is

a range of values indicating a low current when the

heater circuit resistance is high to a high current when

the heater circuit resistance is low.

HO2S Heater Bn 1 Sen. 2: This parameter displays

the current through the control module when the

bank 1 sensor 2 HO2S heater is commanded ON by

the control module. HO2S Heater Bn 1 Sen. 2 is

a range of values indicating a low current when the

heater circuit resistance is high to a high current when

the heater circuit resistance is low.

HO2S Heater Bn 2 Sen. 1: This parameter displays

the current through the control module when the

bank 2 sensor 1 HO2S heater is commanded ON by

the control module. HO2S Heater Bn 2 Sen. 1 is

a range of values indicating a low current when the

heater circuit resistance is high to a high current when

the heater circuit resistance is low.

HO2S Heater Bn 2 Sen. 2: This parameter displays

the current through the control module when the

bank 2 sensor 2 HO2S heater is commanded ON by

the control module. HO2S Heater Bn 2 Sen. 2 is

a range of values indicating a low current when the

heater circuit resistance is high to a high current when

the heater circuit resistance is low.

IAC Position: This parameter displays the position

of the Idle Air Control (IAC) motor pintle as

commandedbythecontrolmodule.TheTech 2 will

display a high count for a higher idle speed

command, and a low count for a lower idle speed

command.

IAT Sensor: This parameter displays the

temperature of the intake air calculated by the control

module based on the input from the intake air

temperature(IAT).TheTech 2 willdisplayalow

value for a low intake air temperature, and a high value

for a high intake air temperature.

Ignition 1 Signal: This parameter displays the

voltage measured at the ignition 1 circuit of the control

module. Voltage is applied to the control module

when the ignition switch is in the ignition 1 position.

TheTech 2 willdisplayahighervaluewithahigher

system voltage, and a lower value with a lower

system voltage.

InjectorPWMBank1Average:TheTech 2

displays in milliseconds. This parameter is the average

time the control module turns on each fuel injector

onthatbank.TheTech 2 willdisplayahighervalue

with a longer pulse width, or a lower value with a

shorter pulse width.

InjectorPWMBank2Average:TheTech 2

displays in milliseconds. This parameter is the average

time the control module turns on each fuel injector

onthatbank.TheTech 2 willdisplayahighervalue

with a longer pulse width, or a lower value with a

shorter pulse width.

KnockRetard:TheTech 2 displaysin°.This

parameter indicates the amount of timing retard

commandedbythecontrolmodule.TheTech 2 will

display a lower value if no knock is detected, and

a higher value as more knock is detected and

the control module retards the ignition timing.

LongTermFTAvg.Bn1:TheTech 2 displaysin

%. This parameter is the average long term fuel

trim for this bank as calculated by the control module.

TheTech 2 willdisplayofmorethan0percent

indicating that time is being added to the injector pulse

width, increasing the amount of fuel to this bank of

theengine.TheTech 2 willdisplayavalueofless

than 0 indicating time is being subtracted from the

injector pulse width, reducing the amount fuel to this

bank of the engine. A value of 0 percent indicates

no compensation is required to operate the engine at

the desired air/fuel ratio.

LongTermFTAvg.Bn2:TheTech 2 displaysin

%. This parameter is the average long term fuel

trim for this bank as calculated by the control module.

TheTech 2 willdisplayofmorethan0percent

indicating that time is being added to the injector pulse

width, increasing the amount of fuel to this bank of

theengine.TheTech 2 willdisplayavalueofless

than 0 indicating time is being subtracted from the

injector pulse width, reducing the amount fuel to this

bank of the engine. A value of 0 percent indicates

no compensation is required to operate the engine at

the desired air/fuel ratio.

LongTermFTBank1:TheTech 2 displaysin%.

This parameter is the long term fuel trim for this

bankascalculatedbythecontrolmodule.TheTech 2

willdisplayofmorethan0percentindicatingthat

time is being added to the injector pulse width,

increasing the amount of fuel to this bank of the

engine.TheTech 2 willdisplayavalueoflessthan

0 indicating time is being subtracted from the

injector pulse width, reducing the amount fuel to this

bank of the engine. A value of 0 percent indicates

no compensation is required to operate the engine at

the desired air/fuel ratio.

LongTermFTBank2:TheTech 2 displaysin%.

This parameter is the long term fuel trim for this

bankascalculatedbythecontrolmodule.TheTech 2

willdisplayofmorethan0percentindicatingthat

time is being added to the injector pulse width,

increasing the amount of fuel to this bank of the

engine.TheTech 2 willdisplayavalueoflessthan

0 indicating time is being subtracted from the

injector pulse width, reducing the amount fuel to this

bank of the engine. A value of 0 percent indicates

no compensation is required to operate the engine at

the desired air/fuel ratio.

LoopStatus:TheTech 2 displaysOpenLoopor

EngineControls-6.0LEngine

ClosedLoop.TheTech 2 displaysClosedLoopif

the control module is controlling the fuel delivery

according to the heated oxygen sensor (HO2S)

voltages.TheTech 2 displaysopenloopifthe

control module is not adjusting for HO2S inputs. In

open loop the control module bases fuel deliver

on throttle position, engine coolant temperature, and

mass airﬂow sensor inputs.

Low Oil Lamp Command: This parameter displays

the commanded state of the low oil lamp control

circuitbythecontrolmodule.TheTech 2 willdisplay

ON if the lamp is commanded ON by the control

module.TheTech 2 willdisplayOFFifthelampis

not being commanded by the control module.

MAFSensor:TheTech 2 displaysg/s.This

parameter indicates the airﬂow into the engine as

calculated by the control module based on mass

airﬂow(MAF)sensorinputs.TheTech 2 willdisplay

a high value at higher engine speeds, and a low

value at idle.

MAFSensor:TheTech 2 displaysinHz.This

parameter indicates the frequency signal sent from the

MAFsensortothecontrolmodule.theTech 2 will

display a high value indicates a higher engine

speed.TheTech 2 willdisplayalowvalueatidle.

MAPSensor:TheTech 2 displayskPa.This

parameter displays the pressure inside of the intake

manifold as calculated by the control module based on

theinputfromtheMAPsensor.TheTech 2 will

display a high value at cruising speed or wide open

throttle(WOT).TheTech 2 willdisplayalowvalueat

idle speed.

MAP Sensor: This parameter displays the voltage

signal from the MAP sensor to the control module. The

Tech 2 willdisplayahighvalueatcruisingspeed

orwideopenthrottle(WOT).TheTech 2 willdisplay

a low vale at idle speed.

MIL Command: This parameter displays the

commanded state of the malfunction indicator

lamp (MIL) control circuit. The malfunction indicator

lampshouldbeonwhentheTech 2 indicates

the MIL Command is On. The malfunction indicator

lampshouldbeoffwhentheTech 2 indicates

the MIL Command is Off. The control module will

command the MIL On when the ignition is ON with the

engine OFF in order to perform a bulb check.

MileageSinceDTCCleared:TheTech 2 displays

km or miles. This parameter indicates the mileage

accumulated since an emission diagnostic trouble code

cleared.

MisﬁreCurrentCyl.#1-8:TheTech 2 willdisplay

in counts. This parameter indicates the number of

cylinder ﬁring events detected as possible misﬁres on

each cylinder during the last 200 crankshaft

revolutions as calculated by the control module. The

Tech 2 willdisplayalownumberforalownumberof

cylindermisﬁreevents.TheTech 2 willdisplaya

high number for a high number of cylinder misﬁre

events.

MisﬁreHistoryCyl.#1-8:TheTech 2 displaysin

counts. This parameter displays the total level of

cylinder misﬁres that have been calculated for each

cylinder by the control module. This parameter will not

update or show activity until a misﬁre DTC has

become active. The misﬁre history counters will update

every 200 cylinder ﬁring events.

NotRunCounter:TheTech 2 displaysthe

number of times a DTC diagnostic has not reached

the predetermined criteria in order to run since

the ﬁrst DTC run failure.

PassCounter:TheTech 2 displaysthenumber

of times a DTC has run and passed.

PCMReset:TheTech 2 displaysYesorNo.This

parameter indicates when the internal PCM resets.

TheTech 2 displaysYESwhenaninternal

PCMresetoccurred.TheTech 2 displaysNOunder

the normal operating conditions.

PCM/VCMinVTDFailEnable:TheTech 2

displaysYesorNo.TheTech 2 displaysYesifthe

body control module (BCM) and the control module

lose communications with each other after the

BCMsendsthecorrectpassword.TheTech 2

displays No if the BCM is communicating the correct

password to the PCM.

PowerEnrichment:Tech 2 displaysACTIVEor

INACTIVE. ACTIVE displayed indicates that the

control module has detected conditions appropriate to

operate in Power Enrichment mode. The control

module commands Power Enrichment mode when a

large increase in throttle position and load is detected.

While in Power Enrichment, the control module will

increase the amount of fuel delivered by entering Open

Loop and increasing the injector pulse width.

ReducedEnginePower:TheTech 2 displays

ActiveorInactive.TheTech 2 displaysActivewhen

the control module receives a signal from the

throttle actuator control (TAC) module that a TAC

systemfaultisoccurring.TheTech 2 displays

inactive when the engine is operating normally.

ShortTermFTAvg.Bn1:TheTech 2 displays

%. This parameter indicates the average short

termfueltrimforthisbank.TheTech 2 willdisplay

a value higher than 0 if the time is being added to

the injector pulse width, increasing the amount of fuel

to that bank of the engine to compensate for a

lean condition sensed by the oxygen sensors on that

bank.TheTech 2 willdisplayavaluelowerthan

0 if time is being subtracted from the injector

pulse width, reducing the amount of fuel to the engine

to compensate for a rich condition sensed by the

oxygen sensors on that bank. A value of 0 percent

indicates no compensation is required to operate

the engine at the desired air/fuel ratio.

ShortTermFTAvg.Bn2:TheTech 2 displays

%. This parameter indicates the average short

termfueltrimforthisbank.TheTech 2 willdisplay

a value higher than 0 if the time is being added to

the injector pulse width, increasing the amount of fuel

to that bank of the engine to compensate for a

lean condition sensed by the oxygen sensors on that

bank.TheTech 2 willdisplayavaluelowerthan

0 if time is being subtracted from the injector

pulse width, reducing the amount of fuel to the engine

EngineEngineControls-6.0L

to compensate for a rich condition sensed by the

oxygen sensors on that bank. A value of 0 percent

indicates no compensation is required to operate

the engine at the desired air/fuel ratio.

ShortTermFTBank1:TheTech 2 displays%.

This parameter indicates the current short term

fueltrimforthisbank.TheTech 2 willdisplaya

value higher than 0 if the time is being added to the

injector pulse width, increasing the amount of fuel

to that bank of the engine to compensate for a lean

condition sensed by the oxygen sensors on that bank.

TheTech 2 willdisplayavaluelowerthan0if

time is being subtracted from the injector pulse width,

reducing the amount of fuel to the engine to

compensate for a rich condition sensed by the oxygen

sensors on that bank. A value of 0 percent indicates

no compensation is required to operate the engine

at the desired air/fuel ratio.

ShortTermFTBank2:TheTech 2 displays%.

This parameter indicates the current short term

fueltrimforthisbank.TheTech 2 willdisplaya

value higher than 0 if the time is being added to the

injector pulse width, increasing the amount of fuel

to that bank of the engine to compensate for a lean

condition sensed by the oxygen sensors on that bank.

TheTech 2 willdisplayavaluelowerthan0if

time is being subtracted from the injector pulse width,

reducing the amount of fuel to the engine to

compensate for a rich condition sensed by the oxygen

sensors on that bank. A value of 0 percent indicates

no compensation is required to operate the engine

at the desired air/fuel ratio.

Spark: This parameter is the desired spark advance

calculated by the control module based on many

sensorinputs.TheTech 2 willdisplayalowervalue

at idle speed, and a higher value under heavy

acceleration and load conditions.

Start Up ECT: This parameter indicates the engine

coolant temperature at startup, as calculated by

the control module based on the input from the engine

coolanttemperaturesensor.TheTech 2 will

display a higher value at higher engine startup

temperatures, and a lower value at lower startup

temperatures.

Stop Lamp Pedal Switch: This parameter displays

the state of the brake pedal as determined by the

control module based on an input from the stop lamp

pedal switch. This switch turns on the stop lamps

whenthebrakepedalisdepressed.TheTech 2 will

display Applied when the brake pedal is depressed.

TCC Enable Solenoid Command: This parameter

displays the commanded state of the torque

converter clutch (TCC) solenoid control circuit. The

Tech 2 willdisplayEnabledordisabled.Enabled

indicates the TCC solenoid control circuit is being

grounded by the control module, operating the torque

converter. Disabled indicates the TCC solenoid is

not being commanded on by the control module.

TCC PWM Solenoid Command: This parameter

indicates the commanded state of the TCC PWM

Solenoidbythecontrolmodule.TheTech 2 displays

ONorOFF.TheTech 2 displaysONwhenthe

commandedstateofthesolenoidisON.TheTech 2

displays OFF when the solenoid is OFF.

TFP Switch: This parameter displays the state of

the Transmission Internal Mode Switch based on

the signal from the IMS inside the transmission. The

Tech 2 willdisplayDrive1,Drive2,Drive3,Drive4,

Park, Reverse, or Neutral. Drive 1 indicates the

Transmission Range switches C and P are closed,

connecting these circuits to ground. Drive 2 indicates

the Transmission Range switches A and C are

closed, connecting these circuits to ground. Drive

3 indicates that all of the Transmission Range switches

are closed, connecting all four circuits to ground.

Drive 4 indicates the Transmission Range switches B

and C are closed, connecting these circuits to

ground. Park indicates the Transmission Range A

switch is closed, connecting the circuit to ground.

Reverse indicates the Transmission Range switches

A, B, and P are closed, connecting these circuits

to ground. Neutral indicates the Transmission Range

switches B and P are closed, connecting these

circuits to ground.

TP Sensor: This parameter displays the voltage

signal sent to the control module from the sensor used

to monitor the position of the throttle plates. The

Tech 2 willdisplayalowvoltagewhenthethrottle

platesareatrest.TheTech 2 willdisplayahigh

voltage when the throttle plates are fully open.

TP Sensor: This parameter displays the angle of the

throttle position (TP) sensor in percent. This

information is calculated by the control module using

the signal from the throttle position sensor. The

Tech 2 willdisplayalowpercentagewhenthe

throttleplatesareclosed.TheTech 2 willdisplaya

high percentage when the throttle plates are

fully open.

TR Switch: This parameter indicates the current

state of the gear select switch on the

transmission/transaxle as calculated by the control

modulebasedontheTRswitch.TheTech 2 status

will switch from High to Low as different combinations

aremet.OntheTech 2 inPark,thePRNDL

would read P and A will be Low, and B and C will

be High.

Vehicle Speed Sensor: This parameter indicates

the vehicle speed calculated by the control module

based on an input from the vehicle speed

sensor(VSS).theTech 2 willdisplayahighvalueat

higher vehicle speeds, and a low value at lower

vehicle speeds.

VTDAutoLearnTimer:TheTech 2 displays

Active/Inactive. This parameter indicates if the control

module is ready to learn the theft deterrent password.

TheTech 2 willdisplayactiveifthesystemis

readytolearn.TheTech 2 willdisplayinactiveifthe

system has timed out or is not ready to learn the

password.

VTD Fuel Disable: This parameter Indicates if the

VTD system has received proper information to enable

ordisablefuel.TheTech 2 willdisplayActiveor

Inactive.TheTech 2 willdisplayActiveifthecontrol

module does not receive the correct password from

EngineControls-6.0LEngine

theBCM.TheTech 2 willdisplayInactiveifthe

control module receives the correct password from the

BCM. If the system is Active, the engine will not start.

VTDFuelDisableUntilIgn.Off:TheTech 2

will display Yes or No. This parameter indicates if the

VTD is disabled until the ignition is turned OFF.

TheTech 2 willdisplayYesiftheignitionisONand

atheftdeterrentDTCispresent.TheTech 2 will

display off if the system is OK and the theft deterrent

system is inactive.

Warm-upsw/oEmissionFaults:TheTech 2

displays in counts. This parameter counts the number

of warm up cycles without an emission fault present.

The parameter increments until a fault occurs. If a fault

occurs, the counter reverts to 0 until the fault is

corrected.ClearinginformationwithaTech 2 ora

loss of power to the PCM also resets the counter to 0.

Warm-upsw/oNon-EmissionFaults:TheTech 2

displaysincounts.Thisparametercounts

the number of warm up cycles without a non-emission

fault present. The parameter increments until a fault

occurs. If a fault occurs, the counter reverts to 0

until the fault is corrected. Clearing information with a

Tech 2 oralossofpowertothePCMalsoresets

the counter to 0.

Tech 2 OutputControls-EngineControls

Tech 2

Output Control Additional Menu

Selection(s) Description

Crankshaft Position

Variation Learn —

Enables the powertrain control module (PCM) to learn the variations in

the crankshaft position (CKP) system. The PCM will learn the variations

once the following conditions are met:

• Engine coolant temperature (ECT) is more than a speciﬁed value.

•AllinstructionsontheTech 2 havebeencompleted.

• The accelerator pedal is smoothly applied until the fuel cut-OFF, as

speciﬁedontheTech 2 ,isachieved,andthenimmediately

released.

The PCM learns the variation values on the deceleration from fuel

cut-OFF.

Cylinder Power Balance Fuel System

Enables/Disables a cylinder by turning OFF the fuel injector to the

cylinder. The fuel injector is normally enabled. The PCM disables the

fuel injector when the following conditions are met:

•AllinstructionontheTech 2 arecompleted

• Stabilized engine speed

• The fuel injector is selected

When Disable is selected the PCM turns the injector OFF for

30 seconds. During this period, the engine operates with a misﬁre.

Engine Speed Control TAC System

Activates the throttle activation control (TAC) system to change engine

RPM. The normal commanded state is None. To enable the RPM

control,allinstructionontheTech 2 mustbecompleted.Thesystem

will increase or decrease the RPM within a range of 350–2000 RPM.

The set step value changes the RPM by increments of 25 RPM, 100

RPM, and 500 RPM. The system remains in the commanded state until

cancelledbytheTech 2 .

EVAP Purge Solenoid Engine Output

Controls/EVAP System

Activates the evaporative emission (EVAP) purge valve. The normal

commanded state is None. The system will increase or decrease the

amount of EVAP purge valve opening by 10 percent increments within

a range of 0–100 percent. The system remains in the commanded

state until cancelled by the tool or the fuel tank pressure (FTP) exceeds

32 mm Hg (17 in H20).

EVAP Purge/Seal Engine Output

Controls/EVAP System

This control enables two functions. One function increases or

decreases the amount of purge by changing the duty cycle of the purge

valve and commanding the vent ON, non-venting. The normal

commanded state of both valves is None. The system will increase or

decrease the amount of EVAP purge valve opening by 10 percent

increments within a range of 0–100 percent. The second function seals

the system after using the purge function to obtain a speciﬁc amount of

FTP. When activated the purge valve is commanded to 0 percent and

the vent valve is commanded ON, non-venting. Both functions remain

in the commanded state until one of the following conditions occurs:

• Cancelled by the tool

• The FTP exceeds 32 mm Hg (17 in H20)

EngineEngineControls-6.0L

Tech 2 OutputControls-EngineControls(cont’d)

Tech 2

Output Control Additional Menu

Selection(s) Description

EVAP Vent Solenoid Engine Output

Controls/EVAP System

Activates the EVAP vent solenoid. The normal commanded state is

None. When commanded ON, the vent valve switches to non-venting.

The system remains in the commanded state until one of the following

conditions occurs:

• Cancelled by the tool

• Purge is greater than 0 percent, and the fuel tank pressure

exceeds 32 mm Hg (17 in H20)

Fuel Injector Balance Fuel System

Enables the fuel injector in order to verify proper fuel injector ﬂow. The

PCM will pulse the selected injector when the following conditions

are met:

•AllinstructionontheTech 2 completed

• Fuel injector selected

• Key ON, engine OFF

The selected fuel injector can only be ﬂowed/pulsed once per

ignition cycle.

Fuel Pump Engine Output Controls

Controls the fuel pump relay. The normal commanded state is None.

When commanded ON/OFF, the PCM turns the fuel pump ON/OFF. If

the engine is running, and the fuel pump is commanded OFF, the

engine will stall. The system remains in the commanded state until

cancelledbytheTech 2 .

Fuel Trim Enable Fuel System Disables the PCMs ability to learn new fuel trim parameters. The

system remains in the commanded state until cancelled by the

Tech 2 .

Fuel Trim Reset Fuel System Activates the reset of fuel trim data in all of the fuel trim cells.

Loop Status Engine Output Controls Controls the system loop status. The commanded states include None,

Open, or Closed. The normal commanded state is None. When

commanded Open or Closed, the system remains in the commanded

stateuntilcancelledbytheTech 2 .

Malfunction

Indicator Lamp Engine Output Controls Controls the malfunction indicator lamp (MIL). The commanded states

include None, ON, and OFF. When commanded ON or OFF, the

system remains in the commanded state until cancelled by the

Tech 2 .

MisﬁreGraphic—Graphstheaccumulatedmisﬁresoccurringineachcylinder.TheTech 2

allowsforaresetofthemisﬁregraph.

O2S Heater Control Engine Output Controls

Activates the HO2S Heater. The commanded states include None,

ON, and OFF. The normal commanded state is None. On a cold

engine, with the key ON, engine OFF, the HO2S signal will continue to

drop below bias when commanded ON. The system remains in the

commanded state until cancelled by the tool.

EngineControls-6.0LEngine

DTC P0016

Circuit Description

The engine control module (ECM) uses the crankshaft

position (CKP) sensor and the camshaft

position (CMP) sensor signals to monitor the

correlation between the crankshaft and camshaft

positions. If the ECM detects that the timing between

the crankshaft and the camshaft is incorrect,

DTC P0016 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0016 Crankshaft Position (CKP) Camshaft

Position (CMP) Correlation

Conditions for Running the DTC

• The engine is cranking, or the engine is running.

• DTCs P0335, P0336, P0340, P0341 are

not set.

• DTC P0016 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM detects that the timing between the

crankshaft and the camshaft is incorrect for one cam

trigger pulse.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores the information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC last test failed clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles if no failures are reported by this or any

other emission related diagnostic.

Test Description

The number below refers to the step number on the

diagnostic table.

5. An incorrectly installed camshaft gear, crankshaft

sprocket, or timing chain can cause this DTC

to set.

DTC P0016

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Start the engine.

2. Allow the engine to reach normal operating temperature.

3.ObservetheDTCinformationwithaTech 2 .

DoestheTech 2 displayDTCP0016failedthisignition?Goto

Step4

Goto

Step3

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 4

Go to

Intermittent

Conditions

ObservetheDTCinformationwithaTech 2 .

DoestheTech 2 displaythatDTCP0335,P0336,P0340,or

P0341 also failed this ignition?

Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

Step 5

EngineEngineControls-

DTC P0016 (cont’d)

Step Action Yes No

Repair one of the following conditions:

• The camshaft gear and the crankshaft sprocket alignment

marks are not aligned properly

• A timing chain tensioner condition

• An incorrectly installed timing chain

• Excessive play in the timing chain

• Incorrect indexing of the timing mark on either the crankshaft

sprocket or the camshaft gear

Refer to

Timing Chain and Sprockets Cleaning and Inspection

Camshaft and Bearings Cleaning and Inspection

, and

Timing

Chain and Sprockets Installation

in Engine Mechanical.

Did you complete the repair? Go to

Step 6

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 7

ObservetheCaptureInfowithaTech 2

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0030, P0036, P0050, or P0056

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. A heating element

inside the HO2S minimizes the time required for

the sensor to reach operating temperature. Voltage is

provided to the heater by the ignition 1 voltage

circuit through a fuse. With the engine running, ground

is provided to the heater by the HO2S heater low

control circuit, through a low side driver within

the engine control module (ECM).

The ECM commands the heater ON or OFF to

maintain a speciﬁc HO2S operating temperature range.

The ECM monitors the voltage on the HO2S heater

low control circuit for heater fault diagnosis. If the ECM

detects that the HO2S heater low control circuit

voltage is not within a speciﬁed range, DTC P0030

sets for HO2S bank 1 sensor 1, DTC P0036 sets

for HO2S bank 1 sensor 2, DTC P0050 sets for HO2S

bank 2 sensor 1, DTC P0056 sets for HO2S bank 2

sensor 2.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0030 HO2S Heater Control Circuit Bank 1

Sensor 1

• DTC P0036 HO2S Heater Control Circuit Bank 1

Sensor 2

• DTC P0050 HO2S Heater Control Circuit Bank 2

Sensor 1

• DTC P0056 HO2S Heater Control Circuit Bank 2

Sensor 2

Conditions for Running the DTC

• The Ignition 1 Signal parameter is between 11–

18 volts.

• The engine speed is more than 425 RPM.

• This diagnostic runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The ECM detects that the affected HO2S heater low

control circuit is not within a speciﬁed range for

25 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P0030, P0036, P0050, or P0056

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

2 Is DTC P0030 or P0050 set? — Go to

Step 4

Go to

Step 3

EngineEngineControls-6.0L

DTC P0030, P0036, P0050, or P0056 (cont’d)

Step Action Values Yes No

1. Start the engine.

2. Wait 1 minute to allow the heated oxygen sensor

(HO2S) heater current to stabilize.

3. Observe the affected HO2S heater current parameter

withaTech 2

Is the HO2S heater current parameter within the

speciﬁed range?

0.25–1.375 A

Go to

Step 5

Go to

Step 6

1. Start the engine.

2. Wait 1 minute to allow the HO2S heater current to

stabilize.

3. Observe the affected HO2S heater current parameter

withaTech 2 .

Is the HO2S heater current parameter within the

speciﬁed range?

0.25–3.125 A

Go to

Step 5

Go to

Step 6

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 6

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Inspect the fuse that supplies the applicable HO2S

heater.

Is the fuse open?

—

Go to

Step 7

Go to

Step 8

Test the ignition 1 voltage circuit for a short to ground.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 10

1. Disconnect the affected HO2S.

2. Turn ON the ignition, with the engine OFF.

3. Probe the ignition 1 voltage circuit of the HO2S

harness connector on the engine harness side with a

test lamp that is connected to a good ground. Refer to

Probing Electrical Connectors

in Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 9

Go to

Step 17

1. Turn OFF the ignition.

2. Probe the HO2S heater low control circuit of the

HO2S harness connector on the engine harness side

with a test lamp connected to battery voltage.

3. With the ignition still OFF, observe the test lamp.

Does the test lamp illuminate?

—

Go to

Step 12

Go to

Step 11

Test the ignition 1 voltage circuit on the sensor side of the

HO2S 1 connector for a short to ground. Refer to

Circuit

Testing

in Wiring Systems.

Is the sensor shorted to ground?

—

Go to

Step 18

Go to

Intermittent

Conditions

11 Start the engine with the test lamp still connected from the

previous step.

Is the test lamp ON steady or blinking? —Go to

Step 15

Go to

Step 13

Test the HO2S heater low control circuit for a short to

ground. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 16

EngineControls-6.0LEngine

DTC P0030, P0036, P0050, or P0056 (cont’d)

Step Action Values Yes No

Test the HO2S heater low control circuit for a short to

voltage. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 14

Test the HO2S heater low control circuit for an open or for

high resistance. Refer to

Circuit Testing

Wiring Repairs

and

Heated Oxygen Sensor (HO2S) Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 16

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 18

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

Heated Oxygen Sensor (HO2S) Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 19

Repair the open or high resistance in the ignition 1 voltage

circuit. Refer to

Wiring Repairs

and

Heated Oxygen Sensor

(HO2S) Wiring Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 20

—

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 1

Heated

Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 2

Heated Oxygen Sensor (HO2S) Replacement Bank 2

Sensor 1

,or

Heated Oxygen Sensor (HO2S) Replacement

Bank 2 Sensor 2

Did you complete the replacement?

—

Go to

Step 20

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 20

—

1. Replace the fuse, if necessary.

2.CleartheDTCswithaTech 2 .

3. Turn OFF the ignition for 30 seconds.

4. Start the engine.

5. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 21

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0068

Circuit Description

The throttle position (TP) is compared to an expected

throttle position based on engine load. The engine

control module (ECM) determines engine load based

on inputs from the mass air ﬂow (MAF) and the

manifold absolute pressure (MAP) sensors. If the ECM

detects that the current load and throttle position

are not consistent with the expected load and throttle

position, DTC P0068 is set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0068 Throttle Body Airﬂow Performance

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0120, P0121, P0122, P0123, P0220,

P0221, P0222, P0223, P0601, P0602, P0603,

P0604, P0606, P0607, P1516, P2101 are not set.

• The engine speed is more than 600 RPM and less

than 6,300 RPM.

• DTC P0068 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM detects that the throttle position and the

indicated engine load do not correspond with the

expected load and throttle position for less than

1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P0068

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Are DTCs P0101, P0102, P0103, P0106, P0107, P0108,

P0120, P0121, P0122, P0123, P0220, P0222, P0223,

P1516, P2101, P2119, P2176 also set? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

EngineControls-6.0LEngine

DTC P0068 (cont’d)

Step Action Value(s) Yes No

Inspect for the following conditions:

• Vacuum hoses for splits, kinks, and proper connections

as shown on Vehicle Emission Control

Information label

• Any type of leak or restriction

• Air leaks at the throttle body mounting area and the

intake manifold sealing surfaces

• Restrictions in the air intake system, including ﬁlter

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 5

Important: Observe the throttle position (TP) sensors 1

and2angleparameterwithaTech 2 .

1. Start the engine.

2. Apply accelerator pedal slightly and record TP 1 and 2

angles.

3. Turn OFF the ignition.

Is the difference between TP sensor 1 angle and TP

sensor 2 angle less than the speciﬁed value?

Go to

Step 10

Go to

Step 6

Test the TP sensor 1 5-volt reference circuit for high

resistance. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 7

Test the TP sensor low reference circuit for high

resistance. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 8

Test the TP sensor 1 signal circuit for high resistance.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 9

Test the TP sensor 2 signal circuit for high resistance.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 10

Inspect the throttle body for the following conditions:

• A loose or damaged throttle blade

• A broken throttle shaft

Did you ﬁnd a condition?

—

Go to

Step 11

—

11 Replace the throttle body assembly. Refer to

Throttle Body

Installation

Did you complete the replacement? —Go to

Step 12

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 3

Go to

Step 13

Important: More than one throttle actuator control (TAC)

system-related DTC may set. This is due to the many

redundant tests run continuously on this system. Locating

and repairing one individual condition may correct more

than one DTC. Be aware of this when reviewing

Captured Info.

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed?

—Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0101

Circuit Description

The mass air ﬂow (MAF) sensor is an air ﬂow meter

that measures the amount of air entering the

engine. The engine control module (ECM) uses the

MAF sensor signal to provide the correct fuel delivery

for all engine speeds and loads. A small quantity

of air entering the engine indicates a deceleration or

idle condition. A large quantity of air entering the

engine indicates an acceleration or high load condition.

The MAF sensor has the following circuits:

• An ignition 1 voltage circuit

• A ground circuit

• A signal circuit

The ECM applies a voltage to the sensor on the signal

circuit. The sensor uses the voltage to produce a

frequency based on the inlet air ﬂow through

the sensor bore. The frequency varies within a range

of near 2,000 Hertz at idle to near 11,500 Hertz at

maximum engine load. The ECM uses the following

sensor inputs to calculate a predicted MAF value:

• The manifold absolute pressure (MAP) estimated

• The intake air temperature (IAT) sensor

• The throttle areas from the engine temperature

control (ETC) and intake air temperature (IAT),

barometric pressure (BARO), and the

estimated MAP

The ECM compares the actual MAF sensor frequency

signal to the predicted MAF value. This comparison

will determine if the signal is stuck too low or too high

for a given operating condition. If the ECM detects

the actual MAF sensor frequency signal is to high of a

delta from the calculated MAF value and a manifold

absolute pressure (MAP) modeled signal is to high of a

delta from measured MAP the DTC P0101 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0101 Mass Air Flow (MAF) Sensor Performance

Conditions for Running the DTC

• DTCs P0102, P0103, P0106, P0107, P0108,

P0112, P0113, P0116, P0117, P0118, P0120,

P0128, P0220, P0315, P0335, P0442, P0446,

P0449, P0455, P0496 and P2135 are not set.

• The engine coolant temperature (ECT) is

between 70°C (158°F) and −7°C (19.4°F).

• The engine RPM is between 555 and 6400.

• DTC P0101 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM detects that the actual MAF sensor

frequency signal is not within a predetermined range

of the calculated MAF value for more than 4 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Inspect the harness of the mass air ﬂow (MAF)

sensor to verify that it is not routed too close

to the following components:

− The secondary ignition wires or coils

− Any solenoids

− Any relays

− Any motors

• A low minimum air rate through the sensor bore at

idle or during deceleration may cause this DTC to

set. Inspect for the following conditions:

− Any deposits on the throttle plate or in the

throttle bore

− Any vacuum leak downstream of the MAF

sensor

• Inspect for any contamination or debris on the

sensing elements of the MAF sensor.

• Inspect the air induction system for any water

intrusion. Any water that reaches the MAF sensor

will skew the sensor and may cause this DTC

to set.

• A wide open throttle acceleration from a stop

should cause the MAF sensor parameter on

theTech 2 toincreaserapidly.Thisincrease

should be from 5–12 g/s at idle to 200 g/s or more

at the time of the 1–2 shift. If the increase is not

observed, inspect for a restriction in the induction

system or the exhaust system.

• Inspect for a skewed or stuck ECT sensor.

EngineControls-6.0LEngine

• A high resistance of 15 ohms or more on the

ignition 1 voltage circuit may cause the DTC to set.

A high resistance may cause a driveability

concern before this DTC sets.

• The barometric pressure that is used to calculate

the predicted mass air ﬂow value is initially

based on the manifold absolute pressure (MAP)

sensor at key ON. When the engine is running the

BARO value is continually updated near wide

open throttle. A skewed MAP sensor will cause the

calculated mass air ﬂow value to be inaccurate

and may result in a no start condition. The value

shown for the MAP sensor parameter varies

with the altitude. With the ignition ON and

the engine OFF, 101 kPa is the approximate value

near sea level. This value will decrease by

approximately 3 kPa for every 305 meters

(1,000 feet) of altitude.

• A high resistance on the low reference circuit of

the MAP sensor may cause this DTC to set.

• A short to voltage on the 5-volt reference circuit of

the MAP sensor may cause this DTC to set.

If the condition is intermittent, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

5. This step will determine if the manifold absolute

pressure (MAP) sensor pressure is within the

proper range for a given altitude.

6. This step will determine if the MAP sensor voltage

is within the proper range at idle.

7. This step will determine if the MAP sensor

responds properly to the change in manifold

pressure.

8. This step will determine if the throttle position (TP)

sensors are operating properly.

9. This step will determine if any mechanical faults

have caused this DTC to set.

10. This voltage drop will determine if high resistance

has caused this DTC to set.

DTC P0101

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

2Attempt to start the engine.

Does the engine start? —Go to

Step 3

Go to

Step 5

Observe the Diagnostic Trouble Code (DTC) Information

withtheTech 2 .

DoestheTech 2 displayanyDTCssetotherthan

DTC P0068 or DTC P0101? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Diagnostic Aids

EngineEngineControls-6.0L

DTC P0101 (cont’d)

Step Action Values Yes No

Important: The Altitude vs. Barometric Pressure table

indicates a pressure range for a given altitude under

normal weather conditions. Weather conditions consisting

of very low or very high pressure and/or temperature may

cause a reading to be slightly out of range.

1. Turn ON the ignition, with the engine OFF.

2. Observe the manifold absolute pressure (MAP) sensor

kPaparameterwithaTech 2 .

3. The MAP sensor pressure should be within the

speciﬁed range for your altitude. Refer to

Altitude vs

Barometric Pressure

Is the MAP sensor pressure within the speciﬁed range, as

indicated on the altitude vs. barometric pressure table?

—

Go to

Step 6

Go to

DTC P0106

1. Start the engine.

2. Turn OFF all accessories.

3. Allow the engine to reach operating temperature.

4. Observe the manifold absolute pressure (MAP) sensor

parameterwithaTech 2 .

Is the MAP sensor parameter within the speciﬁed range?

0.8–2.0 V

Go to

Step 7

Go to

DTC P0106

1. Idle the engine.

2. Observe the manifold absolute pressure (MAP) sensor

parameterwithaTech 2 .

3. Increase the engine speed slowly to 3,000 RPM and

then back to idle.

Does the MAP sensor parameter change smoothly and

gradually through the speciﬁed range of the test?

—

Go to

Step 8

Go to

DTC P0106

1. Turn OFF the ignition for 30 seconds.

2. Turn ON the ignition with the engine OFF.

3. Observe the throttle position (TP) indicated angle

parameterwithaTech 2 .

4. Depress the accelerator pedal completely.

Is the TP indicated angle parameter within the

speciﬁed range?

95–100%

Go to

Step 9

Go to

DTC P0120

1. Turn OFF the ignition.

2. Inspect for the following conditions:

• An improperly routed mass air ﬂow (MAF) sensor

harness

• A restricted or collapsed air intake duct

• A misaligned air intake duct

• A dirty or deteriorating air ﬁlter element

• Any objects blocking the air inlet screen of the

MAF sensor, if equipped

• Any contamination or debris on the sensing

elements of the MAF sensor

• Any water intrusion in the induction system

• Any vacuum leak downstream of the MAF sensor

• A skewed or stuck engine coolant

temperature (ECT) sensor

• Any type of restriction in the exhaust system—

Refer to

Restricted Exhaust

in Engine Exhaust.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 10

EngineControls-6.0LEngine

DTC P0101 (cont’d)

Step Action Values Yes No

1. Disconnect the harness connector of the mass air

ﬂow (MAF) sensor.

2. Measure the battery voltage with a DMM.

3. Turn ON the ignition, with the engine OFF.

4. Connect a test lamp between the ignition 1 voltage

circuit of the MAF sensor and a good ground. Refer to

Circuit Testing

in Wiring Systems.

5. Connect a DMM to the probe of the test lamp and a

good ground. Refer to

Measuring Voltage Drop

Wiring Systems.

Is the voltage within 0.50 volts of the speciﬁed value?

B+

Go to

Step 11

Go to

Step 12

Test for an intermittent and for a poor connection at the

mass air ﬂow (MAF) sensor. Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 13

Repair the high resistance in the ignition 1 voltage circuit of

the mass air ﬂow (MAF) sensor. Refer to

Wiring Repairs

Wiring Systems.

Did you complete the repair?

—

Go to

Step 14

—

Replace the mass air ﬂow (MAF)/intake air

temperature (IAT) sensor. Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor

Replacement

Did you complete the replacement?

—

Go to

Step 14

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 15

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0102

Circuit Description

The mass air ﬂow (MAF) sensor is an air ﬂow meter

that measures the amount of air entering the

engine. The engine control module (ECM) uses the

MAF sensor signal to provide the correct fuel delivery

for all engine speeds and loads. A small quantity

of air entering the engine indicates a deceleration or

idle condition. A large quantity of air entering the

engine indicates an acceleration or high load condition.

The MAF sensor has the following circuits:

• An ignition 1 voltage circuit

• A ground circuit

• A signal circuit

The ECM applies a voltage to the sensor on the signal

circuit. The sensor uses the voltage to produce a

frequency based on inlet air ﬂow through the sensor

bore. The frequency varies within a range of near

2,000 Hertz at idle to near 11,500 Hertz at maximum

engine load. If the ECM detects a frequency signal

less than the possible range of a correctly operating

MAF sensor DTC P0102 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0102 Mass Air Flow (MAF) Sensor Circuit

Low Frequency

Conditions for Running the DTC

• The engine speed is more than 300 RPM.

• The ignition 1 signal is more than 7.9 volts.

• The above conditions are present for more than

3 seconds.

• DTC P0102 runs continuously during the above

conditions.

Conditions for Setting the DTC

The ECM detects that the MAF sensor frequency

signal is less than 10 Hz. for more than 3 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Inspect the harness of the MAF sensor to verify

that it is not routed too close to the following

components:

− The secondary ignition wires or coils

− Any solenoids

− Any relays

− Any motors

• Inspect for any contamination or debris on the

sensing elements of the MAF sensor.

• A wide open throttle acceleration from a stop

should cause the MAF sensor parameter on

theTech 2 toincreaserapidly.Thisincrease

should be from 7–12 g/s at idle to 200 g/s or more

at the time of the 1–2 shift. If the increase is not

observed, inspect for a restriction in the induction

system or the exhaust system.

• A high resistance of 15 ohms or more on the

ignition 1 voltage circuit may cause this DTC

to set. A high resistance may cause a driveability

concern before this DTC sets.

• A high resistance of 15 ohms or more on the

ground circuit of the MAF sensor may cause this

DTC to set. A high resistance may cause a

driveability concern before this DTC sets.

If the condition is intermittent, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

5. This step will determine if any mechanical faults

have caused this DTC to set.

7. This voltage drop test will determine if high

resistance has caused this DTC to set.

9. This step veriﬁes the voltage signal from the ECM

to the MAF sensor connector.

10. This step tests the signal circuit of the MAF

sensor for a short to another 5-volt reference

circuit.

11. This step will determine if the ECM is able to

process the frequency signal that it receives from

the MAF sensor.

14. This step will determine which portion of the

circuit or which component is shorted to ground.

17. This step veriﬁes that the signal circuit is not

shorted to any other ECM circuit.

EngineControls-6.0LEngine

DTC P0102

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Start the engine.

2.ObservetheMAFSensorparameterwithaTech 2 .

Is the MAF Sensor parameter less than the

speciﬁed value?

1,200 Hz

Go to

Step 4

Go to

Step 3

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Diagnostic Aids

1.ObservetheMAFSensorparameterwithaTech 2 .

2. Move the harness and the connector of the mass air

ﬂow (MAF)/intake air temperature (IAT) sensor.

Does the movement of the harness or the connector affect

the MAF Sensor parameter?

—

Go to

Step 20

Go to

Step 5

1. Turn OFF the ignition.

2. Inspect for the following conditions:

• A restricted or collapsed air intake duct

• A misaligned air intake duct

• A dirty or deteriorating air ﬁlter element

• Any objects blocking the air inlet screen of the

MAF/IAT sensor

• Any water intrusion in the Induction System

• Any contamination or debris on the sensing

elements of the MAF sensor

Did you ﬁnd and correct the condition?

—

Go to

Step 28

Go to

Step 6

6Inspect the fuse in the ignition 1 voltage circuit of the MAF

sensor.

Is the fuse open? —Go to

Step 14

Go to

Step 7

1. Turn ON the ignition, with the engine OFF.

2. Measure the battery voltage with a DMM.

3. Disconnect the MAF/IAT sensor.

4. Connect a test lamp between the ignition 1 voltage

circuit of the MAF sensor and a good ground. Refer to

Probing Electrical Connectors

in Wiring Systems.

5. Connect the DMM to the probe of the test lamp and a

good ground. Refer to

Measuring Voltage Drop

and

Circuit Testing

in Wiring Systems.

Is the voltage within 0.5 volts of the speciﬁed value?

B+

Go to

Step 8

Go to

Step 21

EngineEngineControls-6.0L

DTC P0102 (cont’d)

Step Action Values Yes No

Important: All electrical components and accessories must

be turned OFF.

1. Turn OFF the ignition for 60 seconds to allow the

control modules to power down.

2. Measure the resistance from the ground circuit of the

MAF sensor to a good ground with a DMM. Refer to

Circuit Testing

in Wiring Systems.

Is the resistance less than the speciﬁed value?

5Ω

Go to

Step 9

Go to

Step 22

1. Turn ON the ignition, with the engine OFF.

2. Measure the voltage from the signal circuit of the MAF

sensor to a good ground with a DMM. Refer to

Circuit

Testing

in Wiring Systems.

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Step 10

Go to

Step 13

1. Connect a 3-amp fused jumper wire between the

signal circuit of the MAF sensor and a good ground.

Refer to

Circuit Testing

in Wiring Systems.

2. Start the engine.

3.ObservetheDTCInformationwithaTech 2 .

Do any additional DTCs set?

—

Go to

Step 24

Go to

Step 11

1. Turn OFF the ignition.

2. Connect the voltage supply and the ground lead of the

J 38522

Variable Signal Generator to the vehicle.

3. Connect the red lead of the

J 38522

to the signal

circuit of the MAF sensor. Refer to

Probing Electrical

Connectors

in Wiring Systems.

4. Set the Duty Cycle switch of the

J 38522

to Normal.

5. Set the Frequency switch of the

J 38522

to 5 K.

6. Set the Signal switch of the

J 38522

to 5 V.

7. Start the engine and allow it to idle.

8.ObservetheMAFSensorparameterwithaTech 2 .

Is the MAF Sensor parameter within the speciﬁed range?

4,950–5,025 Hz

Go to

Step 12

Go to

Step 15

Important: An abnormal resistance on the signal circuit will

disable the MAF sensor frequency before the voltage starts

to drop out of the correct parameter of 4.8–5.2 volts.

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM).

3. Test the MAF sensor signal circuit for a high

resistance and for a short to the IAT signal circuit.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 28

Go to

Step 18

13 Is the voltage less than the speciﬁed value? 4.8 V Go to

Step 15

Go to

Step 16

Important: The ignition 1 voltage circuit of the MAF sensor

is spliced to other components of the vehicle.

Test the ignition 1 voltage circuit for a short to ground.

Refer to

Testing for Short to Ground

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 28

—

EngineControls-6.0LEngine

DTC P0102 (cont’d)

Step Action Values Yes No

1. Turn OFF the ignition.

2. Disconnect the ECM.

3. Test the signal circuit between the ECM and the MAF

sensor for the following conditions:

• A high resistance

• An open circuit

• A short to ground

Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 28

Go to

Step 17

Important: Disconnecting the ECM connectors may

eliminate the short to voltage if the signal circuit is shorted

to another ECM circuit.

1. Turn OFF the ignition.

2. Disconnect the ECM.

3. Turn ON the ignition, with the engine OFF.

4. Measure the voltage from the signal circuit of the MAF

sensor to a good ground with a DMM. Refer to

Circuit

Testing

in Wiring Systems.

Is the voltage more than the speciﬁed value?

Go to

Step 23

Go to

Step 17

Measure the resistance from the signal circuit of the MAF

sensor to all other circuits at both ECM connectors with a

DMM. Refer to

Circuit Testing

in Wiring Systems.

Is the resistance less than the speciﬁed value? ∞ΩGo to

Step 25

Go to

Step 19

Test for an intermittent and for a poor connection at the

MAF sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 28

Go to

Step 26

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 28

Go to

Step 27

20 Repair the wiring or the connector as needed. Refer to

Wiring Repairs

and

Connector Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 28

—

Repair the high resistance or the open in the MAF sensor

ignition 1 voltage circuit. Refer to

Wiring Repairs

in Wiring

Systems.

Did you complete the repair?

—

Go to

Step 28

—

22 Repair the high resistance or the open in the MAF sensor

ground circuit. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 28

—

23 Repair the short to voltage in the MAF sensor signal circuit.

Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 28

—

Repair the short between the MAF sensor signal circuit and

the 5-volt reference circuit for which the DTC set. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 28

—

25 Repair the circuits that are shorted together. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 28

—

EngineEngineControls-6.0L

DTC P0102 (cont’d)

Step Action Values Yes No

Replace the MAF/IAT sensor. Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor

Replacement

Did you complete the replacement?

—

Go to

Step 28

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 28

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 29

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0103

Circuit Description

The mass air ﬂow (MAF) sensor is an air ﬂow meter

that measures the amount of air entering the

engine. The engine control module (ECM) uses the

MAF sensor signal to provide the correct fuel delivery

for all engine speeds and loads. A small quantity

of air entering the engine indicates a deceleration or

idle condition. A large quantity of air entering the

engine indicates an acceleration or high load condition.

The MAF sensor has the following circuits:

• An ignition 1 voltage circuit

• A ground circuit

• A signal circuit

The ECM applies a voltage to the sensor on the signal

circuit. The sensor uses the voltage to produce a

frequency based on the inlet air ﬂow through

the sensor bore. The frequency varies within a range

of near 2,000 Hertz at idle to near 11,500 Hertz at

maximum engine load. If the ECM detects a frequency

signal more than the possible range of a correctly

operating MAF sensor DTC P0103 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0103 Mass Air Flow (MAF) Sensor Circuit

High Frequency

Conditions for Running the DTC

• The engine speed is more than 300 RPM.

• The ignition 1 signal is more than 7.9 volts.

• The above conditions are present for more than

one second.

• DTC P0103 runs continuously during the above

conditions.

Conditions for Setting the DTC

The engine control module (ECM) detects that the

mass air ﬂow (MAF) sensor frequency signal is more

than 13,500 Hertz for more than 1.8 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records. If

the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Inspect the air induction system for any water

intrusion. The water rapidly cools the hot sensing

elements in the sensor causing a false indication

of excessive air ﬂow. Any water that reaches

the mass air ﬂow (MAF) sensor will skew

the sensor and may cause this DTC to set.

• A poor connection in the ignition 1 voltage circuit

of the MAF sensor may cause this DTC to set.

If the condition is intermittent, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

3. This step tests for electromagnetic

interference (EMI) on the signal circuit of the MAF

sensor. A frequency reading with the mass air

ﬂow (MAF) sensor disconnected indicates an EMI

related fault or a poor connection at the ECM.

Disconnecting the MAF sensor may set additional

related DTCs.

4. This step will determine if incorrect harness

routing has caused this DTC to set.

5. This step will determine if water intrusion has

caused this DTC to set.

DTC P0103

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

EngineEngineControls-6.0L

DTC P0103 (cont’d)

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 3

Go to

Diagnostic Aids

1. Turn OFF the ignition.

2. Disconnect the mass air ﬂow (MAF) sensor.

3. Start the engine.

4.ObservetheMAFsensorparameterwithaTech 2 .

Is the MAF sensor parameter more than the

speciﬁed value?

0Hz

Go to

Step 4

Go to

Step 5

1. Turn OFF the ignition.

2. Inspect the harness of the mass air ﬂow (MAF) sensor

for incorrect routing that is too close to the following

components:

• Any aftermarket accessories—Refer to

Checking

Aftermarket Accessories

in Wiring Systems.

• The secondary ignition wires or the coils

• Any solenoids

• Any relays

• Any motors

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 7

1. Turn OFF the ignition.

2. Inspect the air induction system for any water

intrusion.

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 6

Test for an intermittent and for a poor connection at the

mas air ﬂow (MAF) sensor. Refer to

Testing for Intermittent

Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 8

Test for an intermittent and for a poor connection at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 9

Replace the mass air ﬂow (MAF)/intake air

temperature (IAT) sensor. Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor

Replacement

Did you complete the replacement?

—

Go to

Step 10

—

Replace the engine control module (ECM). Refer to

Control

Module References

in Computer/Integrating Systems for

replacement, setup, and programming.

Did you complete the replacement?

—

Go to

Step 10

—

EngineControls-6.0LEngine

DTC P0103 (cont’d)

Step Action Values Yes No

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 11

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0106

Circuit Description

The manifold absolute pressure (MAP) sensor

responds to pressure changes in the intake manifold.

The pressure changes occur based on the engine

load. The MAP sensor has the following circuits:

• A 5-volt reference circuit

• A low reference circuit

• A MAP sensor signal circuit

The engine control module (ECM) supplies 5 volts to

the MAP sensor on the 5-volt reference circuit.

The ECM, also, provides a ground on the low

reference circuit. The MAP sensor provides a signal to

the ECM on the MAP sensor signal circuit which is

relative to the pressure changes in the manifold. The

ECM should detect a low signal voltage at a low

MAP, such as during an idle or a deceleration. The

ECM should detect a high signal voltage at a

high MAP, such as the ignition is ON, with the engine

OFF, or at a wide-open throttle (WOT). The MAP

sensor is also used in order to determine the

barometric pressure (BARO). This occurs when the

ignition switch is turned ON, with the engine OFF. The

BARO reading may also be updated whenever the

engine is operated at WOT. The ECM monitors

the MAP sensor signal for voltage outside of the

normal range.

The ECM calculates a predicted value for the MAP

sensor based on throttle position (TP) and engine

speed. The ECM then compares the predicted value

to the actual MAP sensor signal. If the ECM detects

that the MAP sensor signal is not within the predicted

range, DTC P0106 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC.

DTC P0106 Manifold Absolute Pressure (MAP)

Sensor Performance

Conditions for Running the DTC

• DTCs P0102, P0103, P0107, P0108, P0112,

P0113, P0117, P0118, P0335, P0336, are not set.

• The engine speed is between 400–

6,800 RPM.

• The change in engine speed is less than

125 RPM.

• The engine coolant temperature (ECT) is between

70°C (158°F) and 125°C (257°F).

• The intake air temperature (IAT) is between −7°C

(19°F) and 125°C (257°F).

• The above conditions are present for more than

one second.

• DTC P0106 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The manifold absolute pressure (MAP) signal is more

than 15 Kpa from the predicted MAP signal for

more than 4 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

4. This step tests the ability of the manifold absolute

pressure (MAP) sensor to correctly indicate

barometric pressure (BARO).

6. This step tests the ability of the MAP sensor to

respond to an increase in engine vacuum.

8. This step tests for a proper MAP sensor pressure

with an applied vacuum.

DTC P0106

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

EngineControls-6.0LEngine

DTC P0106 (cont’d)

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Inspect for the following conditions:

• Vacuum hoses that are disconnected, damaged, or

incorrectly routed

• Manifold absolute pressure (MAP) sensor seal that is

missing or damaged

• Restrictions in the MAP sensor vacuum source

• Intake manifold vacuum leaks

Did you ﬁnd and correct the condition?

—

Go to

Step 21

Go to

Step 3

Important: The vehicle used for the comparison is not

limited to the same type of vehicle as is being serviced. A

vehicle known to provide an accurate reading is

acceptable.

Do you have access to another vehicle in which the MAP

sensorpressurecanbeobservedwithaTech 2 ?

—

Go to

Step 4

Go to

Step 5

1. Turn ON the ignition, with the engine OFF.

2. Observe the manifold absolute pressure (MAP) sensor

pressurewithaTech 2 .

3. Observe the MAP sensor pressure in the known good

vehiclewithaTech 2 .

4. Compare the values.

Is the difference between the values less than the

speciﬁed value?

3 kPa

Go to

Step 6

Go to

Step 11

Important: The Altitude vs. Barometric Pressure table

indicates a pressure range for a given altitude under

normal weather conditions. Weather conditions consisting

of very low or very high pressure and/or very low or very

high temperature may cause a reading to be slightly out

of range.

1. Turn ON the ignition, with the engine OFF.

2. Observe the manifold absolute pressure (MAP) sensor

pressurewithaTech 2 .Referto

Altitudevs

Barometric Pressure

3. The MAP sensor pressure should be within the range

speciﬁed for your altitude.

Does the MAP sensor indicate the correct barometric

pressure?

—

Go to

Step 6

Go to

Step 11

1. Turn OFF the ignition.

2. Remove the manifold absolute pressure (MAP) sensor

from the intake manifold. Refer to

Manifold Absolute

Pressure (MAP) Sensor Replacement

. Leave the MAP

sensor connected to the electrical harness.

3. Connect a

J 23738-A

Mityvac to the MAP sensor.

4. Turn ON the ignition, with the engine OFF.

5.ObservetheMAPsensorpressurewithaTech 2 .

6. Apply vacuum to the MAP sensor with the

J 23738-A

until 5 inch Hg is reached.

Does the MAP sensor pressure change?

—

Go to

Step 7

Go to

Step 11

EngineEngineControls-6.0L

DTC P0106 (cont’d)

Step Action Values Yes No

1. Observe the manifold absolute pressure (MAP) sensor

pressurewiththeTech 2 .

2. Apply vacuum to the MAP sensor with the

J 23738-A

in 1 inch Hg increments until 15 inches Hg is reached.

Each 1 inch Hg should decrease MAP sensor

pressure by 3–4 kPa.

Is the decrease in MAP sensor pressure consistent?

—

Go to

Step 8

Go to

Step 11

1. Observe the manifold absolute pressure (MAP) sensor

pressurewiththeTech 2 .

2. Apply vacuum with the

J 23738-A

until 20 inches Hg is

reached.

Is the MAP sensor pressure less than the speciﬁed value?

34 kPa

Go to

Step 9

Go to

Step 11

1. Observe the manifold absolute pressure (MAP) sensor

pressurewiththeTech 2 .

2. Disconnect the

J 23738-A

from the MAP sensor.

Does the MAP sensor pressure return to the original

reading observed in Step 4 or Step 5?

—

Go to

Step 10

Go to

Step 19

Inspect for the following conditions:

• Incorrect cam timing—Refer to

Timing Chain and

Sprockets Replacement

in Engine Mechanical for the

correct timing.

• Restricted exhaust ﬂow—Refer to

Restricted Exhaust

in Engine Exhaust.

• Worn piston rings—Refer to

Engine Compression Test

in Engine Mechanical.

Did you ﬁnd and correct the condition?

—

Go to

Step 21

Go to

Intermittent

Conditions

Test for an intermittent and a poor connection at the

manifold absolute pressure (MAP) sensor. Refer to

Testing

for Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 21

Go to

Step 12

1. Disconnect the manifold absolute pressure (MAP)

sensor harness connector.

2. Turn ON the ignition, with the engine OFF.

3. Measure the voltage from the 5-volt reference circuit

of the MAP sensor to a good ground, with a DMM.

Note the measurement as “Supply voltage”.

4. Connect a test lamp and a DMM in series between

the 5-volt reference circuit and the low reference

circuit of the MAP sensor at the harness connector.

5. Measure the amperage with the DMM. Note the

measurement as “Amperage”.

Is the amperage equal to the speciﬁed value?

0mA

Go to

Step 16

Go to

Step 13

1. Remove the DMM from the circuit.

2. Connect the test lamp between the 5-volt reference

circuit and the low reference circuit of the MAP

sensor, at the harness connector.

3. Measure the voltage from the 5-volt reference circuit

at the test lamp to a good ground, with the DMM.

Note the measurement as “Load voltage drop”.

4. Subtract the “Load voltage drop” from the “Supply

voltage”. Note the result as “Supply voltage drop”.

5. Divide the “Supply voltage drop” by the amperage.

Is the result more than the speciﬁed value?

5Ω

Go to

Step 15

Go to

Step 14

EngineControls-6.0LEngine

DTC P0106 (cont’d)

Step Action Values Yes No

1. Measure the voltage from the low reference circuit of

the manifold absolute pressure (MAP) sensor at the

test lamp to a good ground, with the DMM. Note the

result as “Low reference voltage drop”.

2. Divide the “Low reference voltage drop” by the

amperage.

Is the result more than the speciﬁed value?

5Ω

Go to

Step 17

Go to

Step 19

Test the 5-volt reference circuit between the engine control

module (ECM) and the manifold absolute pressure (MAP)

sensor for high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 21

Go to

Step 18

Test the low reference circuit between the ECM and the

MAP sensor for an open. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 21

Go to

Step 18

Test the low reference circuit between the ECM and the

MAP sensor for high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 21

Go to

Step 18

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 21

Go to

Step 20

19 Replace the MAP sensor. Refer to

Manifold Absolute

Pressure (MAP) Sensor Replacement

Did you complete the replacement? —Go to

Step 21

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 21

—

1.CleartheDTCswithaTech 2

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the conditions for running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 22

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0107

Circuit Description

The manifold absolute pressure (MAP) sensor

responds to pressure changes in the intake manifold.

The pressure changes occur based on the engine

load. The MAP sensor has the following circuits:

• 5-volt reference circuit

• Low reference circuit

• MAP sensor signal circuit

The engine control module (ECM) supplies 5 volts to

the MAP sensor on the 5-volt reference circuit.

The ECM also provides a ground on the low reference

circuit. The MAP sensor provides a signal to the

ECM on the MAP sensor signal circuit which is relative

to the pressure changes in the manifold. The ECM

should detect a low signal voltage at a low MAP, such

as during an idle or a deceleration. The ECM should

detect a high signal voltage at a high MAP, such as the

ignition is ON, with the engine OFF, or at a wide

open throttle (WOT). The MAP sensor is also used in

order to determine the barometric pressure (BARO).

This occurs when the ignition switch is turned ON, with

the engine OFF. The BARO reading may also be

updated whenever the engine is operated at WOT. The

ECM monitors the MAP sensor signal for voltage

outside of the normal range.

If the ECM detects a MAP sensor signal voltage that

is excessively low, DTC P0107 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0107 Manifold Absolute Pressure (MAP)

Sensor Circuit Low Voltage

Conditions for Running the DTC

• DTCs P0120, P0121, P0122, P0123, P0220,

P0222, P0223, P0641, P0651, P1515, P1516,

P2101, P2119, P2135, P2176 are not set.

• The engine is running.

• The throttle angle is 0 percent when the engine

speed is less than 800 RPM.

• The throttle angle is more than 12.5 percent when

the engine speed is more than 800 RPM.

• The above conditions are present for 3 seconds.

• DTC P0107 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The engine control module (ECM) detects that the

manifold absolute pressure (MAP) sensor voltage is

less than 0.06 volt for more than 3.2 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

4. Operate the vehicle within the same conditions as

when the DTC failed. If you cannot duplicate the

DTC, the information included in the Freeze

Frame/Failure Records can help to locate an

intermittent condition.

DTC P0107

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineControls-6.0LEngine

DTC P0107 (cont’d)

Step Action Values Yes No

1. Turn ON the ignition, with the engine OFF.

2.MonitortheDiagnosticTroubleCode(DTC)

InformationwiththeTech 2 .

Is DTC P0641 also set?

—

Go to

DTC P0641

Go to

Step 3

3Observe the manifold absolute pressure (MAP) sensor

parameterwiththeTech 2 .

Is the voltage less than the speciﬁed value? 0.1 V Go to

Step 5

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the manifold absolute pressure (MAP)

sensor electrical connector.

3. Turn ON the ignition, with the engine OFF.

4. Measure the voltage from the 5-volt reference circuit

of the MAP sensor to a good ground, with a DMM, at

the MAP sensor connector. Refer to

Circuit Testing

Wiring Systems.

Is the voltage more than the speciﬁed value?

4.8 V

Go to

Step 6

Go to

Step 7

1. Connect a 3-amp fused jumper wire between the

5-volt reference circuit of the manifold absolute

pressure (MAP) sensor and the signal circuit of the

MAP sensor.

2. Observe the MAP sensor parameter with the

Tech 2

Is the voltage more than the speciﬁed value?

4.9 V

Go to

Step 9

Go to

Step 8

Test the 5-volt reference circuit between the engine control

module (ECM) and the manifold absolute pressure (MAP)

sensor for an open. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 10

Test the MAP sensor signal circuit between the ECM and

the MAP sensor for a short to ground or an open. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 10

Test for an intermittent and for a poor connection at the

MAP sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 11

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 12

11 Replace the MAP sensor. Refer to

Manifold Absolute

Pressure (MAP) Sensor Replacement

Did you complete the replacement? —Go to

Step 13

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 13

—

EngineEngineControls-6.0L

DTC P0107 (cont’d)

Step Action Values Yes No

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 14

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0108

Circuit Description

The manifold absolute pressure (MAP) sensor

responds to pressure changes in the intake manifold.

The pressure changes occur based on the engine

load. The MAP sensor has the following circuits:

• 5-volt reference circuit

• Low reference circuit

• MAP sensor signal circuit

The engine control module (ECM) supplies 5 volts to

the MAP sensor on the 5-volt reference circuit.

The ECM also provides a ground on the low reference

circuit. The MAP sensor provides a signal to the

ECM on the MAP sensor signal circuit which is relative

to the pressure changes in the manifold. The ECM

should detect a low signal voltage at a low MAP, such

as during an idle or a deceleration. The ECM should

detect a high signal voltage at a high MAP, such as the

ignition is ON, with the engine OFF, or at a wide

open throttle (WOT). The MAP sensor is also used in

order to determine the barometric pressure (BARO).

This occurs when the ignition switch is turned ON, with

the engine OFF. The BARO reading may also be

updated whenever the engine is operated at WOT. The

ECM monitors the MAP sensor signal for voltage

outside of the normal range.

If the ECM detects a MAP sensor signal voltage that

is excessively high, DTC P0108 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0108 Manifold Absolute Pressure (MAP)

Sensor Circuit High Voltage

Conditions for Running the DTC

• DTCs P0120, P0121, P0123, P0220, P0222,

P0223, P0641, P0651, P1516, P2101, P2119,

P2135, P2176, are not set.

• The engine has been running for a length of time

that is determined by the start-up coolant

temperature. The length of time ranges from

4 minutes at less than −6°C (−21°F) to 30 seconds

at more than 30°C (86°F).

• The throttle angle is less than 1 percent when the

engine speed is less than 1,200 RPM.

• The throttle angle is less than 20 percent when

the engine speed is more than 1,200 RPM.

• The above conditions are present for 3 seconds.

• DTC P0108 runs continously when the above

conditions are met.

Conditions for Setting the DTC

The engine control module (ECM) detects that the

manifold absolute pressure (MAP) sensor voltage is

more than 4.9 volts for more than 3.2 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Inspect for any vacuum leaks.

• This DTC may set as the result of a misﬁre.

• This DTC may set as the result of improper

tension or alignment of the timing chain.

• If this DTC is determined to be intermittent, refer

Intermittent Conditions

DTC P0108

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineEngineControls-6.0L

DTC P0108 (cont’d)

Step Action Values Yes No

2Attempt to start the engine.

Does the engine start and run? —Go to

Step 3

Go to

Step 4

3Observe the manifold absolute pressure (MAP) sensor

parameterwithaTech 2 .

Is the voltage more than the speciﬁed value? 4.9 V Go to

Step 6

Go to

Step 5

1. Turn OFF the ignition.

2. Remove the manifold absolute pressure (MAP) sensor

from the intake manifold. Refer to

Manifold Absolute

Pressure (MAP) Sensor Replacement

. Leave the

electrical harness connected.

3. Connect a

J 23738-A

Mityvac to the MAP sensor.

4. Apply vacuum until 5 inch Hg is reached.

5. Observe the MAP Sensor parameter with the

Tech 2 .

Is the voltage more than the speciﬁed value?

4.9 V

Go to

Step 6

Go to

Diagnostic Aids

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Does the DTC fail this ignition?

—

Go to

Step 6

Go to

Diagnostic Aids

Inspect for the following conditions:

• Disconnected, damaged, or incorrectly routed

vacuum hoses

• The manifold absolute pressure (MAP) sensor

disconnected from the vacuum source

• Restrictions in the MAP sensor vacuum source

• Intake manifold vacuum leaks

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 7

1. Turn OFF the ignition.

2. Turn ON the ignition, with the engine OFF.

3. Monitor the Diagnostic Trouble Code (DTC)

InformationwiththeTech 2 .

Is DTC P0641 also set?

—

Go to

Step 10

Go to

Step 8

1. Disconnect the manifold absolute pressure (MAP)

sensor electrical connector.

2.ObservetheMAPsensorparameterwiththe

Tech 2 .

Is the voltage less than the speciﬁed value?

0.1 V

Go to

Step 9

Go to

Step 11

1. Unless already done, remove the MAP sensor from

the intake manifold. Refer to

Manifold Absolute

Pressure (MAP) Sensor Replacement

2. Connect a jumper wire between each of the

terminals in the MAP sensor harness connector and

the corresponding terminal at the MAP sensor. Refer

Using Connector Test Adapters

in Wiring Systems.

3. Measure the voltage from the low reference circuit of

the MAP sensor at the jumper wire terminal to a good

ground with the DMM. Refer to

Measuring Voltage

Drop

in Wiring Systems.

Is the voltage more than the speciﬁed value?

0.2 V

Go to

Step 12

Go to

Step 13

EngineControls-6.0LEngine

DTC P0108 (cont’d)

Step Action Values Yes No

1. Disconnect the MAP sensor electrical connector.

2. Observe the MAP sensor parameter with the

Tech 2 .

Is the voltage less than the speciﬁed value?

0.1 V

Go to

DTC P0641

Go to

Step 11

Test the manifold absolute pressure (MAP) sensor signal

circuit between the engine control module (ECM) and the

MAP sensor for a short to voltage. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 16

Test the low reference circuit between the engine control

module (ECM) and the manifold absolute pressure (MAP)

sensor for high resistance or for an open. Refer to

Circuit

Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Inspect for an intermittent and for a poor connection at the

manifold absolute pressure (MAP) sensor. Refer to

Testing

for Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 15

Inspect for an intermittent and for a poor connection at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 16

15 Replace the MAP sensor. Refer to

Manifold Absolute

Pressure (MAP) Sensor Replacement

Did you complete the replacement? —Go to

Step 17

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 17

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 18

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0112

Circuit Description

The intake air temperature (IAT) sensor is a variable

resistor. The IAT sensor has a signal circuit and a low

reference circuit. The IAT sensor measures the

temperature of the air entering the engine. The engine

control module (ECM) supplies 5 volts to the IAT

signal circuit and a ground for the IAT low reference

circuit. When the IAT sensor is cold, the sensor

resistance is high. When the air temperature increases,

the sensor resistance decreases. With high sensor

resistance, the ECM detects a high voltage on the IAT

signal circuit. With lower sensor resistance, the

ECM detects a lower voltage on the IAT signal circuit.

If the ECM detects an excessively low IAT signal

voltage, indicating a high temperature,

DTC P0112 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0112 Intake Air Temperature (IAT) Sensor

Circuit Low Voltage

Conditions for Running the DTC

• DTCs P0116, P0117, P0118, P0502, P0503 are

not set.

• The engine run time is more than 45 seconds.

• The vehicle speed sensor (VSS) indicates that the

vehicle speed is more than 40 km/h (25 mph).

• The engine coolant temperature (ECT) is less than

125°C (257°F).

• DTC P0112 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM detects that the IAT sensor parameter is

more than 148°C (298°F) for more than 25 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• When the vehicle is at ambient temperature the

IAT sensor and the ECT sensor should be

relatively close to each other. Refer to

Temperature vs Resistance

• If an intermittent condition is suspected, refer to

Intermittent Conditions

DTC P0112

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2. Observe the intake air temperature (IAT) sensor

parameterwithaTech 2 .

Is the IAT sensor parameter more than the speciﬁed value?

148°C (298°F)

Go to

Step 4

Go to

Step 3

EngineControls-6.0LEngine

DTC P0112 (cont’d)

Step Action Values Yes No

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Fame/Failure Records.

Does the DTC fail this ignition?

—

Go to

Step 4

Go to

Diagnostic Aids

41. Disconnect the IAT sensor.

2.ObservetheIATsensorparameterwithaTech 2 .

Is the IAT sensor parameter less than the speciﬁed value? −38°C (−36°F) Go to

Step 6

Go to

Step 5

Test the signal circuit of the IAT sensor for a short to

ground or a short to the IAT low reference circuit. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 8

Test for an intermittent and for a poor connection at the

IAT sensor. Refer to

Testing for Intermittent Conditions and

Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 7

Replace the IAT sensor. Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor

Replacement

Did you complete the replacement?

—

Go to

Step 10

—

Test for an intermittent and for a poor connection at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 9

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 10

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 11

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0113

Circuit Description

The intake air temperature (IAT) sensor is a variable

resistor. The IAT sensor has a signal circuit and a low

reference circuit. The IAT sensor measures the

temperature of the air entering the engine. The engine

control module (ECM) supplies 5 volts to the IAT

signal circuit and a ground for the IAT low reference

circuit. When the IAT sensor is cold, the sensor

resistance is high. When the air temperature increases,

the sensor resistance decreases. With high sensor

resistance, the ECM detects a high voltage on the IAT

signal circuit. With lower sensor resistance, the

ECM detects a lower voltage on the IAT signal circuit.

If the ECM detects an excessively high IAT signal

voltage, indicating a low temperature, DTC P0113 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0113 Intake Air Temperature (IAT) Sensor

Circuit High Voltage

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0116, P0117,

P0118, P0125, P0128, P0502, P0503 are not set.

• The engine run time is more than 120 seconds.

• The vehicle speed sensor (VSS) indicates that the

vehicle speed is less than 11 km/h (7 mph).

• The engine coolant temperature (ECT) is more

than 60°C (140°F).

• The mass air ﬂow (MAF) is less than 15 g/s.

• DTC P0113 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM detects that the IAT Sensor parameter is

less than −38°C (−40°F) for more than 25 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• When the vehicle is at ambient temperature the

IAT sensor and the ECT sensor temperatures

should be relatively close to each other. Refer to

Temperature vs Resistance

• If a short to a separate 5-volt source occurs this

DTC may set.

• If an intermittent condition is suspected, refer to

Intermittent Conditions

Test Description

The number below refers to the step number on the

diagnostic table.

6. This step tests for the proper operation of the

circuit in the low voltage range.

DTC P0113

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

2ObservetheIATsensorparameterwithaTech 2 .

Is the IAT sensor parameter less than the speciﬁed value? −38°C

(−36.4°F) Go to

Step 4

Go to

Step 3

EngineControls-6.0LEngine

DTC P0113 (cont’d)

Step Action Values Yes No

1. Observe the Freeze Frame/Failure Records data for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Diagnostic Aids

1. Disconnect the mass air ﬂow/intake air temperature

(MAF/IAT) sensor.

2. Connect a DMM between the signal circuit of the IAT

sensor and a good ground. Refer to

Circuit Testing

Wiring Systems.

Is the voltage more than the speciﬁed value?

5.2 V

Go to

Step 5

Go to

Step 6

Important: The sensor may be damaged if the circuit is

shorted to a voltage source.

Test the signal circuit for a short to voltage. Refer to

Circuit

Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

1. Connect a 3-amp fused jumper wire between the

signal circuit of the IAT sensor and the low reference

circuit of the IAT sensor. Refer to

Using Fused

Jumper Wires

in Wiring Systems.

2.ObservetheIATsensorparameterwithaTech 2 .

Is the IAT sensor parameter more than the speciﬁed value?

128°C (262°F)

Go to

Step 10

Go to

Step 7

1. Connect a 3-amp fused jumper wire between the

signal circuit of the IAT sensor and a good ground.

Refer to

Using Fused Jumper Wires

in Wiring

Systems.

2.ObservetheIATsensorparameterwithaTech 2 .

Is the IAT sensor parameter more than the speciﬁed value?

128°C (262°F)

Go to

Step 9

Go to

Step 8

Test the signal circuit of the IAT sensor for an open circuit

or high resistance. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Test the IAT sensor low reference circuit for high

resistance or an open. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Test the IAT signal circuit for a short to any 5-volt

reference circuit. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 11

Important: The sensor may be damaged if the circuit is

shorted to a voltage source.

Test for an intermittent and for a poor connection at the IAT

sensor. Refer to

Testing for Intermittent Conditions and

Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 13

Test for an intermittent and for a poor connection at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 14

EngineEngineControls-6.0L

DTC P0113 (cont’d)

Step Action Values Yes No

Replace the IAT sensor. Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor

Replacement

Did you complete the replacement?

—

Go to

Step 15

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 15

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 16

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTCP0116

CircuitDescription

Theenginecoolanttemperature(ECT)sensorisa

variableresistorthatmeasuresthetemperatureofthe

enginecoolant.Theenginecontrolmodule(ECM)

supplies5voltstothesignalcircuitandagroundfor

theECTlowreferencecircuit.WhentheECTis

low,thesensorresistanceishigh.WhentheECTis

high,thesensorresistanceislow.TheECMusesthis

inputforenginecontrolsandenablingcriteriafor

diagnostics.TheECMusesthisHighSideCoolant

RationalitytesttodetermineiftheECTinputisskewed

high.TheinternalclockoftheECMwillrecordthe

amountoftimetheignitionisOFF.AtrestarttheECM

willcomparethetemperaturedifferencebetween

theECTandtheintakeairtemperature(IAT).This

DTCwillonlyrunonceduringtheignitioncyclewithin

theenablingconditions.Beforefailingthistest,the

ECMwillperformacalculationtodeterminethe

presenceofablockheater.IftheECMdetectsthat

thetemperaturedifferenceisnotwithinthecalibrated

rangeaftertheignitionOFFtime,DTCP0116sets.

DTCDescriptor

ThisdiagnosticproceduresupportsthefollowingDTC:

DTCP0116EngineCoolantTemperature(ECT)

SensorPerformance

ConditionsforRunningtheDTC

•TheignitionOFFtimeismorethan10hours.

•TheIATsensortemperatureismorethan

7°C(44.6°F)atkeyup.

•ThedifferencebetweentheIATandtheECTis

morethan15°C(59°F)atkeyup.

•Adiagnostictestwillneedtobeperformedto

determineifthetemperaturedifferenceiscaused

byablockheateraftertheaboveconditions

aremet.Thefollowingitemisthecriterion

toenablethistest.

•Thevehiclespeedmustbemorethan24km/h

(15mph)formorethan400seconds.

ConditionsforSettingtheDTC

•IftheIATdecreasesmorethan3°C(5°F)during

thetest,ablockheaterwasdetected,this

diagnosticwillabortandnoDTCwillset.

•IftheIATdoesnotdecreaseduringthetest,

DTCP0116willset.

ActionTakenWhentheDTCSets

•Thecontrolmoduleilluminatesthemalfunction

indicatorlamp(MIL)onthesecondconsecutive

ignitioncyclethatthediagnosticrunsandfails.

•Thecontrolmodulerecordstheoperating

conditionsatthetimethediagnosticfails.The

ﬁrsttimethediagnosticfails,thecontrolmodule

storesthisinformationintheFailureRecords.

Ifthediagnosticreportsafailureonthe

secondconsecutiveignitioncycle,thecontrol

modulerecordstheoperatingconditionsat

thetimeofthefailure.Thecontrolmodulewrites

theoperatingconditionstotheFreezeFrame

andupdatestheFailureRecords.

ConditionsforClearingtheMIL/DTC

•ThecontrolmoduleturnsOFFthemalfunction

indicatorlamp(MIL)after3consecutiveignition

cyclesthatthediagnosticrunsanddoesnotfail.

•AcurrentDTC,LastTestFailed,clearswhenthe

diagnosticrunsandpasses.

•AhistoryDTCclearsafter40consecutivewarm-up

cycles,ifnofailuresarereportedbythisorany

otheremissionrelateddiagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

7. A snapshot is the quickest method to capture the

data before it changes.

8. An IAT sensor that is skewed low can cause this

DTC to set.

10. This step will determine if high resistance has

caused this DTC to set.

12. A high resistance short from the signal circuit to

the low reference circuit can cause this DTC

to set.

DTC P0116

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineEngineControls-6.0L

DTC P0116 (cont’d)

Step Action Values Yes No

Important: The cooling fans are commanded ON when

certain engine coolant temperature (ECT) DTCs are set.

Inspect the cooling system coolant level.

Is the cooling system coolant low?

—Go to

Draining

and Filling

Cooling System

in Engine Cooling Go to

Step 3

3Observe and record the ambient air temperature of the

vehicle environment using an accurate thermometer.

Did you complete the action? —Go to

Step 4

—

Important: The vehicle needs to have been OFF for at

least 10 hours for the ECT and the intake air

temperature (IAT) to be at ambient temperature. The

vehicle should not have changed environments during

this time.

Has the engine been OFF for the speciﬁed amount of time?

10 hrs

Go to

Step 7

Go to

Step 5

1. Remove the mass air ﬂow/intake air temperature

(MAF/IAT) sensor. Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor

Replacement

2. Remove the ECT sensor. Refer to

Engine Coolant

Temperature (ECT) Sensor Replacement

3. Place the sensors on a work surface away from any

heat source.

4. Allow the sensors to reach the ambient air

temperature for 30–60 minutes.

Are the sensors at the ambient temperature?

—

Go to

Step 6

—

1. Connect the MAF/IAT sensor to the electrical

connector, but DO NOT install it.

2. Insulate the sensor from any engine heat source.

3. Connect the ECT sensor to the electrical connector,

but DO NOT install it.

4. Insulate the sensor from any engine heat source.

Are the sensors connected?

—

Go to

Step 7

—

Important: The IAT sensor will start to warm-up as soon

as the ignition is turned ON.

1. Turn ON the ignition.

2.TakeasnapshotoftheEngineDataListwithaTech 2

tool.Referto

Tech 2 SnapshotProcedure

inWiring

Systems.

3. Review the snapshot data that was taken with the

Tech 2 .

4.ObservetheECTSensorparameterwithaTech 2 .

5.ObservetheIATSensorparameterwithaTech 2 .

Is the difference between the ECT Sensor parameter and

the IAT Sensor parameter more than the speciﬁed value?

15°C (27°F)

Go to

Step 8

Go to

Intermittent

Conditions

Observe the recorded IAT Sensor parameter.

Is the difference between the IAT Sensor parameter and

the ambient air temperature less than the speciﬁed value? 8°C (14°F) Go to

Step 9

Go to

Step 10

9Observe the recorded ECT Sensor parameter.

Is the difference between the ECT Sensor parameter and

the ambient air temperature less than the speciﬁed value? 8°C (14°F) Go to

Intermittent

Conditions

Go to

Step 12

1. Disconnect the MAF/IAT sensor.

2. Test for an intermittent and for a poor connection at

the IAT sensor. Refer to

Testing for Intermittent

Conditions and Poor Connections

and

Connector

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 25

Go to

Step 11

EngineControls-6.0LEngine

DTC P0116 (cont’d)

Step Action Values Yes No

1. At the sensor, measure the resistance between the

IAT signal and the IAT low reference terminals with a

DMM and record the value. Refer to

Circuit Testing

Wiring Systems.

2. Observe the recorded ambient air temperature.

3. Compare the resistance measurement of the IAT

sensor to the ambient air temperature using the

Temperature vs. Resistance table. Refer to

Temperature vs Resistance

Is the resistance measurement of the IAT sensor within the

speciﬁed range?

—

Go to

Step 14

Go to

Step 22

1. Disconnect the ECT sensor.

2. Inspect for the following conditions:

• An ECT sensor leaking engine coolant internally

through the sensor

• Corrosion on the ECT sensor terminals

• Corrosion on the ECT harness connector terminals

Did you ﬁnd and correct the condition?

—

Go to

Step 25

Go to

Step 13

Important: Do not hold the ECT sensor by the probe.

1. At the sensor, measure the resistance between the

ECT signal and the ECT low reference terminals with

a DMM and record the value. Refer to

Circuit Testing

in Wiring Systems.

2. Observe the recorded ambient air temperature.

3. Compare the resistance measurement of the ECT

sensor to the ambient air temperature using the

Temperature vs. Resistance table. Refer to

Temperature vs Resistance

Is the resistance measurement of the ECT sensor within

the speciﬁed range?

—

Go to

Step 15

Go to

Step 23

Measure the voltage from the IAT signal circuit to a good

ground with a DMM. Refer to

Circuit Testing

in Wiring

Systems.

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Step 16

Go to

Step 17

Measure the voltage from the ECT signal circuit to a good

ground with a DMM. Refer to

Circuit Testing

in Wiring

Systems.

Is the voltage within the speciﬁed range?

4.8–5.2 V Go to

Intermittent

Conditions

Go to

Step 19

Important: All electrical components and accessories must

be turned OFF. Performing this step will disable the

diagnostic for 10 hours.

1. Turn OFF the ignition for 90 seconds to allow the

control modules to power down.

2. Measure the resistance from the low reference circuit

of the IAT sensor to a good ground with a DMM.

Refer to

Circuit Testing

in Wiring Systems.

Is the resistance less than the speciﬁed value?

5Ω

Go to

Intermittent

Conditions

Go to

Step 18

17 Test the IAT signal circuit for a high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? —Go to

Step 25

Go to

Step 20

Test the IAT low reference circuit for a high resistance.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 25

Go to

Step 20

EngineEngineControls-6.0L

DTC P0116 (cont’d)

Step Action Values Yes No

Test the ECT signal circuit for a high resistance short to

ground. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 25

Go to

Step 21

Test for an intermittent and for a poor connection at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 25

Go to

Step 24

Test for shorted terminals and poor connections at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

Connector Repairs

in Wiring Systems, and

Intermittent Conditions

Did you ﬁnd and correct the condition?

—

Go to

Step 25

Go to

Step 24

Replace the MAF/IAT sensor. Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor

Replacement

Did you complete the replacement?

—

Go to

Step 25

—

23 Replace the ECT sensor. Refer to

Engine Coolant

Temperature (ECT) Sensor Replacement

Did you complete the replacement? —Go to

Step 25

—

Replace the ECM/PCM. Refer to

Control Module

References

in Computer/Integrating Systems for

replacement, setup, and programming.

Did you complete the replacement?

—

Go to

Step 25

—

25 Reassemble the vehicle as necessary.

Did you complete the action? —Go to

Step 26

—

Important: This DTC will not run without the ignition being

OFF for at least 10 hours.

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 10 hours.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

in the DTC. You may also operate the vehicle within

the conditions that you observed from the Freeze

Frame/Failure Records

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 27

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0117

Circuit Description

The engine coolant temperature (ECT) sensor is a

variable resistor, that measures the temperature of the

engine coolant. The engine control module (ECM)

supplies 5 volts to the ECT signal circuit and a ground

for the ECT low reference circuit. When the ECT is

cold, the sensor resistance is high. When the

ECT increases, the sensor resistance decreases. With

high sensor resistance, the ECM detects a high

voltage on the ECT signal circuit. With lower sensor

resistance, the ECM detects a lower voltage on

the ECT signal circuit. If the ECM detects an

excessively low ECT signal voltage, which is a high

temperature indication, DTC P0117 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0117 Engine Coolant Temperature (ECT)

Sensor Circuit Low Voltage

Conditions for Running the DTC

• The engine run time is more than 60 seconds.

The engine run time is less than 60 seconds

when IAT is less than 0°C (32°F).

• DTC P0117 runs continuously when the above

condition is met.

Conditions for Setting the DTC

The ECT sensor temperature is more than 150°C

(302°F) for more than 45 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• An overheating condition may cause this DTC

to set.

• After starting the engine, the ECT should rise

steadily to about 90°C (194°F) then stabilize when

the thermostat opens.

• Use the Temperature vs. Resistance table to test

the ECT sensor at various temperature levels to

evaluate the possibility of a skewed sensor. A

skewed sensor could result in poor driveability

concerns. Refer to

Temperature vs Resistance

• If the condition is suspected of being intermittent,

refer to

Intermittent Conditions

DTC P0117

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Important: The engine control module (ECM) will enable

the engine cooling fans when certain engine coolant

temperature (ECT) diagnostic trouble codes are set.

ObservetheECTsensorparameterwithaTech 2 .

Is the ECT sensor parameter more than the

speciﬁed value?

138°C (280°F)

Go to

Step 4

Go to

Step 3

EngineEngineControls-6.0L

DTC P0117 (cont’d)

Step Action Values Yes No

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Diagnostic Aids

41. Disconnect the ECT sensor.

2.ObservetheECTsensorparameterwithaTech 2 .

Is the ECT sensor parameter less than the speciﬁed value? −38°C (−36°F) Go to

Step 6

Go to

Step 5

Test the signal circuit of the ECT sensor for a short to

ground or a short to the ECT low reference circuit. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 8

Test for an intermittent and for a poor connection at the

ECT sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 7

7Replace the ECT sensor. Refer to

Engine Coolant

Temperature (ECT) Sensor Replacement

Did you complete the replacement? —Go to

Step 10

—

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and complete the replacement?

—

Go to

Step 10

Go to

Step 9

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 10

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 11

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0118

Circuit Description

The engine coolant temperature (ECT) sensor is a

variable resistor, that measures the temperature of the

engine coolant. The ECT sensor has a signal circuit

and a low reference circuit. The engine control

module (ECM) supplies 5 volts to the ECT signal circuit

and a ground for the ECT low reference circuit.

When the ECT is cold, the sensor resistance is high.

When the ECT increases, the sensor resistance

decreases. With high sensor resistance, the ECM

detects a high voltage on the ECT signal circuit. With

lower sensor resistance, the ECM detects a lower

voltage on the ECT signal circuit. If the ECM detects

an excessively high ECT signal voltage, which is

a low temperature indication, DTC P0118 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0118 Engine Coolant Temperature (ECT)

Sensor Circuit High Voltage

Conditions for Running the DTC

• The engine has been running for more than

60 seconds.

The engine run time is less than 60 seconds

when the intake air temperature (IAT) is more than

0°C (32°F)

• DTC P0118 runs continuously when the above

condition is met.

Conditions for Setting the DTC

The ECM detects that the ECT sensor parameter is

less than −40°C (−40°F) for 45 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• If a short to a separate 5-volt source occurs, this

DTC may set.

• After starting the engine, the ECT should rise

steadily, then stabilize when the thermostat opens.

• Use the Temperature vs. Resistance table to

test the ECT sensor. A skewed sensor could result

in poor driveability conditions. Refer to

Temperature vs Resistance

• If the condition is suspected of being intermittent,

refer to

Intermittent Conditions

DTC P0118

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Important: The engine control module (ECM) will enable

the engine cooling fans when certain engine coolant

temperature (ECT) diagnostic trouble codes are set.

ObservetheECTsensorparameterwithaTech 2 .

Is the ECT sensor parameter less than the speciﬁed value?

−38°C (−36°F)

Go to

Step 4

Go to

Step 3

EngineEngineControls-6.0L

DTC P0118 (cont’d)

Step Action Values Yes No

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Diagnostic Aids

1. Disconnect the ECT sensor.

2. Measure the voltage from the signal circuit of the ECT

sensor to a good ground with a DMM. Refer to

Circuit

Testing

and

Wiring Repairs

in Wiring Systems.

Is the voltage more than the speciﬁed value?

5.2 V

Go to

Step 5

Go to

Step 6

Important: If a short to voltage occurs, the ECT sensor

may be damaged.

Test the ECT signal circuit for a short to voltage. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

1. Connect a 3-amp fused jumper between the signal

circuit of the ECT sensor and the low reference circuit.

Refer to

Using Fused Jumper Wires

in Wiring

Systems.

2. Observe the ECT sensor parameter with the

Tech 2 .

Is the ECT sensor parameter more than the

speciﬁed value?

138°C (280°F)

Go to

Step 10

Go to

Step 7

1. Connect a 3-amp fused jumper between the signal

circuit of the ECT sensor and a good ground.

2.ObservetheECTsensorparameterwithaTech 2 .

Is the ECT sensor parameter more than the

speciﬁed value?

138°C (280°F)

Go to

Step 9

Go to

Step 8

Test the signal circuit of the ECT sensor for a high

resistance or an open. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Test the low reference circuit of the ECT sensor for a high

resistance or an open. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Test the ECT signal circuit for a short to any 5-volt

reference circuit. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 11

Test for an intermittent and for a poor connection at the

ECT sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 13

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 14

13 Replace the ECT sensor. Refer to

Engine Coolant

Temperature (ECT) Sensor Replacement

Did you complete the replacement? —Go to

Step 15

—

EngineControls-6.0LEngine

DTC P0118 (cont’d)

Step Action Values Yes No

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 15

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 16

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0120

Circuit Description

The throttle body assembly contains 2 throttle

position (TP) sensors. The TP sensors are mounted to

the throttle body assembly and are not serviceable.

The TP sensors provide a signal voltage that changes

relative to throttle blade angle. The engine control

module (ECM) supplies the TP sensors with a common

5-volt reference circuit, a common low reference

circuit, and 2 independent signal circuits.

The TP sensors have opposite functionality. TP

sensor 1 signal voltage decreases from above 4 volts

at idle to below 1 volt at wide open throttle (WOT).

TP sensor 2 signal voltage increases from below 1 volt

at idle to above 4 volts at WOT.

If the ECM detects TP sensor 1 signal voltage is too

low or too high, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0120 Throttle Position (TP) Sensor 1 Circuit

Conditions for Running the DTC

• DTCs P0341, P0351, P0601, P0602, P0603,

P0604, P0606, P0607 are not set.

• The ignition is ON, with the engine OFF, or the

engine is operating.

• The ignition 1 voltage is more than 5.23 volts.

• DTC P0120 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The ECM detects the TP sensor 1 signal voltage is

less than 0.275 volts for less than 1 second.

The ECM detects the TP sensor 1 signal voltage is

more than 4.725 volts for less than 1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• If there is a condition with the TP sensors, the

ECM defaults to reduced power mode for the

entire ignition cycle, even if the condition is

corrected.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The number below refers to the step number on the

diagnostic table.

2. This step veriﬁes that other DTCs are set.

DTC P0120

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

Are any other DTCs set? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

DTC P0121

EngineControls-6.0LEngine

DTC P0121

Circuit Description

The throttle body assembly contains 2 throttle

position (TP) sensors. The TP sensors are mounted to

the throttle body assembly and are not serviceable.

The TP sensors provide a signal voltage that changes

relative to throttle blade angle. The engine control

module (ECM) supplies the TP sensors with a common

5-volt reference circuit, a common low reference

circuit, and 2 independent signal circuits.

The TP sensors have opposite functionality. TP

sensor 1 signal voltage decreases from above 4 volts

at idle to below 1 volt at wide open throttle (WOT).

TP sensor 2 signal voltage increases from below 1 volt

at idle to above 4 volts at WOT.

The ECM compares the signal of the TP sensor 1 and

TP sensor 2 through the entire range. If the ECM

detects a predetermined difference between sensor 1

and sensor 2, or a predetermined difference from

the predicted range, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0121 Throttle Position (TP) Sensor 1

Performance

Conditions for Running the DTC

• DTCs P0102, P0103, P0107, P0108, P0112,

P0113, P0116, P0117, P0118, P0128, P0315,

P0335, P0336 are not set.

• The engine speed is more than 450 RPM.

• The ignition 1 voltage is more than 5.23 volts.

• The TP sensor 1 voltage is between 0.17–

4.6 volts.

• DTC P0121 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

• The TP sensor 1 disagrees more than 9 percent

from TP sensor 2.

• The TP sensor 1 disagrees more than 9 percent

from the predicted value.

• The above conditions are met for less than

1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• If there is a condition with the TP sensors, the

ECM defaults to reduced power mode for the

entire ignition cycle, even if the condition is

corrected.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

2. This step veriﬁes that a condition exists. If there is

aconditionwithaTPsensorcircuit,theTech 2

will display Disagree.

5. This step tests for high resistance in the 5-volt

reference circuit of the TP sensors. If the

DMM does not display more than the speciﬁed

voltage, there is high resistance in the circuit.

8. This step tests for high resistance in the low

reference circuit of the TP sensor. The ECM must

be completely powered down to obtain an

accurate resistance reading. It may take up to

30 minutes for the ECM to power down after the

ignition key is removed. Removal of the ECM fuse

allows the ECM to power down completely.

DTC P0121

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

EngineEngineControls-6.0L

DTC P0121 (cont’d)

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2. Perform the following tests:

• Rapidly depress the accelerator pedal from the rest

position to the wide open throttle (WOT) position

and release the pedal. Repeat the procedure

several times.

• Slowly depress the accelerator pedal to WOT and

then slowly return the pedal to closed throttle.

Repeat the procedure several times.

3. Observe the TP Sensor 1 and 2 parameter with a

Tech 2

DoestheTech 2 displayAgree?

—

Go to

Step 3

Go to

Step 5

1. Turn OFF the engine.

2. Turn ON the ignition, with the engine OFF.

3. Observe the TP sensor 1 voltage parameter with a

Tech 2

Is the voltage within the speciﬁed range?

3.4–3.9 V

Go to

Step 4

Go to

Step 5

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Diagnostic Aids

1. Turn OFF the ignition.

Notice:

Refer to

Disengaging Connectors Notice

Cautions and Notices.

2. Disconnect the throttle body harness connector.

3. Turn ON the ignition, with the engine OFF.

Important: Use the

J 35616-200

Test Lamp Kit for this

test. If the

J 35616-200

is not available, use a test lamp

that measures more than 20 ohms.

4. Connect a test lamp between the 5-volt reference

circuit of the throttle position (TP) sensor and a good

ground.

5. Connect a DMM to the probe of the test lamp and a

good ground. Refer to

Measuring Voltage Drop

Wiring Systems.

Is the voltage more than the speciﬁed value?

4.8 V

Go to

Step 6

Go to

Step 11

1. Connect a 3-amp fused jumper wire between the

5-volt reference circuit of the TP sensor and the

signal 1 circuit of the TP sensor.

2. Observe the TP sensor 1 voltage parameter with a

Tech 2 .

Is the voltage more than the speciﬁed value?

4.8 V

Go to

Step 7

Go to

Step 9

EngineControls-6.0LEngine

DTC P0121 (cont’d)

Step Action Values Yes No

1. Connect a 3-amp fused jumper wire between the

5-volt reference circuit of the TP sensor and the

signal 2 circuit of the TP sensor.

2. Observe the TP sensor 2 voltage parameter with a

Tech 2 .

Is the voltage more than the speciﬁed value?

4.8 V

Go to

Step 8

Go to

Step 10

1. Turn OFF the ignition.

2. Remove the ECM fuse from the underhood

fuse block.

Notice:

DoNOTusea

test lamp to test the continuity of the circuit. Damage to the

control module may occur due to excessive current draw.

3. Measure the resistance from the low reference circuit

of the TP sensor to a good ground with a DMM.

Is the resistance less than the speciﬁed value?

5Ω

Go to

Step 13

Go to

Step 12

Test the signal 1 circuit of TP sensor for a high resistance

or an open. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Test the signal 2 circuit of TP sensor for a high resistance

or an open. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Important: The 5-volt reference circuits are internally and

externally connected at the controller. Other sensors that

share the 5-volt reference circuit may also have DTCs set.

Disconnecting a sensor on the shared 5-volt reference

circuit may isolate a shorted sensor. Review the electrical

schematic and diagnose the shared circuits and sensors.

Test the 5-volt reference circuit of the TP sensor and all

shared 5-volt reference circuits for a high resistance or an

open. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Test the low reference circuit of the TP sensor for a high

resistance or an open. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Test for shorted terminals and for poor connections at the

throttle body. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 15

Test for shorted terminals and for poor connections at the

throttle body and at the engine control module (ECM).

Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 16

15 Replace the throttle body assembly. Refer to

Throttle Body

Installation

Did you complete the replacement? —Go to

Step 17

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 17

—

EngineEngineControls-6.0L

DTC P0121 (cont’d)

Step Action Values Yes No

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 18

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0122

Circuit Description

The throttle body assembly contains 2 throttle

position (TP) sensors. The TP sensors are mounted to

the throttle body assembly and are not serviceable.

The TP sensors provide a signal voltage that changes

relative to throttle blade angle. The engine control

module (ECM) supplies the TP sensors with a common

5-volt reference circuit, a common low reference

circuit, and 2 independent signal circuits.

The TP sensors have opposite functionality. TP

sensor 1 signal voltage decreases from above 4 volts

at idle to below 1 volt at wide open throttle (WOT).

TP sensor 2 signal voltage increases from below 1 volt

at idle to above 4 volts at WOT.

If the ECM detects TP sensor 1 signal voltage is too

low, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0122 Throttle Position (TP) Sensor 1 Circuit

Low Voltage

Conditions for Running the DTC

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P0641, P0651 are not set.

• The ignition is ON, with the engine OFF, or the

engine is operating.

• The ignition 1 voltage is more than 5.23 volts.

• DTC P0122 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The ECM detects the TP sensor 1 signal voltage is

less than 0.275 volts for less than 1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• If there is a condition with the TP sensors the ECM

defaults to reduced power mode for the entire

ignition cycle, even if the condition is corrected.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

2. This step veriﬁes that a condition exists.

4. The TP sensors share a 5-volt reference circuit. If

both DTCs P0122 and P0222 set, test for a

condition in the 5-volt reference circuit.

5. The ECM produces a measurable steady-state

amperage that provides the 5 volt reference to

the TP sensors. If the amperage on the 5-volt

reference circuit is less than 50 mA, test the 5-volt

reference circuit for an open or a high resistance.

6. This step tests the signal 1 circuit of the TP

sensor. If the TP sensor 1 voltage parameter is not

4.8–5.2 volts, test for a condition in the signal 1

circuit.

DTC P0122

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineEngineControls-6.0L

DTC P0122 (cont’d)

Step Action Values Yes No

1. Turn ON the ignition, with the engine OFF.

2. Observe the TP sensor 1 voltage parameter with a

Tech 2 .

Is the voltage less than the speciﬁed value?

0.27 V

Go to

Step 4

Go to

Step 3

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Diagnostic Aids

ObservetheDTCinformationwithaTech 2 .

Did DTC P0222 also set? —Go to

Step 5

Go to

Step 6

1. Turn OFF the ignition.

Notice:

Refer to

Disengaging Connectors Notice

Cautions and Notices.

2. Disconnect the throttle body harness connector.

3. Turn ON the ignition, with the engine OFF.

4. Set-up a DMM to test amperage on the 400 mA scale.

5. Measure the amperage from the 5-volt reference

circuit of the throttle position (TP) sensor to a good

ground.

Is the amperage more than the speciﬁed value?

50 mA

Go to

Step 9

Go to

Step 7

1. Turn OFF the ignition.

Notice:

Refer to

Disengaging Connectors Notice

Cautions and Notices.

2. Disconnect the throttle body harness connector.

3. Turn ON the ignition, with the engine OFF.

4. Connect a 3-amp fused jumper wire between the

5-volt reference circuit of the TP sensor and the

signal 1 circuit of the TP sensor.

5. Observe the TP sensor 1 voltage parameter with a

Tech 2 .

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Step 9

Go to

Step 8

Important: The 5-volt reference circuits are internally

connected within the controller. Other sensors that share

the 5-volt reference circuit may also have DTCs set.

Disconnecting a sensor on the shared 5-volt reference

circuit may isolate a shorted sensor. Review the electrical

schematic and diagnose the shared circuits and sensors.

Test the 5-volt reference circuit of the TP sensor and all

shared 5-volt reference circuits for an open, a short to

ground, or for high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 10

Test the signal 1 circuit of the TP sensor for a short to

ground, an open, or for high resistance. Refer to

Circuit

Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 10

Test for an intermittent and for a poor connection at the

throttle body assembly. Refer to

Testing for Intermittent

Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 11

EngineControls-6.0LEngine

DTC P0122 (cont’d)

Step Action Values Yes No

Test for an intermittent and for a poor connection at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 12

11 Replace the throttle body assembly. Refer to

Throttle Body

Installation

Did you complete the replacement? —Go to

Step 13

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 13

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 14

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0123

Circuit Description

The throttle body assembly contains 2 throttle

position (TP) sensors. The TP sensors are mounted to

the throttle body assembly and are not serviceable.

The TP sensors provide a signal voltage that changes

relative to throttle blade angle. The engine control

module (ECM) supplies the TP sensors with a common

5-volt reference circuit, a common low reference

circuit, and 2 independent signal circuits.

The TP sensors have opposite functionality. The TP

sensor 1 signal voltage decreases from above

4 volts at idle to below 1 volt at wide open

throttle (WOT). The TP sensor 2 signal voltage

increases from below 1 volt at idle to above 4 volts

at WOT.

If the ECM detects TP sensor 1 signal voltage is too

high, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0123 Throttle Position (TP) Sensor 1 Circuit

High Voltage

Conditions for Running the DTC

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P0641, P0651 are not set.

• The ignition is ON, with the engine OFF, or the

engine is operating.

• The ignition 1 voltage is more than 5.23 volts.

• DTC P0123 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The ECM detects the TP sensor 1 signal voltage is

more than 4.725 volts for less than 1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• If there is a condition with the TP sensors, the

ECM defaults to reduced power mode for the

entire ignition cycle, even if the condition is

corrected.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

2. This step veriﬁes that a condition exists.

5. This step tests the signal circuit for a short to

voltage.IftheTech 2 displaysavoltageafterthe

TP sensor is disconnected, the circuit is shorted

to a voltage.

7. This step tests for high resistance in the low

reference circuit of the TP sensor. The ECM must

be completely powered down to obtain an

accurate resistance reading. It may take up to

30 minutes for the ECM to power down after the

ignition key is removed. Removal of the ECM fuse

allows the ECM to power down completely.

8. This step tests the low reference circuit for a short

to voltage.

DTC P0123

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

EngineControls-6.0LEngine

DTC P0123 (cont’d)

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2. Observe the TP sensor 1 voltage parameter with a

Tech 2 .

Is the voltage more than the speciﬁed value?

4.6 V

Go to

Step 5

Go to

Step 3

3ObservetheDTCinformationwithaTech 2 .

Did DTC P0223 fail this ignition? —Go to

Step 5

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Diagnostic Aids

1. Turn OFF the ignition.

Notice:

Refer to

Disengaging Connectors Notice

Cautions and Notices.

2. Disconnect the throttle body harness connector.

3. Turn ON the ignition, with the engine OFF.

4. Observe the TP sensor 1 voltage parameter with a

Tech 2 .

Is the voltage less than the speciﬁed value?

0.1 V

Go to

Step 6

Go to

Step 9

Measure the voltage between the 5-volt reference circuit of

the throttle position (TP) sensor and a good ground with

a DMM.

Is the voltage more than the speciﬁed value?

5.2 V

Go to

Step 10

Go to

Step 7

1. Turn OFF the ignition.

2. Remove the ECM fuse from the underhood

fuse block.

Notice:

DoNOTusea

test lamp to test the continuity of the circuit. Damage to the

control module may occur due to excessive current draw.

3. Measure the resistance from the low reference circuit

of the TP sensor to the ECM housing, with a DMM.

Is the resistance less than the speciﬁed value?

5Ω

Go to

Step 12

Go to

Step 8

1. Install the ECM fuse into the underhood electrical

center.

2. Turn ON the ignition, with the engine OFF.

3. Measure the voltage between the low reference circuit

of the TP sensor and the engine control

module (ECM) housing, with a DMM. Refer to

Circuit

Testing

in Wiring Systems.

Is the voltage less than the speciﬁed value?

Go to

Step 11

Go to

Step 14

Test the signal circuit of the TP sensor 1 for a short to

voltage. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 13

EngineEngineControls-6.0L

DTC P0123 (cont’d)

Step Action Values Yes No

Important: The 5-volt reference circuits are internally

connected within the controller. Other sensors that share

the 5-volt reference circuit may also have DTCs set.

Disconnecting a sensor on the shared 5-volt reference

circuit may isolate a shorted sensor. Review the electrical

schematic and diagnose the shared circuits and sensors.

Test the 5-volt reference circuit of the TP sensor and all

shared 5-volt reference circuits for a short to voltage. Refer

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 13

1. Turn OFF the ignition.

2. Disconnect the ECM.

3. Test the low reference circuit of the TP sensor for an

open or a high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 13

Test for shorted terminals and for poor connections at the

TP sensor. Refer to

Testing for Intermittent Conditions and

Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 15

Test for shorted terminals and for poor connections at the

ECM. Refer to

Circuit Testing

and

Connector Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 16

Important: The control module and/or the TP sensor may

be damaged if the circuit is shorted to battery positive

voltage.

Repair the short to voltage in the low reference circuit of

the TP sensor. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 17

—

15 Replace the throttle body assembly. Refer to

Throttle Body

Installation

Did you complete the replacement? —Go to

Step 17

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 17

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 18

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0128

Circuit Description

An engine coolant temperature (ECT) sensor monitors

the temperature of the coolant. This input is used

by the engine control module (ECM) for engine control,

and as an enabling criteria for some diagnostics.

The air ﬂow coming into the engine is accumulated

and used to determine if the vehicle has been driven

within the conditions that would allow the engine

coolant to heat up normally to the thermostat

regulating temperature. If the coolant temperature

does not increase normally or does not reach

the regulating temperature of the thermostat,

diagnostics that use ECT as enabling criteria, may not

run when expected. This DTC will only run once

per ignition cycle within the enabling conditions.

If the ECM detects the calibrated amount of air ﬂow

and engine run time have been met and the ECT has

not met the minimum thermostat regulating

temperature, DTC P0128 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0128 Engine Coolant Temperature (ECT)

Below Thermostat Regulating Temperature

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0116, P0117, P0118,

P0120, P0121, P0122, P0123, P0125, P0220,

P0222, P0223, P0502, P0503 are not present.

• The start up engine coolant temperature is less

than 70°C (158°F).

• The intake air temperature (IAT) sensor parameter

is more than −7°C (+19°F).

• The engine is running between 120–

1,370 seconds.

• The vehicle speed is more than 8 km/h (5 mph)

for more than 2.5 kilometers (1.5 miles).

• The mass air ﬂow (MAF) is between 12–50 g/s

with the average more than 5 g/s.

• The above conditions are met for a time based on

airﬂow.

• DTC P0128 runs once per trip.

Conditions for Setting the DTC

The minimum engine coolant temperature of 75°C

(167°F) has not been met within a speciﬁed amount

of time.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P0128

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Important: The cooling fans are commanded ON when

certain engine coolant temperature (ECT) DTCs are set.

Is the cooling system coolant low? —Go to

Draining

and Filling

Cooling System

in Engine Cooling Go to

Step 3

3Test and verify the proper operation of the thermostat.

Refer to

Thermostat Diagnosis

in Engine Cooling.

Did you ﬁnd and correct the condition? —Go to

Step 14

Go to

Step 4

EngineEngineControls-6.0L

DTC P0128 (cont’d)

Step Action Values Yes No

1. Disconnect the ECT sensor.

2. Inspect for the following conditions:

• Corrosion on the ECT sensor terminals

• Improper or corroded terminals at the ECT harness

connector

• Loose terminals in the ECT harness connector—

Refer to

Testing for Intermittent Conditions and

Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 5

Measure the voltage from the signal circuit of the ECT

sensor to a good ground with a DMM. Refer to

Circuit

Testing

in Wiring Systems.

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Step 6

Go to

Step 8

Measure the voltage from the signal circuit of the ECT

sensor to the low reference circuit of the ECT sensor with a

DMM. Refer to

Circuit Testing

in Wiring Systems.

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Step 9

Go to

Step 7

Test the ECT sensor low reference circuit for high

resistance. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 11

Test the ECT sensor signal circuit for high resistance.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 11

1. Turn OFF the ignition.

2. Remove the ECT sensor. Refer to

Engine Coolant

Temperature (ECT) Sensor Replacement

3. Place the sensor on a work surface away from any

heat source.

4. Allow the sensor to reach the ambient air temperature

for 30–60 minutes.

5. Observe and record the ambient air temperature of

the vehicle environment using an accurate

thermometer.

Important: DO NOT hold the ECT sensor by the probe.

6. Measure the resistance of the ECT sensor and record

the value.

7. Compare the resistance measurement of the ECT

sensor to the ambient air temperature on the

Temperature vs. Resistance table. Refer to

Temperature vs Resistance

Is the resistance measurement of the ECT sensor within

the speciﬁed range?

—

Go to

Step 10

Go to

Step 12

10 Install the ECT sensor. Refer to

Engine Coolant

Temperature (ECT) Sensor Replacement

Is the action complete? —Go to

Intermittent

Conditions

—

Test for an intermittent and for a poor connection at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 13

12 Replace the ECT sensor. Refer to

Engine Coolant

Temperature (ECT) Sensor Replacement

Did you complete the replacement? —Go to

Step 14

—

EngineControls-6.0LEngine

DTC P0128 (cont’d)

Step Action Values Yes No

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 14

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 15

ObservetheCaptureInfo.withaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0131 or P0151

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. Heating elements

inside the HO2S minimize the time required for the

sensors to reach operating temperature. The engine

control module (ECM) supplies the HO2S with a

reference, or bias, voltage of about 450 mV. When the

engine is ﬁrst started the ECM operates in Open

Loop, ignoring the HO2S voltage signal. Once

the HO2S reaches operating temperature and Closed

Loop is achieved, the HO2S generates a voltage

within a range of 0–1,000 mV that ﬂuctuates above

and below bias voltage. High HO2S voltage indicates

a rich exhaust stream. Low HO2S voltage indicates

a lean exhaust stream. If the ECM detects an

HO2S voltage that stays below a speciﬁed value,

DTC P0131 sets for HO2S bank 1 sensor 1, or

DTC P0151 sets for HO2S bank 2 sensor 1.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0131 HO2S Circuit Low Voltage Bank 1

Sensor 1

• DTC P0151 HO2S Circuit Low Voltage Bank 2

Sensor 1

Conditions for Running the DTC

Lean Test Enable:

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, P2176 are

not set.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The TP Indicated Angle parameter is between 3–

70 percent more than the value observed at idle.

• The above conditions are met for 2 seconds.

• This diagnostic runs continuously once the above

conditions are met.

Power Enrichment Test Enable:

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, P2176 are

not set.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The Engine Run Time parameter is more than

30 seconds.

• The Power Enrichment parameter is active for

more than 1 second.

• This diagnostic runs continuously once the above

conditions are met.

Conditions for Setting the DTC

Lean Test:

The ECM detects that the affected HO2S voltage

parameter is less than 200 mV for 165 seconds.

Power Enrichment Test:

The ECM detects that the affected HO2S voltage

parameter is less than 360 mV for 10 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

• The control module commands the Loop

Status open.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. If the voltage is varying above and below the

speciﬁed range, the condition is not present.

EngineControls-6.0LEngine

DTC P0131 or P0151

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Start the engine.

2. Allow the engine to reach operating temperature.

Referto

Tech 2 DataList

3. Observe the affected HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter varying above and below

the speciﬁed range?

300–600 mV

Go to

Step 3

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the affected heated oxygen

sensor (HO2S).

3. Turn ON the ignition, with the engine OFF.

4. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 6

Go to

Step 5

1. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and a good ground.

2. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 7

Go to

Step 8

Test the HO2S high signal circuit for a short to ground.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 9

Test the HO2S low signal circuit for a short to the HO2S

heater low control circuit. Refer to

Circuit Testing

Wiring

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 10

Test the HO2S high signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

EngineEngineControls-6.0L

DTC P0131 or P0151 (cont’d)

Step Action Value(s) Yes No

Test the HO2S high signal circuit for a short to the

following circuits:

• HO2S low signal circuit

• HO2S heater low control circuit

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

1. The HO2S may be detecting a lean exhaust condition

or may be contaminated. Inspect for the following

conditions:

Notice:

Refer to

Silicon Contamination of Heated Oxygen

Sensors Notice

in Cautions and Notices.

• A silicon contaminated HO2S

• Any water intrusion into the HO2S connector

• An exhaust leak between the HO2S and the

engine

• Any vacuum leaks

• An incorrect fuel pressure—Refer to

Fuel System

Diagnosis

• Any lean fuel injectors—Refer to

Fuel Injector

Balance Test with Tech 2

• An inaccurate mass air ﬂow (MAF) sensor—Refer

Tech 2 DataList

2. Repair any of the above or similar engine conditions

as necessary.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 11

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 13

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 14

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 1

Heated

Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1

Did you complete the replacement?

—

Go to

Step 15

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 15

—

1.CleartheDTCswithaTech 2

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 16

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0132 or P0152

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. Heating elements

inside the HO2S minimize the time required for the

sensors to reach operating temperature. The engine

control module (ECM) supplies the HO2S with a

reference, or bias, voltage of about 450 mV. When the

engine is ﬁrst started the ECM operates in Open

Loop, ignoring the HO2S voltage signal. Once

the HO2S reaches operating temperature and Closed

Loop is achieved, the HO2S generates a voltage

within a range of 0–1,000 mV that ﬂuctuates above

and below bias voltage. High HO2S voltage indicates

a rich exhaust stream. low HO2S voltage indicates

a lean exhaust stream. If the ECM detects an HO2S

voltage that stays above a speciﬁed value,

DTC P0132 sets for HO2S bank 1 sensor 1, or

DTC P0152 sets for HO2S bank 2 sensor 1.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0132 HO2S Circuit High Voltage Bank 1

Sensor 1

• DTC P0152 HO2S Circuit High Voltage Bank 2

Sensor 1

Conditions for Running the DTC

Rich Test Enable

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, P2176 are

not set.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The TP Indicated Angle parameter is between 3–

70 percent more than the value observed at idle.

• The above conditions are met for 2 seconds.

• This diagnostic runs continuously once the above

conditions are met.

Decel Fuel Cutoff Test Enable

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, P2176 are

not set.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The Engine Run Time parameter is more than

30 seconds.

• The Decel. Fuel Cutoff parameter is active for

more than 2 seconds.

• This diagnostic runs continuously once the above

conditions are met.

Conditions for Setting the DTC

Rich Test

The ECM detects that the affected HO2S voltage

parameter is more than 1,050 mV for 48 seconds.

Decel Fuel Cutoff Test

The ECM detects that the affected HO2S voltage

parameter is more than 540 mV for 5 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

• The control module commands the Loop

Status open.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. If the voltage is varying above and below the

speciﬁed range, the condition is not present.

6-112 Engine Controls - 6.0L Engine

DTC P0132 or P0152

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Start the engine.

2. Allow the engine to reach operating temperature.

Referto

Tech 2 DataList

3. Observe the affected HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter varying above and below

the speciﬁed range?

300–600 mV

Go to

Step 3

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the affected heated oxygen

sensor (HO2S).

3. Turn ON the ignition, with the engine OFF.

4. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter within the speciﬁed range?

400–500 mV

Go to

Step 5

Go to

Step 6

1. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and a good ground.

2. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 7

Go to

Step 8

Test the HO2S high signal circuit for a short to the HO2S

heater low control circuit. Refer to

Circuit Testing

Wiring

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 10

1. Remove the jumper wire from the previous step.

2. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and the low signal circuit of the

HO2S harness connector on the engine harness side.

3. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 9

Go to

Step 11

Test the HO2S high signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

EngineEngineControls-6.0L

DTC P0132 or P0152 (cont’d)

Step Action Value(s) Yes No

Test the HO2S low signal circuit for a short to the HO2S

heater low control circuit. Refer to

Circuit Testing

Wiring

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 12

Important: The sensor may be damaged if the circuit is

shorted to a voltage source.

Test the HO2S high signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Test the HO2S low signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

1. The HO2S may be detecting a rich exhaust condition

or may be contaminated. Inspect for the following

conditions:

Notice:

Refer to

Silicon Contamination of Heated Oxygen

Sensors Notice

in Cautions and Notices.

• A silicon contaminated HO2S

• Any water intrusion into the HO2S connector

• Engine oil contaminated with fuel

• An evaporative emission (EVAP) canister purge

condition

• An incorrect fuel pressure—Refer to

Fuel System

Diagnosis

• Any rich fuel injectors—Refer to

Fuel Injector

Balance Test with Tech 2

• An inaccurate mass air ﬂow (MAF) sensor—Refer

Tech 2 DataList

• An air intake restriction or collapsed air intake duct

2. Repair any of the above or similar engine conditions

as necessary.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 13

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 15

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 16

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 1

Heated

Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1

Did you complete the replacement?

—

Go to

Step 17

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 17

—

EngineControls-6.0LEngine

DTC P0132 or P0152 (cont’d)

Step Action Value(s) Yes No

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 18

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0133 or P0153

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. Heating elements

inside the HO2S minimize the time required for the

sensors to reach operating temperature. The engine

control module (ECM) supplies the HO2S with a

reference, or bias, voltage of about 450 mV. When the

engine is ﬁrst started the ECM operates in Open

Loop, ignoring the HO2S voltage signal. Once

the HO2S reaches operating temperature and Closed

Loop is achieved, the HO2S generates a voltage

within a range of 0–1,000 mV that ﬂuctuates above

and below bias voltage. High HO2S voltage indicates

a rich exhaust stream. Low HO2S voltage indicates

a lean exhaust stream. This diagnostic will only

run once per ignition cycle. The ECM monitors the

rich-to-lean and lean-to-rich transition time. A transition

is deﬁned as, the HO2S voltage changes from

above 625 mV to below 250 mV or from below 250 mV

to above 625 mV. If the ECM detects that the

transition time is too long, DTC P0133 sets for HO2S

bank 1 sensor 1, or DTC P0153 sets for HO2S

bank 2 sensor 1.

DTC Descriptor

This diagnostic procedure supports the

following DTCs:

• DTC P0133 HO2S Slow Response Bank 1

Sensor 1

• DTC P0153 HO2S Slow Response Bank 2

Sensor 1

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0131, P0132,

P0134, P0135, P0137, P0138, P0140, P0141,

P0151, P0152, P0153, P0154, P0155, P0157,

P0158, P0160, P0161, P0201, P0202, P0203,

P0204, P0205, P0206, P0207, P0208, P0220,

P0442, P0443, P0446, P0449, P0455, P0496,

P1258, P1516, P2101, P2108, P2135, P2176 are

not set.

• The ECT Sensor parameter is more than 55°C

(131°F).

• The EVAP Purge Solenoid Command parameter

is more than 1 percent.

• The MAF Sensor parameter is between 15–

55 g/s.

• The Engine Speed parameter is between 1,000–

3,000 RPM.

• The TP Indicated Angle parameter is 5 percent

more than the value observed at idle.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The Engine Run Time parameter is more than

160 seconds.

• The above conditions are met for 1 second.

• This diagnostic runs one time per drive cycle once

the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the affected HO2S rich-to-lean

or lean-to-rich average response time is more than

a calibrated value. This diagnostic concludes in

60 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. If the voltage is varying above and below the

speciﬁed value, the condition is not present.

EngineControls-6.0LEngine

DTC P0133 or P0153

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Start the engine.

2. Allow the engine to reach operating temperature.

Referto

Tech 2 DataList

3. Operate the engine at 1,500 RPM for 30 seconds.

4. Observe the affected HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter varying above and below

the speciﬁed range?

250–625 mV

Go to

Step 3

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the affected heated oxygen

sensor (HO2S).

3. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and a good ground.

4. Turn ON the ignition, with the engine OFF.

5. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 6

Go to

Step 5

Test the HO2S high signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 9

1. Remove the jumper wire from the previous step.

2. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and the low signal circuit of the

HO2S harness connector on the engine harness side.

3. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 8

Go to

Step 7

Test the HO2S low signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 9

EngineEngineControls-6.0L

DTC P0133 or P0153 (cont’d)

Step Action Value(s) Yes No

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 10

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 11

Notice:

Refer to

Silicon Contamination of Heated Oxygen

Sensors Notice

in Cautions and Notices.

Important: The HO2S may be damaged due to

contamination. Prior to replacing the HO2S, inspect for the

following sources of contamination:

• A silicon contaminated HO2S

• Fuel contamination—Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without

Special Tool)

Alcohol/Contaminants-in-Fuel

Diagnosis (with Special Tool)

• Engine oil consumption—Refer to

Oil Consumption

Diagnosis

in Engine Mechanical.

• Engine coolant consumption—Refer to

Loss of Coolant

(Automatic Transmission)

Loss of Coolant (Manual

Transmission)

in Engine Cooling.

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 1

Heated

Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1

Did you complete the replacement?

—

Go to

Step 12

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 12

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 13

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0134 or P0154

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. Heating elements

inside the HO2S minimize the time required for the

sensors to reach operating temperature. The engine

control module (ECM) supplies the HO2S with a

reference, or bias, voltage of about 450 mV. When the

engine is ﬁrst started the ECM operates in Open

Loop, ignoring the HO2S voltage signal. Once

the HO2S reaches operating temperature and Closed

Loop is achieved, the HO2S generates a voltage

within a range of 0–1,000 mV that ﬂuctuates above

and below bias voltage. High HO2S voltage indicates

a rich exhaust stream. Low HO2S voltage indicates

a lean exhaust stream. If the ECM detects that

the HO2S voltage remains within the bias voltage

range, DTC P0134 sets for HO2S bank 1 sensor 1, or

DTC P0154 sets for HO2S bank 2 sensor 1.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0134 HO2S Circuit Insufficient Activity

Bank 1 Sensor 1

• DTC P0154 HO2S Circuit Insufficient Activity

Bank 2 Sensor 1

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, P2176 are

not set.

• The Engine Run Time parameter is more than

300 seconds.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• This diagnostic runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The ECM detects that the affected HO2S voltage

parameter is between 350–550 mV for 60 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

• The control module commands the Loop

Status open.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

3. If the voltage is varying above and below the

speciﬁed value, the condition is not present.

DTC P0134 or P0154

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector End

Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineEngineControls-6.0L

DTC P0134 or P0154 (cont’d)

Step Action Value(s) Yes No

Important: Whenever the heated oxygen sensor (HO2S)

heatersarecommandedONwithaTech 2 ,theywill

continue to be pulsed ON once per second until the ignition

is turned OFF for 30 seconds.

1. Turn ON the ignition, with the engine OFF.

2.CommandtheHO2SheatersONwithaTech 2 .

3. Wait 15 seconds to allow the HO2S heater current to

stabilize.

4. Observe the affected HO2S heater current parameter

withaTech 2 .

Is the HO2S heater current parameter within the

speciﬁed range?

0.25–3.125 A

Go to

Step 3

Go to

DTC P0135,

P0141, P0155,

or P0161

Vehicle

DTC Information

1. Start the engine.

2. Allow the engine to reach operating temperature.

Referto

Tech 2 DataList

3. Operate the engine at 1,500 RPM for 30 seconds.

4. Observe the affected HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter varying above and below

the speciﬁed range?

300–600 mV

Go to

Step 4

Go to

Step 5

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the affected HO2S.

3. Turn ON the ignition, with the engine OFF.

4. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter more than the

speciﬁed value?

800 mV

Go to

Step 7

Go to

Step 6

Measure the voltage from the high signal circuit of the

HO2S harness connector on the engine harness side to a

good ground with a DMM. Refer to

Circuit Testing

in Wiring

Systems.

Is the voltage more than the speciﬁed value?

0.2 V

Go to

Step 8

Go to

Step 9

Important: The sensor may be damaged if the circuit is

shorted to a voltage source.

Test the HO2S high signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Measure the voltage from the low signal circuit of the

HO2S harness connector on the engine harness side to a

good ground with a DMM. Refer to

Circuit Testing

in Wiring

Systems.

Is the voltage more than the speciﬁed value?

Go to

Step 12

Go to

Step 10

Test the HO2S high signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

EngineControls-6.0LEngine

DTC P0134 or P0154 (cont’d)

Step Action Value(s) Yes No

1. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and the low signal circuit of the

HO2S harness connector on the engine harness side.

2. Observe the HO2S voltage parameter with a

Tech 2

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 13

Go to

Step 11

Test the HO2S low signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Test the HO2S low signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 15

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 16

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 1

Heated

Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1

Did you complete the replacement?

—

Go to

Step 17

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 17

—

1.CleartheDTCswithaTech 2

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 18

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0135, P0141, P0155, or P0161

Circuit Description

The heated oxygen sensor (HO2S) must reach

operating temperature to provide an accurate voltage

signal. A heating element inside the HO2S minimizes

the time required for the sensor to reach operating

temperature. Voltage is provided to the heater by the

ignition 1 voltage circuit through a fuse. With the

engine running, ground is provided to the heater by

the HO2S heater low control circuit, through a low side

driver within the engine control module (ECM). The

ECM commands the heater ON or OFF to maintain a

speciﬁc HO2S operating temperature range. The

ECM determines the temperature by measuring the

current ﬂow through the heater. When the heater is in

the ON state, the ECM will pulse the heater OFF

for a duration of 50 ms, once per second. When the

heater is in the OFF state, the ECM will pulse the

heater ON for a duration of 50 milliseconds, once per

second. The ECM monitors the heater current with

the engine running. The ECM also calculates the

heater resistance on a cold start. Both diagnostics will

only run once per ignition cycle. If the ECM detects

that the heater current or the heater calculated

resistance is not within the expected range, the

following DTCs will set:

• DTC P0135 for HO2S bank 1 sensor 1

• DTC P0141 for HO2S bank 1 sensor 2

• DTC P0155 for HO2S bank 2 sensor 1

• DTC P0161 for HO2S bank 2 sensor 2

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0135 HO2S Heater Performance Bank 1

Sensor 1

• DTC P0141 HO2S Heater Performance Bank 1

Sensor 2

• DTC P0155 HO2S Heater Performance Bank 2

Sensor 1

• DTC P0161 HO2S Heater Performance Bank 2

Sensor 2

Conditions for Running the DTC

Heater Current Test

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, P2176 are

not set.

• The Engine Coolant Temperature (ECT) Sensor

parameter is more than 50°C (122°F).

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Mass Airﬂow (MAF) Sensor parameter is

between 3–40 g/s.

• The Engine Speed parameter is between 500–

3,000 RPM.

• The Engine Run Time parameter is more than

120 seconds.

• The above conditions are met for 2 seconds.

• This diagnostic runs one time per ignition drive

cycle once the above conditions are met.

Heater Resistance Test

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, or P2176

are not set.

• The ignition is OFF for more than 10 hours.

• The ECT Sensor parameter is between −30 and

+45°C (−22 and +113°F) at engine start-up.

• The ECT Sensor parameter minus the Intake Air

Temperature (IAT) Sensor parameter is less

than 8°C (14°F) at engine start-up.

• The engine is started.

• The above conditions are met for up to

100 seconds.

• This diagnostic runs one time per valid cold start

once the above conditions are met.

Conditions for Setting the DTC

Heater Current Test

• DTCs P0135 or P0155

− The ECM detects that the affected HO2S

Heater Current parameter is more than

3.125 amps or less than 0.25 amps.

− The above condition is met for 10 seconds.

• DTCs P0141 or P0161

− The ECM detects that the affected HO2S

Heater Current parameter is more than

1.375 amps or less than 0.25 amps.

− The above condition is met for 10 seconds.

Heater Resistance Test

DTCs P0135, P0141, P0155, or P0161—The

powertrain control module (PCM) detects that the

affected HO2S heater calculated resistance is

not within an expected range at engine start-up for

1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

EngineControls-6.0LEngine

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P0135, P0141, P0155, or P0161

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

2 Is DTC P0135 or P0155 set? — Go to

Step 4

Go to

Step 3

1. Start the engine.

2. Wait 1 minute to allow the heated oxygen sensor

(HO2S) heater current to stabilize.

3. Observe the affected HO2S Heater Current parameter

withaTech 2 .

Is the HO2S Heater Current parameter within the

speciﬁed range?

0.25–1.375 A

Go to

Step 5

Go to

Step 8

1. Start the engine.

2. Wait 1 minute to allow the HO2S heater current to

stabilize.

3. Observe the affected HO2S Heater Current parameter

withaTech 2 .

Is the HO2S Heater Current parameter within the

speciﬁed range?

0.25–3.125 A

Go to

Step 5

Go to

Step 8

5Observe the Freeze Frame/Failure Records for this DTC.

Did the DTC fail with an engine run time of less than

10 seconds? —Go to

Step 6

Go to

Step 7

1. Operate the vehicle within the Conditions for Running

the Heater Resistance Test.

2. Start the engine.

Did the DTC fail this ignition?

—

Go to

Step 8

Go to

Intermittent

Conditions

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the Heater Current Test. You may also operate the

vehicle within the conditions that you observed from

the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 8

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Inspect the fuse that supplies the applicable HO2S

heater.

Is the fuse open?

—

Go to

Step 9

Go to

Step 10

EngineEngineControls-6.0L

DTC P0135, P0141, P0155, or P0161 (cont’d)

Step Action Values Yes No

Test the ignition 1 voltage circuit for a short to ground.

Refer to the following in Wiring Systems:

•

Circuit Testing

•

Wiring Repairs

•

Heated Oxygen Sensor (HO2S) Wiring Repairs

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 12

1. Disconnect the affected HO2S.

2. Turn ON the ignition, with the engine OFF.

3. Probe the ignition 1 voltage circuit of the HO2S

harness connector on the engine harness side with a

test lamp that is connected to a good ground. Refer to

Probing Electrical Connectors

in Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 11

Go to

Step 19

1. Turn OFF the ignition.

2. Probe the HO2S heater low control circuit of the

HO2S harness connector on the engine harness side

with a test lamp connected to battery voltage.

3. With the ignition still OFF, observe the test lamp.

Does the test lamp illuminate?

—

Go to

Step 14

Go to

Step 13

Test the ignition 1 voltage circuit on the sensor side of the

HO2S 1 connector for a short to ground. Refer to

Circuit

Testing

in Wiring Systems.

Is the sensor shorted to ground?

—

Go to

Step 20

Go to

Intermittent

Conditions

13 Start the engine with the test lamp still connected from the

previous step.

Is the test lamp ON steady or blinking? —Go to

Step 17

Go to

Step 15

Test the HO2S heater low control circuit for a short to

ground. Refer to the following in Wiring Systems:

•

Circuit Testing

•

Wiring Repairs

•

Heated Oxygen Sensor (HO2S) Wiring Repairs

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 18

Test the HO2S heater low control circuit for a short to

voltage. Refer to the following in Wiring Systems:

•

Circuit Testing

•

Wiring Repairs

•

Heated Oxygen Sensor (HO2S) Wiring Repairs

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 16

Test the HO2S heater low control circuit for an open or for

high resistance. Refer to the following in Wiring Systems:

•

Circuit Testing

•

Wiring Repairs

•

Heated Oxygen Sensor (HO2S) Wiring Repairs

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 18

Test for shorted terminals and for poor connections at the

HO2S. Refer to the following in Wiring Systems:

•

Testing for Intermittent Conditions and Poor

Connections

•

Connector Repairs

•

Heated Oxygen Sensor (HO2S) Wiring Repairs

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 20

EngineControls-6.0LEngine

DTC P0135, P0141, P0155, or P0161 (cont’d)

Step Action Values Yes No

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to the following in

Wiring Systems:

•

Testing for Intermittent Conditions and Poor

Connections

•

Connector Repairs

•

Heated Oxygen Sensor (HO2S) Wiring Repairs

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 21

Repair the open or high resistance in the ignition 1 voltage

circuit. Refer to

Wiring Repairs

and

Heated Oxygen Sensor

(HO2S) Wiring Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 22

—

Replace the affected HO2S. Refer to the following:

•

Heated Oxygen Sensor (HO2S) Replacement Bank 1

Sensor 1

•

Heated Oxygen Sensor (HO2S) Replacement Bank 1

Sensor 2

•

Heated Oxygen Sensor (HO2S) Replacement Bank 2

Sensor 1

•

Heated Oxygen Sensor (HO2S) Replacement Bank 2

Sensor 2

Did you complete the replacement?

—

Go to

Step 22

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 22

—

22 Were you sent to this diagnostic from DTC P0134

or P0154? —Go to

DTC P0134

or P0154

Go to

Step 23

23 Were you sent to this diagnostic from DTC P0140

or P0160? —Go to

DTC P0140

or P0160

Go to

Step 24

1. Replace the fuse, if necessary.

2.CleartheDTCswithaTech 2 .

3. Turn OFF the ignition for 30 seconds.

4. Start the engine.

5. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 25

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0136 or P0156

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. Heating elements

inside the HO2S minimize the time required for the

sensors to reach operating temperature. The engine

control module (ECM) supplies the HO2S with a

reference, or bias, voltage of about 450 mV. When the

engine is ﬁrst started the ECM operates in open

loop, ignoring the HO2S voltage signal. Once the

HO2S reaches operating temperature and closed loop

is achieved, the HO2S generates a voltage within a

range of 0–1,000 mV that ﬂuctuates above and below

bias voltage. High HO2S voltage indicates a rich

exhaust stream; low HO2S voltage indicates a lean

exhaust stream.

The HO2S bank 1 sensor 2 and HO2S bank 2

sensor 2 are used for catalyst monitoring. This

diagnostic runs once per ignition cycle. This diagnostic

consists of two tests, a passive test and an intrusive

test. During the passive test, if the HO2S bank 1

sensor 2 or HO2S bank 2 sensor 2 voltage transitions

below 349 mV and above 710 mV, the DTC will

pass for this ignition cycle. If the DTC does not pass

during the passive test, the intrusive test will begin.

During the intrusive test, the control module will force

the air-to-fuel ratio rich and/or lean. The control

module then waits for a predicted response from the

HO2S. If the HO2S voltage transitions below

349 mV and/or above 710 mV, the DTC will pass for

this ignition cycle. If the control module does not

receive the expected response from the HO2S,

DTC P0136 will set for HO2S bank 1 sensor 2 or

DTC P0156 will set for HO2S bank 2 sensor 2.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0136 HO2S Circuit Bank 1 Sensor 2

• DTC P0156 HO2S Circuit Bank 2 Sensor 2

Conditions for Running the DTC

DTCs P0101, P0102, P0103, P0106, P0107, P0108,

P0112, P0113, P0117, P0118, P0121, P0122,

P0123, P0131, P0132, P0133, P0134, P0135, P0137,

P0138, P0140, P0141, P0151, P0152, P0153,

P0154, P0155, P0157, P0158, P0160, P0161, P0201,

P0202, P0203, P0204, P0205, P0206, P0207,

P0208, P0442, P0443, P0446, P0449, P0455, P0496,

P1133, P1134, P1153, P1154 are not set.

Passive Test

• The engine is running.

• The Engine Run Time parameter is less than

13.5 minutes.

Intrusive Test

• The Engine Run Time parameter is more than

13.5 minutes.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Engine Speed parameter is between 500–

5,000 RPM.

• The MAF Sensor parameter is between 5–

100 g/s.

• The Vehicle Speed parameter is between 24–

131 km/h (15–82 mph).

• The Short Term FT Bank 1 and Bank 2 parameter

is between −4 and +4 percent.

• The maximum number of intrusive attempts is less

than 25.

• This diagnostic runs one time per drive cycle once

the above conditions are met.

Conditions for Setting the DTC

1. The ECM detects that the HO2S bank 1 sensor 2

or HO2S bank 2 sensor 2 did not transition below

349 mV and above 710 mV during the

passive test.

2. One of the following tests fail:

• Lean Intrusive Test

− The ECM detects that the HO2S bank 1

sensor 2 or HO2S bank 2 sensor 2 is

more than 349 mV for 60 seconds.

− The HO2S bank 1 sensor 1 and HO2S

bank 2 sensor 1 is less than 300 mV.

• Rich Intrusive Test

− The ECM detects that the HO2S bank 1

sensor 2 or HO2S bank 2 sensor 2 is

less than 710 mV for 60 seconds.

− The HO2S bank 1 sensor 1 and HO2S

bank 2 sensor 1 is more than 600 mV.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

EngineControls-6.0LEngine

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. If the voltage does not change more than the

speciﬁed value, the condition is present.

DTC P0136 or P0156

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Start the engine.

2. Allow the engine to reach operating temperature.

Referto

Tech 2 DataList

3. Operate the engine at 1,500 RPM for 30 seconds.

4. While observing the affected HO2S voltage parameter

withaTech 2 ,quicklycyclethethrottlefromclosed

throttle to wide open throttle, 3 times.

Did the HO2S voltage parameter change more than the

speciﬁed value?

200 mV

Go to

Step 3

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the affected heated oxygen

sensor (HO2S).

3. Turn ON the ignition, with the engine OFF.

4. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 6

Go to

Step 5

5ObservetheHO2SvoltageparameterwithaTech 2

Is the HO2S voltage parameter more than the

speciﬁed value? 800 mV Go to

Step 7

Go to

Step 8

Test the HO2S high signal circuit for a short to ground.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 9

Important: The sensor may be damaged if the circuit is

shorted to a voltage source.

Test the HO2S high signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

EngineEngineControls-6.0L

DTC P0136 or P0156 (cont’d)

Step Action Value(s) Yes No

Measure the voltage from the low signal circuit of the

HO2S harness connector on the engine harness side to a

good ground with a DMM. Refer to

Circuit Testing

in Wiring

Systems.

Is the voltage more than the speciﬁed value?

Go to

Step 10

Go to

Step 11

Test the HO2S high signal circuit for a short to the HO2S

low signal circuit. Refer to

Circuit Testing

Wiring Repairs

and

Heated Oxygen Sensor (HO2S) Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

Test the HO2S low signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

1. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and a good ground.

2. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 12

Go to

Step 14

1. Remove the jumper wire from the previous step.

2. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and the low signal circuit of the

HO2S harness connector on the engine harness side.

3. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 15

Go to

Step 13

Test the HO2S low signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

Test the HO2S high signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

EngineControls-6.0LEngine

DTC P0136 or P0156 (cont’d)

Step Action Value(s) Yes No

1. The HO2S may be detecting a rich exhaust condition,

a lean exhaust condition, or the HO2S may be

contaminated. Inspect for the following conditions:

Notice:

Refer to

Silicon Contamination of Heated Oxygen

Sensors Notice

in Cautions and Notices.

• A silicon contaminated HO2S

• Any water intrusion into the HO2S connector

• An exhaust leak between the HO2S and the

engine

• Any vacuum leaks

• Engine oil contaminated with fuel

• An incorrect fuel pressure—Refer to

Fuel System

Diagnosis

• Any lean or rich fuel injectors—Refer to

Fuel

Injector Balance Test with Tech 2

• An inaccurate mass air ﬂow (MAF) sensor—Refer

Tech 2 DataList

2. Repair any of the above or similar engine conditions

as necessary.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 16

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 18

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 19

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 2

Heated

Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 2

Did you complete the replacement?

—

Go to

Step 20

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 20

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 21

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0137 or P0157

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. Heating elements

inside the HO2S minimize the time required for the

sensors to reach operating temperature. The engine

control module (ECM) supplies the HO2S with a

reference, or bias, voltage of about 450 mV. When the

engine is ﬁrst started the ECM operates in Open

Loop, ignoring the HO2S voltage signal. Once

the HO2S reaches operating temperature and Closed

Loop is achieved, the HO2S generates a voltage

within a range of 0–1,000 mV that ﬂuctuates above

and below bias voltage. High HO2S voltage indicates

a rich exhaust stream. Low HO2S voltage indicates

a lean exhaust stream. If the ECM detects an

HO2S voltage that stays below a speciﬁed value,

DTC P0137 sets for HO2S bank 1 sensor 2 or

DTC P0157 sets for HO2S bank 2 sensor 2.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0137 HO2S Circuit Low Voltage Bank 1

Sensor 2

• DTC P0157 HO2S Circuit Low Voltage Bank 2

Sensor 2

Conditions for Running the DTC

Lean Test Enable:

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, P2176 are

not set.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The TP Indicated Angle parameter is between 3–

70 percent more than the value observed at idle.

• The above conditions are met for 2 seconds.

• This diagnostic runs continuously once the above

conditions are met.

Power Enrichment Test Enable:

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, P2176 are

not set.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The Engine Run Time parameter is more than

30 seconds.

• The Power Enrichment parameter is active for

more than 2 seconds.

• This diagnostic runs continuously once the above

conditions are met.

Conditions for Setting the DTC

Lean Test

The ECM detects that the affected HO2S voltage

parameter is less than 80 mV for 200 seconds.

Power Enrichment Test

The ECM detects that the affected HO2S voltage

parameter is less than 420 mV for 10 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. If the voltage does not change more than the

speciﬁed value, the condition is present.

EngineControls-6.0LEngine

DTC P0137 or P0157

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Important: With the engine running, observe the HO2S

Bank 1 Sensor 1 and HO2S Bank 2 Sensor 1 voltage

parameterswithaTech 2 .Thevoltageshouldvaryfrom

below 300 mV to above 600 mV. If the voltage is not

varying, refer to

DTC P0132 or P0152

1. Start the engine.

2. Allow the engine to reach operating temperature.

Referto

Tech 2 DataList

3. Operate the engine at 1,500 RPM for 30 seconds.

4. While observing the affected HO2S voltage parameter

withaTech 2 ,quicklycyclethethrottlefromclosed

throttle to wide open throttle 3 times.

Did the HO2S voltage parameter change more than the

speciﬁed value?

200 mV

Go to

Step 3

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the affected heated oxygen

sensor (HO2S).

3. Turn ON the ignition, with the engine OFF.

4. Observe the HO2S voltage parameter with a

Tech 2

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 6

Go to

Step 5

5ObservetheHO2SvoltageparameterwithaTech 2 .

Is the HO2S voltage parameter more than the

speciﬁed value? 800 mV Go to

Step 7

Go to

Step 8

Test the HO2S high signal circuit for a short to ground.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 9

Important: The sensor may be damaged if the circuit is

shorted to a voltage source.

Test the HO2S high signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

Measure the voltage from the low signal circuit of the

HO2S harness connector on the engine harness side to a

good ground with a DMM. Refer to

Circuit Testing

in Wiring

Systems.

Is the voltage more than the speciﬁed value?

Go to

Step 10

Go to

Step 11

EngineEngineControls-6.0L

DTC P0137 or P0157 (cont’d)

Step Action Value(s) Yes No

Test the HO2S high signal circuit for a short to the HO2S

low signal circuit. Refer to

Circuit Testing

Wiring Repairs

and

Heated Oxygen Sensor (HO2S) Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

Test the HO2S low signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

1. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and a good ground.

2. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 12

Go to

Step 14

1. Remove the jumper wire from the previous step.

2. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and the low signal circuit of the

HO2S harness connector on the engine harness side.

3. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 15

Go to

Step 13

Test the HO2S low signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

Test the HO2S high signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

1. The HO2S may be detecting a lean exhaust condition

or may be contaminated. Inspect for the following

conditions:

Notice:

Refer to

Silicon Contamination of Heated Oxygen

Sensors Notice

in Cautions and Notices.

• A silicon contaminated HO2S

• Any water intrusion into the HO2S connector

• An exhaust leak between the HO2S and the

engine

• Any vacuum leaks

• An incorrect fuel pressure—Refer to

Fuel System

Diagnosis

• Any lean fuel injectors—Refer to

Fuel Injector

Balance Test with Tech 2

• An inaccurate mass air ﬂow (MAF) sensor—Refer

Tech 2 DataList

2. Repair any of the above or similar engine conditions

as necessary.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 16

EngineControls-6.0LEngine

DTC P0137 or P0157 (cont’d)

Step Action Value(s) Yes No

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 18

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 19

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 2

Heated

Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 2

Did you complete the replacement?

—

Go to

Step 20

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 20

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 21

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0138 or P0158

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. Heating elements

inside the HO2S minimize the time required for the

sensors to reach operating temperature. The engine

control module (ECM) supplies the HO2S with a

reference, or bias, voltage of about 450 mV. When the

engine is ﬁrst started the ECM operates in Open

Loop, ignoring the HO2S voltage signal. Once

the HO2S reaches operating temperature and Closed

Loop is achieved, the HO2S generates a voltage

within a range of 0–1,000 mV that ﬂuctuates above

and below bias voltage. High HO2S voltage indicates

a rich exhaust stream. Low HO2S voltage indicates

a lean exhaust stream. If the ECM detects an

HO2S voltage that stays above a speciﬁed value,

DTC P0138 sets for HO2S bank 1 sensor 2, or

DTC P0158 sets for HO2S bank 2 sensor 2.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0138 HO2S Circuit High Voltage Bank 1

Sensor 2

• DTC P0158 HO2S Circuit High Voltage Bank 2

Sensor 2

Conditions for Running the DTC

Rich Test Enable:

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, P2176 are

not set.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The TP Indicated Angle parameter is between 3–

70 percent more than the value observed at idle.

• The above conditions are met for 2 seconds.

• This diagnostic runs continuously once the above

conditions are met.

Decel. Fuel Cutoff Test Enable:

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0220, P0442, P0443, P0446, P0449, P0455,

P0496, P1258, P1516, P2101, P2135, P2176 are

not set.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The Engine Run Time parameter is more than

30 seconds.

• The Decel. Fuel Cutoff parameter is active for

more than 10 seconds.

• This diagnostic runs continuously once the above

conditions are met.

Conditions for Setting the DTC

Rich Test

The ECM detects that the affected HO2S voltage

parameter is more than 950 mV for 200 seconds.

Decel. Fuel Cutoff Test

The ECM detects that the affected HO2S voltage

parameter is more than 480 mV for 5 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. If the voltage does not change more than the

speciﬁed value, the condition is present.

EngineControls-6.0LEngine

DTC P0138 or P0158

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Important: With the engine running, observe the HO2S

Bank 1 Sensor 1 and HO2S Bank 2 Sensor 1 voltage

parameterswithaTech 2 .Thevoltageshouldvaryfrom

below 300 mV to above 600 mV. If the voltage is not

varying, refer to

DTC P0131 or P0151

1. Start the engine.

2. Allow the engine to reach operating temperature.

Referto

Tech 2 DataList

3. Operate the engine at 1,500 RPM for 30 seconds.

4. While observing the affected HO2S voltage parameter

withaTech 2 ,quicklycyclethethrottlefromclosed

throttle to wide open throttle 3 times.

Did the HO2S voltage parameter change more than the

speciﬁed value?

200 mV

Go to

Step 3

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the affected heated oxygen

sensor (HO2S).

3. Turn ON the ignition, with the engine OFF.

4. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter more than the

speciﬁed value?

800 mV

Go to

Step 6

Go to

Step 5

Measure the voltage from the low signal circuit of the

HO2S harness connector on the engine harness side to a

good ground with a DMM. Refer to

Circuit Testing

in Wiring

Systems.

Is the voltage more than the speciﬁed value?

Go to

Step 7

Go to

Step 8

Important: The sensor may be damaged if the circuit is

shorted to a voltage source.

Test the HO2S high signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Test the HO2S low signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

EngineEngineControls-6.0L

DTC P0138 or P0158 (cont’d)

Step Action Value(s) Yes No

1. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and a good ground.

2. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 9

Go to

Step 11

1. Remove the jumper wire from the previous step.

2. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and the low signal circuit of the

HO2S harness connector on the engine harness side.

3. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 12

Go to

Step 10

Test the HO2S low signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Test the HO2S high signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

1. The HO2S may be detecting a rich exhaust condition

or may be contaminated. Inspect for the following

conditions:

Notice:

Refer to

Silicon Contamination of Heated Oxygen

Sensors Notice

in Cautions and Notices.

• A silicon contaminated HO2S

• Any water intrusion into the HO2S connector

• Engine oil contaminated with fuel

• An evaporative emission (EVAP) canister purge

condition

• An incorrect fuel pressure—Refer to

Fuel System

Diagnosis

• Any rich fuel injectors—Refer to

Fuel Injector

Balance Test with Tech 2

• An inaccurate mass air ﬂow (MAF) sensor—Refer

Tech 2 DataList

• An air intake restriction or collapsed air intake duct

2. Repair any of the above or similar engine conditions

as necessary.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 13

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 15

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 16

EngineControls-6.0LEngine

DTC P0138 or P0158 (cont’d)

Step Action Value(s) Yes No

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 2

Heated

Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 2

Did you complete the replacement?

—

Go to

Step 17

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 17

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 18

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0140 or P0160

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. Heating elements

inside the HO2S minimize the time required for the

sensors to reach operating temperature. The engine

control module (ECM) supplies the HO2S with a

reference, or bias, voltage of about 450 mV. When the

engine is ﬁrst started the ECM operates in Open

Loop, ignoring the HO2S voltage signal. Once

the HO2S reaches operating temperature and Closed

Loop is achieved, the HO2S generates a voltage

within a range of 0–1,000 mV that ﬂuctuates above

and below bias voltage. High HO2S voltage indicates

a rich exhaust stream. Low HO2S voltage indicates

a lean exhaust stream. This diagnostic will only

run once per ignition cycle. If the ECM detects that the

HO2S voltage remains within the bias voltage range,

DTC P0140 sets for HO2S bank 1 sensor 2, or

DTC P0160 sets for HO2S bank 2 sensor 2.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0140 HO2S Circuit Insufficient Activity

Bank 1 Sensor 2

• DTC P0160 HO2S Circuit Insufficient Activity

Bank 2 Sensor 2

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0141, P0161,

P0201, P0202, P0203, P0204, P0205, P0206,

P0207, P0208, P0220, P0442, P0443, P0446,

P0449, P0455, P0496, P1258, P1516, P2101,

P2135, P2176 are not set.

• The Engine Run Time parameter is more than

300 seconds.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The Loop Status is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• This diagnostic runs continuously once the above

conditions are met.

Conditions for Setting the DTC

• The ECM detects that the affected HO2S voltage

parameter is between 410–490 mV for

150 seconds.

• The TP Indicated Angle parameter changes more

than 5 percent within 1 second, 6 times.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

3. If the voltage is varying above and below the

speciﬁed value, the condition is not present.

DTC P0140 or P0160

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineControls-6.0LEngine

DTC P0140 or P0160 (cont’d)

Step Action Value(s) Yes No

Important: Whenever the heated oxygen sensor (HO2S)

heatersarecommandedONwithaTech 2 ,theywill

continue to be pulsed ON once per second until the ignition

is turned OFF for 30 seconds.

1. Turn ON the ignition, with the engine OFF.

2.CommandtheHO2SheatersONwithaTech 2

3. Wait 15 seconds to allow the HO2S heater current to

stabilize.

4. Observe the affected HO2S heater current parameter

withaTech 2 .

Is the HO2S heater current parameter within the

speciﬁed range?

0.25–1.375 A

Go to

Step 3

Go to

DTC P0135,

P0141, P0155,

or P0161

Vehicle

DTC Information

1. Start the engine.

2. Allow the engine to reach operating temperature.

Referto

Tech 2 DataList

3. Operate the engine at 1,500 RPM for 30 seconds.

4. While observing the affected HO2S voltage parameter

withaTech 2 ,quicklycyclethethrottlefromclosed

throttle to wide open throttle 3 times.

Did the HO2S voltage parameter change more than the

speciﬁed value?

200 mV

Go to

Step 4

Go to

Step 5

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the affected HO2S.

3. Turn ON the ignition, with the engine OFF.

4. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter more than the

speciﬁed value?

800 mV

Go to

Step 7

Go to

Step 6

Measure the voltage from the high signal circuit of the

HO2S harness connector on the engine harness side to a

good ground with a DMM. Refer to

Circuit Testing

in Wiring

Systems.

Is the voltage more than the speciﬁed value?

0.2 V

Go to

Step 8

Go to

Step 9

Important: The sensor may be damaged if the circuit is

shorted to a voltage source.

Test the HO2S high signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Measure the voltage from the low signal circuit of the

HO2S harness connector on the engine harness side to a

good ground with a DMM. Refer to

Circuit Testing

in Wiring

Systems.

Is the voltage more than the speciﬁed value?

Go to

Step 12

Go to

Step 10

Test the HO2S high signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

EngineEngineControls-6.0L

DTC P0140 or P0160 (cont’d)

Step Action Value(s) Yes No

1. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and the low signal circuit of the

HO2S harness connector on the engine harness side.

2. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 13

Go to

Step 11

Test the HO2S low signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Test the HO2S low signal circuit for a short to voltage.

Refer to

Circuit Testing

Wiring Repairs

, and

Heated

Oxygen Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 14

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 15

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 16

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 2

Heated

Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 2

Did you complete the replacement?

—

Go to

Step 17

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 17

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 18

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0171 or P0174

Circuit Description

The powertrain control module (PCM) controls the

air/fuel metering system in order to provide the best

possible combination of driveability, fuel economy, and

emission control. Fuel delivery is controlled differently

during Open and Closed Loop. During Open Loop,

the PCM determines fuel delivery based on sensor

signals without oxygen sensor input. During Closed

Loop, the PCM adds oxygen sensor inputs and level of

purge to calculate short and long term fuel trim

adjustments. If the oxygen sensors indicate a lean

condition, fuel trim values will be above 0 percent. If

the oxygen sensors indicate a rich condition, fuel

trim values will be below 0 percent. The values for the

short term fuel trim change rapidly in response to

the heated oxygen sensor (HO2S) voltage signals.

Long term fuel trim makes course adjustments in order

to maintain an air/fuel ratio of 14.7:1. A block of

cells contain information arranged in combinations of

engine RPM and engine load for a full range of

vehicle operating conditions. The long term fuel trim

diagnostic is based on an average of cells currently

being used. The PCM selects the cells based on the

engine speed and engine load. If the PCM detects

an excessively lean condition, DTC P0171 or

P0174 sets.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0171 Fuel Trim System Lean Bank 1

• DTC P0172 Fuel Trim System Lean Bank 2

Conditions for Running the DTC

• DTCs P0068, P0101, P0102, P0103, P0106,

P0107, P0108, P0131, P0132, P0133, P0134,

P0135, P0136, P0137, P0138, P0140, P0141,

P0151, P0152, P0153, P0154, P0155, P0156,

P0157, P0158, P0160, P0161, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0300, P0442, P0443, P0446, P0449, P0452,

P0453, P0455, P0496, P0506, P0507, P1133,

P1134, P1153, or P1154 are not set.

• The engine coolant temperature (ECT) is between

−40 and +140°C (−40 and +284°F).

• The intake air temperature (IAT) is between −20

and +152°C (−4 and +304°F).

• The manifold absolute pressure (MAP) is between

15–105 kPa (2.2–15.2 psi).

• The vehicle speed is less than 132 km/h (82 mph).

• The engine speed is between 400–6,500 RPM.

• The barometric pressure (BARO) is more

than 70 kPa (10.2 psi).

• The mass air ﬂow (MAF) is between 1–250 g/s.

• The fuel level is more than 10 percent.

• This diagnostic runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The long term fuel trim weighted average value is

more than a calibrated value for 6 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• The system may become lean if an injector is not

suppling enough fuel.

• Excessive resistance in the fuel injector control

and/or ignition 1 voltage circuits may cause

the following symptoms:

− A lean condition

− Misﬁre

− Rough idle

Refer to

DTC P0201-P0208

• A lean condition could be present during high fuel

demand.

•UseaTech 2 inordertoreviewtheFailure

Records. If an intermittent condition is suspected,

refer to

Intermittent Conditions

EngineEngineControls-6.0L

DTC P0171 or P0174

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Are any DTCs other than DTC P0171 or P0174 also set?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

1.InstalltheTech 2 .

2. Start and idle the engine at the normal operating

temperature in Closed Loop.

3. Record the long term fuel trim.

4. Turn OFF the engine.

5. Turn ON the ignition, with the engine OFF.

6. Review the Freeze Frame/Failure Records and record

the displayed data for this DTC.

DoestheTech 2 indicatethatthelongtermfueltrimis

greater than the speciﬁed value?

24%

Go to

Step 4

Go to

Diagnostic Aids

1. Operate the engine at idle.

2.ObservetheHO2SparameterswithaTech 2 .

DoestheTech 2 indicatethattheparameteriswithinthe

speciﬁed range and ﬂuctuating?

200–800 mV

Go to

Step 5

Go to

Step 6

1. Turn OFF the engine.

2. Visually and physically inspect the following items:

• The vacuum hoses for splits, kinks, and proper

connections—Refer to

Emission Hose Routing

Diagram

• Ensure that the vehicle has sufficient fuel in tank. If

fuel pressure is too low this DTC may set. Refer to

Fuel System Diagnosis

• Fuel contamination—Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without

Special Tool)

Alcohol/Contaminants-in-Fuel

Diagnosis (with Special Tool)

• Any lean fuel injectors—Refer to

Fuel Injector

Balance Test with Tech 2

Did you ﬁnd and correct the condition?

—

Go to

Step 8

Go to

Step 7

1. Turn OFF the engine.

2. Inspect the heated oxygen sensor (HO2S) for proper

installation.

3. Verify that the electrical connectors and the wires are

secure, and not contacting the exhaust system.

4. Test for continuity between the HO2S signal circuit

and the low reference circuit. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S)

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 8

Go to

Fuel

System

Diagnosis

EngineControls-6.0LEngine

DTC P0171 or P0174 (cont’d)

Step Action Values Yes No

1. Operate the engine at idle.

2. Inspect for any missing, loose, or leaking exhaust

components forward of the HO2S.

3. Inspect for vacuum leaks at the intake manifold,

throttle body, and injector O-rings.

4. Inspect the air induction system and the air intake

ducts for leaks.

5. Inspect the secondary air injection (AIR) system for

leaks, improper air delivery, and for the shut-off valves

not closing.

6. Inspect the crankcase ventilation system for leaks.

Refer to

Crankcase Ventilation System

Inspection/Diagnosis

in Engine Mechanical.

7. Inspect the evaporative emission (EVAP) lines and

components for damage or blockage. Refer to

Evaporative Emissions (EVAP) Hose Routing

Diagram

Did you ﬁnd and correct the condition?

—

Go to

Step 8

Go to

Symptoms

- Engine

Mechanical

Engine

Mechanical

Important: After repairs, reset the Long Term Fuel Trim

withtheTech 2 FuelTrimResetfunction.

1. Turn ON the ignition, with the engine OFF.

2.CleartheDTCswithaTech 2

3. Turn OFF the ignition for 30 seconds.

4. Start the engine.

5. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 9

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0172 or P0175

Circuit Description

The powertrain control module (PCM) controls the

air/fuel metering system in order to provide the best

possible combination of driveability, fuel economy, and

emission control. Fuel delivery is controlled differently

during Open and Closed Loop. During Open Loop,

the PCM determines fuel delivery based on sensor

signals without oxygen sensor input. During Closed

Loop, the PCM adds oxygen sensor inputs and level of

purge to calculate short and long term fuel trim

adjustments. If the oxygen sensors indicated a lean

condition, fuel trim values will be above 0 percent.

If the oxygen sensors indicate a rich condition, fuel trim

values will be below 0 percent. The values for the

short term fuel trim change rapidly in response to the

heated oxygen sensor (HO2S) voltage signals.

Long term fuel trim makes coarse adjustments in

order to maintain an air/fuel ratio of 14.7:1. A block of

cells contain information arranged in combinations

of engine RPM and engine load for a fuel range

of vehicle operating conditions. The long term fuel trim

diagnostic is based on an average of cells currently

being used. The PCM selects the cells based on

the engine speed and engine load. The fuel trim

diagnostic will conduct a test to determine if a rich

failure actually exists, or if excessive vapor from the

evaporative emission (EVAP) canister is causing a rich

condition. If the PCM detects an excessively rich

condition, DTC P0172 or P0175 sets.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0172 Fuel Trim System Rich Bank 1

• DTC P0175 Fuel Trim System Rich Bank 2

Conditions for Running the DTC

• DTCs P0068, P0101, P0102, P0103, P0106,

P0107, P0108, P0131, P0132, P0133, P0134,

P0135, P0136, P0137, P0138, P0140, P0141,

P0151, P0152, P0153, P0154, P0155, P0156,

P0157, P0158, P0160, P0161, P0201, P0202,

P0203, P0204, P0205, P0206, P0207, P0208,

P0300, P0442, P0443, P0446, P0449, P0452,

P0453, P0455, P0496, P0506, P0507, P1133,

P1134, P1153, or P1154 are not set.

• The engine coolant temperature (ECT) is between

−40 and +140°C (−40 and +284° F).

• The intake air temperature (IAT) is between –20

and +152°C (−4 and +304°F).

• The manifold absolute pressure (MAP) is between

15–105 kPa (2.2–15.2 psi).

• The vehicle speed is less than 132 km/h (82 mph).

• The engine speed is between 400–6,500 RPM.

• The barometric pressure (BARO) is more than

70 kPa (10.2 psi).

• The mass air ﬂow (MAF) is between 1–250 g/s.

• The fuel level is more than 10 percent.

• This diagnostic runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The long term fuel trim weighted average value is

more than a calibrated value for 40 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Fuel contamination, such as water or alcohol, will

effect fuel trim.

• A malfunctioning MAF sensor can cause a rich

condition and set this DTC. Refer to

DTC P0101

•ReviewtheFailureRecordswithaTech 2 .Ifan

intermittent condition is suspected, refer to

Intermittent Conditions

Test Description

The number below refers to the step number on the

diagnostic table.

7. An EVAP canister that is saturated will cause a

rich condition.

EngineControls-6.0LEngine

DTC P0172 or P0175

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Are any DTCs other than DTC P0172 or P0175 also set?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

1.InstallTech 2 .

2. Start and idle the engine at the normal operating

temperature in Closed Loop.

3. Record the long term fuel trim data.

4. Turn OFF the engine.

5. Turn ON ignition, with the engine OFF.

6. Review the Freeze Frame/Failure Records and record

the displayed data for this DTC.

DoestheTech 2 indicatethatthelongtermfueltrimis

less than the speciﬁed value?

−17%

Go to

Step 4

Go to

Diagnostic Aids

1. Operate the engine at idle.

2.ObservetheHO2SparameterswithaTech 2 .

DoestheTech 2 indicatethatthevaluesarewithinthe

speciﬁed range and ﬂuctuating?

200–800 mV

Go to

Step 5

Go to

Step 6

1. Turn OFF the engine.

2. Visually and physically inspect the following items:

• The evaporative emission (EVAP) lines and

components for damage or blockage—Refer to

Evaporative Emissions (EVAP) Hose Routing

Diagram

• The inlet screen of the mass air ﬂow (MAF) sensor

for blockage

• The vacuum hoses for splits, kinks, and proper

connections—Refer to

Emission Hose Routing

Diagram

• The air intake duct for being collapsed or restricted

• The air ﬁlter for being dirty or restricted

• Objects blocking the throttle body

Did you ﬁnd and correct the condition?

—

Go to

Step 8

Go to

Step 7

1. Turn OFF the engine.

2. Inspect the heated oxygen sensor (HO2S) for proper

installation.

3. Inspect to ensure that the electrical connectors and

the wires are secure and not contacting the exhaust

system.

4. Test for continuity between the signal circuit and the

low reference circuit. Refer to

Circuit Testing

Wiring

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 8

Go to

Fuel

System

Diagnosis

Inspect for the following:

• Excessive fuel in the crankcase

• Proper operation of the fuel pressure regulator—Refer

Fuel System Diagnosis

• All injectors are functioning properly—Refer to

Fuel

Injector Coil Test

Did you ﬁnd and correct the condition?

—

Go to

Step 8

Go to

Symptoms

- Engine

Mechanical

Engine

Mechanical

EngineEngineControls-6.0L

DTC P0172 or P0175 (cont’d)

Step Action Values Yes No

Important: After repairs, reset the Long Term Fuel Trim

withtheTech 2 FuelTrimResetfunction.

1. Turn ON the ignition, with the engine OFF.

2.CleartheDTCswithaTech 2 .

3. Turn OFF the ignition for 30 seconds.

4. Start the engine.

5. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 9

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0201-P0208

Circuit Description

The control module enables the appropriate fuel

injector on the intake stroke for each cylinder.

Ignition 1 voltage is supplied to the fuel injectors. The

control module controls each fuel injector by

grounding the control circuit via a solid state device

called a driver. The control module monitors the status

of each driver. If the control module detects an

incorrect voltage for the commanded state of the

driver, a fuel injector control DTC sets.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0201 Injector 1 Control Circuit

• DTC P0202 Injector 2 Control Circuit

• DTC P0203 Injector 3 Control Circuit

• DTC P0204 Injector 4 Control Circuit

• DTC P0205 Injector 5 Control Circuit

• DTC P0206 Injector 6 Control Circuit

• DTC P0207 Injector 7 Control Circuit

• DTC P0208 Injector 8 Control Circuit

Conditions for Running the DTC

• The engine speed is more than 400 RPM.

• The ignition voltage is between 6–18 volts.

Conditions for Setting the DTC

• The engine control module (ECM) detects an

incorrect voltage on a fuel injector control circuit.

• The condition exists for 5 seconds.

SIO-ID = 727820 LMD = 17-jan-2002

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Performing the Fuel Injector Coil Test may help to

isolate an intermittent condition. Refer to

Fuel

Injector Coil Test

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

5. This step veriﬁes that the ECM is able to control

the fuel injector.

6. This step tests if a ground is constantly being

applied to the fuel injector.

DTC P0201-P0208

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1.CleartheDTCswithaTech 2 .

2. Idle the engine at the normal operating temperature.

3.MonitorthemisﬁrecurrentcounterswithaTech 2 .

Are any of the misﬁre current counters incrementing? Go to

Step 4

Go to

Step 3

EngineEngineControls-6.0L

DTC P0201-P0208 (cont’d)

Step Action Yes No

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the DTC.

You may also operate the vehicle within the conditions that you

observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 4

Go to

Diagnostic Aids

1. Turn OFF the ignition.

2. Disconnect the injector which displays the highest number of

misﬁre current counters.

3. Turn ON the ignition, with the engine OFF.

4. Probe the ignition 1 voltage circuit of the fuel injector with a test

lamp that is connected to a good ground.

Does the test lamp illuminate? Go to

Step 5

Go to

Step 11

1. Connect the

J 34730-2C

Fuel Injector Test Lamp between the

control circuit of the fuel injector and the ignition 1 voltage circuit

of the fuel injector.

2. Start the engine.

Does the test lamp ﬂash? Go to

Step 9

Go to

Step 6

Does the test lamp remain illuminated? Go to

Step 8

Go to

Step 7

Test the fuel injector control circuit for the following conditions:

• A short to voltage

• An open

• High resistance

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 10

8Test the fuel injector control circuit for a short to ground. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 13

Test for an intermittent and for a poor connection at the fuel injector.

Refer to

Testing for Intermittent Conditions and Poor Connections

and

Repairing Connector Terminals

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 12

Test for an intermittent and for a poor connection at the engine

control module (ECM). Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Repairing Connector Terminals

in Wiring

Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 13

Important: The INJ fuse also supplies voltage to the ignition coil

modules. If the fuse is open, inspect all related circuits and

components for a short to ground. Refer to

Circuit Testing

in Wiring

Systems.

Test the ignition 1 voltage circuit of the fuel injector for:

• An open

• High resistance

• A short to ground

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

—

12 Replace the fuel injector. Refer to

Fuel Injector Replacement

Did you complete the replacement? Go to

Step 14

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement? Go to

Step 14

—

EngineControls-6.0LEngine

DTC P0201-P0208 (cont’d)

Step Action Yes No

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the DTC.

You may also operate the vehicle within the conditions that you

observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 15

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0220

Circuit Description

The throttle body assembly contains 2 throttle

position (TP) sensors. The TP sensors are mounted to

the throttle body assembly and are not serviceable.

The TP sensors provide a signal voltage that changes

relative to throttle blade angle. The engine control

module (ECM) supplies the TP sensors with a common

5-volt reference circuit, a common low reference

circuit, and 2 independent signal circuits.

The TP sensors have opposite functionality. TP

sensor 1 signal voltage decreases from above 4 volts

at idle to below 1 volt at wide open throttle (WOT).

TP sensor 2 signal voltage increases from below 1 volt

at idle to above 4 volts at WOT.

If the ECM detects TP sensor 2 signal voltage is too

low or too high, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0220 Throttle Position (TP) Sensor 2 Circuit

Conditions for Running the DTC

• DTCs P0341, P0351, P0601, P0602, P0603,

P0604, P0606, P0607 are not set.

• The ignition is ON, with the engine OFF, or the

engine is operating.

• The ignition 1 voltage is more than 5.23 volts.

• DTC P0220 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The ECM detects the TP sensor 2 signal voltage is

less than 0.275 volts for less than 1 second.

The ECM detects the TP sensor 2 signal voltage is

more than 4.725 volts for less than 1 second.

SIO-ID = 746917 LMD = 22-dec-2003

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• If there is a condition with the TP sensors, the

ECM defaults to reduced power mode for the

entire ignition cycle, even if the condition is

corrected.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The number below refers to the step number on the

diagnostic table.

2. This step veriﬁes that other DTCs are set.

DTC P0220

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

Are any other DTCs set? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

DTC P0121

EngineControls-6.0LEngine

DTC P0222

Circuit Description

The throttle body assembly contains 2 throttle

position (TP) sensors. The TP sensors are mounted to

the throttle body assembly and are not serviceable.

The TP sensors provide a signal voltage that changes

relative to throttle blade angle. The engine control

module (ECM) supplies the TP sensors with a common

5-volt reference circuit, a common low reference

circuit, and 2 independent signal circuits.

The TP sensors have opposite functionality. TP

sensor 1 signal voltage decreases from above 4 volts

at idle to below 1 volt at wide open throttle (WOT).

TP sensor 2 signal voltage increases from below 1 volt

at idle to above 4 volts at WOT.

If the ECM detects TP sensor 2 signal voltage is too

low, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0222 Throttle Position (TP) Sensor 2 Circuit

Low Voltage

Conditions for Running the DTC

• The ignition is ON, with the engine OFF, or the

engine is operating.

• The ignition 1 voltage is more than 5.23 volts.

• DTC P0222 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The ECM detects the TP sensor 2 signal voltage is

less than 0.275 volts for less than 1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• If there is a condition with the TP sensors, the

ECM defaults to reduced power mode for the

entire ignition cycle, even if the condition is

corrected.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

2. This step veriﬁes that a condition exists.

4. The TP sensors share a 5-volt reference circuit. If

both DTCs P0122 and P0222 set, test for a

condition in the 5-volt reference circuit.

5. The ECM produces a measurable steady-state

amperage that provides the 5-volt reference

to the TP sensors. If the amperage on the 5-volt

reference circuit is less than 50 mA, test the 5-volt

reference circuit for an open or a high resistance.

6. This step tests the signal 2 circuit of the TP

sensor. If the TP sensor 2 voltage parameter is not

4.8–5.2 volts, test for a condition in the signal 2

circuit.

DTC P0222

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineEngineControls-6.0L

DTC P0222 (cont’d)

Step Action Values Yes No

1. Turn ON the ignition, with the engine OFF.

2. Observe the TP sensor 2 voltage parameter with a

Tech 2 .

Is the voltage less than the speciﬁed value?

0.275 V

Go to

Step 4

Go to

Step 3

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Diagnostic Aids

ObservetheDTCinformationwithaTech 2

Did DTC P0122 also set? —Go to

Step 5

Go to

Step 6

1. Turn OFF the ignition.

Notice:

Refer to

Disengaging Connectors Notice

Cautions and Notices.

2. Disconnect the throttle body harness connector.

3. Turn ON the ignition, with the engine OFF.

4. Set-up a DMM to test amperage on the 400 mA scale.

5. Measure the amperage from the 5-volt reference

circuit of the throttle position (TP) sensor to a good

ground.

Is the amperage more than the speciﬁed value?

50 mA

Go to

Step 9

Go to

Step 7

1. Turn OFF the ignition.

Notice:

Refer to

Disengaging Connectors Notice

Cautions and Notices.

2. Disconnect the throttle body harness connector.

3. Turn ON the ignition, with the engine OFF.

4. Connect a 3-amp fused jumper wire between the

5-volt reference circuit of the TP sensor and the

signal 2 circuit of the TP sensor.

5. Observe the TP sensor 2 voltage parameter with a

Tech 2 .

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Step 9

Go to

Step 8

Important: The 5-volt reference circuits are internally

connected within the controller. Other sensors that share

the 5-volt reference circuit may also have DTCs set.

Disconnecting a sensor on the shared 5-volt reference

circuit may isolate a shorted sensor. Review the electrical

schematic and diagnose the shared circuits and sensors.

Test the 5-volt reference circuit of the TP sensor and all

shared 5-volt reference circuits for an open, a short to

ground, or for high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 10

Test the signal 2 circuit of the TP sensor for a short to

ground, an open, or for high resistance. Refer to

Circuit

Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 10

Test for an intermittent and for a poor connection at the

throttle body assembly. Refer to

Testing for Intermittent

Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 11

EngineControls-6.0LEngine

DTC P0222 (cont’d)

Step Action Values Yes No

Test for an intermittent and for a poor connection at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 12

11 Replace the throttle body assembly. Refer to

Throttle Body

Removal

Did you complete the replacement? —Go to

Step 13

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 13

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 14

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0223

Circuit Description

The throttle body assembly contains 2 throttle

position (TP) sensors. The TP sensors are mounted to

the throttle body assembly and are not serviceable.

The TP sensors provide a signal voltage that changes

relative to throttle blade angle. The engine control

module (ECM) supplies the TP sensors with a common

5-volt reference circuit, a common low reference

circuit, and 2 independent signal circuits.

The TP sensors have opposite functionality. TP

sensor 1 signal voltage decreases from above 4 volts

at idle to below 1 volt at wide open throttle (WOT).

TP sensor 2 signal voltage increases from below 1 volt

at idle to above 4 volts at WOT.

If the ECM detects TP sensor 2 signal voltage is too

high, this DTC will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0223 Throttle Position (TP) Sensor 2 Circuit

High Voltage

Conditions for Running the DTC

• The ignition is ON, with the engine OFF, or the

engine is operating.

• The ignition 1 voltage is more than 5.23 volts.

• DTC P0223 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The ECM detects the TP sensor 2 signal voltage is

more than 4.725 volts for less than 1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• If there is a condition with the TP sensors, the

ECM defaults to reduced power mode for the

entire ignition cycle, even if the condition is

corrected.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

2. This step determines if a condition exists.

4. This step tests the signal circuit for a short to

voltage.IftheTech 2 displaysavoltageafterthe

TP sensor is disconnected, the circuit is shorted

to a voltage.

6. This step tests for high resistance in the low

reference circuit of the TP sensor. The ECM must

be completely powered down to obtain an

accurate resistance reading. It may take up to

30 minutes for the ECM to power down after the

ignition key is removed. Removal of the ECM/TCM

fuse allows the ECM to power down completely.

7. This step tests the low reference circuit for a short

to voltage.

DTC P0223

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineControls-6.0LEngine

DTC P0223 (cont’d)

Step Action Values Yes No

1. Turn ON the ignition, with the engine OFF.

2. Observe the TP sensor 2 voltage parameter with a

Tech 2 .

Is the voltage more than the speciﬁed value?

4.725 V

Go to

Step 4

Go to

Step 3

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Diagnostic Aids

1. Turn OFF the ignition.

Notice:

Refer to

Disengaging Connectors Notice

Cautions and Notices.

2. Disconnect the throttle body harness connector.

3. Turn ON the ignition, with the engine OFF.

4. Observe the TP sensor 2 voltage parameter with a

Tech 2 .

Is the voltage less than the speciﬁed value?

0.1 V

Go to

Step 5

Go to

Step 8

Measure the voltage between the 5-volt reference circuit of

the throttle position (TP) sensor and a good ground with

a DMM.

Is the voltage more than the speciﬁed value?

5.2 V

Go to

Step 9

Go to

Step 6

1. Turn OFF the ignition.

2. Remove the ECM fuse from the underhood

fuse block.

Notice:

SIO-ID = 802647 LMD = 18-jun-2001 Do NOT use a

test lamp to test the continuity of the circuit. Damage to the

control module may occur due to excessive current draw.

3. Measure the resistance from the low reference circuit

of the TP sensor to the engine control module (ECM)

housing with a DMM.

Is the resistance less than the speciﬁed value?

5Ω

Go to

Step 11

Go to

Step 7

1. Install the ECM fuse into the underhood electrical

center.

2. Turn ON the ignition, with the engine OFF.

3. Measure the voltage between the low reference circuit

of the TP sensor and the ECM housing.

Is the voltage more than the speciﬁed value?

Go to

Step 13

Go to

Step 10

Test the signal 2 circuit of the TP sensor for a short to

voltage. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 12

Important: The 5-volt reference circuits are internally

connected within the controller. Other sensors that share

the 5-volt reference circuit may also have DTCs set.

Disconnecting a sensor on the shared 5-volt reference

circuit may isolate a shorted sensor. Review the electrical

schematic and diagnose the shared circuits and sensors.

Test the 5-volt reference circuit of the TP sensor and all

shared 5-volt reference circuits for a short to voltage. Refer

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 12

EngineEngineControls-6.0L

DTC P0223 (cont’d)

Step Action Values Yes No

1. Turn OFF the ignition.

2. Disconnect the ECM.

3. Test the low reference circuit of the TP sensor for an

open or a high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 12

Test for shorted terminals and for poor connections at the

throttle body assembly. Refer to

Testing for Intermittent

Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 14

Test for shorted terminals and for poor connections at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 15

Important: The control module and/or the TP sensor may

be damaged if the circuit is shorted to battery positive

voltage.

Repair the short to voltage in the low reference circuit of

the TP sensor. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 16

—

14 Replace the throttle body assembly. Refer to

Throttle Body

Removal

Did you complete the replacement? —Go to

Step 16

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 16

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 17

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0230

Circuit Description

When the ignition switch is turned ON, the control

module enables the fuel pump relay, which supplies

current to the fuel pump. The fuel pump remains

enabled as long as the engine is cranking or running

and the control module receives ignition reference

pulses. If there are no ignition reference pulses,

the control module shuts the fuel pump OFF

approximately 2 seconds after the ignition was

switched to the ON position or if the engine stops. The

control module monitors the voltage on the fuel

pump relay control circuit. If the control module detects

an incorrect voltage on the fuel pump relay control

circuit, a fuel pump relay control DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0230 Fuel Pump Relay Control Circuit

Conditions for Running the DTC

• The engine speed is more than 400 RPM.

• The ignition voltage is between 6–18 volts.

Conditions for Setting the DTC

• The engine control module (ECM) detects that the

commanded state of the driver and the actual

state of the control circuit do not match.

• The above conditions are present for a minimum

of 2.5 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records. If

the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2

Diagnostic Aids

Fuel Pump Relay Underhood Electrical Center

Terminal Identiﬁcation

Front of vehicle

Left side of

vehicle

Ground Ignition Right side of

vehicle

Fuel Pump

Supply Control

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

4. This step veriﬁes that the ECM is providing

voltage to the fuel pump relay.

5. This step tests for an open in the ground circuit to

the fuel pump relay.

6. This step tests if the voltage is constantly being

applied to the control circuit of the fuel

pump relay.

DTC P0230

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2.CommandthefuelpumprelayONandOFFwithaTech 2 .

Does the fuel pump relay turn ON and OFF when commanded

withaTech 2 ?Goto

Step3

Goto

Step4

EngineEngineControls-6.0L

DTC P0230 (cont’d)

Step Action Yes No

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Remove the fuel pump relay.

3. Turn ON the ignition, with the engine OFF.

4. Probe the control circuit of the fuel pump relay with a test

lamp that is connected to a good ground. Refer to

Probing

Electrical Connectors

in Wiring Systems.

5.CommandthefuelpumprelayONandOFFwithaTech 2 .

Does the test lamp turn ON and OFF when commanded with a

Tech 2 ?Goto

Step5

Goto

Step6

1. Connect a test lamp between the control circuit of the fuel

pump relay and the ground circuit of the fuel pump relay.

2.CommandthefuelpumprelayONandOFFwithaTech 2 .

Does the test lamp turn ON and OFF when commanded with a

Tech 2 ?Goto

Step9

Goto

Step11

Does the test lamp remain illuminated? Go to

Step 8

Go to

Step 7

Test the control circuit of the fuel pump relay for a short to ground

or an open. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 10

Test the control circuit of the fuel pump relay for a short to

voltage. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 10

Test for an intermittent and for a poor connection at the fuel pump

relay. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 12

Test for an intermittent and for a poor connection at the engine

control module (ECM). Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 13

11 Test the ground circuit of the fuel pump relay for an open. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

—

12 Replace the fuel pump relay.

Did you complete the replacement? Go to

Step 14

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement? Go to

Step 14

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 15

EngineControls-6.0LEngine

DTC P0230 (cont’d)

Step Action Yes No

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0300

System Description

The engine control module (ECM) uses information

from the crankshaft position (CKP) sensor and

the camshaft position (CMP) sensor to determine

when an engine misﬁre is occurring. By monitoring

variations in the crankshaft rotation speed for

each cylinder, the ECM is able to detect individual

misﬁre events. A misﬁre rate that is high enough can

cause the 3-way catalytic converter (TWC) to

overheat under certain driving conditions. The

malfunction indicator lamp (MIL) will ﬂash ON and

OFF when the conditions for TWC overheating

are present. If the ECM detects a misﬁre rate sufficient

to cause emission levels to exceed mandated

standards, DTC P0300 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0300 Engine Misﬁre Detected

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0116, P0117, P0118, P0128, P0220,

P0315, P0335, P0336, P0341, P0502, P0503,

P1258 are not set.

• The engine speed is between 425–6,200 RPM.

• The ignition voltage is between 9–18 volts.

• The engine coolant temperature (ECT) is between

−7 and +130°C (+19 and +266°F).

• The fuel level is more than 10 percent.

• The throttle angle is steady within 1 percent.

• The antilock brake system (ABS) and the traction

control system (TCS) are not active.

• The transmission is not changing gears.

• The A/C clutch is not changing states.

• The ECM is not in fuel shut-off or decel fuel

cut-off mode.

• The ECM is not receiving a rough road signal.

• DTC P0300 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM is detecting a crankshaft rotation speed

variation indicating a misﬁre sufficient to cause

emission levels to exceed mandated standards.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Excessive vibration from sources other than the

engine could cause DTC P0300 to set. The

following are possible sources of vibration:

− Thickness variation of the brake

rotors—Refer to

Symptoms - Hydraulic

Brakes

in Hydraulic Brakes.

− Excessive driveline vibration—Refer to

Vibration Analysis - Road Testing

in Vibration

Diagnosis and Correction.

− Worn or damaged accessory drive belt—

Refer to

Symptoms - Engine Mechanical

in Engine Mechanical – 4.8L, 5.3L and 6.0L.

• There may be more or less cylinders actually

misﬁringthanindicatedbytheTech 2 .

• Spray water on the secondary ignition components

using a spray bottle. Look and listen for arcing or

misﬁring.

• If there are multiple misﬁres on only one bank,

inspect the fuel injector and ignition coil, power

and ground circuits for that bank. Refer to

Engine

Controls Schematics

Test Description

The number below refers to the step number on the

diagnostic table.

2. If the actual CKP variation values are not within

the learned values, the misﬁre counters may

increment.

EngineControls-6.0LEngine

DTC P0300

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Important: You must perform the Crankshaft

Position (CKP) System Variation Learn Procedure before

proceeding with this diagnostic table. Refer to

CKP System

Variation Learn Procedure

1. Start the engine.

2. Allow the engine to idle or operate within the

conditions listed in the Freeze Frame/Failure Records.

3.MonitoralloftheMisﬁrecounterswiththeTech 2

Are any of the Misﬁre current counters incrementing?

—

Go to

Step 3

Go to

Diagnostic Aids

Are any other DTCs set?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 4

Can any abnormal engine noise be heard?

—

Go to

Symptoms

- Engine

Mechanical

Engine

Mechanical –

4.8L, 5.3L

and 6.0L Go to

Step 5

5DoestheTech 2 indicatethattheheatedoxygensensor

(HO2S) bank 1 sensor 1 or HO2S bank 2 sensor 1 voltage

parameters are below the speciﬁed value? 200 mV Go to

DTC P0131

or P0151

Go to

Step 6

6DoestheTech 2 indicatethattheHO2Sbank1sensor1

or HO2S bank 2 sensor 1 voltage parameters are ﬁxed

above the speciﬁed value? 900 mV Go to

DTC P0132

or P0152

Go to

Step 7

Inspect the following components:

• The vacuum hoses and seals for splits, restrictions,

and improper connections—Refer to

Emission Hose

Routing Diagram

• The throttle body and intake manifold for vacuum leaks

• The crankcase ventilation system for vacuum leaks—

Refer to

Crankcase Ventilation System

Inspection/Diagnosis

in Engine Mechanical – 4.8L,

5.3L, and 6.0L.

• The engine control module (ECM) grounds for

corrosion and loose connections—Refer to

Ground

Distribution Schematics

in Wiring Systems.

• The exhaust system for restrictions—Refer to

Restricted Exhaust

in Engine Exhaust.

• The fuel for contamination—Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without

Special Tool)

Alcohol/Contaminants-in-Fuel

Diagnosis (with Special Tool)

Did you ﬁnd and correct the condition?

—

Go to

Step 19

Go to

Step 8

EngineEngineControls-6.0L

DTC P0300 (cont’d)

Step Action Values Yes No

Important: An erratic or inconsistent spark is considered a

no spark.

1. Turn OFF the ignition.

2. Disconnect the spark plug wire from the spark plug

that corresponds to the Misﬁre Current counters that

were incrementing. Refer to

Spark Plug Wire

Replacement

3. Install the

J 26792

Spark Tester.

4. Start the engine.

Does the spark jump the tester gap?

—

Go to

Step 10

Go to

Step 9

1. Remove the spark plug wire for the affected cylinders.

Refer to

Spark Plug Wire Replacement

2. Inspect the spark plug wire. Refer to

Spark Plug Wire

Inspection

3. Measure the resistance of the spark plug wire with

a DMM.

Is the resistance within the speciﬁed value?

188–312 ΩGo to

Electronic

Ignition (EI)

System Diagnosis

Go to

Step 19

1. Remove the spark plug from the cylinder that

indicated a misﬁre. Refer to

Spark Plug Replacement

2. Inspect the spark plug. Refer to

Spark Plug

Inspection

Does the spark plug appear to be OK?

—

Go to

Step 11

Go to

Step 12

1. Exchange the suspected spark plug with another

cylinder that is operating properly. Refer to

Spark Plug

Replacement

2. Operate the vehicle under the same conditions that

the misﬁre occurred.

Did the misﬁre move with the spark plug?

—

Go to

Step 17

Go to

Step 15

Is the spark plug oil or coolant fouled?

—

Go to

Symptoms

- Engine

Mechanical

Engine

Mechanical –

4.8L, 5.3L,

and 6.0L Go to

Step 13

13 Is the spark plug gas fouled? — Go to

Step 16

Go to

Step 14

14 Did the spark plug show any signs of being cracked, worn,

or improperly gapped? —Go to

Step 17

Go to

Step 15

Perform the fuel injector coil test. Refer to

Fuel Injector

Coil Test

Did you ﬁnd and correct the condition? —

Go to

Step 19

Go to

Symptoms

- Engine

Mechanical

Engine

Mechanical –

4.8L, 5.3L,

and 6.0L

Perform the fuel system diagnosis. Refer to

Fuel System

Diagnosis

Did you ﬁnd and correct the condition? —

Go to

Step 19

Go to

Symptoms

- Engine

Mechanical

Engine

Mechanical –

4.8L, 5.3L,

and 6.0L

17 Replace the faulty spark plug. Refer to

Spark Plug

Replacement

Did you complete the replacement? —Go to

Step 19

—

18 Replace the faulty spark plug wires. Refer to

Spark Plug

Wire Replacement

Did you complete the replacement? —Go to

Step 19

—

EngineControls-6.0LEngine

DTC P0300 (cont’d)

Step Action Values Yes No

19 Was the customer concern the malfunction indicator

lamp (MIL) ﬂashing? —Go to

Step 20

Go to

Step 21

1. Operate the vehicle at the speciﬁed value for

4 minutes.

2. Operate the vehicle within the Conditions for Running

the DTC P0420 or P0430 as speciﬁed in the

supporting text. Refer to

DTC P0420 or P0430

Does the DTC run and pass?

2,500 RPM

Go to

Step 21

Go to

DTC P0420

or P0430

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 22

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0315

Circuit Description

The crankshaft position (CKP) system variation learn

feature is used to calculate reference period errors

caused by slight tolerance variations in the crankshaft,

and the CKP sensor. The calculated error allows

the engine control module (ECM) to accurately

compensate for reference period variations. This

enhances the ability of the ECM to detect misﬁre

events over a wide range of engine speed and load.

The ECM stores the Crankshaft Position System

Variation values after a learn procedure has been

performed. If the actual crankshaft position variation is

not within the Crankshaft Position System Variation

compensating values stored in the ECM, DTC P0300

may set. If the CKP system variation values are

not stored in the ECM memory, DTC P0315 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0315 Crankshaft Position (CKP) System

Variation Not Learned

Conditions for Running the DTC

• DTCs P0335, P0336, or P0341, are not set.

• DTC P0315 runs every 100 milliseconds.

Conditions for Setting the DTC

• The CKP system variation values are not stored in

the ECM memory.

• The enable counter equals 0.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 tool.

DTC P0315

Step Action Yes No

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

Important: The Crankshaft Position Variation Learn Procedure may

have to be repeated up to 5 times before the procedure is learned.

Perform the Crankshaft Position (CKP) System Variation Learn

Procedure. Refer to

CKP System Variation Learn Procedure

DoestheTech 2 displayLearnedthisignition?Goto

Step4

Goto

Step3

If the CKP system variation learn procedure cannot be performed

successfully, inspect for the following conditions and correct as

necessary:

• Worn crankshaft main bearings

• A damaged reluctor wheel

• Excessive crankshaft runout

• A damaged crankshaft

• Interference in the signal circuit of the CKP sensor

• Any foreign material passing between the CKP sensor and the

reluctor wheel

• A coolant temperature that is not within the Conditions For

Running the DTC

• The ignition switch is in the ON position until the battery is

drained.

• A engine control module (ECM) power disconnect with the ignition

ON may erase the stored value and set the DTC P0315.

Did you complete the inspection? Go to

Step 4

—

EngineControls-6.0LEngine

DTC P0315 (cont’d)

Step Action Yes No

1.CleartheDTCswithaTech 2

2. Turn OFF the ignition.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the DTC

as speciﬁed in the supporting text.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 5

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0325

Circuit Description

The knock sensor (KS) system enables the engine

control module (ECM) to control the ignition timing for

the best possible performance while protecting the

engine from potentially damaging levels of detonation.

The ECM monitors two separate KS, one on each

side of the engine block. Each KS produces an

AC voltage signal that varies with different engine

speeds and loads. The ECM adjusts the spark timing

based on the amplitude and the frequency of the

KS signal. The ECM receives the KS signal through a

signal circuit. The KS ground is supplied by the

ECM through a low reference circuit. The ECM uses

the KS signal to calculate the average voltage,

then assign a voltage range value. The ECM will then

monitor for a normal KS signal within the assigned

voltage range. If the ECM malfunctions in a condition

that will not allow proper diagnosis of the KS

system, DTC P0325 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0325 Knock Sensor (KS) Circuit

Conditions for Running the DTC

• The engine run time is more than 10 seconds.

• The engine speed is greater than 500 RPM.

• DTC P0325 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM detects a malfunction in the KS diagnostic

circuitry that will not allow proper diagnosis of the

KS system for 100 milliseconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of failure. The control module writes the

operating conditions to the Freeze Frame and

updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC last test failed clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2

DTC P0325

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 3

Go to

Intermittent

Conditions

Replace the engine control module (ECM). Refer to

Control

Module References

in Computer/Integrating Systems for

replacement, setup, and programming.

Did you complete the replacement? Go to

Step 4

—

EngineControls-6.0LEngine

DTC P0325 (cont’d)

Step Action Yes No

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 5

ObservetheCaptureInfowithaTech 2

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0326

Circuit Description

The knock sensor (KS) system enables the engine

control module (ECM) to control the ignition timing for

the best possible performance while protecting the

engine from potentially damaging levels of detonation.

The KS produces an A/C signal that varies with

different engine speeds and loads. The ECM makes

adjustments to the spark timing based on the

amplitude and frequency of either KS signal. The ECM

receives the KS signal through a signal circuit. The

ECM supplies the KS ground through a low reference

circuit. The ECM uses the KS to calculate the

amount of normal engine noise for a wide range of

engine speeds and loads. The normal engine

noise that has been calculated and retained in the

ECM memory is called the learned noise channel. The

ECM compares the actual KS signal to the learned

noise channel in memory. When the ECM determines

that the KS signal is outside the limits of the learned

noise channel, the ECM will retard the spark

timing until the knock goes away. If the knock is such

that the engine requires a large amount of spark

retard and the ECM is unable to eliminate the knock,

this DTC will set. DTC P0326 refers to either the

bank 1 KS or the bank 2 KS.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0326 Knock Sensor (KS) Performance

Conditions for Running the DTC

• The engine speed is more than 500 RPM.

• The engine load is equal to or greater than a

calibrated speciﬁcation.

• DTC P0326 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

• The KS signal indicates an engine knock is

present.

• The ECM commanded spark retard at a given

engine speed and load is more than the

calibrated value.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of failure. The control module writes the

operating conditions to the Freeze Frame and

updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC last test failed clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P0326

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 3

Go to

Intermittent

Conditions

Is DTC P0325 set? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

Step 4

EngineControls-6.0LEngine

DTC P0326 (cont’d)

Step Action Yes No

1. Inspect for a loose or broken vehicle accessory and/or

accessory bracket.

2. If a condition is found, repair as necessary.

Did you ﬁnd and correct the condition? Go to

Step 6

Go to

Step 5

1. Start the engine.

2. Inspect for excessive engine mechanical noise. Refer to

Symptoms - Engine Mechanical

in Engine Mechanical 6.0L.

3. If a condition is found, repair as necessary.

Did you ﬁnd and correct the condition? Go to

Step 6

Go to

Detonation/Spark Knock

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 7

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0327 or P0332

Circuit Description

The knock sensor (KS) system enables the engine

control module (ECM) to control the ignition timing for

the best possible performance while protecting the

engine from potentially damaging levels of detonation.

The ECM monitors two separate KS, one on each

side of the engine block. Each KS produces an

AC voltage signal that varies with different engine

speeds and loads. The ECM adjusts the spark timing

based on the amplitude and the frequency of the

KS signal. The ECM receives the KS signal through a

signal circuit. The KS ground is supplied by the

ECM through a low reference circuit. The ECM uses

the KS signal to calculate the average voltage,

then assign a voltage range value. The ECM will then

monitor for a normal KS signal within the assigned

voltage range. If the ECM detects a KS signal outside

of the assigned voltage reange, or the KS signal is

not present, this DTC will set. DTC P0327 refers

to KS 2.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0327 Knock Sensor (KS) 1 Circuit Low

Frequency

• DTC P0332 Knock Sensor (KS) 2 Circuit Low

Frequency

Conditions for Running the DTC

• The engine run time is more than 10 seconds.

• The engine speed is greater than 1,000 RPM.

• DTC P0327 and P0332 runs continuously

when the above conditions are met.

Conditions for Setting the DTC

The KS signal is outside of the assigned voltage

range, or the siganl is not present for 100 milliseconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of failure. The control module writes the

operating conditions to the Freeze Frame and

updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC last test failed clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Inspect the KS for physical damage. A KS that is

dropped or damaged may cause a DTC to set.

• Inspect the KS for proper installation. A KS that is

loose or over torqued may cause a DTC to set.

The KS and the KS fasterner should be free

of thread sealant. The KS mounting surface must

be free of burrs, casting ﬂash, and foreign

material.

• The KS should be clear of hoses, brackets, and

engine electrical wiring.

• For an intermittent condition, refer to

Intermittent

Conditions

DTC P0327 or P0332

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineControls-6.0LEngine

DTC P0327 or P0332 (cont’d)

Step Action Values Yes No

Important: If an engine mechanical noise can be heard,

repair the condition before proceeding with this diagnostic.

Refer to

Symptoms - Engine Mechanical

in Engine

Mechanical 6.0L.

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 3

Go to

Diagnostic Aids

1. Turn OFF the ignition.

2. Disconnect the affected knock sensor (KS).

3. Set the DMM to the ohms scale.

4. Meassure the resistance from the siganl terminal on

the KS to a good ground with a DMM. Refer to

Troubleshooting with a Digital Multimeter

in Wiring

Systems.

5. Measure the resistance from the low reference

terminal on the KS to a good ground with the DMM.

Does the DMM display OL for both terminals?

—

Go to

Step 4

Go to

Step 10

1. Connect the DMM between the terminals of the

affected KS.

2. Set the DMM to the 400 mV, AC hertz scale, and wait

for the DMM to stabilize at zero hertz. Refer to

Measuring Frequency

in Wiring Systems.

Important: DO NOT tap on any plastic engine

components.

3. Tap on the engine block with a non-metalic object

near the affected KS while observing the signal

indicated on the DMM.

Does the DMM display a ﬂuctuating frequency while

tapping on the engine block?

—

Go to

Step 5

Go to

Step 10

1. Turn ON the engine, with the engine OFF.

2. Measure the voltage at the KS signal circuit to a good

ground wiht a DMM.

3. Measure the voltage at the KS low reference circuit to

a good ground with a DMM.

Does the DMM display a voltage above the speciﬁed value

on either circuit?

Go to

Step 6

Go to

Step 7

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM).

3. Test the KS signal circuit or the KS low reference

circuit for a short to voltage. Refer to

Testing for a

Short to Voltage

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 11

1. Turn OFF the ignition.

2. Disconnect the ECM.

3. Test the KS signal circuit and the KS low reference

circuit for an open, a high resistance, and a short to

ground. Refer to

Testing for Continuity

Testing for

Short to Ground

, and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 9

EngineEngineControls-6.0L

DTC P0327 or P0332 (cont’d)

Step Action Values Yes No

Test for an intermittent and for a poor connection at the

affected KS. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 10

Test for an intermittent and fora poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 11

Replace the affected KS. Refer to

Knock Sensor (KS)

Replacement (Left)

Knock Sensor (KS) Replacement

(Right)

Did you complete the replacement?

—

Go to

Step 12

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 12

—

1.CleartheDTCswithaTech 2

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 13

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0335

Circuit Description

The crankshaft position (CKP) sensor signal indicates

the crankshaft speed and position. The CKP sensor

circuits are connected directly to the engine control

module (ECM) and consists of the following circuits:

• The 12-volt reference circuit

• The low reference circuit

• The CKP sensor signal circuit

If the ECM detects that there is no signal from the

CKP sensor for 3 seconds, DTC P0335 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0335 Crankshaft Position (CKP) Sensor

Circuit

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0341, P0342, or

P0343 are not set.

• The camshaft position (CMP) sensor signal is

incrementing.

• The mass air ﬂow (MAF) is more than 5 g/s.

• The engine is cranking or running.

• DTC P0335 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM detects that there is no signal from the CKP

sensor for 3 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

3. This step determines if the fault is present.

6. This step simulates a CKP sensor signal to the

ECM. If the ECM receives the signal, the fuel

pump will operate for about 2 seconds.

DTC P0335

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

2Attempt to start the engine.

Does the engine start and continue to run? —Go to

Step 3

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

EngineEngineControls-6.0L

DTC P0335 (cont’d)

Step Action Values Yes No

1. Raise the vehicle. Refer to

Lifting and Jacking the

Vehicle

in General Information.

2. Remove the starter. Refer to

Starter Motor

Replacement

in Engine Mechanical.

3. Disconnect the crankshaft position (CKP) sensor

connector.

4. Turn ON the ignition, with the engine OFF.

5. Measure the voltage from the 12-volt reference circuit

of the CKP sensor to a good ground with a DMM.

Refer to

Troubleshooting with a Digital Multimeter

Wiring Systems.

Is the voltage within the speciﬁed value?

B+

Go to

Step 5

Go to

Step 7

Measure the voltage between the 12-volt reference circuit

of the CKP sensor and the low reference circuit of the CKP

sensor with a DMM.

Is the voltage within the speciﬁed value?

B+

Go to

Step 6

Go to

Step 8

Momentarily connect a test lamp between the CKP sensor

signal circuit and the 12-volt reference of the CKP sensor.

Does the fuel pump operate when the test lamp is applied

to the CKP sensor signal circuit?

—

Go to

Step 10

Go to

Step 9

Test the 12-volt reference circuit for the following

conditions:

• An open

• A short to ground

• High resistance

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct condition?

—

Go to

Step 16

Go to

Step 12

Test the low reference circuit for the following conditions:

• An open

• A short to voltage

• High Resistance

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 12

Test the CKP sensor signal circuit for the following

conditions:

• An open

• A short to ground

• A short to voltage

• High resistance

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 12

EngineControls-6.0LEngine

DTC P0335 (cont’d)

Step Action Values Yes No

1. Remove the CKP sensor. Refer to

Crankshaft

Position (CKP) Sensor Replacement

2. Visually inspect the CKP sensor for the following

conditions:

• Physical damage

• Loose or improper installation

• Wiring routed too closely to the secondary ignition

components

3. The following conditions may cause this DTC to set:

• Excessive air gap between the CKP sensor and

the reluctor wheel

• The CKP sensor coming in contact with the

reluctor wheel

• Foreign material passing between the CKP sensor

and the reluctor wheel

• Insufficient fuel

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 11

Visually inspect the CKP sensor reluctor wheel for the

following conditions:

• Loose or improper installation

• Physical damage

• Excessive end play or looseness

Refer to

Crankshaft and Bearings Cleaning and Inspection

in Engine Mechanical.

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 14

Test for poor connections at the CKP sensor. Refer to

Testing for Intermittent Conditions and Poor Connections

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 13

Test for poor connections at the engine control

module (ECM). Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 16

Go to

Step 15

14 Replace the CKP sensor. Refer to

Crankshaft

Position (CKP) Sensor Replacement

Did you complete the replacement? —Go to

Step 16

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 16

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 17

ObservetheCaptureInfowithaTech 2

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0336

Circuit Description

The crankshaft position (CKP) sensor signal indicates

the crankshaft speed and position. The CKP sensor

circuits are connected directly to the engine control

module (ECM) and consists of the following circuits:

• The 12-volt reference circuit

• The low reference circuit

• The CKP sensor signal circuit

If the ECM detects that the CKP sensor signal is

inconsistent, DTC P0336 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0336 Crankshaft Position (CKP) Sensor

Circuit

Conditions for Running the DTC

• The engine is cranking or running.

• DTC P0336 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM detects that the CKP sensor signal is

inconsistent for 10 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P0336

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Important: If DTC P0335 is also set, diagnose DTC P0335

before proceeding with this DTC.

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 3

Go to

Intermittent

Conditions

EngineControls-6.0LEngine

DTC P0336 (cont’d)

Step Action Values Yes No

Inspect all of the crankshaft position sensor (CKP) circuits

for the following conditions:

• Wiring routed too closely to secondary ignition wires or

components

• Wiring routed too closely to after-market add-on

electrical equipment

• Wiring routed to closely to solenoids, relays, and

motors

• Electromagnetic interference in the CKP sensor circuits

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 4

1. Raise the vehicle. Refer to

Lifting and Jacking the

Vehicle

in General Information.

2. Remove the starter. Refer to

Starter Motor

Replacement

in Engine Mechanical.

3. Disconnect the CKP sensor connector.

4. Turn ON the ignition, with the engine OFF.

5. Measure the voltage from the 12-volt reference circuit

of the CKP sensor with a DMM. Refer to

Troubleshooting with a Digital Multimeter

in Wiring

Systems.

Is the voltage within the speciﬁed value?

B+

Go to

Step 5

Go to

Step 13

Test the 12-volt reference circuit for an intermittent

condition or shorted to other circuits. Refer to

Testing for

Electrical Intermittents

and

Inducing Intermittent Fault

Conditions

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 6

Test the low reference circuit for an intermittent condition.

Refer to

Testing for Electrical Intermittents

and

Inducing

Intermittent Fault Conditions

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 7

Test the CKP sensor signal circuit for an intermittent

condition. Refer to

Testing for Electrical Intermittents

and

Inducing Intermittent Fault Conditions

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 8

Test for an intermittent and for a poor connection at the

CKP sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 9

Test for an intermittent and for a poor connection at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 10

1. Remove the CKP sensor. Refer to

Crankshaft

Position (CKP) Sensor Replacement

2. Inspect the CKP sensor for the following conditions:

• Physical damage

• Loose or improper installation

• Excessive play or looseness

• Excessive air gap between the CKP sensor and

the reluctor wheel

• Foreign material passing between the CKP sensor

and the reluctor wheel

• Insufficient fuel

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 11

EngineEngineControls-6.0L

DTC P0336 (cont’d)

Step Action Values Yes No

Inspect the reluctor wheel for the following conditions:

• Physical damage

• Loose or improper installation

• Excessive end play or looseness

Refer to

Crankshaft and Bearings Cleaning and Inspection

in Engine Mechanical.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 12

12 Replace the CKP sensor. Refer to

Crankshaft

Position (CKP) Sensor Replacement

Did you complete the replacement? —Go to

Step 14

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 14

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 15

Go to

Step 2

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0340

Circuit Description

The camshaft position (CMP) sensor works in

conjunction with the 1X reluctor trigger wheel on the

front of the camshaft gear. The engine control

module (ECM) provides a 12-volt reference to the

CMP sensor, as well as a low reference and a signal

circuit. As the camshaft gear rotates, the reluctor

trigger wheel interrupts a magnetic ﬁeld produced by a

magnet within the sensor. The CMP sensor internal

circuitry detects this interruption of the magnetic

ﬁeld and produces a signal, which the ECM reads.

The 1X signal produced by the CMP sensor is used by

the ECM to determine if the cylinder at the top dead

center (TDC) is on the ﬁring stroke or the exhaust

stroke. The ECM can determine TDC for all cylinders

by using the crankshaft position (CKP) sensor

24X signal. If the 1X signal is not received by the

ECM, a slightly longer cranking time may be

experienced. The ECM will attempt synchronization

and looks for an increase in engine speed, indicating

that the engine is running. If the ECM does not

detect an increase in engine speed, the ECM assumes

that it incorrectly synchronized to the exhaust stroke,

and then will synchronize to the opposite cam

position. If the ECM detects that there is no output

signal from the CMP sensor, DTC P0340 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0340 Camshaft Position (CMP) Sensor Circuit

Conditions for Running the DTC

• The engine is cranking, or the engine is running.

• DTC P0340 runs continuously when the above

condition is met.

Conditions for Setting the DTC

The ECM detects no CMP sensor output for more

than 3 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores the information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC last test failed clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles if no failures are reported by this or any

other emission related diagnostic.

Test Description

The number below refers to the step number on the

diagnostic table.

4. The test lamp in this step is used to apply a load

to the 12-volt reference circuit of the CMP

sensor.

DTC P0340

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Start and idle the engine.

2. Monitor the camshaft position (CMP) sensor active

counterparameterwithaTech 2 .

Does the CMP sensor active counter number increment?

—Go to

Intermittent

Conditions

Go to

Step 3

1. Turn OFF the ignition.

2. Disconnect the CMP sensor electrical connector.

3. Test for shorted terminals and poor connections at the

CMP sensor wire harness electrical connector and the

mating electrical connector on the CMP sensor. Refer

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 4

EngineEngineControls-6.0L

DTC P0340 (cont’d)

Step Action Values Yes No

1. Turn ON the ignition, with the engine OFF.

2. Connect a jumper wire to the 12-volt reference circuit

at the CMP sensor wire harness electrical connector.

3. Connect a test lamp between the jumper wire and a

good ground.

4. Connect the positive lead of the DMM to the junction

of the jumper wire and test lamp.

5. Connect the negative lead of the DMM to a good

engine ground.

6. Measure the voltage from the 12-volt reference circuit

to a good ground with a DMM. Refer to

Circuit Testing

in Wiring Systems.

Is the voltage within the speciﬁed range?

10–13 V

Go to

Step 5

Go to

Step 6

1. Remove the test lamp from the jumper wire.

2. Connect another jumper wire to the signal circuit of

the CMP sensor wire harness electrical connector.

3. Turn ON the ignition, with the engine OFF.

4. monitor the CMP active counter parameter with a

Tech 2 .

5. Momentarily connect the two ends of the jumper wire

together several times.

Does the CMP sensor active counter number increment?

—

Go to

Step 10

Go to

Step 7

Test the CMP 12-volt reference circuit between the CMP

sensor and the engine control module (ECM) for the

following conditions:

• An open

• High resistance

• A short to ground

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 9

Test the CMP low reference circuit between the CMP

sensor and the ECM for the following conditions:

• An open

• High resistance

• A short to ground

• A short to ignition 1 battery positive voltage

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 8

Test the CMP signal circuit between the CMP sensor and

the ECM for the following conditions:

• An open

• High resistance

• A short to ground

• A short to ignition 1 battery positive voltage

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 9

Test for shorted terminals and poor connections at the

ECM wire harness electrical connector. Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 11

10 Replace the CMP sensor. Refer to

Camshaft

Position (CMP) Sensor Replacement

Did you complete the replacement? —Go to

Step 12

—

EngineControls-6.0LEngine

DTC P0340 (cont’d)

Step Action Values Yes No

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 12

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 13

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0341

Circuit Description

The camshaft position (CMP) sensor works in

conjunction with the 1X reluctor trigger wheel on the

front of the camshaft gear. The engine control

module (ECM) provides a 12-volt reference to the

CMP sensor, as well as a low reference and a signal

circuit. As the camshaft gear rotates, the reluctor

trigger wheel interrupts a magnetic ﬁeld produced by a

magnet within the sensor. The CMP sensor internal

circuitry detects this interruption of the magnetic

ﬁeld and produces a signal, which the ECM reads.

The 1X signal produced by the CMP sensor is used by

the ECM to determine if the cylinder at the top dead

center (TDC) is on the ﬁring stroke or the exhaust

stroke. The ECM can determine TDC for all cylinders

by using the crankshaft position (CKP) sensor

24X signal. The engine will start without a CMP sensor

signal as long as the ECM receives the CKP sensor

24X signal. If the 1X signal is not received by the ECM,

a slightly longer cranking time may be experienced.

The ECM will attempt synchronization and looks for an

increase in engine speed, indicating that the engine

is running. If the ECM does not detect an increase in

engine speed, the ECM assumes that it incorrectly

synchronized to the exhaust stroke, and then will

synchronize to the opposite cam position. If the ECM

detects that the ratio of the CMP sensor to CKP

sensor trigger pulses are missing or incorrect,

DTC P0341 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0341 Camshaft Position (CMP) Sensor

Performance

Conditions for Running the DTC

• The engine is cranking, or the engine is running.

• DTCs P0335, P0336, and P0340 are not set.

• DTC P0341 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM detects a missing or a noisy CMP sensor

signal for 100 engine cycles.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores the information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC last test failed clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles if no failures are reported by this or any

other emission related diagnostic.

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

4. This step inspects for electromagnetic

interference (EMI) on the CMP circuits.

7. Damage to the face of the sensor could indicate

material passing between the CMP sensor and

the reluctor wheel. This condition could cause this

DTC to set. Damage to the reluctor wheel

would affect the CMP sensor output signal.

DTC P0341

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

Is DTC P0340 also set? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

Step 3

EngineControls-6.0LEngine

DTC P0341 (cont’d)

Step Action Yes No

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 4

Go to

Intermittent

Conditions

1. Visually and physically inspect all circuits going to the

camshaft position (CMP) sensor for the following:

• The wire harness routed too close to the secondary

ignition wires or components

• The wire harness routed too close to the aftermarket

add-on electrical equipment

• The wire harness routed too close to the solenoids,

relays, and motors

2. If you ﬁnd the wiring harness incorrectly routed, then position

the wire harness correctly. Refer to

Harness Routing Views

Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 9

Go to

Step 5

1. Disconnect the CMP sensor electrical connector.

2. Test for an intermittent and for a poor connection at the CMP

sensor wiring harness electrical connector and the mating

connector on the CMP sensor. Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 10

Go to

Step 6

Test for an intermittent and for a poor connection at the engine

control module (ECM). Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 10

Go to

Step 7

1. Remove the CMP sensor. Refer to

Camshaft Position (CMP)

Sensor Replacement

2. Visually inspect the CMP sensor for the following conditions:

• Physical damage

• Excessive wear of the sensor

• Loose or improper installation

• The sensor coming in contact with the reluctor wheel

• Foreign material passing between the sensor and the

reluctor wheel

Did you ﬁnd and correct the condition? Go to

Step 10

Go to

Step 8

Visually inspect the CMP sensor reluctor ring or camshaft gear for

the following conditions:

• Physical damage

• Excessive end play or looseness

• Loose or improper installation

Did you ﬁnd and correct the condition? Go to

Step 10

Go to

Step 9

9Replace the CMP sensor. Refer to

Camshaft Position (CMP)

Sensor Replacement

Did you complete the replacement? Go to

Step 10

—

EngineEngineControls-6.0L

DTC P0341 (cont’d)

Step Action Yes No

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 11

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0351-P0358

Circuit Description

The ignition system on this engine uses an individual

ignition coil for each cylinder. The engine control

module (ECM) controls the spark event for each

cylinder through 8 individual ignition control (IC)

circuits. When the ECM commands the IC circuit ON,

electrical current will ﬂow through the primary

winding of the ignition coil, creating a magnetic ﬁeld.

When a spark event is requested, the ECM will

command the IC circuit OFF, interrupting current ﬂow

through the primary winding. The magnetic ﬁeld

created by the primary winding will collapse across the

secondary coil winding, producing a high voltage

across the spark plug electrodes. The ECM uses

information from the crankshaft position (CKP) and the

camshaft position (CMP) sensor for sequencing and

timing of the spark events. Each ignition coil/module

has the following circuits:

• An ignition 1 voltage circuit

• A ground circuit

• An IC circuit

• A low reference circuit

If the ECM detects that the IC circuit has an incorrect

voltage level, DTC P0351–P0358 will set.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0351 Ignition Coil 1 Control Circuit

• DTC P0352 Ignition Coil 2 Control Circuit

• DTC P0353 Ignition Coil 3 Control Circuit

• DTC P0354 Ignition Coil 4 Control Circuit

• DTC P0355 Ignition Coil 5 Control Circuit

• DTC P0356 Ignition Coil 6 Control Circuit

• DTC P0357 Ignition Coil 7 Control Circuit

• DTC P0358 Ignition Coil 8 Control Circuit

Conditions for Running the DTC

• The engine is running.

• DTC P0351–P0358 runs continuously when the

above condition is met.

Conditions for Setting the DTC

The ECM detects the IC circuit is grounded, open, or

shorted to voltage for less than 1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

3. This step veriﬁes the integrity of the IC circuit and

the ECM output.

4. This step tests for a short to voltage on the IC

circuit.

DTC P0351-P0358

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineEngineControls-6.0L

DTC P0351-P0358 (cont’d)

Step Action Values Yes No

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 3

Go to

Intermittent

Conditions

1. Turn OFF the engine.

2. Disconnect the respective ignition coil electrical

connector.

3. Disconnect the respective fuel injector electrical

connector.

4. Start the engine.

5. Measure the frequency at the ignition (IC) circuit with

the DMM set to DC Hertz. Refer to

Measuring

Frequency

in Wiring Systems.

Is the frequency within the speciﬁed range?

3–20 Hz

Go to

Step 7

Go to

Step 4

1. Turn ON the ignition, with the engine OFF.

2. Measure the voltage from the IC circuit of the ignition

coil to a good ground with a DMM.

Is the voltage more than the speciﬁed value?

Go to

Step 13

Go to

Step 5

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM)

connector.

3. Test the IC circuit between the ignition coil connector

and the ECM connector for continuity with the DMM.

Does the DMM indicate continuity?

—

Go to

Step 6

Go to

Step 14

6Test the respective IC circuit for a short to ground. Refer to

Testing for Short to Ground

in Wiring Systems.

Did you ﬁnd and correct the condition? —Go to

Step 17

Go to

Step 10

1. Turn ON the ignition, with the engine OFF.

2. Probe the ignition 1 voltage circuit of the ignition coil

with a test lamp that is connected to battery ground.

Refer to

Troubleshooting with a Test Lamp

in Wiring

Systems.

Does the test lamp illuminate?

—

Go to

Step 8

Go to

Step 11

Probe the ground circuit of the ignition coil with a test lamp

connected to battery voltage. Refer to

Troubleshooting with

a Test Lamp

in Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 9

Go to

Step 12

Test for an intermittent and for a poor connection at the

ignition coil. Refer to

Testing for Intermittent Conditions and

Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 15

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 16

11 Repair the open or high resistance in the ignition 1 voltage

circuit. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 17

—

EngineControls-6.0LEngine

DTC P0351-P0358 (cont’d)

Step Action Values Yes No

12 Repair the open or high resistance in the ground circuit for

the ignition coil. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 17

—

13 Repair the IC circuit for a short to voltage. Refer to

Wiring

Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 17

—

14 Repair the open or high resistance in the IC circuit. Refer

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 17

—

15 Replace the ignition coil. Refer to

Ignition Coil(s)

Replacement

Did you complete the replacement? —Go to

Step 17

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 17

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 18

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0420 or P0430

Circuit Description

The three-way catalytic converter (TWC) reduces

emissions of hydrocarbons (HC), carbon

monoxide (CO), and oxides of nitrogen (NOx). The

catalyst within the converter promotes a chemical

reaction, which oxidizes the HC and CO that

are present in the exhaust gas. This process converts

these chemicals into water vapor and carbon dioxide

(CO2), and will reduce the NOx, by converting

them into nitrogen. The catalytic converter also stores

oxygen. The engine control module (ECM) monitors

this process using heated oxygen sensor (HO2S)

bank 1 sensor 2 and HO2S bank 2 sensor 2, located

in the exhaust stream after the TWC. These

sensors are referred to as the catalyst monitor

sensors. The catalyst monitor sensors produce an

output signal the ECM uses to indicate the oxygen

storage capacity of the catalyst. This determines the

catalysts ability to effectively convert the exhaust

emissions.

If the catalyst is functioning correctly, the HO2S

bank 1 sensor 2 and HO2S bank 2 sensor 2 signals

will be far less active than the signals that are

produced by HO2S bank 1 sensor 1 and HO2S

bank 2 sensor 1. This indicates that the TWC oxygen

storage capacity is at an acceptable threshold.

When the response time of the catalyst monitor

sensors are close to that of the fuel control sensors,

the ability of the catalyst to store oxygen may be below

an acceptable threshold.

The ECM performs this diagnostic test at idle. When

the conditions for running this DTC are met, the

following occurs:

• The air-to-fuel ratio transitions from lean to rich.

• The air-to-fuel ratio transitions from rich to

lean, opposite the ﬁrst air-to-fuel ratio transition.

• The ECM captures the response time of the front

and the rear HO2S when the air-to-fuel ratio

transitions occur. The HO2S response time

changes from less than 350 mV to more than

600 mV, and from more than 600 mV to less than

350 mV.

• The ECM measures the time necessary for the

rear HO2S voltage to cross a reference

lean-to-rich threshold, and the time necessary for

the front HO2S voltage to cross the same

lean-to-rich threshold. The difference between the

front HO2S time and the rear HO2S time

indicates the oxygen storage capacity of the

catalyst. If the ECM detects that this time

difference is less than a predetermined value,

DTC P0420 for bank 1 or DTC P0430 for

bank 2 sets.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0420 Catalyst System Low Efficiency

Bank 1

• DTC P0430 Catalyst System Low Efficiency

Bank 2

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0116, P0117, P0118,

P0121, P0131, P0132, P0133, P0134, P0135,

P0137, P0138, P0140, P0141, P0151, P0152,

P0153, P0154, P0155, P0157, P0158, P0160,

P0161, P0171, P0172, P0174, P0175, P0200,

P0201–P0208, P0220, P0300, P0335, P0336,

P0340, P0341, P0351–P0358, P0442, P0443,

P0446, P0449, P0452, P0453, P0455, P0496,

P0500, P0502, P0503, P0506, P0507, P1133,

P1134, P1153, P1154, P1258, P1516, P2101,

P2119 are not set.

• The engine has been running for more than

10 minutes.

• The intake air temperature (IAT) is between −20

to +85°C (−4 and +185°F).

• The barometric pressure (BARO) is more than

70 kPa.

• The engine coolant temperature (ECT) is between

70–125.5°C (158–258°F).

• Since the end of the last idle period, the engine

speed has been more than 750 RPM for

36 seconds.

• The engine must be at a stable idle speed, within

200 RPM of desired idle.

• The battery voltage is more than 11 volts.

• The Closed Loop fuel control is enabled.

• This diagnostic attempts one test during each

valid idle period once the above conditions

have been met. This diagnostic attempts up to

12 tests during each drive cycle.

Conditions for Setting the DTC

• The ECM determines that the oxygen storage

capability of the TWC has degraded to less than a

calibrated threshold.

• This diagnostic may conclude in as few as

one test attempt. However, this diagnostic may

require as many as 18 test attempts, which would

require at least 3 drive cycles. Each test attempt

concludes within 1 minute.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

EngineControls-6.0LEngine

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• The catalyst test may abort due to a change in

the engine load. Do not change the engine

load, ensure the AC is OFF, the coolant fan is not

cycling, while a catalyst test is in progress.

• Driving the vehicle under the conditions outlined in

the Inspection/Maintenance (I/M) section can

verify whether the fault is present.

• These conditions may cause a catalytic converter

to degrade. Inspect for the following conditions:

− An engine misﬁre

− High engine oil or high coolant consumption

− Retarded spark timing

− A weak or poor spark

− A lean fuel mixture

− A rich fuel mixture

− A damaged oxygen sensor or wiring harness

− If an intermittent condition cannot be

duplicated, the information included in Freeze

Frame data can be useful in determining

the vehicle operating conditions when

the DTC was set.

• The catalyst may have been temporarily

contaminated with a chemical from a fuel additive,

fuel contamination, or any of the above conditions.

If the condition is determined to be intermittent, refer

Intermittent Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

5. A catalytic converter which has been discolored

may be due to an engine running rich, lean, or

had a previous misﬁre. Verifying the fuel trim

percentages may be of assistance in determining

if such a condition exists.

6. This steps inspects for conditions than can cause

the TWC efficiency to appear degraded.

DTC P0420 or P0430

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

ReviewtheDTCinformationontheTech 2 .

Are any other DTCs set? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

1. Start and idle the engine.

2. Allow the engine to reach operating temperature.

3. Increase the engine speed to 2,000 RPM for

2 minutes.

4. Ensure Closed Loop operation is enabled.

5. Return the engine to a stabilized idle.

6.ObservetheHO2S2voltageparameterontheTech 2

tool for the applicable bank.

Is the applicable HO2S 2 voltage parameter transitioning

below the ﬁrst speciﬁed value and above the

second speciﬁed value?

350 mV

600 mV

Go to

Step 5

Go to

Step 4

1.CleartheDTCswithaTech 2 .

2. Start the engine.

3. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did DTC P0420 or P0430 set?

—

Go to

Step 5

Go to

Diagnostic Aids

EngineEngineControls-6.0L

DTC P0420 or P0430 (cont’d)

Step Action Values Yes No

Important: Verify that the three-way catalytic

converter (TWC) is a high quality part that meets the OEM

speciﬁcations.

Visually and physically inspect the TWC for the following

conditions:

• Physical damage

• Severe discoloration caused by excessive

temperatures

• Internal rattles caused by loose catalyst substrate

• Restrictions—Refer to

Restricted Exhaust

in Engine

Exhaust.

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 6

Visually inspect the exhaust system for the following

conditions:

• Leaks—Refer to

Exhaust Leakage

in Engine Exhaust.

• Physical damage

• Loose or missing hardware

• The heated oxygen sensor (HO2S) 2 for the applicable

bank for proper torque

Did you ﬁnd and correct the condition?

—

Go to

Step 10

Go to

Step 7

Visually inspect the HO2S 2 at the applicable bank for the

following conditions:

• The pigtail and wiring harness contacting the exhaust

or any ground

• Road damage

Did you ﬁnd a condition?

—

Go to

Step 8

Go to

Step 9

Replace the applicable HO2S 2 sensor. Refer to

Heated

Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 2

Heated Oxygen Sensor (HO2S) Replacement Bank 2

Sensor 2

Did you complete the replacement?

—

Go to

Step 10

—

Notice:

SIO-ID = 11009 LMD = 24-sep-1996 In order to avoid

damaging the replacement three-way catalytic converter,

correct the engine misﬁre or mechanical fault before

replacing the three-way catalytic converter.

Replace the TWC. Refer to

Catalytic Converter

Replacement (Left)

Catalytic Converter Replacement

(Right)

in Engine Exhaust.

Did you complete the replacement?

—

Go to

Step 10

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

Caution: Refer to Road Test Caution in Cautions and

Notices.

Important: A new catalyst may fail this test due to

out-gassing of the internal matting. If this occurs, operate

the vehicle at highway speeds for approximately 1 hour and

retest the vehicle.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 11

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0442

System Description

This diagnostic tests the Evaporative Emission (EVAP)

System for a small leak when the key is turned OFF

and the correct conditions are met.

Heat is transferred into a vehicle fuel tank while the

vehicle is operating. When the vehicle is turned OFF, a

change in the fuel tank vapor temperature occurs,

which results in corresponding pressure changes in the

fuel tank vapor space. This change is monitored by

the control module using the fuel tank pressure sensor

input. The control module then makes a judgement

on the integrity of the system. With a 0.51 mm (0.02 in)

leak in the system, the amount of pressure change

observed is signiﬁcantly less than that of a sealed

system.

If the control module detects a pressure change less

than a calibrated amount, DTC P0442 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0442 Evaporative Emission (EVAP) System

Small Leak Detected

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0116, P0117, P0118,

P0125, P0335, P0336, P0443, P0446, P0449,

P0451, P0452, P0453, P0454, P0455, P0464,

P0496, P0500, P0502, P0503, P1683 are not set.

• The start up intake air temperature (IAT) is

between 4–30°C (39–86°F).

• The start up engine coolant temperature (ECT) is

less than 30°C (86°F).

• The start up IAT and ECT are within 8°C (15°F).

• The barometric pressure (BARO) is more than

74 kPa.

• The ambient air temperature (AAT) is between 2–

32°C (36–90°F).

• The engine run time minimum is 10 minutes.

• The odometer displays more than 10 miles.

• The vehicle has traveled more than 3 miles

this trip.

• The ECT is more than 70°C (158°F).

• The fuel level is between 15–85 percent.

• The ignition is OFF.

• DTC P0442 runs once per cold start with a

10-hour minimum between tests.

Conditions for Setting the DTC

The control module detects a pressure change that is

less than a calibrated amount.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• To help locate intermittent leaks, use the

J 41413-200

evaporative emissions system

tester (EEST) to introduce smoke into the EVAP

system. Move all EVAP components while

observing smoke with the

J 41413-SPT

High

Intensity White Light.

• A condition may exist where a leak in the EVAP

system only exists under a vacuum condition.

ByusingtheTech 2 PURGE/SEALfunctionto

create a vacuum, seal the system, and observe

the fuel tank pressure (FTP) parameter for vacuum

decay, this type of leak may be detected.

• To improve the visibility of the smoke exiting the

EVAP system, observe the suspected leak area

from different angles with the

J 41413-SPT

• For intermittent conditions, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

3. Introducing smoke in 15 second intervals may

allow smaller leak areas to be more noticeable.

When the system is less pressurized, the smoke

will sometimes escape in a more condensed

manner.

5. This step veriﬁes that repairs are complete and

that no other condition is present.

DTC P0442

Step Action Yes No

Schematic Reference:

Evaporative Emissions (EVAP) Hose Routing Diagram

EngineEngineControls-6.0L

DTC P0442 (cont’d)

Step Action Yes No

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Inspect the Evaporative Emission (EVAP) System for the

following conditions:

• Loose, missing, or damaged service port dust cap and/or

schrader valve

• Loose, incorrect, missing, or damaged fuel ﬁll cap

• A damaged EVAP canister purge solenoid valve

2. Raise the vehicle on a hoist. Refer to

Lifting and Jacking the

Vehicle

in General Information.

3. Inspect the EVAP system for the following conditions:

• Disconnected, improperly routed, kinked, or damaged

EVAP pipes and hose

• A damaged EVAP canister vent solenoid valve or EVAP

canister

Did you ﬁnd and correct the condition? Go to

Step 5

Go to

Step 3

Important: Ensure that the vehicle underbody temperature is

similar to the ambient temperature and allow the surrounding air to

stabilize before starting the diagnostic procedure. System ﬂow will

be less with higher temperatures.

1. Turn OFF the ignition.

2. Connect the

J 41413-200

Evaporative Emissions System

Tester (EEST) power supply clips to a known good 12-volt

source.

3. Install the

J 41415-40

Fuel Tank Cap Adapter or the

GE-41415-50

Interrupted Thread Fuel Tank Cap Adapter to

the fuel ﬁll pipe.

4. Connect the

J 41413-200

Nitrogen/Smoke Supply Hose to

the

J 41415-40

or the

GE-41415-50

5. Turn ON the ignition, with the engine OFF.

6. Command the EVAP canister vent solenoid valve closed with

aTech 2 .

7. Turn the nitrogen/smoke valve on the

J 41413-200

control

panel to SMOKE.

8. Use the remote switch to introduce smoke into the EVAP

system.

9. Use the

J 41413-VLV

EVAP Service Port Vent Fitting to open

the EVAP service port.

10. Remove the

J 41413-VLV

once smoke is observed.

11. Continue to introduce smoke into the EVAP system for an

additional 60 seconds.

12. Inspect the entire EVAP system for exiting smoke with the

J 41413-SPT

High Intensity White Light.

13. Continue to introduce smoke at 15 second intervals until the

leak source has been located.

Did you locate and repair a leak source? Go to

Step 5

Go to

Step 4

EngineControls-6.0LEngine

DTC P0442 (cont’d)

Step Action Yes No

1. Disconnect the

J 41415-40

or the

GE-41415-50

from the fuel

ﬁll pipe.

2. Install the fuel ﬁll cap to the fuel ﬁll pipe.

3. Connect the

J 41413-200

to the EVAP service port.

4. Use the remote switch to introduce smoke into the EVAP

system.

5. Inspect the entire EVAP system for exiting smoke with the

J 41413-SPT

6. Continue to introduce smoke at 15-second intervals until the

leak source has been located.

Did you locate and repair a leak source? Go to

Step 5

Go to Diagnostic Aids

Important: Larger volume fuel tanks and/or those with lower fuel

levels may require several minutes for the ﬂoating indicator to

stabilize.

1. Turn the nitrogen/smoke valve to nitrogen.

2. Connect the nitrogen/smoke hose to the 0.5 mm (0.20 in) test

oriﬁce on the bottom-front of the

J 41413-200

3. Use the remote switch to activate the

J 41413-200

4. Align the red ﬂag on the ﬂow meter with the ﬂoating indicator.

Use the remote switch to de-activate the

J 41413-200

5. Install the

J 41415-40

or the

GE-41415-50

to the fuel ﬁll pipe.

6. Remove the nitrogen/smoke hose from the test oriﬁce and

install the hose onto the

J 41415-40

or the

GE-41415-50

7. Turn ON the ignition, with the engine OFF.

8. Command the EVAP canister vent solenoid valve closed with

aTech 2 .

9. Use the remote switch to introduce nitrogen and ﬁll the EVAP

system until the ﬂoating stabilizes.

10. Compare the ﬂow meter’s stable ﬂoating indicator position to

the red ﬂag.

Is the ﬂoating indicator below the red ﬂag? Go to

Step 6

Go to

Step 2

ObservetheCaptureInfowithaTech 2 .

Have any DTCs not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0443

Circuit Description

An ignition voltage is supplied directly to the

evaporative emission (EVAP) canister purge solenoid

valve. The EVAP canister purge solenoid valve is

pulsewidthmodulated(PWM).TheTech 2 displays

the amount of ON time as a percentage. The

control module monitors the status of the driver. The

control module controls the EVAP canister purge

solenoid valve ON time by grounding the control circuit

via an internal switch called a driver. If the control

module detects an incorrect voltage for the

commanded state of the driver, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0443 Evaporative Emission (EVAP) Purge

Solenoid Control Circuit

Conditions for Running the DTC

• The engine speed is more than 400 RPM.

• The system voltage is between 6–18 volts.

• DTC P0443 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

• The control module detects that the commanded

state of the driver and the actual state of the

control circuit do not match.

• The above conditions are present for a minimum

of 5 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records. If

the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

2. This step tests if the concern is active. The EVAP

canister purge solenoid valve is PWM. A clicking

should be heard or felt when the EVAP canister

purge solenoid valve is commanded to 50 percent

and should stop when the EVAP canister purge

solenoid valve is commanded to 0 percent.

The rate at which the EVAP canister purge

solenoid valve cycles should increase as the

commanded state is increased and decrease as

the commanded state is decreased. Repeat

the commands as necessary.

5. This step tests if a ground is constantly being

applied to the EVAP canister purge solenoid valve.

6. This step veriﬁes that the control module is

providing ground to the EVAP canister purge

solenoid valve.

DTC P0443

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2. Command the evaporative emission (EVAP) canister purge

solenoid valve to 50 percent and then to 0 percent with a

Tech 2 .

Do you hear or feel a clicking from the EVAP canister purge solenoid

valve when it is commanded to 50 percent? Go to

Step 3

Go to

Step 4

EngineControls-6.0LEngine

DTC P0443 (cont’d)

Step Action Yes No

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Turn ON the ignition, with the engine OFF.

4. Operate the vehicle within the Conditions for Running the DTC.

You may also operate the vehicle within the conditions that you

observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the EVAP canister purge solenoid valve harness

connector.

3. Turn ON the ignition, with the engine OFF.

4. Probe the ignition 1 voltage circuit of the EVAP canister purge

solenoid valve with a test lamp that is connected to a good

ground.

Does the test lamp illuminate? Go to

Step 5

Go to

Step 11

1. Connect a test lamp between the control circuit of the EVAP

canister purge solenoid valve and the ignition 1 voltage circuit of

the EVAP canister purge solenoid valve.

2. Command the EVAP canister purge solenoid valve to 0 percent

withaTech 2 .

Does the test lamp illuminate? Go to

Step 8

Go to

Step 6

Command the EVAP canister purge solenoid valve to 50 percent with

aTech 2 .

Does the test lamp illuminate or pulse when the EVAP canister purge

solenoid valve is commanded to 50 percent? Go to

Step 9

Go to

Step 7

Test the control circuit of the EVAP canister purge solenoid valve for

an open or short to voltage. Refer to

Circuit Testing

and to

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 10

Test the control circuit of the EVAP canister purge solenoid valve for

a short to ground. Refer to

Circuit Testing

and to

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 13

Test for an intermittent and for a poor connection at the EVAP

canister purge solenoid valve. Refer to

Testing for Intermittent

Conditions and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 12

Test for an intermittent and for a poor connection at the control

module. Refer to

Testing for Intermittent Conditions and Poor

Connections

and to

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 13

Repair the open or short to ground in the ignition 1 voltage circuit.

Refer to

Wiring Repairs

in Wiring Systems. Replace the fuse if

necessary.

Did you complete the repair? Go to

Step 14

—

Replace the EVAP canister purge solenoid valve. Refer to

Evaporative Emission (EVAP) Canister Purge Solenoid Valve

Replacement

Did you complete the replacement? Go to

Step 14

—

Replace the engine control module (ECM). Refer to

Control Module

References

in Computer/Integrating Systems for replacement, setup,

and programming.

Did you complete the replacement? Go to

Step 14

—

EngineEngineControls-6.0L

DTC P0443 (cont’d)

Step Action Yes No

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the DTC.

You may also operate the vehicle within the conditions that you

observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 15

ObservetheCaptureInfowithaTech 2 .

Have any DTCs not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0446

System Description

This DTC tests the Evaporative Emission (EVAP)

System for a restricted or blocked EVAP canister vent

path. The control module commands the EVAP

canister purge solenoid valve Open and the EVAP

canister vent solenoid valve Closed. This allows

vacuum to be applied to the EVAP system. Once a

calibrated vacuum level has been reached, the control

module commands the EVAP canister purge solenoid

valve Closed and the EVAP canister vent solenoid

valve Open. The control module monitors the fuel tank

pressure (FTP) sensor for a decrease in vacuum. If

the vacuum does not decrease to near 0 inches H2O

in a calibrated time, this DTC sets.

The following table illustrates the relationship between

the ON and OFF states, and the Open or Closed

states of the EVAP canister purge and vent solenoid

valves.

Control Module

Command

EVAP Canister

Purge Solenoid

Valve

EVAP Canister

Vent Solenoid

Valve

ON Open Closed

OFF Closed Open

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0446 Evaporative Emission (EVAP) Vent

System Performance

Conditions for Running the DTC

• DTCs P0107, P0108, P0112, P0113, P0116,

P0117, P0118, P0125, P0442, P0443, P0449,

P0451, P0452, P0453, P0454, P0455, P0464,

P0502, P0503, P1112, P1114, P1115, P1120,

P1133, P1134, P1153, P1154, P1220, P1221 are

not set.

• The ignition voltage is between 10–18 volts.

• The barometric pressure (BARO) is more than

75 kPa.

• The fuel level is between 15–85 percent.

• The engine coolant temperature (ECT) is between

4–30°C (39–86°F).

• The intake air temperature (IAT) is between 4–

30°C (39–86°F).

• The startup ECT and IAT are within 9°C (16°F) of

each other.

• DTC P0446 runs once per cold start when the

above conditions are met.

Conditions for Setting the DTC

• The FTP sensor is less than −12 inches H2O.

• The condition is present for more than 5 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2

Diagnostic Aids

• An intermittent condition could be caused by a

damaged EVAP vent housing, a temporary

blockage at the EVAP canister vent solenoid valve

inlet, or a pinched vent hose. A blockage in the

Vent System will also cause a poor fuel ﬁll

problem.

• For intermittent conditions, refer to

Intermittent

Conditions

DTC P0446

Step Action Values Yes No

Schematic Reference:

Evaporative Emissions (EVAP) Hose Routing Diagram

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineEngineControls-6.0L

DTC P0446 (cont’d)

Step Action Values Yes No

Inspect the Evaporative Emission (EVAP) System for the

following conditions:

• A damaged EVAP canister vent solenoid valve—Refer

Evaporative Emission (EVAP) Canister Vent

Solenoid Valve Replacement

• A pinched EVAP canister vent hose

• A damaged EVAP canister—Refer to

Evaporative

Emission (EVAP) Canister Replacement

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 3

1. Turn OFF the ignition.

2. Disconnect the purge line from the EVAP canister

vent solenoid valve. Refer to

Evaporative

Emission (EVAP) Canister Purge Solenoid Valve

Replacement

3. Turn ON the ignition, with the engine OFF.

Is the fuel tank pressure sensor parameter within the

speciﬁed range?

−1to

+1 in H2O

Go to

Step 4

Go to

Step 9

Important: DO NOT exceed the speciﬁed value in this

step. Exceeding the speciﬁed value may produce incorrect

test results.

1. Turn OFF the ignition.

2. Connect the EVAP canister purge pipe.

3. Connect the

J 41413-200

Evaporative Emissions

System Tester (EEST) power supply clips to a known

good 12-volt source.

4. Install the

J 41415-40

Fuel Tank Cap Adapter or

GE-41415-50

Interrupted Thread Fuel Tank Cap

Adapter to the fuel ﬁll pipe.

5. Connect the fuel ﬁll cap to the

J 41415-40

GE-41415-50

6. Connect the

J 41413-200

Nitrogen/Smoke Supply

Hose to the

J 41415-40

GE-41415-50

7. Turn ON the ignition, with the engine OFF.

8. Command the EVAP canister vent solenoid valve

closedwithaTech 2 .

9. Turn the nitrogen/smoke valve on the

J 41413-200

control panel to NITROGEN.

10. Use the remote switch to pressurize the EVAP system

to the ﬁrst speciﬁed value.

11. Observe the fuel tank pressure sensor in H2O with a

Tech 2 .

12. Command the EVAP canister vent solenoid valve

openwithaTech 2 .

Is the fuel tank pressure sensor parameter less than the

second speciﬁed value?

5inH2O

1inH2O

Go to

Step 5

Go to

Step 7

EngineControls-6.0LEngine

DTC P0446 (cont’d)

Step Action Values Yes No

1. Connect the nitrogen/smoke hose to the EVAP

service port.

2. Remove the

J 41415-40

GE-41415-50

3. Install the fuel ﬁll cap to the fuel ﬁll pipe.

4. Start the engine.

5. Allow the engine to idle.

6. Use the purge/seal function to seal the system with a

Tech 2 .

7. Command the EVAP canister purge solenoid valve to

30 percent.

8. Observe the vacuum/pressure gage of the

J41413-200

andtheFTPparameterontheTech 2 .

9. Allow the vacuum to increase on the gage of the

J 41413-200

, until it reaches approximately

16 inch H2O.

10. Use the purge/seal function to seal the system, with a

Tech 2 .

IstheFTPparameteronaTech 2 withinthespeciﬁed

value of the vacuum/pressure gage on the

J 41413-200

untilthevacuumreachedtheabortlimitonaTech 2 ?

1inH2O

Go to

Step 6

Go to

Step 9

6DidtheFTPparameteronaTech 2 displaymorethan

the speciﬁed value? 3.2 V Go to

Diagnostic Aids Go to

Step 9

Disconnect the EVAP vent hose from the EVAP canister

vent solenoid valve.

Is the fuel tank pressure sensor parameter less than the

speciﬁed value?

1inH2O

Go to

Step 13

Go to

Step 8

Disconnect the EVAP canister vent hose from the EVAP

canister.

Is the fuel tank pressure sensor parameter less than the

speciﬁed value?

1inH2O

Go to

Step 11

Go to

Step 14

Test the low reference circuit of the fuel tank

pressure (FTP) sensor for an open or high resistance.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 10

Test for poor connections at the harness connector of the

FTP sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

11 Repair the pinched or restricted EVAP canister vent hose.

Did you complete the repair? —Go to

Step 15

—

12 Replace the FTP sensor. Refer to

Fuel Tank Pressure

Sensor Replacement

Did you complete the replacement? —Go to

Step 15

—

Replace the EVAP canister vent solenoid valve. Refer to

Evaporative Emission (EVAP) Canister Vent Solenoid Valve

Replacement

Did you complete the replacement?

—

Go to

Step 15

—

14 Replace the EVAP canister. Refer to

Evaporative

Emission (EVAP) Canister Replacement

Did you complete the replacement? —Go to

Step 15

—

EngineEngineControls-6.0L

DTC P0446 (cont’d)

Step Action Values Yes No

1. Turn OFF the ignition.

2. Disconnect the purge line from the EVAP canister

purge solenoid valve. Refer to

Evaporative

Emission (EVAP) Canister Purge Solenoid Valve

Replacement

3. Turn ON the ignition, with the engine OFF.

Is the fuel tank pressure sensor parameter within the

speciﬁed range?

−1to

+1 in H2O

Go to

Step 16

Go to

Step 2

Important: DO NOT exceed the speciﬁed value in this

step. Exceeding the speciﬁed value may produce incorrect

test results.

1. Turn OFF the ignition.

2. Reconnect all disconnected components.

3. Connect the

J 41413-200

to the fuel ﬁll pipe.

4. Turn ON the ignition, with the engine OFF

5. Command the EVAP canister vent solenoid valve

closedwithaTech 2

6. Turn the nitrogen/smoke valve on the

J 41413-200

control panel to NITROGEN.

7. Use the remote switch to pressurize the EVAP system

to the ﬁrst speciﬁed value.

8.ObservetheFTPsensorinH2OwithaTech 2 .

9. Command the EVAP canister vent solenoid valve

openwithaTech 2 .

Is the fuel tank pressure sensor parameter less than the

second speciﬁed value?

5inH2O

1inH2O

Go to

Step 17

Go to

Step 2

ObservetheCaptureInfowithaTech 2

Have any DTCs not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0449

Circuit Description

An ignition voltage is supplied to the evaporative

emission (EVAP) canister vent solenoid valve. The

control module grounds the EVAP canister vent

solenoid valve control circuit to close the valve by

meansofaninternalswitchcalledadriver.TheTech 2

tool displays the commanded state of the EVAP

canister vent solenoid valve as ON or OFF. The control

module monitors the status of the driver. If the

control module detects an incorrect voltage for the

commanded state of the driver, this DTC sets.

The following table illustrates the relationship between

the ON and OFF states, and the OPEN or CLOSED

states of the EVAP canister vent solenoid valve.

Control Module

Command EVAP Canister Vent Valve

Position

ON CLOSED

OFF OPEN

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0449 Evaporative Emission (EVAP) Vent

Solenoid Control Circuit

Conditions for Running the DTC

• The engine speed is more than 400 RPM.

• The system voltage is between 6–18 volts.

• DTC P0449 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

• The control module detects that the commanded

state of the driver and the actual state of the

control circuit do not match.

• The above conditions are present for a minimum

of 5 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

2. A click should be heard or felt when the EVAP

canister vent solenoid valve operates. Be sure

that both the ON and the OFF states are

commanded. Repeat the commands as necessary.

5. This step veriﬁes that the control module is

providing ground to the EVAP canister vent

solenoid valve.

6. This step tests if the EVAP canister vent solenoid

valve control circuit is grounded.

DTC P0449

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector End

Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2. Command the evaporative emission (EVAP) canister vent

solenoidvalveONandOFFwithaTech 2 .

Do you hear or feel a click from the EVAP canister vent solenoid valve

when it is commanded ON and OFF? Go to

Step 3

Go to

Step 4

EngineEngineControls-6.0L

DTC P0449 (cont’d)

Step Action Yes No

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Turn ON the ignition, with the engine OFF.

4. Operate the vehicle within the Conditions for Running the DTC.

You may also operate the vehicle within the conditions that you

observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the EVAP canister vent solenoid valve.

3. Turn ON the ignition, with the engine OFF.

4. Probe the ignition 1 voltage circuit of the EVAP canister vent

solenoid valve with a test lamp that is connected to a good

ground. Refer to

Troubleshooting with a Test Lamp

in Wiring

Systems.

Does the test lamp illuminate? Go to

Step 5

Go to

Step 11

1. Connect a test lamp between the control circuit of the EVAP

canister vent solenoid valve and the ignition 1 voltage circuit of

the EVAP canister vent solenoid valve. Refer to

Troubleshooting

with a Test Lamp

in Wiring Systems.

2. Command the EVAP canister vent solenoid valve ON and OFF

withaTech 2 .

Does the test lamp turn ON or OFF with each command? Go to

Step 9

Go to

Step 6

Does the test lamp remain illuminated with each command? Go to

Step 8

Go to

Step 7

7Test the control circuit for a short to voltage or an open. Refer to

Circuit Testing

and to

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 10

8Test the control circuit for a short to ground. Refer to

Testing for Short

to Ground

and to

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 10

Test for an intermittent and for a poor connection at the EVAP

canister vent solenoid valve. Refer to

Testing for Intermittent

Conditions and Poor Connections

and to

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 12

Test for an intermittent and for a poor connection at the control

module. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 14

Go to

Step 13

1. Repair the open or short to ground in the ignition 1 voltage

circuit. Refer to

Circuit Testing

and to

Wiring Repairs

in Wiring

Systems.

2. Replace the fuse if necessary.

Did you complete the repair? Go to

Step 14

—

12 Replace the EVAP canister vent solenoid valve. Refer to

Evaporative

Emission (EVAP) Canister Vent Solenoid Valve Replacement

Did you complete the replacement? Go to

Step 14

—

Replace the engine control module (ECM). Refer to

Control Module

References

in Computer/Integrating Systems for replacement, setup,

and programming.

Did you complete the replacement? Go to

Step 14

—

EngineControls-6.0LEngine

DTC P0449 (cont’d)

Step Action Yes No

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the DTC.

You may also operate the vehicle within the conditions that you

observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 15

ObservetheCaptureInfowithaTech 2 .

Have any DTCs not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0451

System Description

The fuel tank pressure (FTP) sensor measures air

pressure or vacuum in the evaporative

emission (EVAP) system. The control module supplies

a 5-volt reference and a low reference circuit to the

FTP sensor. The FTP sensor signal voltage varies,

depending on EVAP system pressure or vacuum. The

controller uses this FTP signal to determine

atmospheric pressure for use in the engine-off small

leak test, P0442. Before using this signal as an

atmospheric reference, it must ﬁrst be re-zeroed. If the

FTP signal is out of range during the re-zero

procedure, this DTC will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0451 Fuel Tank Pressure (FTP) Sensor

Performance

Conditions for Running the DTC

• DTC P0451 runs only when the engine-off natural

vacuum small leak test, P0442, executes.

• The number of times this test runs can range from

0–2 per engine-off period. The length of the test

can be up to 40 minutes.

Conditions for Setting the DTC

This DTC will set if the controller is unable to re-zero

the FTP sensor voltage within a calibrated range

during the engine-off small leak test, P0442.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandDTCwithaTech 2 .

Diagnostic Aids

• A restriction in the EVAP canister or vent lines

could prevent fuel vapor pressure from bleeding

off fast enough. If the vent system cannot bleed off

pressure fast enough, this code can set. When

pressure is applied to the system and released, a

properly operating system will return to the

atmosphericpressurerapidly.ByusingaTech 2

tool and the

J 41413-200

Evaporative Emission

System Tester (EEST), pressure can be applied to

the system, then released, while monitoring the

FTP sensor parameter to see that pressure can be

released quickly, within 30 seconds.

• An FTP sensor that is skewed or does not have a

linear transition from low to high may cause this

codetoset.ATech 2 outputcontrols,snapshot,

and plot functions can help detect erratic sensor

response. To test the sensor signal under vacuum

conditions, use the Quick Snapshot and the

Purge/Seal functions to capture data while

commanding purge to 20 percent, then plot the

data to look for erratic sensor operation. A similar

test can be done for the pressure side of the

sensor operation by applying pressure with the

J 41413-200

while taking a snapshot.

• A full fuel tank may cause misdiagnosis.

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

4. This step tests for the signal voltage that

represents atmospheric pressure. Removing the

fuel ﬁll cap ensures a vented EVAP system.

Record the value for possible use later in

the diagnostic table.

7. This step tests the accuracy of the FTP sensor by

comparing the electrical signal value to the EEST

mechanical gage value.

8. A restricted EVAP system will not allow the

nitrogen to ﬂow freely through the system.

A restriction will cause the FTP signal voltage

parameter to decrease as the pressure builds.

DTC P0451

Step Action Values Yes No

Schematic Reference:

Evaporative Emissions (EVAP) Hose Routing Diagram

and

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

EngineControls-6.0LEngine

DTC P0451 (cont’d)

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Is DTC P0446, P0452, P0453, or P0651 also set?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

Inspect the evaporative emission (EVAP) system for the

following conditions:

• A damaged EVAP canister vent solenoid valve—Refer

Evaporative Emission (EVAP) Canister Vent

Solenoid Valve Replacement

• A pinched EVAP hose

• A damaged EVAP canister—Refer to

Evaporative

Emission (EVAP) Canister Replacement

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 4

1. Remove the fuel ﬁll cap.

2. Turn ON the ignition, with the engine OFF.

3. Observe and record the fuel tank pressure (FTP)

parameterinvoltswithaTech 2 .

Is the fuel tank pressure sensor parameter within the

speciﬁed amount?

1.3–1.7 V

Go to

Step 5

Go to

Step 14

Important: Ensure that the vehicle underbody temperature

is similar to the ambient temperature.

1. Turn OFF the ignition.

2. Install the fuel ﬁll cap.

3. Connect the

J 41413-200

Evaporative Emission

System Tester (EEST) power supply clips to a known

good 12-volt source.

4. Install the

J 41415-40

Fuel Tank Cap Adapter or the

GE-41415-50

Fuel Cap Adapter to the fuel ﬁll pipe.

5. Connect the

J 41413-200

NITROGEN/SMOKE supply

hose to the

J 41415-40

or the

GE-41415-50

to the fuel

ﬁll pipe.

6. Turn the ignition ON, with the engine OFF.

7. Turn the NITROGEN/SMOKE valve on the

J 41413-200

to NITROGEN.

8.UsingaTech 2 PURGE/SEALfunction,sealthe

EVAP system.

9. Observe the fuel tank pressure sensor in H2O using a

Tech 2 tool.

10. Use a remote switch to pressurize the EVAP system

to the ﬁrst speciﬁed value.

11. Allow at least 30 seconds for pressure in the EVAP

system to stabilize. Compare the fuel tank

pressure (FTP) parameter in H2O to the

J 41413-200

VACUUM/PRESSURE gage.

IsthedifferencebetweentheFTPparameteronaTech 2

and the VACUUM/PRESSURE gage on the

J 41413-200

within the speciﬁed value?

5inH2O

1inH2O

Go to

Step 6

Go to

Step 14

Release the pressure on the EVAP system with the

Tech 2 .

IsthedifferencebetweentheFTPparameterontheTech 2

tool and the VACUUM/PRESSURE gage on the

J 41413-200

within the speciﬁed value?

1inH2O

Go to

Step 7

Go to

Step 14

EngineEngineControls-6.0L

DTC P0451 (cont’d)

Step Action Values Yes No

1. Start the engine.

2. Allow the engine to idle.

Important: Using more than 20 percent purge can cause a

misdiagnosis.

3.UsethePURGE/SEALfunctionofaTech 2 to

command 20 percent purge.

4. Observe the VACUUM/PRESSURE gage on the

J 41413-200

and the fuel tank pressure parameter on

theTech 2 .Allowthevacuumtoincreasetothe

ﬁrst speciﬁed value.

IsthedifferencebetweentheFTPparameterontheTech 2

tool and the VACUUM/PRESSURE gage on the

J 41413-200

within the second speciﬁed value?

5inH2O

1inH2O

Go to

Step 8

Go to

Step 14

1. Turn ON the ignition, with the engine OFF.

2. Turn the NITROGEN/SMOKE valve on the

J 41413-200

to NITROGEN.

3.ObservetheFTPsensorinvoltsusingaTech 2 .

4. Pressurize the EVAP system with the remote switch.

5. Allow enough time for pressure to stabilize.

Is the difference between the observed FTP sensor voltage

and the voltage recorded in Step 4 more than the

speciﬁed value?

0.2 V

Go to

Step 9

System OK

1. Disconnect the EVAP vent hose from the EVAP

canister vent solenoid valve with pressure still applied

from the

J 41413-200

. Refer to

Emission Hose

Routing Diagram

2.ObservetheFTPsensorinvoltsusingaTech 2 .

Is the difference between the observed FTP sensor voltage

and the voltage recorded in Step 4 more than the

speciﬁed value?

0.2 V

Go to

Step 10

Go to

Step 11

1. Disconnect the EVAP vapor pipe from the EVAP

canister with pressure still applied from the

J 41413-200

. Refer to

Emission Hose Routing

Diagram

2.ObservetheFTPsensorinvoltsusingaTech 2 .

Is the difference between the observed FTP sensor voltage

and the voltage recorded in Step 4 more than the

speciﬁed value?

0.2 V

Go to

Step 13

Go to

Step 12

Repair or replace the EVAP canister vent solenoid. Refer

Evaporative Emission (EVAP) Canister Vent Solenoid

Valve Replacement

Did you complete the action?

—

Go to

Step 17

—

12 Replace the EVAP canister. Refer to

Evaporative

Emission (EVAP) Canister Replacement

Did you complete the replacement? —Go to

Step 17

—

Repair or replace the pinched or restricted EVAP vapor

pipe. Refer to

Evaporative Emissions (EVAP) Hose Routing

Diagram

Did you complete the action?

—

Go to

Step 17

—

Test for an intermittent and for a poor connection at the

FTP sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 15

Test the low reference circuit of the FTP sensor for an

open or high resistance. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 17

Go to

Step 16

EngineControls-6.0LEngine

DTC P0451 (cont’d)

Step Action Values Yes No

16 Replace the FTP sensor. Refer to

Fuel Tank Pressure

Sensor Replacement

Did you complete the replacement? —Go to

Step 17

—

1. Reconnect all components and release any pressure

or vacuum applied to the EVAP system.

2. Turn ON the ignition, with the engine OFF.

3. Observe and record the fuel tank pressure (FTP)

parameterinH2OwithaTech 2 .

Is the fuel tank pressure sensor parameter within the

speciﬁed amount?

−1to

+1 in H2O

Go to

Step 18

Go to

Step 2

1. Turn ON the ignition, with the engine OFF.

2. Command the EVAP canister vent solenoid closed

withaTech 2 .

3. Turn the NITROGEN/SMOKE valve on the

J 41413-200

to NITROGEN.

4. Pressurize the EVAP system to the ﬁrst speciﬁed

value with the remote switch.

5. Observe the fuel pressure sensor in H2O using a

Tech 2

6. Command the EVAP canister vent solenoid valve

openwithaTech 2 .

Is the fuel tank pressure sensor parameter less than the

second speciﬁed value?

5inH2O

1inH2O

Go to

Step 19

Go to

Step 4

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 20

Important: The malfunction indicator lamp (MIL) may

remain ON after the repair unless the DTCs are cleared.

CleartheDTCswithaTech 2 .

Did you complete the action?

—

System OK

—

EngineEngineControls-6.0L

DTC P0452

Circuit Description

The fuel tank pressure (FTP) sensor measures the

difference between the air pressure or vacuum in the

evaporative emission (EVAP) system, and the

outside air pressure. The control module supplies a

5-volt reference and a low reference circuit to the FTP

sensor. The FTP sensor signal circuit voltage varies

depending on EVAP system pressure or vacuum. If the

FTP sensor signal voltage goes below a calibrated

value, this DTC sets.

The following table illustrates the relationship between

the FTP sensor signal voltage and the EVAP system

pressure/vacuum.

FTP Sensor Signal

Voltage Fuel Tank Pressure

High, Approximately 1.5

Volts or More Negative Pressure/Vacuum

Low, Approximately 1.5

Volts or Less Positive Pressure

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0452 Fuel Tank Pressure (FTP) Sensor

Circuit Low Voltage

Conditions for Running the DTC

• The ignition is ON.

• DTC P0452 runs continuously once the above

condition is met.

Conditions for Setting the DTC

• The FTP sensor voltage is less than 0.1 volts.

• All conditions present for more than 5 seconds

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

5. Tests for the proper operation of the circuit in the

high voltage range.

DTC P0452

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Idle the engine for 1 minute.

2. Monitor the diagnostic trouble codes (DTC)

informationusingtheTech 2 .

Did DTC P1639 fail this ignition?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

Observe the Fuel Tank Pressure sensor parameter with a

Tech 2 .

Is the Fuel Tank Pressure sensor parameter less than the

speciﬁed value?

0.1 V

Go to

Step 5

Go to

Step 4

EngineControls-6.0LEngine

DTC P0452 (cont’d)

Step Action Value(s) Yes No

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Turn ON the ignition, with the engine OFF.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the fuel tank pressure (FTP) sensor

harness connector.

3. Connect a 3-amp fused jumper wire between the

5-volt reference circuit of the FTP sensor and the

signal circuit of the FTP sensor.

4. Turn ON the ignition, with the engine OFF.

5.ObservetheFTPvoltagewithaTech 2

Is the Fuel Tank Pressure sensor parameter within the

speciﬁed value?

4.9–5.1 V

Go to

Step 8

Go to

Step 6

Test the 5-volt reference circuit for an open circuit or high

resistance. Refer to

Circuit Testing

and to

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 7

Test the signal circuit for the following conditions:

• A short to ground

• An open

• High resistance

Refer to

Circuit Testing

and to

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 9

Test for an intermittent and for a poor connection at the

FTP sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and to

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 10

Test for an intermittent and for a poor connection at the

control module. Refer to

Testing for Intermittent Conditions

and Poor Connections

and to

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 11

10 Replace the FTP sensor. Refer to

Fuel Tank Pressure

Sensor Replacement

Did you complete the replacement? —Go to

Step 12

—

Replace the engine control module (ECM). Refer to

Control

Module References

in Computer/Integrating Systems for

replacement, setup, and programming.

Did you complete the replacement?

—

Go to

Step 12

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 13

EngineEngineControls-6.0L

DTC P0452 (cont’d)

Step Action Value(s) Yes No

ObservetheCaptureInfowithaTech 2 .

Have any DTCs not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0453

Circuit Description

The fuel tank pressure (FTP) sensor measures the

difference between the air pressure or vacuum in the

evaporative emission (EVAP) system, and the

outside air pressure. The control module supplies a

5-volt reference and a low reference circuit to the FTP

sensor. The FTP sensor signal circuit voltage varies

depending on EVAP system pressure or vacuum. If the

FTP sensor signal voltage increases above a

calibrated value, this DTC sets.

The following table illustrates the relationship between

FTP sensor signal voltage and the EVAP system

pressure/vacuum.

FTP Sensor Signal

Voltage Fuel Tank Pressure

High, Approximately

1.5 Volts or More Negative Pressure/Vacuum

Low, Approximately

1.5 Volts or Less Positive Pressure

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0453 Fuel Tank Pressure (FTP) Sensor

Circuit High Voltage

Conditions for Running the DTC

• The ignition is ON.

• DTC P0453 runs continuously once the above

condition is met.

Conditions for Setting the DTC

• The FTP sensor voltage is more than 4.9 volts.

• All conditions present for more than 5 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. If DTC P1639 is set, the 5-volt reference circuit

may be shorted to a voltage.

DTC P0453

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector End

Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Idle the engine for 1 minute.

2. Monitor the Diagnostic Trouble Code (DTC)

InformationusingtheTech 2 .

Did DTC P1639 fail this ignition?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

1. Turn ON the ignition, with the engine OFF.

2. Observe the Fuel Tank Pressure sensor parameter

withaTech 2 .

Is the Fuel Tank Pressure sensor parameter more than the

speciﬁed value?

4.3 V

Go to

Step 5

Go to

Step 4

EngineEngineControls-6.0L

DTC P0453 (cont’d)

Step Action Values Yes No

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Turn ON the ignition, with the engine OFF.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the fuel tank pressure (FTP) sensor

harness connector.

3. Turn ON the ignition, with the engine OFF.

4. Observe the Fuel Tank Pressure sensor parameter

withaTech 2 .

DoestheTech 2 indicatethattheFTPsensorvoltageis

more than the speciﬁed value?

4.3 V

Go to

Step 6

Go to

Step 7

Test the signal circuit for a short to voltage. Refer to

Testing for Short to Ground

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 10

Probe the low reference circuit of the FTP sensor with a

test lamp that is connected to battery voltage. Refer to

Troubleshooting with a Test Lamp

in Wiring Systems.

Did the test lamp illuminate?

—

Go to

Step 9

Go to

Step 8

8Test the low reference circuit for an open. Refer to

Testing

for Continuity

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? —Go to

Step 13

Go to

Step 10

Test for an intermittent and for a poor connection at the

FTP sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 11

Test for an intermittent and for a poor connection at the

control module. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 12

11 Replace the FTP sensor. Refer to

Fuel Tank Pressure

Sensor Replacement

Did you complete the replacement? —Go to

Step 13

—

Replace the engine control module (ECM). Refer to

Control

Module References

in Computer/Integrating Systems for

replacement, setup, and programming.

Did you complete the replacement?

—

Go to

Step 13

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 14

EngineControls-6.0LEngine

DTC P0453 (cont’d)

Step Action Values Yes No

ObservetheCaptureInfowithaTech 2 .

Have any DTCs not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0454

System Description

The fuel tank pressure (FTP) sensor measures air

pressure or vacuum in the evaporative

emission (EVAP) system. The control module supplies

a 5-volt reference and a low reference circuit to the

FTP sensor. The FTP sensor signal voltage varies

depending on EVAP system pressure or vacuum. The

controller uses this FTP signal to determine

atmospheric pressure for use in the engine OFF small

leak test, DTC P0442. This DTC will set if the

control module detects an intermittent signal from the

FTP that would prevent the engine-off small leak

test, DTC P0442, from running.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0454 Fuel Tank Pressure (FTP) Sensor

Circuit Intermittent

Conditions for Running the DTC

• DTC P0454 runs only when the engine-off natural

vacuum small leak test, DTC P0442, executes.

• This test can run once per engine-off period. The

length of the test can be up to 40 minutes.

Conditions for Setting the DTC

If, during the engine-off natural vacuum small leak

test, DTC P0442, the powertrain control module (PCM)

detects an abrupt FTP signal change, other than a

refueling event, this DTC will set.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandDTCwithaTech 2 .

Diagnostic Aids

Tech 2 outputcontrols,snapshot,andplotfunctions

can help detect erratic sensor response. To look at

the sensor signal under vacuum conditions, use

snapshot and the purge/seal function to capture data

while commanding purge to 20 percent, then plot

the data to look for non-linear sensor operation.

A similar inspection can be done for the pressure side

of the sensor range by applying pressure with the

J 41413-200

Evaporative Emissions System

Tester (EEST) while taking a snapshot. DO NOT

exceed 5 inches H2O when applying pressure.

Test Description

The number below refers to the step number on the

diagnostic table.

3. Sealing the system will allow normal pressure in

the EVAP system to preload the sensor. This

will help put the sensor in a range that is more

sensitive, making the test more accurate.

DTC P0454

Step Action Yes No

Schematic Reference:

Evaporative Emissions (EVAP) Hose Routing Diagram

and

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

Are DTCs P0442, P0446, P0452, P0453, or P0651 also set? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

Step 3

Inspect for an intermittent and for a poor connection at the fuel

tank pressure (FTP) sensor. Refer to

Testing for Intermittent

Conditions and Poor Connections

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 5

Go to

Step 4

EngineControls-6.0LEngine

DTC P0454 (cont’d)

Step Action Yes No

4Replace the FTP sensor. Refer to

Fuel Tank Pressure Sensor

Replacement

Did you complete the replacement? Go to

Step 5

—

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0455

System Description

The control module tests the Evaporative

Emission (EVAP) System for a large leak. The control

module monitors the fuel tank pressure (FTP)

sensor signal to determine the EVAP system vacuum

level. When the conditions for running are met, the

control module commands the EVAP canister

purge solenoid valve OPEN and the EVAP canister

vent solenoid valve CLOSED. This allows engine

vacuum to enter the EVAP system. At a calibrated

time, or vacuum level, the control module commands

the EVAP canister purge solenoid valve closed,

sealing the system, and monitors the FTP sensor input

in order to determine the EVAP system vacuum

level. If the system is unable to achieve the calibrated

vacuum level, or the vacuum level decreases too

rapidly, this DTC sets.

The following table illustrates the relationship between

the ON and OFF states, and the OPEN or CLOSED

states of the EVAP canister purge and vent solenoid

valves.

Control Module

Command

EVAP Canister

Purge Solenoid

Valve

EVAP Canister

Vent Solenoid

Valve

ON Open Closed

OFF Closed Open

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0455 Evaporative Emission (EVAP) System

Large Leak Detected

Conditions for Running the DTC

• Before the PCM can report DTC P0455 failed,

DTC P0496 must run and pass.

• DTCs P0107, P0108, P0112, P0113, P0116,

P0117, P0118, P0125, P0442, P0443, P0449,

P0451, P0452, P0453, P0454, P0464, P1112,

P1114, P1115, P1120, P1133, P1134, P1153,

P1154, P1220, P1221 are not set.

• The engine is running.

• The ignition voltage is between 10–18 volts.

• The barometric pressure (BARO) is more than

75 kPa.

• The fuel level is between 15–85 percent.

• The engine coolant temperature (ECT) is between

4–30°C (39–86°F).

• The intake air temperature (IAT) is between 4–

30°C (39–86°F).

• The start-up ECT and IAT are within 9°C (16°F) of

each other.

• The vehicle speed sensor (VSS) is less than

121 km/h (75 mph).

• DTC P0455 runs once per cold start.

Conditions For Setting the DTC

The EVAP system is not able to achieve or maintain

vacuum during the diagnostic test.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• To help locate intermittent leaks, use the

J 41413-200

Evaporative Emissions System

Tester (EEST) to introduce smoke into the EVAP

system. Move all EVAP components while

observing smoke with the

J 41413-SPT

High

Intensity White Light. Introducing smoke in 15

second intervals will allow less pressure into

the EVAP System. When the system is less

pressurized, the smoke will sometimes escape in

a more condensed manner.

• A temporary blockage in the EVAP canister purge

solenoid valve, purge pipe or EVAP canister

could cause an intermittent condition. Inspect and

repair any restriction in the EVAP system.

• To improve the visibility of the smoke exiting the

EVAP System, observe the suspected leak

area from different angles with the

J 41413-SPT

• Reviewing the Failure Records vehicle mileage

since the diagnostic test last failed may help

determine how often the condition that caused the

DTC to be set occurs. This may assist in

diagnosing the condition.

• A condition may exist where a leak in the EVAP

System only exists under a vacuum condition.

ByusingtheTech 2 PURGE/SEALfunctionto

EngineControls-6.0LEngine

create a vacuum, seal the system and observe

the FTP parameter for vacuum decay, this type of

leak may be detected.

• For intermittent conditions, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

6. This step veriﬁes proper operation of the FTP

sensor.

7. A normal operating FTP sensor should increase

above 5 inches of H2O and stop between

6 inches of H2O and 7 inches of H2O.

DTC P0455

Step Action Values Yes No

Schematic Reference:

Evaporative Emissions (EVAP) Hose Routing Diagram

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Inspect the Evaporative Emission (EVAP) System for

the following conditions:

• A loose, missing, or damaged service port

schrader valve

• A loose, incorrect, missing, or damaged fuel ﬁll cap

• A damaged EVAP canister purge solenoid valve

2. Raise the vehicle on a hoist. Refer to

Lifting and

Jacking the Vehicle

in General Information.

3. Inspect the EVAP System for the following conditions:

• Any disconnected, improperly routed, kinked, or

damaged EVAP pipes and hoses

• A damaged EVAP canister vent solenoid valve or

EVAP canister

Did you ﬁnd and correct the condition?

—

Go to

Step 21

Go to

Step 3

EngineEngineControls-6.0L

DTC P0455 (cont’d)

Step Action Values Yes No

Important: Larger volume fuel tanks and/or those with

lower fuel levels may require several minutes for the

ﬂoating indicator to stabilize.

1. Turn OFF the ignition.

2. Connect the

J 41413-200

Evaporative Emissions

System Tester (EEST) power supply clips to a known

good 12-volt source.

3. Turn the nitrogen/smoke valve to nitrogen.

4. Connect the nitrogen/smoke hose to the 0.5 mm

(0.20 in) test oriﬁce on the bottom-front of the

J 41413-200

5. Use the remote switch to activate the

J 41413-200

6. Align the red ﬂag on the ﬂow meter with the ﬂoating

indicator. Use the remote switch to de-activate the

J 41413-200

7. Install the

J 41415-40

Fuel Tank Cap Adapter or

GE-41415-50

Interrupted Thread Fuel Tank Cap

Adapter to the fuel ﬁll pipe.

8. Install the fuel ﬁll cap to the

J 41415-40

GE-41415-50

9. Remove the nitrogen/smoke hose from the test oriﬁce

and install the hose onto the

J 41415-40

GE-41415-50

10. Turn ON the ignition, with the engine OFF.

11. Command the EVAP canister vent solenoid valve

closedwithaTech 2 .

12. Use the remote switch to induce nitrogen and ﬁll the

EVAP System until the ﬂoating indicator stabilizes.

13. Compare the ﬂow meter’s stable ﬂoating indicator

position to the red ﬂag.

Is the ﬂoating indicator below the red ﬂag?

—

Go to

Step 6

Go to

Step 4

EngineControls-6.0LEngine

DTC P0455 (cont’d)

Step Action Values Yes No

Important: Ensure that the vehicle underbody temperature

is similar to the ambient temperature and allow the

surrounding air to stabilize before starting the diagnostic

procedure. System ﬂow will be less with higher

temperatures.

1. Turn OFF the ignition.

2. Connect the

J 41413-200

power supply clips to a

known good 12-volt source.

3. Install the

J 41415-40

GE-41415-50

to the fuel

ﬁll pipe.

4. Connect the

J 41413-200

nitrogen/smoke supply hose

and vehicle fuel ﬁll cap to the

J 41415-40

GE-41415-50

5. Turn ON the ignition, with the engine OFF.

6. Command the EVAP canister vent solenoid valve

closedwithaTech 2 .

7. Turn the nitrogen/smoke valve on the

J 41413-200

control panel to SMOKE.

8. Use the remote switch to introduce smoke into the

EVAP System.

9. Use the

J 41413-VLV

EVAP Service Port Vent Fitting

to open the EVAP service port.

10. Remove the

J 41413-VLV

once smoke is observed.

11. Continue to introduce smoke into the EVAP System

for an additional 60 seconds.

12. Inspect the entire EVAP System for exiting smoke

with the

J 41413-SPT

High Intensity White Light.

13. Continue to introduce smoke at 15 second intervals

until the leak source has been located.

Did you locate and repair a leak source?

—

Go to

Step 21

Go to

Step 5

1. Disconnect the

J 41415-40

GE-41415-50

from the

fuel ﬁll pipe.

2. Install the fuel ﬁll cap to the fuel ﬁll pipe.

3. Connect the

J 41413-200

nitrogen/smoke supply hose

to the EVAP service port.

4. Use the remote switch to introduce smoke into the

EVAP System.

5. Inspect the entire EVAP System for exiting smoke

with the

J 41413-SPT

6. Continue to introduce smoke at 15 second intervals

until the leak source has been located

Did you locate and repair a leak source?

—

Go to

Step 21

Go to

Step 6

1. Use the remote switch to stop introducing smoke.

2. Install the

J 41415-40

GE-41415-50

to the fuel

ﬁll pipe.

3. Connect the

J 41413-200

nitrogen/smoke supply hose

and vehicle fuel ﬁll cap to the

J 41415-40

GE-41415-50

4. Command the EVAP canister vent solenoid valve

openwithaTech 2 .

5. Compare the fuel tank pressure sensor parameter

withaTech 2 tothe

J41413-200

pressure/vacuum gage.

IstheTech 2 fueltankpressuresensorparameterwithin

the speciﬁed value of the

J 41413-200

pressure/vacuum gage?

1inH2O

Go to

Step 7

Go to

Step 17

EngineEngineControls-6.0L

DTC P0455 (cont’d)

Step Action Values Yes No

1. Seal the EVAP System using the EVAP Purge/Seal

functionwithaTech 2 .

2. Turn the nitrogen/smoke valve on the

J 41413-200

control panel to NITROGEN.

3. Use the

J 41413-200

to pressurize the EVAP System

to the ﬁrst speciﬁed value.

Is the fuel tank pressure sensor parameter more than the

second speciﬁed value?

10 in H2O

5inH2O

Go to

Step 8

Go to

Step 17

1. Use the remote switch to stop introducing nitrogen

into the EVAP System.

2. Increase the EVAP canister purge solenoid valve to

100 percent.

Is the fuel tank pressure sensor parameter less than the

speciﬁed value?

1inH2O

Go to

Step 9

Go to

Step 11

1. Connect the nitrogen/smoke hose to the EVAP

service port.

2. Remove the

J 41415-40

GE-41415-50

3. Install the fuel ﬁll cap to the fuel ﬁll pipe.

4. Start the engine.

5. Allow the engine to idle.

6. Use the purge/seal function to seal the system with a

Tech 2 .

7. Command the EVAP canister purge solenoid valve to

30 percent.

8. Observe the vacuum/pressure gage of the

J41413-200

andtheFTPparameterontheTech 2 .

9. Allow the vacuum to increase on the gage of the

J 41413-200

, until it reaches approximately

16 inch H2O.

10. Use the purge/seal function to seal the system, with a

Tech 2 .

IstheFTPparameteronaTech 2 withinthespeciﬁed

value of the vacuum/pressure gage on the

J 41413-200

untilthevacuumreachedtheabortlimitonaTech 2 ?

1inH2O

Go to

Step 10

Go to

Step 17

10 DidtheFTPparameteronaTech 2 displaymorethan

the speciﬁed value? 3.2 V Go to

Diagnostic Aids Go to

Step 17

Disconnect the EVAP purge vacuum source from the EVAP

canister purge solenoid valve.

Is the Fuel Tank Pressure sensor parameter less than the

speciﬁed value?

1inH2O

Go to

Step 15

Go to

Step 12

Disconnect the EVAP canister purge pipe from the EVAP

canister purge solenoid valve.

Is the fuel tank pressure sensor parameter less than the

speciﬁed value?

1inH2O

Go to

Step 18

Go to

Step 13

Disconnect the EVAP canister purge pipe at the EVAP

canister.

Is the fuel tank pressure sensor parameter less than the

speciﬁed value?

1inH2O

Go to

Step 19

Go to

Step 14

Disconnect the EVAP canister vapor pipe at the EVAP

canister.

Is the fuel tank pressure sensor parameter less than the

speciﬁed value?

1inH2O

Go to

Step 20

Go to

Step 16

15 Repair the pinched or obstructed EVAP canister solenoid

valve vacuum source.

Did you complete the repair? —Go to

Step 21

—

EngineControls-6.0LEngine

DTC P0455 (cont’d)

Step Action Values Yes No

16 Repair the pinched or obstructed EVAP canister

vapor pipe.

Did you complete the repair? —Go to

Step 21

—

17 Replace the fuel tank pressure (FTP) sensor. Refer to

Fuel

Tank Pressure Sensor Replacement

Did you complete the replacement? —Go to

Step 21

—

Replace the EVAP canister purge solenoid valve. Refer to

Evaporative Emission (EVAP) Canister Purge Solenoid

Valve Replacement

Did you complete the replacement?

—

Go to

Step 21

—

Repair the restriction in the EVAP canister purge pipe.

Refer to

Evaporative Emission (EVAP) System

Hoses/Pipes Replacement (Vacuum Supply)

Evaporative

Emission (EVAP) System Hoses/Pipes Replacement

(Engine Purge Pipe)

Did you complete the repair?

—

Go to

Step 21

—

20 Replace the EVAP canister. Refer to

Evaporative

Emission (EVAP) Canister Replacement

Did you complete the replacement? —Go to

Step 21

—

Important: DO NOT exceed the speciﬁed value in this

step. Exceeding the speciﬁed value may produce incorrect

test results.

1. Connect the

J 41413-200

to the fuel ﬁll pipe.

2. Turn the nitrogen/smoke valve to NITROGEN.

3. Seal the EVAP System using the EVAP Purge/Seal

functionwithaTech 2 .

4. Pressurize the EVAP System to the speciﬁed value.

5. Observe the

J 41413-200

pressure/vacuum gage for

5 minutes.

Does the

J 41413-200

pressure/vacuum gage remain

constant?

5inH2O

Go to

Step 22

Go to

Step 3

Observe the fuel tank pressure sensor parameter with a

Tech 2 .

IstheTech 2 fueltankpressureparameterwithinthe

speciﬁed value of the

J 41413-200

pressure/vacuum gage?

1inH2O

Go to

Step 23

Go to

Step 6

1. Observe the

J 41413-200

pressure/vacuum gage.

2. Increase the EVAP canister purge solenoid valve to

100 percent.

Does the pressure decrease?

—

Go to

Step 24

Go to

Step 12

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0496

System Description

This DTC tests for undesired intake manifold vacuum

ﬂow to the Evaporative Emission (EVAP) System.

The control module seals the EVAP System by

commanding the EVAP canister purge solenoid valve

Closed and the EVAP canister vent solenoid valve

Closed. The control module monitors the fuel

tank pressure (FTP) sensor to determine if a vacuum

is being drawn on the EVAP System. If vacuum in

the EVAP system is more than a predetermined value

within a predetermined time, this DTC sets.

The following table illustrates the relationship between

the ON and OFF states, and the Open or Closed

states of the EVAP canister purge and vent solenoid

valves.

Control Module

Command

EVAP Canister

Purge Solenoid

Valve

EVAP Canister

Vent Solenoid

Valve

ON Open Closed

OFF Closed Open

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0496 Evaporative Emission (EVAP) System

Flow During Non-Purge

Conditions for Running the DTC

• DTCs P0107, P0108, P0112, P0113, P0116,

P0117, P0118, P0125, P0442, P0443, P0449,

P0451, P0452, P0453, P0454, P0455, P0464,

P1112, P1114, P1115, P1120, P1133, P1134,

P1153, P1154, P1220, P1221 are not set.

• The ignition voltage is between 10–18 volts.

• The barometric pressure (BARO) is more than

75 kPa.

• The fuel level is between 15–85 percent.

• The engine coolant temperature (ECT) is between

4–30°C (39–86°F).

• The intake air temperature (IAT) is between 4–

30°C (39–86°F).

• The start up ECT and IAT are within 9°C (16°F) of

each other.

• The vehicle speed sensor (VSS) is less than

121 km/h (75 mph).

• DTC P0496 runs once per cold start when the

above conditions are met.

Conditions for Setting the DTC

The control module detects vacuum during a

non-purge condition.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P0496

Step Action Values Yes No

Schematic Reference:

Evaporative Emissions (EVAP) Hose Routing Diagram

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Start the engine.

2. Seal the Evaporative Emission (EVAP) System using

thePurge/SealfunctionwithaTech 2 .

3. Increase the engine idle to 1,200–1,500 RPM.

4. Observe the fuel tank pressure (FTP) sensor in H2O

withaTech 2 .

Is the fuel tank pressure sensor parameter within the

speciﬁed value?

−1to+1H2O

Go to

Diagnostic Aids Go to

Step 3

EngineControls-6.0LEngine

DTC P0496 (cont’d)

Step Action Values Yes No

1. Turn OFF the ignition.

2. Disconnect the EVAP purge pipe from the EVAP

canister purge solenoid valve.

3. Turn ON the ignition, with the engine OFF.

4.ObservetheFTPsensorinH2OwithaTech 2 .

Is the fuel tank pressure sensor parameter within the

speciﬁed range?

−1to+1H2O

Go to

Step 4

Go to

Step 5

Replace the EVAP canister purge solenoid valve. Refer to

Evaporative Emission (EVAP) Canister Purge Solenoid

Valve Replacement

Did you complete the replacement?

—

Go to

Step 6

—

5Replace the FTP sensor. Refer to

Fuel Tank Pressure

Sensor Replacement

Did you complete the replacement? —Go to

Step 6

—

1. Connect all EVAP hardware that was previously

disconnected.

2. Seal the EVAP System using the Purge/Seal function

withaTech 2 .

3. Start the engine and idle at 1,200–1,500 RPM.

4. Observe the fuel tank pressure sensor parameter with

aTech 2 .

Is the fuel tank pressure sensor parameter within the

speciﬁed range?

−1to+1H2O

Go to

Step 7

Go to

Step 2

ObservetheCaptureInfowithaTech 2 .

Have any DTCs not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0506

Circuit Description

The throttle actuator control (TAC) motor is controlled

by the engine control module (ECM). The DC motor

located in the throttle body drives the throttle plate. In

order to decrease idle speed, the ECM commands

the throttle closed reducing air ﬂow into the engine and

the idle speed decreases. In order to increase idle

speed, the ECM commands the throttle plate

open allowing more air to pass the throttle plate. If the

actual idle RPM does not match the desired idle

RPM within a calibrated time, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0506 Idle Speed Low

Conditions for Running the DTC

• DTCs P0068, P0101, P0102, P0103, P0106,

P0107, P0108, P0112, P0113, P0117, P0118,

P0120, P0122, P0123, P0171, P0172, P0201,

P0202, P0203, P0204, P0205, P0206, P0207,

P0208, P0220, P0121, P0222, P0223, P0230,

P0300, P0336, P0442, P0446, P0449, P0452,

P0453, P0455, P0462, P0463, P0496, P1516,

P2101, P2135, P2176 are not set.

• The engine is operating for at least 60 seconds.

• The engine coolant temperature (ECT) is

more than −60°C (−140°F).

• The intake air temperature (IAT) is more than

−10°C (−14°F).

• The barometric pressure (BARO) is more than

65 kPa.

• The system voltage is between 9–18 volts.

• The vehicle speed is less than 1.6 km/h (1 mph).

• DTC P0506 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

• The actual idle speed is approximately 100 RPM

lower than the desired idle speed.

• The above condition is present for 5 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. This test determines whether the engine can

achieve the commanded RPM. If the engine does

not reach the commanded RPMs, the test

determines whether the RPM is too high or

too low.

DTC P0506

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Start the engine.

2. Command the engine speed up to 1,500 RPM, down to

500RPM,andupto1,500RPM,withaTech 2 .

3. Exit the RPM control function.

Does the engine speed correspond, within 100 RPM, with each

command? Go to

Intermittent

Conditions

Go to

Step 3

EngineControls-6.0LEngine

DTC P0506 (cont’d)

Step Action Yes No

Inspect for any condition that can reduce idle speed by increasing

engine load. Examples include:

• Incorrect torque converter clutch (TCC) operation

• Accessories that require additional torque to operate

• Restricted exhaust

• Mechanical conditions that limit engine speed

Did you complete the action? Go to

Step 4

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 5

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0507

Circuit Description

The throttle actuator control (TAC) motor is controlled

by the engine control module (ECM). The DC motor

located in the throttle body drives the throttle plate. In

order to decrease idle speed, the ECM commands

the throttle closed reducing air ﬂow into the engine and

the idle speed decreases. In order to increase idle

speed, the ECM commands the throttle plate

open allowing more air to pass the throttle plate. If the

actual idle RPM does not match the desired idle

RPM within a calibrated time, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0507 Idle Speed High

Conditions for Running the DTC

• DTCs P0068, P0101, P0102, P0103, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0171, P0172, P0201,

P0202, P0203, P0204, P0205, P0206, P0207,

P0208, P0220, P0222, P0223, P0230, P0300,

P0336, P0442, P0446, P0449, P0452, P0453,

P0455, P0462, P0463, P1516, P2101, P2135,

P2176 are not set.

• The engine is operating for at least 60 seconds.

• The engine coolant temperature (ECT) is

more than −60°C (−140°F).

• The intake air temperature (IAT) is more than

−10°C (−14°F).

• The barometric pressure (BARO) is more than

65 kPa.

• The system voltage is between 9–18 volts.

• The vehicle speed is less than 1.6 km/h (1 mph).

• DTC P0507 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

• The actual idle speed is approximately 200 RPM

greater than the desired idle speed.

• The above condition is present for 5 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. This test determines whether the engine can

achieve the commanded RPM. If the engine does

not reach the commanded RPMs, the test

determines whether the RPM is too high or

too low.

DTC P0507

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Start the engine.

2. Command the engine speed up to 1,500 RPM, down to

500RPM,andupto1,500RPMwithaTech 2 .

3. Exit the RPM control function.

Does the engine speed correspond, within 100 RPM, with each

command? Go to

Intermittent

Conditions

Go to

Step 3

EngineControls-6.0LEngine

DTC P0507 (cont’d)

Step Action Yes No

Inspect for the following conditions:

• Vacuum leaks

• Excessive deposits in the throttle body

• A faulty positive crankcase ventilation (PCV) valve

Did you ﬁnd and correct the condition? Go to

Step 4

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 5

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0601-P0607, P060E, P1600, P1621, P1627, P1681, P1683, or P2610

Description

This diagnostic applies to internal microprocessor

integrity conditions within the engine control

module (ECM). This diagnostic also addresses

whether or not the ECM is not programmed.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P0601 Control Module Read Only

Memory (ROM)

• DTC P0602 Control Module Not Programmed

• DTC P0603 Control Module Long Term

Memory Reset

• DTC P0604 Control Module Random Access

Memory (RAM)

• DTC P0606 Control Module Internal Performance

• DTC P0607 Control Module Performance

• DTC P060E Control Module Throttle Position (TP)

System Performance

• DTC P1621 Control Module Long Term Memory

Performance

• DTC P2610 Control Module Ignition OFF Timer

Performance

Conditions for Running the DTC

DTC P0601

• The ignition switch is in the Run or the Crank

position.

• DTC P0601 runs continuously when the above

condition is met.

DTC P0602

• The ignition switch is in the ON position.

• DTC P0602 runs continuously when the above

condition is met.

DTC P0603

• The ignition switch is in the ON position.

• DTC P0603 runs continuously when the above

condition is met.

DTC P0604

• The ignition switch is in the Run or the Crank

position.

• DTC P0604 runs continuously when the above

condition is met.

DTC P0606

• The ignition switch is in the Unlock, Accessory,

Run, or Crank position.

• The system voltage is more than 5.23 volts.

• DTC P0606 runs continuously when the above

conditions are met.

DTC P060E

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P1621, P2610 are not set.

• The system voltage is more than 5.23 volts.

• The ignition switch is in the Unlock, Accessory, or

Run position.

• The above conditions are met for more than

one second.

• DTC P060E runs continuously when the above

conditions are met.

DTC P1621

• The ignition switch is in the ON position.

• DTC P1621 runs continuously when the above

conditions are met.

DTC P2610

• The ignition switch is in the ON position.

• The intake air temperature (IAT) is between −7

and +75°C (+20–167°F).

• The above conditions are met for more than

14 seconds.

• The ECM is powered down.

• DTC P2610 runs continuously when the above

conditions are met.

Action Taken When DTCs P0601, P0602,

P0604, P0606, P060E, and P1621 Set

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Action Taken When DTCs P0603 and P2610

Set

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTCs P0601,

P0602, P0603, P0604, P0606, P0607, P060E,

P1621, and P2610

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

EngineControls-6.0LEngine

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Conditions for Setting the DTC

The PCM detects an internal failure or incomplete

programming for more than 14 seconds.

Test Description

The number below refers to the step number on the

diagnostic table.

2. A DTC P0602 indicates the ECM is not

programmed.

DTC P0601-P0607, P060E, P1600, P1621, P1627, P1681, P1683, or P2610

Step Action Yes No

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

Is DTC P0602 set? Go to

Step 3

Go to

Step 5

3Program the engine control module (ECM). Refer to

Service

Programming System (SPS)

in Programming and Setup.

Does DTC P0602 reset? Go to

Step 4

Go to

Step 6

1. Ensure that all tool connections are secure.

2. Ensure that the programming equipment is operating

correctly.

3. Ensure that the correct software/calibration package is used.

4. Attempt to program the ECM. Refer to

Service Programming

System (SPS)

in Programming and Setup.

Does DTC P0602 reset? Go to

Step 5

Go to

Step 6

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement? Go to

Step 6

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 7

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P060D

Circuit Description

The throttle actuator control (TAC) system uses

two accelerator pedal position (APP) sensors to

monitor the pedal position. Two processors are also

used to monitor the TAC system data. The engine

control module (ECM) performs an intrusive test

in order to detect that the APP signals are not shorted

together. The ECM accomplishes this by pulling the

APP sensor 2 low momentarily and looking for

sensor 1 to also be low. The TAC system also

performs this test on the throttle position (TP) sensors.

This diagnostic monitors the transistor used to pull

one pedal and one throttle sensor to ground

simultaneously. Additionally, Both processors monitor

each other’s data to verify that the indicated APP

calculation is correct.

If the transistor does not toggle within a calibrated

period, or the indicated APP calculation is incorrect,

DTC P060D sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P060D Control Module Accelerator Pedal

Position (APP) System Performance

Conditions for Running the DTC

• The system voltage is more than 5.23 volts.

• The ignition is in Unlock/Accessory or Run

position.

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607 are not set.

• DTC P060D runs continuously when the above

conditions are met.

Conditions for Setting the DTC

• The APP sensor 2 voltage is more than 2.05 volts

for more than 0.3 second during the intrusive test.

• The APP sensor calculations in the main

processor differ from the motor control processor

by more than 5 percent.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

2. A DTC P0602 indicates that the ECM is not

programmed.

5. Resistance is measured at the pedal assembly

because a pedal resistance that is lower than

the speciﬁed value will set this DTC.

DTC P060D

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Is DTC P0602 set? — Go to

Step 3

Go to

Step 5

Program the engine control module (ECM). Refer to

Service Programming System (SPS)

in Programming

and Setup.

Does DTC P0602 reset?

—

Go to

Step 4

Go to

Step 8

EngineControls-6.0LEngine

DTC P060D (cont’d)

Step Action Values Yes No

1. Ensure that all tool connections are secure.

2. Ensure that the programming equipment is operating

correctly.

3. Ensure that the correct software/calibration package

is used.

4. Attempt to program the ECM. Refer to

Service

Programming System (SPS)

in Programming

and Setup.

Does DTC P0602 reset?

—

Go to

Step 7

Go to

Step 8

1. Turn OFF the ignition.

2. Disconnect the accelerator pedal connector.

3. Ensure that the pedal is at the rest position.

4. Measure the resistance from the 5-volt reference of

the accelerator pedal assembly to the accelerator

pedal position (APP) sensor 2 signal of the accelerator

pedal assembly with a DMM. Refer to

Circuit Testing

in Wiring Systems.

Is the resistance less than the speciﬁed value?

450 Ω

Go to

Step 6

Go to

Step 7

6Replace the accelerator pedal assembly. Refer to

Accelerator Pedal Position (APP) Sensor Replacement

Did you complete the replacement? —Go to

Step 8

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 8

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 9

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0641

Circuit Description

The engine control module (ECM) provides 5 volts to

the following sensors:

• The manifold absolute pressure (MAP) sensor

• The engine oil pressure (EOP) sensor

• The fuel tank pressure (FTP) sensor

• The air conditioning (A/C) refrigerant pressure

sensor

• The accelerator pedal position (APP) sensor 2

These 5-volt reference circuits are independent of each

other outside the ECM, but are bussed together

inside the ECM. Therefore a circuit condition on one

sensor 5-volt reference circuit may affect the other

sensor 5-volt reference circuits. The ECM monitors the

voltage on the 5-volt reference circuit. If the ECM

detects that the voltage is out of tolerance,

DTC P0641 sets.

DTC Descriptor

The diagnostic procedure supports the following DTC:

DTC P0641 5-Volt Reference 1 Circuit

Conditions for Running the DTC

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P1621, P2610 are not set.

• The ignition is ON.

• The ignition voltage is more than 5.23 volts.

• DTC P0641 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The ECM detects a voltage out of tolerance condition

on the 5-volt reference circuit for more than

0.5 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2

Test Description

The number below refers to the step number on the

diagnostic table.

9. A short to voltage on the signal circuit of the FTP

sensor will backfeed through the sensor into the

5-volt reference circuit and set this DTC.

DTC P0641

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Observe the Freeze Frame and/or Failure Records for

the DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Does the DTC fail this ignition?

—

Go to

Step 3

Go to

Intermittent

Conditions

EngineControls-6.0LEngine

DTC P0641 (cont’d)

Step Action Values Yes No

1. Turn OFF the ignition.

2. Disconnect the manifold absolute pressure (MAP)

sensor electrical connector.

3. Turn ON the ignition, with the engine OFF.

4. Measure the voltage from the 5-volt reference circuit

of the MAP sensor to a good ground with a DMM.

Refer to

Circuit Testing

in Wiring Systems.

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Step 5

Go to

Step 4

4Is the voltage from the previous step more than the

speciﬁed value? 5.2 V Go to

Step 8

Go to

Step 6

1. Reconnect the MAP sensor.

2. Disconnect the A/C refrigerant pressure sensor

3. Measure the voltage from the 5-volt reference circuit

of the A/C refrigerant pressure sensor to a good

ground with a DMM. Refer to

Circuit Testing

in Wiring

Systems.

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Intermittent

Conditions

Go to

Step 10

1. Monitor the DMM while disconnecting all other

sensors connected to this 5-volt reference bus, one at

a time.

2. If the voltage changes when one of the above

components is disconnected, replace the component.

Refer to the appropriate replacement procedure.

Was a component replaced?

—

Go to

Step 13

Go to

Step 7

Test the 5-volt reference circuits of all of the sensors

connected to this 5-volt reference bus for a short to ground

or any sensor low reference circuit. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 12

Test the 5-volt reference circuits of all the sensors

connected to this 5-volt reference bus for a short to

voltage. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 9

Test the fuel tank pressure (FTP) sensor signal circuit for a

short to voltage. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 12

Test the MAP sensor signal circuit for a short to voltage.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 11

11 Replace the MAP sensor. Refer to

Manifold Absolute

Pressure (MAP) Sensor Replacement

Is the action complete? —Go to

Step 13

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 13

—

1.UsetheTech 2 inordertocleartheDTCs.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC as speciﬁed in the supporting text.

Does the DTC run and pass?

—

Go to

Step 14

Go to

Step 2

EngineEngineControls-6.0L

DTC P0641 (cont’d)

Step Action Values Yes No

WithaTech 2 ,observethestoredinformation,

Capture Info.

DoestheTech 2 displayanyDTCsthatyouhavenot

diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0650

Circuit Description

The malfunction indicator lamp (MIL) is located on the

instrument panel cluster (IPC). The MIL informs the

driver that an emission system fault has occurred and

that the engine control system requires service.

The control module monitors the MIL control circuit for

conditions that are incorrect for the commanded

state of the MIL. For example, a failure condition exists

if the control module detects low voltage when the

MIL is commanded OFF, or high voltage when the MIL

is commanded ON. If the control module detects an

improper voltage on the MIL control circuit, DTC P0650

will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0650 Malfunction Indicator Lamp (MIL)

Control Circuit

Conditions for Running the DTC

• The ignition is ON.

• The ignition voltage is between 10–18 volts.

• DTC P0650 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The control module detects that the commanded state

of the MIL driver and the actual state of the control

circuit do not match for 0.5 seconds.

Action Taken When the DTC Sets

The control module records the operating conditions at

the time the diagnostic fails. The ﬁrst time the

diagnostic fails, the control module stores this

information in the Failure Records. If the diagnostic

reports a failure on the second consecutive ignition

cycle, the control module records the operating

conditions at the time of the failure. The control module

writes the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

6. This step tests for a short to ground in the MIL

control circuit. With the engine control

module (ECM) disconnected and the ignition ON,

the MIL should be OFF.

7. This step tests for a short to voltage on the MIL

control circuit. With the fuse removed, there

should be no voltage on the MIL control circuit.

DTC P0650

Step Action Values Yes No

Schematic Reference:

Instrument Cluster Schematics

in Instrument Panel, Gages, and Console or

Engine Controls

Schematics

Connector End View Reference:

Instrument Panel, Gages, and Console Connector End Views

in Instrument Panel, Gages,

and Console or

Engine Control Module (ECM) Connector End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Command the malfunction indicator lamp (MIL) ON and

OFFwithaTech 2 .

Does the MIL turn ON and OFF when commanded with a

Tech 2 ?

—

Go to

Step 3

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Does the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

4 Is the MIL always ON? — Go to

Step 6

Go to

Step 5

EngineEngineControls-6.0L

DTC P0650 (cont’d)

Step Action Values Yes No

5Inspect the fuse that supplies battery voltage to the MIL.

Is the fuse open? —Go to

Step 13

Go to

Step 7

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM).

3. Turn ON the ignition.

Is the MIL OFF?

—

Go to

Step 12

Go to

Step 14

1. Turn OFF the ignition.

2. Remove the fuse that supplies voltage to the MIL.

3. Turn ON the ignition, with the engine OFF.

4. Measure the voltage from the MIL control circuit in the

ECM to a good ground.

Is the voltage less than the speciﬁed value?

0.3 V

Go to

Step 8

Go to

Step 15

1. Turn OFF the ignition.

2. Install the fuse that supplies voltage to the MIL.

3. Turn ON the ignition, with the engine OFF.

4. Connect a 3-amp fused jumper wire between the MIL

control circuit of the ECM and a good ground.

Is the MIL illuminated?

—

Go to

Step 12

Go to

Step 9

1. Turn OFF the ignition.

2. Remove the instrument panel cluster (IPC).

3. Probe the MIL battery positive voltage circuit of the

IPC harness connector with a test lamp that is

connected to a good ground.

Does the test lamp illuminate?

—

Go to

Step 10

Go to

Step 16

Test the MIL control circuit for an open or high resistance.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct a condition?

—

Go to

Step 19

Go to

Step 11

Test for an intermittent and for a poor connection at the

IPC. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 19

Go to

Step 17

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 19

Go to

Step 18

13 Repair the short to ground on the voltage supply circuit.

Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 19

—

14 Repair the short to ground in the MIL control circuit. Refer

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 19

—

15 Repair the short to voltage in the MIL control circuit. Refer

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 19

—

16 Repair the open in the MIL battery positive voltage. Refer

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 19

—

17 Replace the IPC. Refer to

Instrument Panel Cluster (IPC)

Replacement

in Instrument Panel, Gages, and Console.

Did you complete the replacement? —Go to

Step 19

—

EngineControls-6.0LEngine

DTC P0650 (cont’d)

Step Action Values Yes No

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 19

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 20

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0651

Circuit Description

The engine control module (ECM) provides 5 volts to

the following sensors:

• The accelerator pedal position (APP) sensor 1

• The throttle position (TP) sensor 1 and 2

These 5-volt reference circuits are independent of

each other outside the ECM, but are bussed together

inside the ECM. Therefore a circuit condition on

one sensor 5-volt reference circuit may affect the other

sensor 5-volt reference circuits. The ECM monitors

the voltage on the 5-volt reference circuit. If the ECM

detects that the voltage is out of tolerance,

DTC P0651 sets.

DTC Descriptor

The diagnostic procedure supports the following DTC:

DTC P0651 5-Volt Reference 2 Circuit

Conditions for Running the DTC

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P1621, P2610 are not set.

• The ignition is ON.

• The ignition voltage is more than 5.23 volts.

• DTC P0651 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The ECM detects a voltage out of tolerance condition

on the 5-volt reference circuit for more than

0.5 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P0651

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Does the DTC fail this ignition?

—

Go to

Step 3

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the throttle body electrical connector.

3. Turn ON the ignition, with the engine OFF.

4. Measure the voltage from the 5-volt reference circuit

of the throttle position (TP) sensor 1 and 2 of the

throttle body harness connector to a good ground with

a DMM. Refer to

Circuit Testing

in Wiring Systems.

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Step 4

Go to

Step 5

EngineControls-6.0LEngine

DTC P0651 (cont’d)

Step Action Values Yes No

1. Connect the throttle body electrical connector.

2. Disconnect the electrical connector of the accelerator

pedal sensor module.

3. Measure the voltage from the 5-volt reference circuit

of APP sensor 1 to a good ground with a DMM. Refer

Circuit Testing

in Wiring Systems.

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Intermittent

Conditions

Go to

Step 11

5Is the voltage measured in step 3 more than the

speciﬁed value? 5.2 V Go to

Step 8

Go to

Step 6

6Monitor the DMM while disconnecting the APP sensor 1.

Does the voltage return to within the speciﬁed range when

the APP sensor 1 is disconnected? 4.8–5.2 V Go to

Step 10

Go to

Step 7

Test the 5-volt reference circuit of APP sensor 1 and the

TP sensors 1 and 2 for a short to ground or any sensor low

reference circuit. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 9

Test the 5-volt reference circuits of the APP sensor 1 and

TP sensors 1 and 2 for a short to voltage. Refer to

Circuit

Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 12

Test the 5-volt reference circuits of the APP sensor 1 and

TP sensors 1 and 2 for a short to the throttle actuator

control (TAC) motor control 1 or 2 circuits. Refer to

Circuit

Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 13

Go to

Step 12

10 Replace the APP sensor 1. Refer to

Accelerator Pedal

Position (APP) Sensor Replacement

Did you complete the replacement? —Go to

Step 13

—

11 Replace the throttle body assembly. Refer to

Throttle Body

Assembly Replacement

Did you complete the replacement? —Go to

Step 13

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 13

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 14

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0685

Circuit Description

The powertrain ignition 1 relay is a normally open

relay. The relay armature is held in the open position

by spring tension. Battery positive voltage is

supplied directly to the relay coil and the armature

contact at all times. The engine control module (ECM)

supplies the ground path to the relay coil control

circuit via an internal integrated circuit called an output

driver module (ODM). One ODM output control is

conﬁgured to operate as a low side driver for

the powertrain ignition 1 relay. The ODM for the

powertrain ignition 1 relay also incorporates a fault

detection circuit, which is continuously monitored

by the ECM. When the ECM commands the ODM for

the powertrain ignition 1 relay to turn OFF the

expected voltage on the relay coil control circuit should

be a high voltage condition. When the ECM

commands the ODM to turn ON the expected voltage

on the relay coil control circuit should be low

voltage. DTC P0685 indicates that the powertrain

ignition 1 relay control circuit voltage does not match

the commanded state of the ODM. DTC P0685

sets when an open, high resistance, short to ground,

or a short to battery positive voltage is detected

on the powertrain relay coil control circuit.

The underhood fuse block features an alphanumeric

grid system for the terminals of the relays and the mini

fuses. Along the top forward edge of the underhood

fuse block the letters A, B, C, D, E, F, G, H, J, K,

L, and M are used. Along the top right edge of

the underhood fuse block the numbers 1 through 20

are used. The powertrain ignition 1 relay circuits

are assigned to the following cavities of the underhood

fuse block:

• H13 – Battery positive voltage to the relay coil,

hot at all times

• H14 – Battery positive voltage to the relay

armature, hot at all times

• F14 – Relay coil control circuit, ECM controlled

• F13 – Relay load circuit, ignition 1 voltage to

the following fuses and relay

− Fuel Fuse

− O2 Sensor Fuse

− ETC fuse

− Emission Fuse

− Even INJ Fuse

− Odd INJ Fuse

− A/C Comp Relay – Relay coil side

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0685 Engine Controls Ignition Relay Control

Circuit

Conditions for Running the DTC

• The battery voltage is between 9–16 volts.

• The ignition switch is turned ON.

• The powertrain ignition 1 relay has been

commanded ON.

Conditions for Setting the DTC

• The commanded state of the ODM and the actual

state of the control circuit do not match.

• The condition is present for more than 5 seconds.

Action Taken When the DTC Sets

• The control module stores the DTC information

into memory when the diagnostic runs and fails.

• The malfunction indicator lamp (MIL) will

illuminate.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in Failure

Records.

• The driver information center, if equipped, may

display a message.

Conditions for Clearing the MIL/DTC

• A current DTC, last test failed clears when the

diagnostic runs and passes.

• A history DTC clears 40 consecutive warm-up

cycles, if this or any other related diagnostic

reports no other failures.

•CleartheDTCwithaTech 2 .

DTC P0685

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector End

Views

, and

Electrical Center Identiﬁcation Views

in Wiring Systems

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineControls-6.0LEngine

DTC P0685 (cont’d)

Step Action Values Yes No

1. Observe the Freeze Frame/Failure Records for

the DTC.

2. Turn OFF the ignition for 30 seconds.

3. Turn ON the ignition, with the engine OFF.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 3

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Remove the powertrain ignition 1 relay from the

underhood fuse block with the

J 43244

Relay Puller

Pliers. Refer to

Relay Replacement (Within an

Electrical Center)

Relay Replacement (Attached to

Wire Harness)

in Wiring Systems.

Notice:

Refer to

Test Probe Notice

in Cautions and

Notices.

3. Probe the powertrain ignition 1 relay coil control

terminal F14 on the underhood fuse block, with a test

lamp that is connected to a good ground. Refer to

Troubleshooting with a Test Lamp

in Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 12

Go to

Step 4

1. Turn OFF the ignition.

2. Probe the battery positive voltage terminal H13 for the

powertrain ignition 1 relay coil, on the underhood fuse

block, with a test lamp that is connected to a good

ground. Refer to

Troubleshooting with a Test Lamp

Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 5

Go to

Step 11

1. Turn OFF the ignition.

2. Probe the powertrain ignition 1 relay coil control

terminal F14, on the underhood fuse block, with a test

lamp that is connected to battery positive voltage.

Refer to

Troubleshooting with a Test Lamp

in Wiring

Systems.

Does the test lamp illuminate?

—

Go to

Step 7

Go to

Step 6

1. Turn ON the ignition, with the engine OFF.

2. Probe the powertrain ignition 1 relay coil control

terminal F14, on the underhood fuse block, with a test

lamp that is connected to battery positive voltage.

Refer to

Troubleshooting with a Test Lamp

in Wiring

Systems.

Does the test lamp illuminate?

—

Go to

Step 14

Go to

Step 9

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM) wire

harness electrical connector that contains the

powertrain ignition 1 relay coil control circuit. Refer to

Control Module References

in Computer/Integrating

Systems for replacement, setup, and programming.

Notice:

Refer to

Test Probe Notice

in Cautions and

Notices.

3. Probe the powertrain ignition 1 relay coil control

terminal F14, on the underhood fuse block, with a test

lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

—

Go to

Step 8

Go to

Step 17

EngineEngineControls-6.0L

DTC P0685 (cont’d)

Step Action Values Yes No

1. Turn OFF the ignition.

2. Disconnect the negative battery cable at the battery.

Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

3. Disconnect the underhood fuse block wire harness

electrical connector that contains the powertrain

ignition 1 relay coil control circuit. Refer to

Underhood

Electrical Center or Junction Block Replacement

Wiring Systems.

4. Probe the powertrain ignition 1 relay coil control circuit

terminal, at the underhood fuse block wire harness

electrical connector, with a test lamp that is connected

to battery positive voltage.

Does the test lamp illuminate?

—

Go to

Step 19

Go to

Step 18

1. Turn OFF the ignition.

2. Disconnect the negative battery cable at the battery.

Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

3. Disconnect the underhood fuse block wire harness

electrical connector that contains the powertrain

ignition 1 relay coil control circuit. Refer to

Underhood

Electrical Center or Junction Block Replacement

Wiring Systems.

4. Disconnect the ECM wire harness electrical connector

that contains the powertrain ignition 1 relay coil control

circuit. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup,

and programming.

5. Measure the resistance of the powertrain ignition 1

relay coil control circuit from the underhood fuse block

wire harness electrical connector, to the ECM wire

harness electrical connector with a DMM. Refer to

Troubleshooting with a Test Lamp

in Wiring Systems.

Does the resistance measure more than the

speciﬁed value?

3Ω

Go to

Step 20

Go to

Step 10

Test the powertrain ignition 1 relay coil control bus bar

circuit of the underhood fuse block for a high resistance or

an open. Refer to

Circuit Testing

in Wiring Systems.

Does the resistance measure more than the

speciﬁed value?

3Ω

Go to

Step 18

Go to

Step 17

Probe the mounting stud for the battery positive cable at

the underhood fuse block, with a test lamp that is

connected to a good ground.

Does the test lamp illuminate?

—

Go to

Step 18

Go to

Starter

Solenoid Does

Not Click

Engine Electrical

1. Turn OFF the ignition.

2. Disconnect the ECM wire harness electrical connector

that contains the powertrain relay coil control circuit.

Refer to

Control Module References

Computer/Integrating Systems for replacement, setup,

and programming.

3. Probe the powertrain ignition 1 relay coil control

terminal F14, on the underhood fuse block, with a test

lamp that is connected to a good ground.

Does the test lamp illuminate?

—

Go to

Step 13

Go to

Step 17

EngineControls-6.0LEngine

DTC P0685 (cont’d)

Step Action Values Yes No

1. Turn OFF the ignition.

2. Disconnect the negative battery cable at the battery.

Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

3. Disconnect the underhood fuse block wire harness

electrical connector that contains the powertrain

ignition 1 relay coil control circuit. Refer to

Underhood

Electrical Center or Junction Block Replacement

Wiring Systems.

4. Connect the negative battery cable at the battery.

5. Probe the powertrain ignition 1 relay coil control circuit

terminal at the underhood fuse block wire harness

electrical connector, with a test lamp that is connected

to a good ground.

Does the test lamp illuminate?

—

Go to

Step 21

Go to

Step 23

Measure the resistance from terminal #85 of the powertrain

ignition 1 relay to terminal #86 with a DMM. Refer to

Troubleshooting with a Digital Multimeter

in Wiring

Systems.

Does the resistance measure within the speciﬁed value?

70–110 Ω

Go to

Step 15

Go to

Step 22

Measure the resistance from terminal #30 of the powertrain

ignition 1 relay to terminal #86 with a DMM. Refer to

Troubleshooting with a Digital Multimeter

in Wiring

Systems.

Does the DMM display OL?

—

Go to

Step 16

Go to

Step 22

Test for an intermittent and for a poor connection at the

powertrain ignition 1 relay terminals F14 and H13 on the

underhood fuse block. Refer to

Testing for Intermittent

Conditions and Poor Connections

in Wiring Systems.

Did you ﬁnd a condition?

—

Go to

Step 23

Go to

Intermittent

Conditions

Test for shorted terminals and poor connections at the

ECM electrical connector, and at the ECM wire harness

electrical connector. Refer to

Testing for Intermittent

Conditions and Poor Connections

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 25

Go to

Step 24

Test for shorted terminals and poor connections at the

underhood fuse block electrical connector, and at the

underhood fuse block wire harness electrical connector.

Refer to

Testing for Intermittent Conditions and Poor

Connections

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 25

Go to

Step 23

Repair the short to ground in the powertrain ignition 1 relay

coil control circuit, between the underhood fuse block wire

harness electrical connector and the ECM wire harness

electrical connector. Refer to

Wiring Repairs

in Wiring

Systems.

Did you complete the repair?

—

Go to

Step 25

—

Repair the high resistance or the open in the powertrain

ignition 1 relay coil control circuit, between the underhood

fuse block wire harness electrical connector and the ECM

wire harness electrical connector. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 25

—

Repair the short to battery positive voltage in the

powertrain ignition 1 relay coil control circuit, between the

underhood fuse block wire harness electrical connector and

the ECM wire harness electrical connector. Refer to

Wiring

Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 25

—

EngineEngineControls-6.0L

DTC P0685 (cont’d)

Step Action Values Yes No

Replace the powertrain ignition 1 relay. Refer to

Relay

Replacement (Within an Electrical Center)

Relay

Replacement (Attached to Wire Harness)

in Wiring

Systems.

Did you complete the replacement?

—

Go to

Step 25

—

Replace the underhood fuse block. Refer to

Underhood

Electrical Center or Junction Block Replacement

in Wiring

Systems.

Did you complete the replacement?

—

Go to

Step 25

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 25

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Turn ON the ignition, with the engine OFF.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 3

Go to

Step 26

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0689

Circuit Description

The powertrain ignition 1 relay is a normally open

relay. The relay armature is held in the open position

by spring tension. Battery positive voltage is

supplied directly to the relay coil and the armature

contact at all times. The engine control module (ECM)

supplies the ground path to the relay coil control

circuit via an internal integrated circuit called an output

driver module (ODM). When the ECM commands

the powertrain ignition 1 relay ON, ignition 1 voltage is

supplied to the ECM through the ETC fuse in the

underhood fuse block. This ignition 1 voltage input to

the ECM provides the ignition power for the

electronic throttle control (ETC) circuitry, and is also

used to conﬁrm the powertrain ignition 1 relay contacts

have closed. This DTC will set when the ECM

detects less than 10 volts on the ETC ignition 1 voltage

circuit to the ECM, after the ignition switch is turned

ON. DTC P0689 indicates an open, high resistance, or

short to ground on the ETC ignition 1 voltage circuit

to the ECM.

The underhood fuse block features an alphanumeric

grid system for the terminals of the relays and the mini

fuses. Along the top forward edge of the underhood

fuse block, the letters A, B, C, D, E, F, G, H, J,

K, L, and M are used. Along the top right edge of the

underhood fuse block the numbers 1 through 20

are used. The powertrain ignition 1 relay circuits are

assigned to the following cavities of the underhood

fuse block.

• H13 – Battery positive voltage to the relay coil,

hot at all times

• H14 – Battery positive voltage to the relay

armature, hot at all times

• F14 – Relay coil control circuit, ECM controlled

• F13 – Relay load circuit, ignition 1 voltage to

the following fuses and relay

− Fuel Fuse

− O2 Sensor Fuse

− ETC fuse

− Emission Fuse

− Even INJ Fuse

− Odd INJ Fuse

− A/C Comp Relay – Relay coil side

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0689 Engine Controls Ignition Relay Feedback

Circuit Low Voltage

Conditions for Running the DTC

• The battery voltage is between 9–16 volts.

• The ignition switch is turned ON.

• The powertrain ignition 1 relay has been

commanded ON.

Conditions for Setting the DTC

The ECM detects less than 10 volts on the ETC

ignition 1 voltage circuit for more than 5 seconds.

Action Taken When the DTC Sets

• The control module stores the DTC information

into memory when the diagnostic runs and fails.

• The malfunction indicator lamp (MIL) will

illuminate.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in Failure

Records.

• The driver information center, if equipped, may

display a message.

Conditions for Clearing the MIL/DTC

• A current DTC, last test failed clears when the

diagnostic runs and passes.

• A history DTC clears 40 consecutive warm-up

cycles, if this or any other related diagnostic

reports no other failures.

•CleartheDTCwithaTech 2 .

DTC P0689

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector End

Views

, and

Electrical Center Identiﬁcation Views

in Wiring Systems

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineEngineControls-6.0L

DTC P0689 (cont’d)

Step Action Values Yes No

1. Observe the Freeze Frame/Failure Records for

the DTC.

2. Turn OFF the ignition for 30 seconds.

3. Turn ON the ignition, with the engine OFF.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 3

Go to

Intermittent

Conditions

1. Turn ON the ignition, with the engine OFF.

2. Probe both test points of the ETC fuse in the

underhood fuse block, with a test lamp that is

connected to a good ground. Refer to

Troubleshooting

with a Test Lamp

in Wiring Systems.

Does the test lamp illuminate on both test points of the

ETC fuse?

—

Go to

Step 7

Go to

Step 4

4Does the test lamp illuminate on one test point of the

ETC fuse? —Go to

Step 5

Go to

Step 9

1. Turn OFF the ignition.

2. Disconnect the negative battery cable at the battery.

Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

3. Disconnect the underhood fuse block wire harness

electrical connector that contains the ignition 1 voltage

circuit, from the ETC fuse to the engine control

module (ECM).

4. Disconnect the ECM wire harness electrical

connector, that contains the ignition 1 voltage circuit,

from the ETC fuse.

5. Probe the ignition 1 voltage circuit, at the ECM wire

harness electrical connector, with a test lamp that is

connected to battery positive voltage. Refer to

Probing

Electrical Connectors

in Wiring System.

Does the test lamp illuminate?

—

Go to

Step 19

Go to

Step 6

Test the underhood fuse block bus bar circuit from the ETC

fuse to the underhood fuse block electrical connector for a

short to ground. Refer to

Circuit Testing

in Wiring Systems.

Did you ﬁnd a condition?

—

Go to

Step 21

Go to

Step 18

1. Turn OFF the ignition.

2. Disconnect the negative battery cable at the battery.

Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

3. Disconnect the underhood fuse block wire harness

electrical connector, that contains the

ignition 1 voltage circuit, from the ETC fuse to

the ECM.

4. Disconnect the ECM wire harness electrical

connector, that contains the ignition 1 voltage circuit,

from the ETC fuse.

5. Measure the resistance of the ignition 1 voltage circuit,

from the underhood fuse block wire harness electrical

connector, to the ECM wire harness electrical

connector with a DMM. Refer to

Troubleshooting with

a Test Lamp

in Wiring Systems.

Does the resistance measure greater than the

speciﬁed value?

3Ω

Go to

Step 20

Go to

Step 8

EngineControls-6.0LEngine

DTC P0689 (cont’d)

Step Action Values Yes No

Test the underhood fuse block ignition 1 voltage bus bar

circuit, from the ETC fuse to the underhood fuse block

electrical connector for a high resistance or an open. Refer

Circuit Testing

in Wiring Systems.

Did you ﬁnd a condition?

—

Go to

Step 21

Go to

Step 18

1. Turn OFF the ignition.

2. Remove the powertrain ignition 1 relay from the

underhood fuse block with the

J 43244

Relay Puller

Pliers. Refer to

Relay Replacement (Within an

Electrical Center)

Relay Replacement (Attached to

Wire Harness)

in Wiring Systems.

Notice:

Refer to

Test Probe Notice

in Cautions and

Notices.

3. Probe the battery positive voltage terminal H14 for the

powertrain ignition 1 relay armature, at the underhood

fuse block, with a test lamp that is connected to a

good ground. Refer to

Troubleshooting with a Test

Lamp

in Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 10

Go to

Step 11

Test the underhood fuse block ignition 1 voltage bus bar

circuit, between the powertrain ignition 1 relay and the ETC

fuse, for a high resistance or an open. Refer to

Circuit

Testing

in Wiring Systems.

Did you ﬁnd and condition?

—

Go to

Step 21

Go to

Step 12

Probe the mounting stud for the battery positive cable at

the underhood fuse block, with a test lamp that is

connected to a good ground.

Does the test lamp illuminate?

—

Go to

Step 23

Go to

Starter

Solenoid Does

Not Click

Engine Electrical

Measure the resistance from terminal #85 of the powertrain

ignition 1 relay to terminal #86 with a DMM. Refer to

Troubleshooting with a Digital Multimeter

in Wiring

Systems.

Does the resistance measure within the speciﬁed value?

70–110 Ω

Go to

Step 13

Go to

Step 22

13 Measure the resistance from terminal #30 of the powertrain

ignition 1 relay to terminal #387 with a DMM.

Does the DMM display OL? —Go to

Step 14

Go to

Step 22

Measure the resistance from terminal #30 of the powertrain

ignition 1 relay to terminal #85 with a DMM. Refer to

Troubleshooting with a Digital Multimeter

in Wiring

Systems.

Does the DMM display OL?

—

Go to

Step 15

Go to

Step 22

Measure the resistance from terminal #85 of the powertrain

ignition 1 relay to terminal #87 with a DMM. Refer to

Troubleshooting with a Digital Multimeter

in Wiring

Systems.

Does the DMM display OL?

—

Go to

Step 16

Go to

Step 22

1. Connect a 20-amp fused jumper wire from the battery

positive cable at the battery to powertrain ignition 1

relay terminal #85. Refer to

Using Fused Jumper

Wires

in Wiring Systems.

2. Connect a jumper wire from the negative battery cable

at the battery to the powertrain ignition 1 relay

terminal #86.

3. Measure the resistance from terminal 30 of the

powertrain ignition 1 relay to terminal #87 with a DMM.

Does the resistance measure greater than the

speciﬁed value?

2Ω

Go to

Step 22

Go to

Step 17

EngineEngineControls-6.0L

DTC P0689 (cont’d)

Step Action Values Yes No

Test for an intermittent and for a poor connection at the

powertrain ignition 1 relay terminals, F13 and H14, on the

underhood fuse block. Refer to

Testing for Intermittent

Conditions and Poor Connections

in Wiring Systems.

Did you ﬁnd a condition?

—

Go to

Step 21

Refer to

Intermittent

Conditions

Test for shorted terminals and poor connections at the

ECM electrical connector and the ECM wire harness

electrical connector. Refer to

Testing for Intermittent

Conditions and Poor Connections

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 24

Go to

Step 23

19 Repair the short to ground in the ignition 1 voltage circuit,

between the underhood fuse block wire harness electrical

connector and the ECM wire harness electrical connector.

Refer to

Wiring Repairs

in Wiring Systems. —Go to

Step 24

—

Repair the high resistance or an open in the

ignition 1 voltage circuit, between the underhood fuse block

wire harness electrical connector and the ECM wire

harness electrical connector. Refer to

Wiring Repairs

Wiring Systems.

Did you complete the repair?

—

Go to

Step 24

—

Replace the underhood fuse block. Refer to

Underhood

Electrical Center or Junction Block Replacement

in Wiring

Systems.

Did you complete the replacement?

—

Go to

Step 24

—

Replace the powertrain ignition 1 relay. Refer to

Relay

Replacement (Within an Electrical Center)

Relay

Replacement (Attached to Wire Harness)

in Wiring

Systems.

Did you complete the replacement?

—

Go to

Step 24

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 24

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Turn ON the ignition, with the engine OFF.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 3

Go to

Step 25

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P0690

Circuit Description

The powertrain ignition 1 relay is a normally open

relay. The relay armature is held in the open position

by spring tension. Battery positive voltage is

supplied directly to the relay coil and the armature

contact at all times. The engine control module (ECM)

supplies the ground path to the relay coil control

circuit via an internal integrated circuit called an output

driver module (ODM). When the ECM commands

the powertrain ignition 1 relay ON, ignition 1 voltage is

supplied to the ECM through the ETC fuse in the

underhood fuse block. The ignition 1 voltage input to

the ECM provides the ignition power for the electronic

throttle control (ETC) circuitry, and is also used to

conﬁrm that the powertrain ignition 1 relay has closed.

This DTC will set when the ECM detects more than

2 volts on the ETC ignition 1 voltage circuit to the

ECM, after the ignition switch is turned OFF.

DTC P0690 indicates a short to battery positive

voltage, on the ETC ignition 1 voltage circuit to the

body control module (BCM).

The underhood fuse block features an alphanumeric

grid system for the terminals of the relays and the mini

fuses. Along the top forward edge of the underhood

fuse block, the letters A, B, C, D, E, F, G, H, J,

K, L, and M are used. Along the top right edge of the

underhood fuse block the numbers 1 through 20

are used. The powertrain ignition 1 relay circuits are

assigned to the following cavities of the underhood

fuse block.

• H13 – Battery positive voltage to the relay coil,

hot at all times

• H14 – Battery positive voltage to the relay

armature, hot at all times

• F14 – Relay coil control circuit, ECM controlled

• F13 – Relay load circuit, ignition 1 voltage to

the following fuses and relay

− Fuel Fuse

− O2 Sensor Fuse

− ETC fuse

− Emission Fuse

− Even INJ Fuse

− Odd INJ Fuse

− A/C Comp Relay – Relay coil side

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0690 Engine Controls Ignition Relay Feedback

Circuit High Voltage

Conditions for Running the DTC

• The battery voltage is between 9–16 volts.

• The ignition switch is turned OFF.

• The powertrain ignition 1 relay has been

commanded OFF.

Conditions for Setting the DTC

The ECM detects greater than 2 volts on the ETC

ignition 1 voltage circuit for more than 2 seconds.

Action Taken When the DTC Sets

• The control module stores the DTC information

into memory when the diagnostic runs and fails.

• The malfunction indicator lamp (MIL) will

illuminate.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in Failure

Records.

• The driver information center, if equipped, may

display a message.

Conditions for Clearing the MIL/DTC

• A current DTC, last test failed clears when the

diagnostic runs and passes.

• A history DTC clears 40 consecutive warm-up

cycles, if no other failures are reported by

this or any other emission related diagnostic.

•CleartheDTCwithaTech 2 .

DTC P0690

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector End

Views

, and

Electrical Center Identiﬁcation Views

in Wiring Systems

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

EngineEngineControls-6.0L

DTC P0690 (cont’d)

Step Action Yes No

1. Observe the Freeze Frame/Failure Records for the DTC.

2. Turn OFF the ignition for 30 seconds.

3. Turn ON the ignition, with the engine OFF.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 3

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Remove the powertrain ignition 1 relay from the underhood

fuse block with the

J 43244

Relay Puller Pliers. Refer to

Relay Replacement (Within an Electrical Center)

Relay

Replacement (Attached to Wire Harness)

in Wiring Systems.

3. Probe either test point of the ETC fuse with a test lamp that

is connected to a good ground. Refer to

Troubleshooting with

a Test Lamp

in Wiring Systems.

Does the test lamp illuminate on either test point of the fuse? Go to

Step 4

Go to

Step 6

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM) wire harness

electrical connector that contains the ignition 1 voltage circuit

from the ETC fuse. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

3. Probe either test point of the ETC fuse with a test lamp that

is connected to a good ground. Refer to

Troubleshooting with

a Test Lamp

in Wiring Systems.

Does the test lamp illuminate on either test point of the fuse? Go to

Step 5

Go to

Step 9

1. Turn OFF the ignition.

Notice:

Refer to

Test Probe Notice

in Cautions and Notices.

2. Probe the ignition 1 voltage terminal F13 at the powertrain

ignition 1 relay location, on the underhood fuse block, with a

test lamp that is connected to a good ground. This terminal is

the one that leads from the powertrain relay to the fuses.

3. Monitor the test lamp.

4. Remove the following fuses from the underhood fuse block,

one fuse at a time.

• ENG 1 fuse

• O2A fuse

• O2B fuse

• TAC fuse

• INJ A fuse

• INJ B fuse

Does the test lamp go out when a fuse is removed from the

underhood fuse block? Go to

Step 10

Go to

Step 13

Measure the resistance from terminal 30, of the powertrain

ignition 1 relay, to terminal 87 with a DMM. Refer to

Troubleshooting with a Digital Multimeter

in Wiring Systems.

Does the DMM display OL? Go to

Step 7

Go to

Step 11

7Measure the resistance from terminal 30, of the powertrain

ignition 1 relay, to terminal 85 with a DMM.

Does the test lamp illuminate? Go to

Step 8

Go to

Step 11

8Measure the resistance from terminal 85, of the powertrain

ignition 1 relay, to terminal 87 with a DMM

Does the DMM display OL? Go to

Intermittent

Conditions

Go to

Step 11

EngineControls-6.0LEngine

DTC P0690 (cont’d)

Step Action Yes No

Test for shorted terminals and poor connections at the ECM

electrical connector, and the ECM wire harness electrical

connector.

Does the resistance measure more than the speciﬁed value? Refer

Testing for Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems. Go to

Step 14

Go to

Step 12

Test the short to battery positive voltage in the ignition 1 voltage

circuit, which caused the test lamp to go out, when the fuse for

that circuit was removed. Refer to

Wiring Repairs

in Wiring

Systems.

Did you complete the repair? Go to

Step 14

—

Replace the powertrain ignition 1 relay. Refer to

Relay

Replacement (Within an Electrical Center)

Relay Replacement

(Attached to Wire Harness)

in Wiring Systems.

Did you complete the replacement? Go to

Step 14

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement? Go to

Step 14

—

13 Replace the underhood fuse block. Refer to

Underhood Electrical

Center or Junction Block Replacement

in Wiring Systems.

Did you complete the replacement? Go to

Step 14

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Turn ON the ignition, with the engine OFF.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze/Frame Records.

Did the DTC fail the ignition? Go to

Step 3

Go to

Step 15

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P0700

Circuit Description

The malfunction indicator lamp (MIL) request circuit

signals the engine control module (ECM) that the

transmission control module (TCM) is requesting MIL

illumination.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The TCM is requesting MIL illumination or the MIL

request circuit is shorted to ground.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. If the TCM has DTCs set that are requesting MIL

illumination, those DTCs must be diagnosed ﬁrst.

DTC P0700

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

ConnectaTech 2 .

Are there any transmission DTCs set? —Go to

Step 3

Go to

Step 5

Diagnose and repair any transmission DTCs.

Are there any transmission DTCs? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 4

1. Observe the Freeze Frame/Failure Records data for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Does the DTC fail this ignition?

—

Go to

Step 5

Go to

Intermittent

Conditions

1. Disconnect the transmission control module (TCM).

Refer to

Transmission Control Module (TCM)

Replacement

in Automatic Transmission – Allison.

2. Connect a DMM from the malfunction indicator

lamp (MIL) request circuit in the TCM harness

connector to a good ground.

3. Turn ON the ignition, with the engine OFF.

Does the voltage measure near the speciﬁed value?

B+

Go to

Step 7

Go to

Step 6

EngineControls-6.0LEngine

DTC P0700 (cont’d)

Step Action Values Yes No

6Test the MIL request circuit for a short to ground. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? —Go to

Step 11

Go to

Step 8

Test for shorted terminals and for intermittent and poor

connections at the TCM. Refer to

Testing for Intermittent

Conditions and Poor Connections

Repairing Connector

Terminals

, and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 11

Go to

Step 9

Test for shorted terminals and for intermittent and poor

connections at the engine control module (ECM). Refer to

Testing for Intermittent Conditions and Poor Connections

Repairing Connector Terminals

, and

Connector Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 11

Go to

Step 10

9Replace the TCM. Refer to

Control Module References

Did you complete the replacement? —Go to

Step 11

—

10 Replace the ECM. Refer to

Engine Control Module (ECM)

Replacement

Did you complete the replacement? —Go to

Step 11

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 12

ObservetheCaptureInfowithaTech 2

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P1101

Circuit Description

The intake ﬂow rationality diagnostic provides the

within-range rationality check for the mass air

ﬂow (MAF), manifold absolute pressure (MAP), and

the throttle position (TP) sensors. This is an explicit

model-based diagnostic containing 3 separate models

for the intake system.

• One model, the throttle model, describes the ﬂow

through the throttle body and is used to estimate

the MAF through the throttle body as a function

of barometric pressure (BARO), TP, intake

air temperature (IAT), and estimated MAP.

• Another model, the ﬁrst intake manifold model,

describes the intake manifold and is used to

estimate MAP as a function of the MAF into the

manifold from the throttle body and the MAF out of

the manifold caused by engine pumping. The

ﬂow into the manifold from the throttle uses the

MAF estimate calculated from the above

throttle model.

• Another model is the second intake manifold

model and is identical to the ﬁrst intake manifold

model except that the MAF sensor measurement

is used instead of the throttle model estimate

for the throttle air input.

• Finally, a fourth model is created from the

combination and additional calculations of the

throttle model and the ﬁrst intake manifold model.

The estimates of MAF and MAP obtained from

this system of models and calculations are then

compared to the actual measured values from the

MAF, MAP, and the TP sensors and to each other to

determine the appropriate DTC to fail. The following

table illustrates the possible failure combinations

and the resulting DTC or DTCs.

Throttle Model First Intake

Manifold Model Second Intake

Manifold Model Fourth Model DTCs Passed DTCs Failed

X X Pass Pass

P0101

P0106

P0121

P1101

None

Pass Pass Failed Pass

P0101

P0106

P0121

P1101

None

Failed Pass Failed Pass P0106

P0121

P1101 P0101

Pass Failed Failed Pass P0101

P0121

P1101 P0106

Failed Failed Failed Pass P0121

P1101 P0101

P0106

X X Pass Failed P0101

P0106

P1101 P0121

Pass Pass Failed Failed

P0101

P0106

P0121

P1101

None

Failed Pass Failed Failed P0101

P0106

P0121 P1101

X Failed Failed Failed P0101

P0106

P0121 P1101

If the engine control module (ECM) detects that the

actual measured airﬂow from MAF, MAP, and TP is not

within range of the calculated airﬂow that is derived

from the system of models, DTC P1101 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1101 Intake Air Flow System Performance

EngineControls-6.0LEngine

Conditions for Running the DTC

• DTCs P0102, P0103, P0112, P0113, P0107,

P0108, P0117, P0118, P0335, P0336 are not set.

• The engine speed is between 400–6,400 RPM.

• The IAT Sensor parameter is between −7°C

and +125°C (19–257°F).

• The ECT Sensor parameter is between 70–125°C

(158–257°F).

• This DTC runs continuously within the enabling

conditions.

Conditions for Setting the DTC

The ECM detects that the actual measured airﬂow

from MAF, MAP, and TP is not within range of

the calculated airﬂow that is derived from the system

of models for more than 0.5 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Any condition that can cause the MAF, MAP, and

TP sensors to be shifted in value at the same

time will cause this DTC to set.

• Inspect the harness of the MAF sensor to verify

that it is not routed too close to the following

components:

− Any aftermarket accessories—Refer to

Checking Aftermarket Accessories

in Wiring

Systems.

− The secondary ignition wires or coils

− Any solenoids

− Any relays

− Any motors

• A wide open throttle acceleration from a stop

should cause the MAF sensor parameter on

theTech 2 toincreaserapidly.Thisincrease

should be from 3–6 g/s at idle to 120 g/s or more

at the time of the 1-2 shift. If the increase is

not observed, inspect for a restriction in the

induction system or the exhaust system.

• A skewed or stuck engine coolant

temperature (ECT) or IAT sensor will cause the

calculated models to be inaccurate and may cause

this DTC to run when it should not.

• A steady or intermittent high resistance of

15 ohms or more on the ignition 1 voltage circuit

will cause the MAF sensor values to be skewed

high by up to 60 g/s, and may cause this DTC to

set. A high resistance will cause a driveability

concern before this DTC sets.

• The BARO that is used by the ECM to calculate

the air ﬂow models is initially based on the

MAP sensor at key ON. When the engine is

running, the ECM will continually update

the BARO value near wide open throttle using the

MAP sensor and a calculation. A skewed MAP

sensor will cause the calculated mass air

ﬂow value to be inaccurate and may result in a no

start condition. With the ignition ON and the

engine OFF, the MAP Sensor parameter varies

with the altitude. 101 kPa is the approximate value

near sea level. This value will decrease by

approximately 3 kPa for every 305 meters

(1,000 feet) of altitude.

• A high resistance on the low reference circuit of

the MAP sensor will skew the sensor value and

may cause this DTC to set.

• A short to battery voltage on the 5-volt reference

circuit of the MAP sensor will cause this DTC

to set.

• If the condition is intermittent, refer to

Inducing

Intermittent Fault Conditions

in Wiring Systems

and

Intermittent Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

5. This step will determine if any mechanical faults

have caused this DTC to set.

12. This voltage drop test will determine if high

resistance has caused this DTC to set.

14. This step veriﬁes the voltage signal from the ECM

to the MAF sensor connector.

15. This step will determine if the ECM can accurately

process the frequency signal that it receives from

the MAF sensor.

16. This step will determine if an abnormal resistance

of less than 1,150 ohms has skewed the MAF

sensor frequency signal.

EngineEngineControls-6.0L

DTC P1101

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Important: A stalling condition created by any of the

following DTCs may cause this DTC to set.

Are DTCs P0641, P0651, P1516, P2101, P2119, or

P2135 set? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

Important: This Diagnostic Routine may have to be

followed more than once. This is because multiple failures

cause DTC P1101 to set.

Attempt to start the engine.

Does the engine start?

—

Go to

Step 4

Go to

Step 5

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 60 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Diagnostic Aids

1. Turn OFF the ignition.

2. Inspect for the following conditions:

• A restricted or collapsed air intake duct

• A misaligned or damaged air intake duct

• A dirty or deteriorating air ﬁlter element

• Any objects blocking the air inlet probe of the mass

air ﬂow (MAF)/intake air temperature (IAT) sensor

• Any contamination or debris on the sensing

elements in the probe of the MAF/IAT sensor

• Any water intrusion in the induction system

• Any vacuum leak downstream of the MAF/IAT

sensor

• An intake manifold leak

• An engine misﬁre—Review the Freeze

Frame/Failure records.

• A manifold absolute pressure (MAP) sensor seal

that is missing or damaged

• A skewed or stuck engine coolant

temperature (ECT) or IAT sensor—Refer to

Temperature vs Resistance

• Any type of restriction in the exhaust system—

Refer to

Restricted Exhaust

in Engine Exhaust.

Did you ﬁnd and correct the condition?

—

Go to

Step 24

Go to

Step 6

EngineControls-6.0LEngine

DTC P1101 (cont’d)

Step Action Values Yes No

Important: The Altitude vs. Barometric (BARO) Pressure

table indicates a pressure range for a given altitude under

normal weather conditions. Weather conditions consisting

of very low or very high pressure and/or temperature may

cause a reading to be slightly out of range.

1. Accurately determine the altitude.

2. Turn ON the ignition, with the engine OFF.

3. Observe the MAP Sensor kPa parameter with a

Tech 2 .

4. The MAP sensor pressure should be within the

speciﬁed range for your altitude. Refer to

Altitude vs

Barometric Pressure

Is the MAP sensor pressure within the speciﬁed range as

indicated on the Altitude vs. Barometric pressure table?

—

Go to

Step 7

Go to

DTC P0106

1. Start the engine.

2. Turn OFF all lights and accessories.

3. Allow the engine to reach operating temperature.

4.ObservetheMAPSensorparameterwithaTech 2 .

Is the MAP Sensor parameter within the speciﬁed range?

19–40 kPa

Go to

Step 8

Go to

DTC P0106

1. Idle the engine.

2. Take a snapshot of the Engine Data list while

performingthefollowingaction.Referto

Tech 2

Snapshot Procedure

in Wiring Systems.

3. Increase the engine speed slowly to 3,000 RPM and

then slowly back to idle.

4. Exit from the snapshot and review the data.

5. Observe the MAP Sensor kPa parameter frame by

framewithaTech 2 .

Does the MAP Sensor parameter change smoothly and

gradually through the speciﬁed range of the test?

—

Go to

Step 9

Go to

DTC P0106

1. Turn OFF the ignition.

2. Turn ON the ignition, with the engine OFF.

3. Observe The TP Indicated Angle parameter with a

Tech 2 .

4. Depress the accelerator pedal completely.

Is the TP Indicated Angle parameter within the

speciﬁed range?

99–100%

Go to

Step 10

Go to

DTC P1516

1. Take a snapshot of the TAC Data list while performing

thefollowingaction.Referto

Tech 2 Snapshot

Procedure

in Wiring Systems.

2. Slowly depress the accelerator pedal to wide-open

throttle and then slowly release the pedal.

3. Exit from the snapshot and review the data.

4. Compare the TP Sensor 1 and the TP Sensor 2

parameters frame by frame.

Is the difference between the parameters at any time more

than the speciﬁed value?

Go to

DTC P2135

Go to

Step 11

Inspect the throttle body and the throttle valve for the

following conditions:

• Any damage

• Any restriction that could affect the air ﬂow through the

throttle body or the throttle valve

• Any missing parts

• A throttle valve that is not fully open when the

accelerator pedal is fully depressed

Did you ﬁnd and correct the condition?

—

Go to

Step 24

Go to

Step 12

EngineEngineControls-6.0L

DTC P1101 (cont’d)

Step Action Values Yes No

1. Measure the battery voltage with a DMM.

2. Disconnect the MAF/IAT sensor.

3. Connect a test lamp between the ignition 1 voltage

circuit of the MAF sensor and a good ground. Refer to

Probing Electrical Connectors

in Wiring Systems.

4. Connect the DMM to the probe of the test lamp and a

good ground. Refer to

Measuring Voltage Drop

and

Circuit Testing

in Wiring Systems.

Is the voltage within 0.50 volts of the speciﬁed value?

B+

Go to

Step 13

Go to

Step 20

Important: All electrical components and accessories must

be turned OFF.

1. Turn OFF the ignition for 60 seconds to allow the

control modules to power down.

2. Measure the resistance from the ground circuit of the

MAF sensor to a good ground with a DMM. Refer to

Circuit Testing

in Wiring Systems.

Is the resistance less than the speciﬁed value?

5Ω

Go to

Step 14

Go to

Step 21

1. Turn ON the ignition, with the engine OFF.

2. Measure the voltage from the signal circuit of the MAF

sensor to a good ground with a DMM. Refer to

Circuit

Testing

in Wiring Systems.

Is the voltage within the speciﬁed range?

4.9–5.2 V

Go to

Step 15

Go to

Step 17

1. Turn OFF the ignition.

2. Connect the voltage supply and the ground lead of the

J 38522

Variable Signal Generator to the vehicle.

3. Connect the red lead of the

J 38522

to the signal

circuit of the MAF sensor. Refer to

Probing Electrical

Connectors

in Wiring Systems.

4. Set the Duty Cycle switch of the

J 38522

to Normal.

5. Set the Frequency switch of the

J 38522

to 5 K.

6. Set the Signal switch of the

J 38522

to 5 V.

7. Start the engine and allow it to idle.

8.ObservetheMAFSensorparameterwithaTech 2 .

Is the MAF Sensor parameter within the speciﬁed range?

4,950–5,025 Hz

Go to

Step 16

Go to

Step 17

Important: The

J 38522

is able to overcome an abnormal

resistance on the signal circuit of up to 1,150 ohms. The

MAF sensor will not be able to overcome a resistance

this high.

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM).

3. Test the MAF sensor signal circuit for the following

conditions:

• A high resistance

Important: The following short will skew the MAF sensor

reading by 35 g/s or more at a wide-open throttle (WOT)

acceleration.

• A short to the IAT signal circuit

Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 24

Go to

Step 18

EngineControls-6.0LEngine

DTC P1101 (cont’d)

Step Action Values Yes No

1. Turn OFF the ignition.

2. Disconnect the ECM.

3. Test the MAF sensor signal circuit for the following

conditions:

• A high resistance

• An intermittent open circuit

• A high resistance short to ground

• A short to the IAT signal circuit

Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 24

Go to

Step 19

Test for an intermittent and for a poor connection at the

MAF/IAT sensor. Refer to

Testing for Intermittent

Conditions and Poor Connections

Connector Repairs

and

Repairing Connector Terminals

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 24

Go to

Step 22

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

Connector Repairs

, and

Repairing Connector

Terminals

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 24

Go to

Step 23

Repair the high resistance or the intermittent open in the

MAF sensor ignition 1 voltage circuit. Refer to

Wiring

Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 24

—

Repair the high resistance or the intermittent open in the

MAF sensor ground circuit. Refer to

Wiring Repairs

Wiring Systems.

Did you complete the repair?

—

Go to

Step 24

—

Replace the MAF/IAT sensor. Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor

Replacement

Did you complete the replacement?

—

Go to

Step 24

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 24

—

Important: This diagnostic routine may have to be followed

more than once.

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 60 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 25

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P1133 or P1153

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. Heating elements

inside the HO2S minimize the time required for the

sensors to reach operating temperature. The engine

control module (ECM) supplies the HO2S with a

reference, or bias, voltage of about 450 mV. When the

engine is ﬁrst started the ECM operates in Open

Loop, ignoring the HO2S voltage signal. Once

the HO2S reaches operating temperature and Closed

Loop is achieved, the HO2S generates a voltage

within a range of 0–1,000 mV that ﬂuctuates above

and below bias voltage. High HO2S voltage indicates

a rich exhaust stream. Low HO2S voltage indicates

a lean exhaust stream. This diagnostic will only

run once per ignition cycle. The ECM monitors the

number of rich-to-lean and lean-to-rich transitions. If

the ECM detects that the number of transitions

were less than a speciﬁed value, DTC P1133 sets for

HO2S bank 1 sensor 1, or DTC P1153 sets for

HO2S bank 2 sensor 1.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P1133 HO2S Insufficient Switching Bank 1

Sensor 1

• DTC P1153 HO2S Insufficient Switching Bank 2

Sensor 1

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0131, P0132,

P0134, P0135, P0151, P0152, P0154, P0155,

P0201, P0202, P0203, P0204, P0205, P0206,

P0207, P0208, P0220, P0300, P0442, P0443,

P0446, P0449, P0455, P0496, P1258, P1516,

P2101, P2135, P2176 are not set.

• The ECT Sensor parameter is more than 55°C

(131°F).

• The EVAP Purge Solenoid Command parameter

is more than 1 percent.

• The MAF Sensor parameter is between 15–

55 g/s.

• The Engine Speed parameter is between 1,000–

3,000 RPM.

• The TP Indicated Angle parameter is 5 percent

more than the value observed at idle.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The Engine Run Time parameter is more than

160 seconds.

• This diagnostic runs one time per drive cycle once

the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the affected HO2S lean-to-rich

or rich-to-lean transitions are less than a calibrated

value for a 60 second monitoring period.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. If the voltage is varying above and below the

speciﬁed value, the condition is not present.

DTC P1133 or P1153

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

EngineControls-6.0LEngine

DTC P1133 or P1153 (cont’d)

Step Action Value(s) Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Start the engine.

2. Allow the engine to reach operating temperature.

Referto

Tech 2 DataList

3. Operate the engine at 1,500 RPM for 30 seconds.

4. Observe the affected heated oxygen sensor (HO2S)

voltageparameterwithaTech 2 .

Is the HO2S voltage parameter varying above and below

the speciﬁed range?

250–625 mV

Go to

Step 3

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the affected HO2S.

3. Turn ON the ignition, with the engine OFF.

4. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 6

Go to

Step 5

1. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and a good ground.

2. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 8

Go to

Step 7

Test the HO2S high signal circuit for a short to the HO2S

low signal circuit. Refer to

Circuit Testing

Wiring Repairs

and

Heated Oxygen Sensor (HO2S) Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 11

Test the HO2S high signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 11

1. Remove the jumper wire from the previous step.

2. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and the low signal circuit of the

HO2S harness connector on the engine harness side.

3. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 10

Go to

Step 9

EngineEngineControls-6.0L

DTC P1133 or P1153 (cont’d)

Step Action Value(s) Yes No

Test the HO2S low signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 11

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 12

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 14

Go to

Step 13

Notice:

Refer to

Silicon Contamination of Heated Oxygen

Sensors Notice

in Cautions and Notices.

Important: The HO2S may be damaged due to

contamination. Prior to replacing the HO2S, inspect for the

following sources of contamination:

• A silicon contaminated HO2S

• Fuel contamination—Refer to

Fuel System Diagnosis

• Engine oil consumption—Refer to

Oil Consumption

Diagnosis

in Engine Mechanical.

• Engine coolant consumption—Refer to

Loss of Coolant

(Automatic Transmission)

Loss of Coolant (Manual

Transmission)

in Engine Cooling.

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 1

Heated

Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1

Did you complete the replacement?

—

Go to

Step 14

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 14

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 15

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P1134 or P1154

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel

control and post catalyst monitoring. Each HO2S

compares the oxygen content of the surrounding air

with the oxygen content in the exhaust stream.

The HO2S must reach operating temperature to

provide an accurate voltage signal. Heating elements

inside the HO2S minimize the time required for the

sensors to reach operating temperature. The engine

control module (ECM) supplies the HO2S with a

reference, or bias, voltage of about 450 mV. When the

engine is ﬁrst started the ECM operates in Open

Loop, ignoring the HO2S voltage signal. Once

the HO2S reaches operating temperature and Closed

Loop is achieved, the HO2S generates a voltage

within a range of 0–1,000 mV that ﬂuctuates above

and below bias voltage. High HO2S voltage indicates

a rich exhaust stream. Low HO2S voltage indicates

a lean exhaust stream. This diagnostic will only

run once per ignition cycle. The ECM monitors the

rich-to-lean and lean-to-rich transition time. A transition

is deﬁned as, the HO2S voltage changes from

above 625 mV to below 250 mV or from below 250 mV

to above 625 mV. If the ECM detects that the

difference between the rich-to-lean average transition

time and lean-to-rich average transition time is

more than a speciﬁed value, DTC P1134 sets for

HO2S bank 1 sensor 1, or DTC P1154 sets for HO2S

bank 2 sensor 1.

DTC Descriptors

This diagnostic procedure supports the

following DTCs:

• DTC P1134 HO2S Transition Time Ratio Bank 1

Sensor 1

• DTC P1154 HO2S Transition Time Ratio Bank 2

Sensor 1

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107,

P0108, P0112, P0113, P0117, P0118, P0120,

P0121, P0122, P0123, P0128, P0131, P0132,

P0134, P0135, P0151, P0152, P0154, P0155,

P0201, P0202, P0203, P0204, P0205, P0206,

P0207, P0208, P0220, P0300, P0442, P0443,

P0446, P0449, P0455, P0496, P1258, P1516,

P2101, P2135, P2176 are not set.

• The ECT Sensor parameter is more than 55°C

(131°F).

• The EVAP Purge Solenoid Command parameter

is more than 1 percent.

• The MAF Sensor parameter is between 15–

55 g/s.

• The Engine Speed parameter is between 1,000–

3,000 RPM.

• The TP Indicated Angle parameter is 5 percent

more than the value observed at idle.

• The Loop Status parameter is closed.

• The Ignition 1 Signal parameter is between 10–

18 volts.

• The Fuel Tank Level Remaining parameter is

more than 10 percent.

• The Engine Run Time parameter is more than

160 seconds.

• This diagnostic runs one time per drive cycle once

the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the difference between the

HO2S rich-to-lean average transition time and

the lean-to-rich average transition time is more than a

calibrated value for a 60 second monitoring period.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) on the second consecutive

ignition cycle that the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

ﬁrst time the diagnostic fails, the control module

stores this information in the Failure Records.

If the diagnostic reports a failure on the

second consecutive ignition cycle, the control

module records the operating conditions at

the time of the failure. The control module writes

the operating conditions to the Freeze Frame

and updates the Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Test Description

The number below refers to the step number on the

diagnostic table.

2. If the voltage is varying above and below the

speciﬁed value, the condition is not present.

EngineEngineControls-6.0L

DTC P1134 or P1154

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Start the engine.

2. Allow the engine to reach operating temperature.

Referto

Tech 2 DataList

3. Operate the engine at 1,500 RPM for 30 seconds.

4. Observe the affected heated oxygen sensor (HO2S)

voltageparameterwithaTech 2

Is the HO2S voltage parameter varying above and below

the speciﬁed range?

250–625 mV

Go to

Step 3

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the affected HO2S.

3. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and a good ground.

4. Turn ON the ignition, with the engine OFF.

5. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 6

Go to

Step 5

Test the HO2S high signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 9

1. Remove the jumper wire from the previous step.

2. Connect a 3-amp fused jumper wire between the high

signal circuit of the HO2S harness connector on the

engine harness side and the low signal circuit of the

HO2S harness connector on the engine harness side.

3. Observe the HO2S voltage parameter with a

Tech 2 .

Is the HO2S voltage parameter less than the

speciﬁed value?

100 mV

Go to

Step 8

Go to

Step 7

Test the HO2S low signal circuit for an open or high

resistance. Refer to

Circuit Testing

Wiring Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 9

EngineControls-6.0LEngine

DTC P1134 or P1154 (cont’d)

Step Action Value(s) Yes No

Test for shorted terminals and for poor connections at the

HO2S. Refer to

Testing for Intermittent Conditions and

Poor Connections

Connector Repairs

, and

Heated Oxygen

Sensor (HO2S) Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 10

Test for shorted terminals and for poor connections at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

Connector

Repairs

, and

Heated Oxygen Sensor (HO2S) Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 11

Notice:

Refer to

Silicon Contamination of Heated Oxygen

Sensors Notice

in Cautions and Notices.

Important: The HO2S may be damaged due to

contamination. Prior to replacing the HO2S, inspect for the

following sources of contamination:

• A silicon contaminated HO2S

• Fuel contamination—Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without

Special Tool)

Alcohol/Contaminants-in-Fuel

Diagnosis (with Special Tool)

• Engine oil consumption—Refer to

Oil Consumption

Diagnosis

in Engine Mechanical.

• Engine coolant consumption—Refer to

Loss of Coolant

(Automatic Transmission)

Loss of Coolant (Manual

Transmission)

in Engine Cooling.

Replace the affected HO2S. Refer to

Heated Oxygen

Sensor (HO2S) Replacement Bank 1 Sensor 1

Heated

Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1

Did you complete the replacement?

—

Go to

Step 12

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 12

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 13

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P1380

System Description

The engine control module (ECM) detects engine

misﬁre events by monitoring variations in the

crankshaft rotation speed. Wheel speed changes

caused by rough road conditions can cause changes

in crankshaft speed. By monitoring the wheel

speed sensors, the antilock brake system (ABS) can

determine if the vehicle is operating on a rough road. If

the ABS is detecting a rough road condition severe

enough to effect misﬁre detection, a rough road signal

is sent to the ECM on the serial data circuit. If

DTC P0300 is set and the rough road information is

not available due to an ABS malfunction, DTC P1380

will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1380 Misﬁre Detected – Rough Road Data

Not Available

Conditions for Running the DTC

• The vehicle speed is greater than 8 km/h (5 mph).

• The engine load is less than 60 percent.

• Engine misﬁre is detected and DTC P0300 sets.

• The engine speed is less than 6,600 RPM.

• DTC P1380 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

An ABS malfunction exists for more than 10 seconds

preventing the ECM from receiving rough road

detection data.

Action Taken When the DTC Sets

• The control module stores the DTC information

into memory when the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Failure Records.

• The driver information center, if equipped, may

display a message.

Conditions for Clearing the DTC

• A current DTC Last Test Failed clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other non-emission related diagnostic.

•CleartheDTCwithaTech 2 .

DTC P1380

Step Action Yes No

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

DoestheTech 2 displayanyantilockbrake

system (ABS) DTCs? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information

Go to

Symptoms -

Antilock Brake System

in Antilock Brake

System

EngineControls-6.0LEngine

DTC P1381

System Description

The engine control module (ECM) detects engine

misﬁre events by monitoring variations in the

crankshaft rotation speed. Wheel speed changes

caused by rough road conditions can cause changes

in crankshaft speed. By monitoring the wheel

speed sensors, the antilock brake system (ABS) can

determine if the vehicle is operating on a rough road. If

the ABS is detecting a rough road condition severe

enough to effect misﬁre detection, a rough road signal

is sent to the ECM on the serial data circuit. If

DTC P0300 is set and there is no communication with

the brake control module, DTC P1381 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1381 Misﬁre Detected – No Communication

With Brake Control Module

Conditions for Running the DTC

• The vehicle speed is greater than 8 km/h (5 mph).

• The engine speed is less than 6,600 RPM.

• The engine load is less than 60 percent.

• Engine misﬁre is detected and DTC P0300 sets.

Conditions for Setting the DTC

The ECM cannot communicate with the brake control

module for more than 10 seconds.

Action Taken When the DTC Sets

• The control module stores the DTC information

into memory when the diagnostic runs and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Failure Records.

• The driver information center, if equipped, may

display a message.

Conditions for Clearing the DTC

• A current DTC Last Test Failed clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other non-emission related diagnostic.

•CleartheDTCwithaTech 2 .

DTC P1381

Step Action Yes No

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

DoestheTech 2 displayanyantilockbrake

system (ABS) DTCs? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information

Go to

Symptoms -

Antilock Brake System

in Antilock Brake

System

EngineEngineControls-6.0L

DTC P1516

Circuit Description

The commanded throttle position is compared to the

actual throttle position based on accelerator pedal

position (APP) and possibly other limiting factors. Both

values should be within a calibrated range of each

other. The engine control module (ECM) continuously

monitors the commanded and actual throttle

positions. This DTC sets if the values are greater than

the calibrated range.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1516 Throttle Actuator Control (TAC) Module

Throttle Actuator Position Performance

Conditions for Running the DTC

• The ignition is ON.

• The ignition voltage is greater than 6.5 volts.

• The system is not in the battery save mode.

• The engine is running.

• DTCs P0068, P2119, P2176 are not set.

Conditions for Setting the DTC

The difference between the predicted and the actual

throttle position is more than a calibrated amount.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

The throttle valve are spring loaded to a slightly open

position. The throttle valve should be open

approximately 20 percent. This is referred to as the

rest position. The throttle valve should not be

completely closed nor should they be open any more

than the speciﬁed amount. The throttle valve should

move open and to the closed position without binding

under the normal spring pressure. The throttle

should NOT be free to move open or closed WITHOUT

spring pressure. Replace the throttle body if any of

these conditions are found.

Important: Operating the throttle blade with the

ThrottleBladeControlfunctionoftheTech 2 may

cause additional DTCs to set. Do not attempt to

diagnose DTCs set during this function.

TheTech 2 hastheabilitytooperatethethrottle

control system using special functions. Actuate

the throttle valve using the throttle blade control

function located in the throttle actuator control (TAC)

system menu. This function will operate the throttle

valve through the entire range in order to determine if

the throttle body and system operate correctly.

Check for the following conditions:

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the engine control

module (ECM) harness connector or a component

harness connector.

• Poor connections at the ECM or at the

component—Inspect the harness connectors for a

poor terminal to wire connection. Refer to

Testing for Intermittent Conditions and Poor

Connections

in Wiring Systems for the proper

procedure.

• For intermittents, refer to

Intermittent Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

8. The throttle valve is spring loaded in a slightly

open position and should move in either direction

without binding. The throttle valve should

always be under spring pressure.

11. When the ignition is turned ON, the ECM operates

the throttle control motor to verify the integrity of

the system prior to start-up. This can be seen

by the momentary ﬂash of the test lamp as

the ignition is turned ON.

DTC P1516

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Controls Connector End Views

Engine Control Module (ECM) Connector

End Views

EngineControls-6.0LEngine

DTC P1516 (cont’d)

Step Action Yes No

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

Are DTCs P0120, P0220, P2120, P2125, P2135, P2138 also set? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

Step 3

Important: The throttle angle and pedal angle may not correspond

during this procedure.

1. Turn ON the ignition, with the engine OFF.

2. Observe the throttle position (TP) sensor 1 and 2 angle

parameters.

3. Apply and release the accelerator pedal several times.

Does the TP sensor 1 and 2 angle parameters increase as the

pedal is applied and decrease as the pedal is released? Go to

Step 4

Go to

Step 5

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Start the engine.

3. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 5

Go to Diagnostic Aids

1. Turn ON the ignition, with the engine OFF.

2. Probe both sides of the ETC fuse with a test lamp connected

to ground.

Does the test lamp illuminate on both sides of the fuse? Go to

Step 6

Go to

Step 16

1. Turn OFF the ignition.

2. Probe both sides of the ETC fuse with a test lamp connected

to ground.

Does the test lamp illuminate on both sides of the fuse? Go to

Step 22

Go to

Step 7

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM) connector

containing the ETC ignition 1 voltage circuit.

3. Turn ON the ignition.

4. Probe the ETC ignition 1 voltage circuit with a test lamp

connected to ground.

Does the test lamp illuminate? Go to

Step 8

Go to

Step 23

1. Turn OFF the ignition.

2. Inspect the throttle body for the following conditions. Refer to

Diagnostic Aids:

• A throttle valve that is NOT in the rest position

• A throttle valve that is binding open or closed

• A throttle valve that is free to move open or closed

WITHOUT spring pressure

Did you ﬁnd any of these conditions with the throttle body? Go to

Step 24

Go to

Step 9

Important: The test lamp may momentarily ﬂash when testing

these circuits. This is considered normal.

1. Disconnect the throttle body harness connector.

2. Turn ON the ignition, with the engine OFF.

3. Probe the throttle actuator control (TAC) motor control 1 and

2 circuits with the test lamp connected to ground.

Did the test lamp illuminate and remain illuminated on either

circuit? Go to

Step 13

Go to

Step 10

EngineEngineControls-6.0L

DTC P1516 (cont’d)

Step Action Yes No

Important: The test lamp may momentarily ﬂash when testing

these circuits. This is considered normal.

Probe the TAC motor control 1 and 2 circuits with the test lamp

connected to battery positive.

Did the test lamp illuminate and remain illuminated on either

circuit? Go to

Step 14

Go to

Step 11

1. Turn OFF the ignition.

2. Connect the test lamp between the TAC motor control 1 and

battery ground.

3. Observe the test lamp as you turn ON the ignition.

Does the test lamp ﬂash ON and then turn OFF? Go to

Step 12

Go to

Step 15

1. Turn OFF the ignition.

2. Connect a test lamp between the TAC motor control 2 circuit

and battery ground.

3. Observe the test lamp as you turn ON the ignition.

Does the test lamp ﬂash ON and then OFF? Go to

Step 18

Go to

Step 15

1. Turn OFF the ignition.

2. Disconnect the ECM connector that contains the TAC motor

control circuits.

3. Turn ON the ignition, with the engine OFF.

4. Probe the TAC motor control 1 and 2 circuits with the test

lamp connected to ground.

Does the test lamp illuminate? Go to

Step 20

Go to

Step 19

1. Turn OFF the ignition.

2. Disconnect the ECM connector that contains the TAC motor

control circuits.

3. Probe the TAC motor control 1 and 2 circuits with the test

lamp connected to battery positive.

Does the test lamp illuminate? Go to

Step 21

Go to

Step 19

1. Turn OFF the ignition.

2. Disconnect the ECM connector that contains the TAC motor

controls circuits.

3. Test the TAC motor control 1 and 2 circuits for an open or

high resistance.

4. Repair the circuit as necessary. Refer to

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 26

Go to

Step 19

16 Test the ETC ignition 1 voltage circuit for a short to ground. Refer

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 26

Go to

Step 17

17 Test the motor control 1 circuit for a short to ground. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 26

Go to

Step 24

Test for a poor connection or terminal tension at the throttle body

connector. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 26

Go to

Step 24

Test for a poor connection or terminal tension at the ECM. Refer

Testing for Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 26

Go to

Step 24

20 Repair the short to voltage on the circuit where the test lamp

remained illuminated. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 26

—

EngineControls-6.0LEngine

DTC P1516 (cont’d)

Step Action Yes No

21 Repair the short to ground on the circuit where the test lamp

remained illuminated. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 26

—

22 Repair the short to voltage on the ETC ignition 1 voltage circuit.

Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 26

—

23 Repair the open or high resistance in the ETC ignition 1 voltage

circuit. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 26

—

24 Replace the throttle body assembly. Refer to

Throttle Body

Assembly Replacement

Did you complete the replacement? Go to

Step 26

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement? Go to

Step 26

—

1.CleartheDTCswithaTech 2

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 27

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P1682

Circuit Description

The ignition 1 voltage circuit supplied by the powertrain

ignition 1 relay is used to power the electronic

throttle control (ETC) circuitry internal to the engine

control module (ECM). The second ignition 1 voltage

circuit is supplied by the run/crank relay, and is used to

power the remaining internal ECM circuits. If the

ECM detects a voltage difference between the

two ignition 1 voltage circuits, DTC P1682 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1682 Ignition 1 Switch Circuit 2

Conditions for Running the DTC

• The ignition is ON.

• The powertrain relay is commanded ON.

• DTC P1682 runs continuously.

Conditions for Setting the DTC

The ECM detects that the voltage level difference is

greater than 3 volts between the run/crank and

the ETC ignition 1 voltage circuits for more than

3 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores the information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the MIL after

3 consecutive ignition cycles that the diagnostic

runs and does not fail.

• A current DTC last test failed clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles if no failures are reported by this or any

other emission related diagnostic.

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

4. This step inspects for electromagnetic

interference (EMI) on the CMP circuits.

7. Damage to the face of the sensor could indicate

material passing between the CMP sensor and

the reluctor wheel. This condition could cause this

DTC to set. Damage to the reluctor wheel

would affect the CMP sensor output signal.

DTC P1682

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Are DTCs P0615, P0685, P0689, or P0690 also set?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

EngineControls-6.0LEngine

DTC P1682 (cont’d)

Step Action Values Yes No

1. Turn ON the ignition, with the engine OFF.

2. Probe both test points of the ECM fuse at the

underhood fuse block with a test lamp that is

connected to a good ground. Refer to

Troubleshooting

with a Test Lamp

in Wiring Systems.

Does the test lamp illuminate on one test point of the

ECM fuse?

—

Go to

Step 6

Go to

Step 5

5Does the test lamp illuminate on one test point of the

ECM fuse? —Go to

Step 7

Go to

Starter

Solenoid Does

Not Click

Engine Electrical

1. Turn OFF the ignition.

2. Disconnect the negative batter cable at the battery.

Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

3. Disconnect the underhood fuse block electrical

connector that contains the ignition 1 voltage circuit

from the ECM fuse in the underhood fuse block.

4. Disconnect the engine control module (ECM) electrical

connector that contains the ignition 1 voltage circuit

from the ECM fuse in the underhood fuse block.

5. Measure the resistance of the ignition 1 circuit from

the ECM electrical connector to the underhood fuse

block electrical connector with a DMM. Refer to

Troubleshooting with a Digital Multimeter

in Wiring

Systems.

Does the resistance measure greater than the

speciﬁed value?

2Ω

Go to

Step 9

Go to

Step 8

1. Turn OFF the ignition.

2. Disconnect the negative battery cable at the battery.

Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

3. Disconnect the underhood fuse block electrical

connector that contains the ignition 1 voltage circuit

from the ECM fuse in the underhood fuse block.

4. Disconnect the ECM electrical connector that contains

the ignition 1 voltage circuit from the ECM fuse in the

underhood fuse block.

5. Probe the ignition 1 voltage circuit at the ECM

electrical connector with a test lamp that is connected

to battery positive voltage.

Does the test lamp illuminate?

—

Go to

Step 10

Go to

Step 8

Test for shorted terminals and poor connections at the

ECM wire harness electrical connector. Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 12

Go to

Step 11

Repair the high resistance or an open in the

ignition 1 voltage circuit between the underhood fuse block

and the ECM. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 12

—

Repair the short to ground in the ignition 1 voltage circuit

between the underhood fuse block and the ECM. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 12

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 12

—

EngineEngineControls-6.0L

DTC P1682 (cont’d)

Step Action Values Yes No

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 13

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P2101

Circuit Description

The commanded throttle position is compared to the

actual throttle position based on accelerator pedal

position (APP) and possibly other limiting factors. Both

values should be within a calibrated range of each

other. The engine control module (ECM) continuously

monitors the commanded and actual throttle

positions. This DTC sets if the values are greater than

the calibrated range.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2101 Control Module Throttle Actuator

Position Performance

Conditions for Running the DTC

• The ignition is ON.

• The ignition voltage is greater than 6.5 volts.

• The system is not in the battery save mode.

• The engine is running.

• DTCs P0068, P2119, P2176 are not set.

Conditions for Setting the DTC

The difference between the predicted and the actual

throttle position is more than a calibrated amount.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

The throttle valve are spring loaded to a slightly open

position. The throttle valve should be open

approximately 20 percent. This is referred to as the

rest position. The throttle valve should not be

completely closed nor should they be open any more

than the speciﬁed amount. The throttle valve should

move open and to the closed position without binding

under the normal spring pressure. The throttle

should NOT be free to move open or closed WITHOUT

spring pressure. Replace the throttle body if any of

these conditions are found.

Important: Operating the throttle blade with the

ThrottleBladeControlfunctionoftheTech 2 may

cause additional DTCs to set. Do not attempt to

diagnose DTCs set during this function.

TheTech 2 hastheabilitytooperatethethrottle

control system using special functions. Actuate

the throttle valve using the throttle blade control

function located in the throttle actuator control (TAC)

system menu. This function will operate the throttle

valve through the entire range in order to determine if

the throttle body and system operate correctly.

Check for the following conditions:

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the engine control

module (ECM) harness connector or a component

harness connector.

• Poor connections at the ECM or at the

component—Inspect the harness connectors for a

poor terminal to wire connection. Refer to

Testing for Intermittent Conditions and Poor

Connections

in Wiring Systems for the proper

procedure.

• For intermittents, refer to

Intermittent Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

8. The throttle valve is spring loaded in a slightly

open position and should move in either direction

without binding. The throttle valve should

always be under spring pressure.

11. When the ignition is turned ON, the ECM operates

the throttle control motor to verify the integrity of

the system prior to start-up. This can be seen

by the momentary ﬂash of the test lamp as

the ignition is turned ON.

DTC P2101

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

EngineEngineControls-6.0L

DTC P2101 (cont’d)

Step Action Yes No

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

Are DTCs P0120, P0220, P2120, P2125, P2135, P2138 also set? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

Step 3

Important: The throttle angle and pedal angle may not correspond

during this procedure.

1. Turn ON the ignition, with the engine OFF.

2. Observe the throttle position (TP) sensor 1 and 2 angle

parameters.

3. Apply and release the accelerator pedal several times.

Does the TP sensor 1 and 2 angle parameters increase as the

pedal is applied and decrease as the pedal is released? Go to

Step 4

Go to

Step 5

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Start the engine.

3. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 5

Go to Diagnostic Aids

1. Turn ON the ignition, with the engine OFF.

2. Probe both sides of the ETC fuse with a test lamp connected

to ground.

Does the test lamp illuminate on both sides of the fuse? Go to

Step 6

Go to

Step 16

1. Turn OFF the ignition.

2. Probe both sides of the ETC fuse with a test lamp connected

to ground.

Does the test lamp illuminate on both sides of the fuse? Go to

Step 22

Go to

Step 7

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM) connector

containing the ETC ignition 1 voltage circuit.

3. Turn ON the ignition.

4. Probe the ETC ignition 1 voltage circuit with a test lamp

connected to ground.

Does the test lamp illuminate? Go to

Step 8

Go to

Step 23

1. Turn OFF the ignition.

2. Inspect the throttle body for the following conditions. Refer to

Diagnostic Aids:

• A throttle valve that is NOT in the rest position

• A throttle valve that is binding open or closed

• A throttle valve that is free to move open or closed

WITHOUT spring pressure

Did you ﬁnd any of these conditions with the throttle body? Go to

Step 24

Go to

Step 9

Important: The test lamp may momentarily ﬂash when testing

these circuits. This is considered normal.

1. Disconnect the throttle body harness connector.

2. Turn ON the ignition, with the engine OFF.

3. Probe the throttle actuator control (TAC) motor control 1 and

2 circuits with the test lamp connected to ground.

Did the test lamp illuminate and remain illuminated on either

circuit? Go to

Step 13

Go to

Step 10

EngineControls-6.0LEngine

DTC P2101 (cont’d)

Step Action Yes No

Important: The test lamp may momentarily ﬂash when testing

these circuits. This is considered normal.

Probe the TAC motor control 1 and 2 circuits with the test lamp

connected to battery positive.

Did the test lamp illuminate and remain illuminated on either

circuit? Go to

Step 14

Go to

Step 11

1. Turn OFF the ignition.

2. Connect the test lamp between the TAC motor control 1 and

battery ground.

3. Observe the test lamp as you turn ON the ignition.

Does the test lamp ﬂash ON and then turn OFF? Go to

Step 12

Go to

Step 15

1. Turn OFF the ignition.

2. Connect a test lamp between the TAC motor control 2 circuit

and battery ground.

3. Observe the test lamp as you turn ON the ignition.

Does the test lamp ﬂash ON and then OFF? Go to

Step 18

Go to

Step 15

1. Turn OFF the ignition.

2. Disconnect the ECM connector that contains the TAC motor

control circuits.

3. Turn ON the ignition, with the engine OFF.

4. Probe the TAC motor control 1 and 2 circuits with the test

lamp connected to ground.

Does the test lamp illuminate? Go to

Step 20

Go to

Step 19

1. Turn OFF the ignition.

2. Disconnect the ECM connector that contains the TAC motor

control circuits.

3. Probe the TAC motor control 1 and 2 circuits with the test

lamp connected to battery positive.

Does the test lamp illuminate? Go to

Step 21

Go to

Step 19

1. Turn OFF the ignition.

2. Disconnect the ECM connector that contains the TAC motor

controls circuits.

3. Test the TAC motor control 1 and 2 circuits for an open or

high resistance.

4. Repair the circuit as necessary. Refer to

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 26

Go to

Step 19

16 Test the ETC ignition 1 voltage circuit for a short to ground. Refer

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 26

Go to

Step 17

17 Test the motor control 1 circuit for a short to ground. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 26

Go to

Step 24

Test for a poor connection or terminal tension at the throttle body

connector. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 26

Go to

Step 24

Test for a poor connection or terminal tension at the ECM. Refer

Testing for Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 26

Go to

Step 24

20 Repair the short to voltage on the circuit where the test lamp

remained illuminated. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 26

—

EngineEngineControls-6.0L

DTC P2101 (cont’d)

Step Action Yes No

21 Repair the short to ground on the circuit where the test lamp

remained illuminated. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 26

—

22 Repair the short to voltage on the ETC ignition 1 voltage circuit.

Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 26

—

23 Repair the open or high resistance in the ETC ignition 1 voltage

circuit. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 26

—

24 Replace the throttle body assembly. Refer to

Throttle Body

Assembly Replacement

Did you complete the replacement? Go to

Step 26

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement? Go to

Step 26

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 27

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P2119

Circuit Description

The engine control module (ECM) controls the throttle

valve by applying a varying voltage to the throttle

actuator control motor. The ECM monitors the actual

throttle valve position using throttle position (TP)

sensor 1 and 2. If the ECM detects the throttle valve

did not return to the rest position within a calibrated

time, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2119 Throttle Closed Position Performance

Conditions for Running the DTC

• The ignition is ON.

• The vehicle speed is 0 km/h (0 mph).

• The engine speed is less than 40 RPM.

• The engine coolant temperature (ECT) is 5–60°C

(41–140°F).

• The intake air temperature (IAT) is 5–60°C (41–

140°F).

• The ignition 1 voltage is more than 10 volts.

• The accelerator pedal position (APP) is less than

15 percent.

• DTC P2119 runs once per ignition cycle when the

above conditions are met for more than 1 second.

Conditions for Setting the DTC

The ECM determines that the throttle valve did not

return to the rest position within 720 milliseconds.

Action Taken When the DTC Sets

• The control module stores the DTC information

into memory when the diagnostic runs and fails.

• The malfunction indicator lamp (MIL) will not

illuminate.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Failure Records.

• The driver information center, if equipped, may

display a message.

Conditions for Clearing the DTC

• A current DTC Last Test Failed clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other non-emission related diagnostic.

•CleartheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• Inspect for a condition in which the throttle valve

may have been held open. For example, ice

may have formed in the throttle bore causing the

throttle valve not to close. Observe the Freeze

Frame/Failure Records.

• The throttle valve is spring loaded to a slightly

open position. The throttle valve should be

open approximately 15–20 percent. This is

referred to as the rest position.

• The throttle valve should not be completely closed

or open any more than a speciﬁed amount.

• The throttle valve should move open and to the

closed position without binding under the

normal spring pressure.

• The throttle should NOT be free to move open or

closed WITHOUT spring pressure.

•TheTech 2 hastheabilitytooperatethethrottle

control system using the TP function located in

the TAC System menu. This function operates the

throttle valve through the entire range in order

to determine if the throttle actuator control (TAC)

system operates correctly.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

2. This step determines if the condition exists. A TP

sensor DTC may cause this DTC to set.

3. Depending on the condition, DTC P1516, P2101,

P2119, P2176 may set individually or together.

8. When the ignition is turned ON, the ECM operates

the throttle actuator control motor to verify the

integrity of the system prior to start-up. This can

be seen by the momentary ﬂash of the test

lamp as the ignition is turned ON.

DTC P2119

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

EngineEngineControls-6.0L

DTC P2119 (cont’d)

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2.CleartheDTCswithaTech 2 .

3. Start the engine.

4. Perform the following tests:

• Rapidly depress the accelerator pedal from the rest

position to the wide open throttle (WOT) position

and release pedal. Repeat the procedure

several times.

• Slowly depress the accelerator pedal to WOT, then

slowly return the pedal to closed throttle. Repeat

the procedure several times.

5.ObservetheDTCinformationwithaTech 2 .

Did DTC P0120, P0121, P0122, P0123, P0220, P0222, or

P0223 fail this ignition?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

Did DTC P1516, P2101, P2119, and/or P2176 fail this

ignition? —Go to

Step 5

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Diagnostic Aids

1. Turn OFF the engine.

2. Turn ON the ignition, with the engine OFF.

3. Observe the throttle position (TP) sensor 1 voltage

parameterwithaTech 2 .

Is the voltage within the speciﬁed range?

3.5–4 V

Go to

Step 6

Go to

DTC P0121

6Observe the TP sensor 2 voltage parameter with a

Tech 2 .

Is the voltage within the speciﬁed range? 1.1–1.5 V Go to

Step 7

Go to

DTC P0121

EngineControls-6.0LEngine

DTC P2119 (cont’d)

Step Action Values Yes No

Notice:

SIO-ID = 1294900 LMD = 11-apr-2003 DO NOT use

any mechanical device such as pliers or screwdrivers to

disengage the connector. In order to prevent damage to

the connector or harness wiring, both of the latches on the

connector must be depressed with ﬁnger pressure only.

When the latches are depressed the connector must then

be pulled straight back without pulling on the wires in order

to disengage. Failure to follow this procedure can lead to

connector or wiring harness damage and failure.

Important: Disconnecting the throttle body harness

connector causes additional DTCs to set.

1. Disconnect the throttle body harness connector. Refer

Throttle Body Assembly Replacement

2. Turn ON the ignition, with the engine OFF.

3. Measure the voltage of the throttle actuator

control (TAC) motor control 1 and TAC motor control 2

circuits of the throttle actuator control motor with a

DMM connected to the engine control module (ECM)

housing.

Is the voltage less than the speciﬁed value for both

circuits?

Go to

Step 8

Go to

Step 9

1. Turn OFF the ignition.

2. Connect the

J 34730-405

Injector Test Lamp between

the TAC motor control 1 and TAC motor control 2

circuit of the throttle body harness connector.

Important: The test lamp intensity should be bright.

Compare to another vehicle.

3. Turn ON the ignition for about 5 seconds and then

turn OFF the ignition while you observe the test lamp.

Repeat this procedure, as necessary.

Does the test lamp turn ON and then OFF each time the

ignition is cycled?

—

Go to

Step 12

Go to

Step 11

9 Is the voltage more than the speciﬁed value? 1 V Go to

Step 14

Go to

Step 10

Test the TAC motor control circuit that measured below the

speciﬁed value for an open or a short to ground. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 18

Go to

Step 13

1. Turn OFF the ignition.

2. Disconnect the ECM.

3. Test for continuity between the TAC motor control 1

and TAC motor control 2 circuit of the throttle body

harness connector.

Is there continuity?

—

Go to

Step 15

Go to

Step 13

Test for shorted terminals and for poor connections at the

throttle body connector. Refer to

Testing for Intermittent

Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 18

Go to

Step 16

Test for shorted terminals and for poor connections at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 18

Go to

Step 17

14 Repair the appropriate TAC motor control circuit for a short

to voltage. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 18

—

15 Repair the short between the TAC motor control circuits 1

and 2. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 18

—

EngineEngineControls-6.0L

DTC P2119 (cont’d)

Step Action Values Yes No

16 Replace the throttle body assembly. Refer to

Throttle Body

Assembly Replacement

Did you complete the replacement? —Go to

Step 18

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 18

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 19

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P2120

Circuit Description

The accelerator pedal position (APP) sensors 1 and 2

are located within the accelerator pedal assembly.

Each sensor has the following circuits:

• A 5-volt reference circuit

• A low reference circuit

• A signal circuit

This provides the engine control module (ECM) with a

signal voltage proportional to accelerator pedal

movement. The APP sensors have opposite

functionality. APP sensor 1 signal voltage increases as

the pedal is depressed, from below 1 volt at rest to

above 2.5 volts when fully depressed. The APP

sensor 2 signal voltage decreases as the pedal is

depressed, from 4 volts at rest to less than 1 volt with

the accelerator pedal fully depressed. If the ECM

detects that the APP sensor 1 signal voltage is

not within the predicted range, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2120 Accelerator Pedal Position (APP)

Sensor 1 Circuit

Conditions for Running the DTC

• The ignition is ON.

• The ignition voltage is greater than 5.23 volts.

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P0641, P0651 are not set.

• DTC P2120 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The APP sensor 1 voltage is less than 0.3625 volt or

more than 2.6 volts for more than 0.4 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P2120

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2. Observe the accelerator pedal position (APP)

sensor 1 voltage, with the accelerator pedal in the rest

position,withaTech 2 .

DoestheTech 2 indicatevoltagelessthantheﬁrstvalue

or greater than the second value?

0.3625 V

2.6 V

Go to

Step 4

Go to

Step 3

EngineEngineControls-6.0L

DTC P2120 (cont’d)

Step Action Values Yes No

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze/Frame

Failure Records.

Does the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the accelerator pedal harness connector.

3. Turn ON the ignition, with the engine OFF.

4. Observe the accelerator pedal position (APP)

sensor1voltageparameter,withaTech 2 .

DoestheTech 2 indicatevoltageatthespeciﬁedvalue?

Go to

Step 5

Go to

Step 10

1. Connect a fused jumper wire between the APP

sensor 1 5-volt reference circuit and the APP sensor 1

signal circuit at the accelerator pedal harness

connector.

2. Observe the APP sensor 1 voltage parameter, with a

Tech 2 .

DoestheTech 2 indicatetheAPPsensor1voltageatthe

speciﬁed value?

Go to

Step 6

Go to

Step 7

6Probe the APP sensor low reference circuit with a test

lamp connected to B+.

Does the test lamp illuminate? —Go to

Step 16

Go to

Step 12

7Measure the voltage of the APP sensor 1 5-volt reference

circuit with a DMM.

Does the DMM indicate voltage at the speciﬁed value? 5V Go to

Step 9

Go to

Step 8

8Does the DMM indicate voltage less than the speciﬁed

value on the APP sensor 1 5-volt reference circuit? 5V Go to

Step 13

Go to

Step 15

Test the APP sensor 1 signal circuit for an open or high

resistance. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 11

Test the APP sensor 1 signal circuit for a short to voltage.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 18

Test the APP sensor 1 signal circuit for a short to ground.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 18

Test the APP sensor 1 low reference circuit for an open or

high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 18

Test the APP sensor 1 5-volt reference circuit for an open

or high resistance. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 14

Test the APP sensor 1 5-volt reference circuit for a short to

ground. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 18

EngineControls-6.0LEngine

DTC P2120 (cont’d)

Step Action Values Yes No

Test the APP sensor 1 5-volt reference circuit for a short to

voltage. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

—

Inspect for poor connections at the accelerator pedal

harness connector. Refer to

Testing for Intermittent

Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 17

17 Replace the accelerator pedal assembly. Refer to

Accelerator Pedal Position (APP) Sensor Replacement

Did you complete the replacement? —Go to

Step 20

—

Inspect for poor connections at the engine control

module (ECM) harness connector. Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 20

Go to

Step 19

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 20

—

1.CleartheDTCswithaTech 2

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze/Frame

Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 21

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P2122

Circuit Description

The accelerator pedal assembly contains 2 accelerator

pedal position (APP) sensors. The APP sensors are

mounted in the pedal assembly and are not

serviceable. The APP sensors provide a signal voltage

that changes relative to the position of the accelerator

pedal. The engine control module (ECM) supplies

a separate 5-volt reference and low reference circuit

for each of the APP sensors.

The APP sensor 1 signal voltage increases as the

pedal is depressed, from approximately 1 volt at rest

to above 2.5 volts when fully depressed. The APP

sensor 2 signal voltage decreases as the pedal

is depressed, from approximately 4 volts at rest to less

than 1 volt with the accelerator pedal fully depressed.

If the ECM detects that the APP sensor 1 signal

voltage is too low, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2122 Accelerator Pedal Position (APP)

Sensor 1 Circuit Low Voltage

Conditions for Running the DTC

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P0641, P0651 are not set.

• The ignition is ON or the engine is operating.

• The ignition 1 voltage is more than 5.23 volts.

• DTC P2122 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The APP sensor 1 voltage is less than 0.3625 volts for

more than 1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• If DTCs P0700, P2122, P2128, and P2138 are set

together in various combinations, inspect the APP

sensor 1 and 2 signal circuits for being shorted

together.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

3. This step tests the internal circuits of the APP

sensor 1 throughout its range of motion. If

this DTC sets when slowly moving the pedal from

the rest position to wide open throttle (WOT),

replace the APP assembly for an internal fault.

5. The ECM produces a measurable steady-state

amperage that provides the 5-volt reference

to the APP sensor 1. If the amperage on the 5-volt

reference circuit is less than 80 mA, there is a

condition with the 5-volt reference circuit or

the ECM.

7. This step tests for high resistance in the low

reference circuit of the APP sensor 1. The ECM

must be completely powered down to obtain

an accurate resistance reading. It may take up to

30 minutes for the ECM to power down after

the ignition key is removed. Removal of the

ECM/TCM fuse allows the ECM to power down

completely.

DTC P2122

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

EngineControls-6.0LEngine

DTC P2122 (cont’d)

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2. Observe the accelerator pedal position (APP)

sensor1voltageparameterwithaTech 2

Is the voltage less than the speciﬁed value?

0.36 V

Go to

Step 5

Go to

Step 3

1.ObservetheDTCinformationwithaTech 2 .

2. Slowly depress the accelerator pedal to wide open

throttle (WOT), then slowly return the accelerator

pedal to the closed position.

3. Repeat this action several times.

Did the DTC fail this ignition?

—

Go to

Step 13

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Diagnostic Aids

1. Turn OFF the ignition.

2. Disconnect the APP sensor harness connector. Refer

Accelerator Pedal Position (APP) Sensor

Replacement

3. Turn ON the ignition, with the engine OFF.

4. Set up a DMM to test amperage on the 400 mA scale.

5. Measure the amperage from the 5-volt reference

circuit of APP sensor 1 to the low reference circuit of

APP sensor 1, with a DMM.

Is the amperage more than the speciﬁed value?

80 mA

Go to

Step 6

Go to

Step 9

1. Turn OFF the ignition.

2. Connect a 3-amp fused jumper wire between the

5-volt reference circuit of the APP sensor 1 and the

signal circuit of the APP sensor 1.

3. Turn ON the ignition, with the engine OFF.

4. Observe the APP sensor 1 voltage parameter with a

Tech 2 .

Is the voltage within the speciﬁed range?

4.8–5.2 V

Go to

Step 7

Go to

Step 10

1. Turn OFF the ignition.

2. Remove the engine control

module (ECM)/transmission control module (TCM)

fuse from the underhood fuse block.

Notice:

SIO-ID = 802647 LMD = 18-jun-2001 Do NOT use a

test lamp to test the continuity of the circuit. Damage to the

control module may occur due to excessive current draw.

3. Measure the resistance from the low reference circuit

of the APP sensor 1 to a good ground, with a DMM.

Is the resistance less than the speciﬁed value?

10 Ω

Go to

Step 11

Go to

Step 8

EngineEngineControls-6.0L

DTC P2122 (cont’d)

Step Action Values Yes No

1. Disconnect the ECM.

2. Test the low reference circuit of the APP sensor 1 for

an open or high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Important: The 5-volt reference circuits are internally and

externally connected at the controller. Other sensors that

share the 5-volt reference circuit may also have DTCs set.

Disconnecting a sensor on the shared 5-volt reference

circuit may isolate a shorted sensor. Review the electrical

schematic and diagnose the shared circuits and sensors.

1. Test the 5-volt reference circuit of the APP sensor 1

for the following conditions:

• A short to ground

• High resistance

• An open circuit

2. Repair as necessary. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

1. Test the signal circuit of the APP sensor 1 for the

following conditions:

• A short to ground

• High resistance

• An open circuit

2. Repair as necessary. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Test for an intermittent and for a poor connection at the

APP assembly. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 13

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 14

13 Replace the APP assembly. Refer to

Accelerator Pedal

Position (APP) Sensor Replacement

Did you complete the replacement? —Go to

Step 15

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 15

—

1. Clear the DTCs with a scan tool.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 16

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P2123

Circuit Description

The accelerator pedal assembly contains 2 accelerator

pedal position (APP) sensors. The APP sensors are

mounted in the pedal assembly and are not

serviceable. The APP sensors provide a signal voltage

that changes relative to the position of the accelerator

pedal. The engine control module (ECM) supplies

a separate 5-volt reference and low reference circuit

for each of the APP sensors.

The APP sensor 1 signal voltage increases as the

pedal is depressed, from approximately 1 volt at rest

to above 2.5 volts when fully depressed. The APP

sensor 2 signal voltage decreases as the pedal

is depressed, from approximately 4 volts at rest to less

than 1 volt with the accelerator pedal fully depressed.

If the ECM detects that the APP 1 signal voltage

is too high, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2123 Accelerator Pedal Position (APP)

Sensor 1 Circuit High Voltage

Conditions for Running the DTC

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P0641, P0651 are not set.

• The ignition is ON or the engine is operating.

• The ignition 1 voltage is more than 5.23 volts.

• DTC P2123 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The APP sensor 1 voltage is more than 2.6 volts for

more than 1 second.

SIO-ID = 727819 LMD = 12-sep-2000

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

3. This step tests the internal circuits of the APP

sensor 1 throughout its range of motion. If

this DTC sets when slowly moving the pedal from

the rest position to wide open throttle (WOT),

replace the APP assembly for an internal fault.

7. This step tests for high resistance in the low

reference circuit of the APP sensor 1. The ECM

must be completely powered down to obtain

an accurate resistance reading. It may take up to

30 minutes for the ECM to power down after

the ignition key is removed. Removal of the

ECM/TCM fuse allows the ECM to power down

completely.

DTC P2123

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2. Observe the accelerator pedal position (APP)

sensor1voltageparameter,withaTech 2 .

Is the voltage more than the speciﬁed value?

2.6 V

Go to

Step 5

Go to

Step 3

EngineEngineControls-6.0L

DTC P2123 (cont’d)

Step Action Values Yes No

1.ObservetheDTCinformationwithaTech 2 .

2. Slowly depress the accelerator pedal to wide open

throttle (WOT), then slowly return the accelerator

pedal to the closed position.

3. Repeat this action several times.

Did the DTC fail this ignition?

—

Go to

Step 13

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Diagnostic Aids

1. Turn OFF the ignition.

2. Disconnect the APP sensor harness connector. Refer

Accelerator Pedal Position (APP) Sensor

Replacement

3. Turn ON the ignition, with the engine OFF.

4.ObservetheAPPsensor1voltagewiththeTech 2 .

Is the voltage less than the speciﬁed value?

0.1 V

Go to

Step 6

Go to

Step 10

6Measure the voltage from the 5-volt reference circuit of the

APP sensor 1 to a good ground, with a DMM.

Is the voltage more than the speciﬁed value? 6V Go to

Step 9

Go to

Step 7

1. Turn OFF the ignition.

2. Remove the engine control

module (ECM)/transmission control module (TCM)

fuse from the underhood fuse block.

Notice:

SIO-ID = 802647 LMD = 18-jun-2001 Do NOT use a

test lamp to test the continuity of the circuit. Damage to the

control module may occur due to excessive current draw.

3. Measure the resistance from the low reference circuit

of APP sensor 1 to a good ground, with a DMM.

Is the resistance less than the speciﬁed value?

10 Ω

Go to

Step 11

Go to

Step 8

1. Turn OFF the ignition.

2. Disconnect the ECM.

Important: A short to voltage on the low reference circuit

may cause internal ECM damage and sensor damage.

3. Test the low reference circuit of the APP sensor 1 for

an open, for a short to voltage, or for a high

resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Important: The 5-volt reference circuits are internally and

externally connected at the controller. Other sensors that

share the 5-volt reference circuit may also have DTCs set.

Disconnecting a sensor on the shared 5-volt reference

circuit may isolate a shorted sensor. Review the electrical

schematic and diagnose the shared circuits and sensors.

Test the 5-volt reference circuit of the APP sensor 1 for a

short to voltage. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

EngineControls-6.0LEngine

DTC P2123 (cont’d)

Step Action Values Yes No

Test the signal circuit of the APP sensor 1 for a short to

voltage. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Test for shorted terminals and poor connections at the APP

sensor. Refer to

Testing for Intermittent Conditions and

Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 13

Test for shorted terminals and poor connections at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 14

13 Replace the accelerator pedal assembly. Refer to

Accelerator Pedal Position (APP) Sensor Replacement

Did you complete the replacement? —Go to

Step 15

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 15

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 16

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P2125

Circuit Description

The accelerator pedal position (APP) sensors 1 and 2

are located within the accelerator pedal assembly.

Each sensor has the following circuits:

• A 5-volt reference circuit

• A low reference circuit

• A signal circuit

This provides the engine control module (ECM) with a

signal voltage proportional to accelerator pedal

movement. The APP sensors have opposite

functionality. APP sensor 1 signal voltage increases as

the pedal is depressed, from below 1 volt at rest to

above 2.5 volts when fully depressed. The APP

sensor 2 signal voltage decreases as the pedal is

depressed, from 4 volts at rest to less than 1 volt with

the accelerator pedal fully depressed. If the ECM

detects that the APP sensor 2 signal voltage is

not within the predicted range, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2125 Accelerator Pedal Position (APP)

Sensor 2 Circuit

Conditions for Running the DTC

• The ignition is ON.

• The ignition voltage is greater than 5.23 volts.

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P0641, P0651 are not set.

• DTC P2125 runs continuously when the above

conditions are met.

Conditions for Setting the DTC

The APP sensor 2 voltage is less than 0.3625 volt or

more than 4.225 volts for more than 0.4 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P2125

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2.WithaTech 2 ,observetheacceleratorpedal

position (APP) sensor 2 voltage with the accelerator

pedal in the rest position.

DoestheTech 2 indicatevoltagelessthantheﬁrstvalue

or greater than the second value?

0.3625 V

4.225 V

Go to

Step 5

Go to

Step 3

EngineControls-6.0LEngine

DTC P2125 (cont’d)

Step Action Values Yes No

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Does the DTC fail this ignition?

—

Go to

Step 4

Go to

Intermittent

Conditions

1. Turn OFF the ignition.

2. Disconnect the accelerator pedal harness connector.

3. Turn ON the ignition, with the engine OFF.

4. Observe the APP Sensor 2 Voltage parameter with a

Tech 2 .

DoestheTech 2 indicatevoltageatthespeciﬁedvalue?

Go to

Step 5

Go to

Step 12

5Probe the APP sensor 2 signal circuit with a test lamp

connected to ground.

Does the test lamp illuminate? —Go to

Step 12

Go to

Step 6

6Observe the APP Sensor 2 parameter with the test lamp

still connected to the APP sensor 2 signal circuit.

DoestheTech 2 indicatevoltageatthespeciﬁedvalue? 0V Go to

Step 7

Go to

Step 11

7Measure the voltage of the APP sensor 2 5-volt reference

circuit with a DMM.

Does the DMM indicate voltage at the speciﬁed value? 5V Go to

Step 8

Go to

Step 10

8Probe the APP sensor 2 low reference circuit with a test

lamp connected to B+.

Does the test lamp illuminate? —Go to

Step 9

Go to

Step 14

9Test the APP sensor low reference circuit for a short to

ground.

Did you ﬁnd and correct the condition? —Go to

Step 22

Go to

Step 18

10 Does the DMM indicate voltage less than the speciﬁed

value on the APP sensor 2 5-volt reference circuit? 5V Go to

Step 15

Go to

Step 17

Test the APP sensor 2 signal circuit for an open or high

resistance. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 13

Test the APP sensor 2 signal circuit for a short to voltage.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 20

Test the APP sensor 2 signal circuit for a short to ground.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 20

Test the APP sensor 2 low reference circuit for an open or

high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 20

Test the APP sensor 2 5-volt reference circuit for an open

or high resistance. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 16

Test the APP sensor 2 5-volt reference circuit for a short to

ground. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 20

EngineEngineControls-6.0L

DTC P2125 (cont’d)

Step Action Values Yes No

Test the APP sensor 2 5-volt reference circuit for a short to

voltage. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 22

—

Inspect for poor connections at the accelerator pedal

harness connector. Refer to

Testing for Intermittent

Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 19

19 Replace the accelerator pedal assembly. Refer to

Accelerator Pedal Position (APP) Sensor Replacement

Did you complete the replacement? —Go to

Step 22

—

Inspect for poor connections at the engine control

module (ECM) harness connector. Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 22

Go to

Step 21

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 22

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze/Frame

Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 23

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P2127

Circuit Description

The accelerator pedal assembly contains 2 accelerator

pedal position (APP) sensors. The APP sensors are

mounted in the pedal assembly and are not

serviceable. The APP sensors provide a signal voltage

that changes relative to the position of the accelerator

pedal. The engine control module (ECM) supplies

a separate 5-volt reference and low reference circuit

for each of the APP sensors.

The APP sensor 1 signal voltage increases as the

pedal is depressed, from approximately 1 volt at rest

to above 2.5 volts when fully depressed. The APP

sensor 2 signal voltage decreases as the pedal

is depressed, from approximately 4 volts at rest to less

than 1 volt with the accelerator pedal fully depressed.

If the ECM detects that the APP sensor 2 signal

voltage is too low, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2127 Accelerator Pedal Position (APP)

Sensor 2 Circuit Low Voltage

Conditions for Running the DTC

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P0641, P0651 are not set.

• The ignition is ON or the engine is operating.

• The ignition 1 voltage is more than 5.23 volts.

• DTC P2127 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The APP sensor 2 voltage is less than 0.3625 volts for

more than 1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 4 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

3. This step tests the internal circuits of the APP

sensor 2 throughout its range of motion. If

this DTC sets when slowly moving the pedal from

the rest position to wide open throttle (WOT),

replace the APP assembly for an internal fault.

5. The ECM produces a measurable steady-state

amperage that provides the 5-volt reference

to the APP sensor 2. If the amperage on the 5-volt

reference circuit is less than 50 mA, there is a

condition with the 5-volt reference circuit or

the ECM.

7. This step tests for high resistance in the low

reference circuit of the APP sensor 2. The ECM

must be completely powered down to obtain

an accurate resistance reading. It may take up to

30 minutes for the ECM to power down after

the ignition key is removed. Removal of the

ECM/TCM fuse allows the ECM to power down

completely.

DTC P2127

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineEngineControls-6.0L

DTC P2127 (cont’d)

Step Action Values Yes No

1. Turn ON the ignition, with the engine OFF.

2. Observe the accelerator pedal position (APP)

sensor2voltagewithaTech 2 .

Is the voltage less than the speciﬁed value?

0.36 V

Go to

Step 5

Go to

Step 3

1.ObservetheDTCinformationwithaTech 2 .

2. Slowly depress the accelerator pedal to wide open

throttle (WOT), then slowly return the accelerator

pedal to the closed position.

3. Repeat this action several times.

Did the DTC fail this ignition?

—

Go to

Step 13

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Diagnostic Aids

1. Turn OFF the ignition.

2. Disconnect the APP sensor harness connector. Refer

Accelerator Pedal Position (APP) Sensor

Replacement

3. Turn ON the ignition, with the engine OFF.

4. Set up a DMM to test amperage on the 400 mA scale.

5. Measure the amperage from the 5-volt reference

circuit of APP sensor 2 to the low reference circuit of

APP sensor 2, with a DMM.

Is the amperage more than the speciﬁed value?

50 mA

Go to

Step 6

Go to

Step 9

1. Turn OFF the ignition.

2. Connect a 3-amp fused jumper wire between the

5-volt reference circuit of the APP sensor 2 and the

signal circuit of the APP sensor 2.

3. Turn ON the ignition, with the engine OFF.

4.ObservetheAPPsensor2voltage,withaTech 2 .

Is the voltage within the speciﬁed value?

4.8–5.2 V

Go to

Step 7

Go to

Step 10

1. Turn OFF the ignition.

2. Remove the engine control

module (ECM)/transmission control module (TCM)

fuse from the underhood fuse block.

Notice:

SIO-ID = 802647 LMD = 18-jun-2001 Do NOT use a

test lamp to test the continuity of the circuit. Damage to the

control module may occur due to excessive current draw.

3. Measure the resistance from the low reference circuit

of the APP sensor 2 to a good ground, with a DMM.

Is the resistance less than the speciﬁed value?

10 Ω

Go to

Step 11

Go to

Step 8

1. Disconnect the ECM.

2. Test the low reference circuit of the APP sensor 2 for

an open or high resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

EngineControls-6.0LEngine

DTC P2127 (cont’d)

Step Action Values Yes No

Important: The 5-volt reference circuits are internally and

externally connected at the controller. Other sensors that

share the 5-volt reference circuit may also have DTCs set.

Disconnecting a sensor on the shared 5-volt reference

circuit may isolate a shorted sensor. Review the electrical

schematic and diagnose the shared circuits and sensors.

1. Test the 5-volt reference circuit of the APP sensor 2

for the following conditions:

• A short to ground

• High resistance

• An open circuit

2. Repair as necessary. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

1. Test the signal circuit of the APP sensor 2 for the

following conditions:

• A short to ground

• High resistance

• An open circuit

2. Repair as necessary. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Test for an intermittent and for a poor connection at the

APP assembly. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 13

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 14

13 Replace the APP assembly. Refer to

Accelerator Pedal

Position (APP) Sensor Replacement

Did you complete the replacement? —Go to

Step 15

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 15

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 16

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

DTC P2128

Circuit Description

The accelerator pedal assembly contains 2 accelerator

pedal position (APP) sensors. The APP sensors are

mounted in the pedal assembly and are not

serviceable. The APP sensors provide a signal voltage

that changes relative to the position of the accelerator

pedal. The engine control module (ECM) supplies

a separate 5-volt reference and low reference circuit

for each of the APP sensors.

The APP sensor 1 signal voltage increases as the

pedal is depressed, from approximately 1 volt at rest

to above 2.5 volts when fully depressed. The APP

sensor 2 signal voltage decreases as the pedal

is depressed, from approximately 4 volts at rest to less

than 1 volt with the accelerator pedal fully depressed.

If the ECM detects that the APP sensor 2 signal

voltage is too high, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2128 Accelerator Pedal Position (APP)

Sensor 2 Circuit High Voltage

Conditions for Running the DTC

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P0641, P0651 are not set.

• The ignition is ON or the engine is operating.

• The ignition 1 voltage is more than 5.23 volts.

• DTC P2128 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The APP sensor 2 voltage is more than 4.725 volts for

more than 1 second.

SIO-ID = 727819 LMD = 12-sep-2000

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 4 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

Diagnostic Aids

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• If DTCs P0700, P2122, P2128, and P2138 are set

together in various combinations, inspect the APP

sensor 1 and 2 signal circuits for being shorted

together.

• For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

3. This step tests the internal circuits of the APP

sensor 2 throughout its range of motion. If

this DTC sets when slowly moving the pedal from

the rest position to wide open throttle (WOT),

replace the APP assembly for an internal fault.

7. This step tests for high resistance in the low

reference circuit of the APP sensor 2. The ECM

must be completely powered down to obtain

an accurate resistance reading. It may take up to

30 minutes for the ECM to power down after

the ignition key is removed. Removal of the

ECM/TCM fuse allows the ECM to power down

completely.

DTC P2128

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineControls-6.0LEngine

DTC P2128 (cont’d)

Step Action Values Yes No

1. Turn ON the ignition, with the engine OFF.

2. Observe the accelerator pedal position (APP)

sensor2voltagewithaTech 2 .

3. Depress the accelerator pedal to wide open

throttle (WOT).

Is the voltage more than the speciﬁed value?

2.4 V

Go to

Step 5

Go to

Step 3

1.ObservetheDTCinformationwithaTech 2 .

2. Slowly depress the accelerator pedal to WOT, then

slowly return the accelerator pedal to the closed

position.

3. Repeat this action several times.

Did the DTC fail this ignition?

—

Go to

Step 13

Go to

Step 4

1. Observe the Freeze Frame/Failure Records for

this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 5

Go to

Diagnostic Aids

1. Turn OFF the ignition.

2. Disconnect the APP sensor harness connector. Refer

Accelerator Pedal Position (APP) Sensor

Replacement

3. Turn ON the ignition, with the engine OFF.

4.ObservetheAPPsensor2voltagewiththeTech 2 .

Is the voltage less than the speciﬁed value?

0.1 V

Go to

Step 6

Go to

Step 10

6Measure the voltage from the 5-volt reference circuit of the

APP sensor 2 to a good ground, with a DMM.

Is the voltage more than the speciﬁed value? 6V Go to

Step 9

Go to

Step 7

1. Turn OFF the ignition.

2. Remove the engine control

module (ECM)/transmission control module (TCM)

fuse from the underhood fuse block.

Notice:

SIO-ID = 802647 LMD = 18-jun-2001 Do NOT use a

test lamp to test the continuity of the circuit. Damage to the

control module may occur due to excessive current draw.

3. Measure the resistance from the low reference circuit

of the APP sensor 2 to good ground, with a DMM.

Is the resistance less than the speciﬁed value?

10 Ω

Go to

Step 11

Go to

Step 8

1. Turn OFF the ignition.

2. Disconnect the ECM.

Important: A short to voltage on the low reference circuit

may cause internal ECM damage and sensor damage.

3. Test the low reference circuit of the APP sensor 2 for

an open, for a short to voltage, or for a high

resistance. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

EngineEngineControls-6.0L

DTC P2128 (cont’d)

Step Action Values Yes No

Important: The 5-volt reference circuits are internally and

externally connected at the controller. Other sensors that

share the 5-volt reference circuit may also have DTCs set.

Disconnecting a sensor on the shared 5-volt reference

circuit may isolate a shorted sensor. Review the electrical

schematic and diagnose the shared circuits and sensors.

Test the 5-volt reference circuit of the APP sensor 2 for a

short to voltage. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Test the signal circuit of the APP sensor 2 for a short to

voltage. Refer to

Circuit Testing

and

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 12

Test for shorted terminals and poor connections at the APP

sensor. Refer to

Testing for Intermittent Conditions and

Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 13

Test for shorted terminals and poor connections at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 14

13 Replace the accelerator pedal assembly. Refer to

Accelerator Pedal Position (APP) Sensor Replacement

Did you complete the replacement? —Go to

Step 15

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 15

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 16

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P2135

Circuit Description

The throttle position (TP) sensors 1 and 2 are located

within the throttle body assembly. The TP sensors

share a common 5-volt reference circuit and a

common low reference circuit. The 5-volt reference

circuit is also shared with the accelerator pedal

position (APP) sensor 2. The 5-volt reference voltage

is supplied on 2 separate engine control module (ECM)

terminals, but the terminals are connected internally

to the same voltage supply. Each TP sensor has

an individual signal circuit, which provides the ECM

with a signal voltage proportional to throttle the

plate movement. When the throttle plate is in the

closed position, the TP sensor 1 signal voltage is near

the low reference and increases as the throttle

plate is opened. The TP sensor 2 signal voltage at

closed throttle is near the 5-volt reference and

decreases as the throttle plate is opened. If the ECM

detects that the TP sensors are not within a

predicted value from each other, DTC P2135 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2135 Throttle Position (TP) Sensor 1–2

Correlation

Conditions for Running the DTC

• DTCs P0122, P0123, P0222, P0223, P0601,

P0602, P0603, P0604, P0606, P0607, P0641,

P0651 are not set.

• The ignition is ON.

• DTC P2135 runs continuously once the above

condition is met.

Conditions for Setting the DTC

The ECM detects that the difference between TP

sensor 1 and TP sensor 2 is more than the predicted

value for less than 1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P2135

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

ObservetheDTCinformationwithaTech 2 .

Is DTC P0101, P0121, P0122, P0123, P0222, P0223,

P2120, P2122, P2123, P2125, P2127, P2128 also set? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

EngineEngineControls-6.0L

DTC P2135 (cont’d)

Step Action Value(s) Yes No

1. Turn OFF the ignition.

2. Disconnect the throttle position (TP) sensor electrical

connector.

3. Disconnect the engine control module (ECM). Refer to

Engine Control Module (ECM) Replacement

4. Measure the resistance of the following circuits with a

DMM for each of the TP sensors:

• The low reference circuit

• The TP sensor signal circuit

• The 5-volt reference circuit

Is the resistance more than the speciﬁed value for any

circuit?

5Ω

Go to

Step 7

Go to

Step 4

Test the signal circuit of the TP sensor 1 for a short to the

signal circuit of TP sensor 2. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 9

Go to

Step 5

Test for an intermittent and for a poor connection at the TP

sensor. Refer to

Testing for Intermittent Conditions and

Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 9

Go to

Step 6

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 9

Go to

Step 8

Repair the high resistance in the circuit that measured

above the speciﬁed value. Refer to

Wiring Repairs

Wiring Systems.

Did you complete the repair?

—

Go to

Step 9

—

8Replace the throttle body assembly. Refer to

Throttle Body

Removal

Did you complete the replacement? —Go to

Step 9

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 10

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P2138

Circuit Description

The accelerator pedal position (APP) sensor is made

up of 2 sensors that are housed inside one assembly.

The engine control module (ECM) supplies a

separate 5-volt reference circuit and a low reference

circuit for each of the sensors. The 5-volt reference for

APP sensor 1 is supplied from the same source in

the ECM as the 5-volt reference for the mass air

ﬂow (MAF) sensor and the fuel tank pressure (FTP)

sensor. The 5-volt reference voltage for all of the

sensors is supplied on separate ECM terminals, but

the terminals are connected internally to a voltage

supply. The APP sensor 1 sends a signal from

the sensor to the ECM indicating the accelerator pedal

position. The ECM actuates the throttle plates based

on this information. If the ECM detects that the

APP sensors are not within a predicted value from

each other, DTC P2138 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2138 Accelerator Pedal Position (APP)

Sensor 1–2 Correlation

Conditions for Running the DTC

• DTCs P0601, P0602, P0603, P0604, P0606,

P0607, P0641, P0651, P2120, P2122, P2123,

P2125, P2127, P2128 are not set.

• The ignition is ON.

• DTC P2138 runs continuously once the above

conditions are met.

Conditions for Setting the DTC

The ECM detects that the difference between APP

sensor 1 and APP sensor 2 is more than the predicted

value for less than 1 second.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The control module turns OFF the malfunction

indicator lamp (MIL) after 3 consecutive ignition

cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the

diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up

cycles, if no failures are reported by this or any

other emission related diagnostic.

•CleartheMILandtheDTCwithaTech 2 .

DTC P2138

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

ObservetheDTCinformationwithaTech 2 .

Is DTC P0101, P0121, P0122, P0123, P0222, P0223,

P2120, P2122, P2123, P2125, P2127, P2128 also set? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

EngineEngineControls-6.0L

DTC P2138 (cont’d)

Step Action Values Yes No

1. Turn OFF the ignition.

2. Disconnect the accelerator pedal position (APP)

sensor electrical connector.

3. Disconnect the engine control module (ECM). Refer to

Engine Control Module (ECM) Replacement

4. Measure the resistance of the following circuits with a

DMM for each of the APP sensors:

• The low reference circuit

• The signal circuit

• The 5-volt reference circuit

Is the resistance more than the speciﬁed value for any

circuit?

5Ω

Go to

Step 7

Go to

Step 4

Test the signal circuit of APP sensor 1 for a short to the

signal circuit of the APP sensor 2. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 9

Go to

Step 5

Test for an intermittent and for a poor connection at the

APP sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 9

Go to

Step 6

Test for an intermittent and for a poor connection at the

ECM. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 9

Go to

Step 8

Repair the high resistance in the circuit that measure

above the speciﬁed value. Refer to

Wiring Repairs

Wiring Systems.

Did you complete the repair?

—

Go to

Step 9

—

8Replace the APP sensor. Refer to

Accelerator Pedal

Position (APP) Sensor Replacement

Did you complete the replacement? —Go to

Step 9

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Operate the vehicle with in the Conditions for Running

the DTC. You may also operate the vehicle within the

conditions that you observed from the Freeze

Frame/Failure Records.

Did the DTC fail this ignition?

—

Go to

Step 2

Go to

Step 10

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineControls-6.0LEngine

DTC P2176

Circuit Description

The commanded throttle position is compared to the

actual throttle position based on accelerator pedal

position and possibly other limiting factors. Both values

should be within a calibrated range of each other.

The engine control module (ECM) continuously

monitors the commanded and actual throttle positions.

This DTC sets if the values are greater than the

calibrated range.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2176 Minimum Throttle Position Not Learned

Conditions for Running the DTC

• The ignition is ON.

• DTCs P0120, P0122, P0123, P0220, P0222,

P0223 are not set.

• DTC P2176 runs once per key cycle.

Conditions for Setting the DTC

• The difference between the predicted and the

actual throttle position is more than a calibrated

amount.

• The above condition is met for more than

3 seconds.

Action Taken When the DTC Sets

• The control module illuminates the malfunction

indicator lamp (MIL) when the diagnostic runs

and fails.

• The control module records the operating

conditions at the time the diagnostic fails. The

control module stores this information in the

Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to

operate in the Reduced Engine Power mode.

• A message center or an indicator displays

Reduced Engine Power.

• Under certain conditions the control module

commands the engine OFF.

Conditions for Clearing the MIL/DTC

• The ECM turns OFF the MIL after 3 consecutive

drive trips that the diagnostic runs and passes.

• A History DTC clears after 40 consecutive

warm-up cycles in which there are no failures

reported of this diagnostic or any other emission

related diagnostic.

•TheTech 2 clearstheMIL/DTC.

Diagnostic Aids

The throttle valve is spring loaded to a slightly open

position. The throttle valve should be open

approximately 20–25 percent. This is referred to as

the rest position. The throttle valve should not be

completely closed nor should they be open any more

than the speciﬁed amount. The throttle valve should

move open and to the closed position without binding

under the normal spring pressure. The throttle

should NOT be free to move open or closed WITHOUT

spring pressure. Replace the throttle body if any of

these conditions are found.

Important: Operating the throttle blade with the

ThrottleBladeControlfunctionoftheTech 2 may

cause additional DTCs to set. Do not attempt to

diagnose DTCs set during this function.

TheTech 2 hastheabilitytooperatethethrottle

control system using Special Functions. Actuate

the throttle valve using the throttle blade control

function located in the TAC System menu. This

function will operate the throttle valve through the

entire range in order to determine if the throttle body

and system operate correctly.

Check for the following conditions:

• Use the

J 35616-B

Connector Test Adapter Kit for

any test that requires probing the ECM harness

connector or a component harness connector.

• Poor connections at the ECM or at the

component—Inspect the harness connectors for a

poor terminal to wire connection. Refer to

Testing for Intermittent Conditions and Poor

Connections

in Wiring Systems for the proper

procedure.

• For intermittents, refer to

Intermittent Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

8. The throttle valve is spring loaded in a slightly

open position and should move in either direction

without binding. The throttle valve should

always be under spring pressure.

11. When the ignition is turned ON, the ECM operates

the throttle control motor to verify the integrity of

the system prior to start-up. This can be seen

by the momentary ﬂash of the test lamp as

the ignition is turned ON.

DTC P2176

Step Action Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

EngineEngineControls-6.0L

DTC P2176 (cont’d)

Step Action Yes No

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2.CleartheDTCswithaTech 2

3. Start the engine.

4. Perform the following tests:

• Rapidly depress the accelerator pedal from the rest

position to the wide open throttle (WOT) position and

release the pedal. Repeat the procedure several times.

• Slowly depress the accelerator pedal to WOT, then slowly

return the pedal to closed throttle. Repeat the procedure

several times.

5. Turn OFF the ignition.

6. Turn ON the ignition, with the engine OFF.

7.ObservetheDTCinformationwithaTech 2 .

Does DTC P0121, P0122, P0123, P0222, P0223, P0689, P0690,

P2135, or P2138 fail this ignition?

Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

Step 3

Important: The throttle angle and pedal angle may not correspond

during this procedure.

1. Turn ON the ignition, with the engine OFF.

2. Observe the Throttle Position (TP) Sensor 1 and 2 Angle

parameters.

3. Apply and release the accelerator pedal several times.

Does the TP Sensor 1 and 2 Angle parameters increase as the

pedal is applied and decrease as the pedal is released? Go to

Step 4

Go to

Step 5

1. Observe the Freeze Frame/Failure Records for this DTC.

2. Start the engine.

3. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 5

Go to Diagnostic Aids

1. Turn ON the ignition, with the engine OFF.

2. Probe both sides of the ETC fuse with a test lamp connected

to ground.

Does the test lamp illuminate on both sides of the fuse? Go to

Step 6

Go to

Step 16

1. Turn OFF the ignition.

2. Probe both sides of the ETC fuse with a test lamp connected

to ground.

Does the test lamp illuminate on both sides of the fuse? Go to

Step 23

Go to

Step 7

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM) connector

containing the ETC ignition 1 voltage circuit.

3. Turn ON the ignition.

4. Probe the ETC ignition 1 voltage circuit with a test lamp

connected to ground.

Does the test lamp illuminate? Go to

Step 8

Go to

Step 24

EngineControls-6.0LEngine

DTC P2176 (cont’d)

Step Action Yes No

1. Turn OFF the ignition.

2. Inspect the throttle body for the following conditions: Refer to

Diagnostic Aids:

• A throttle valve that is NOT in the rest position

• A throttle valve that is binding open or closed

• A throttle valve that is free to move open or closed

WITHOUT spring pressure

Did you ﬁnd any of these conditions with the throttle body? Go to

Step 25

Go to

Step 9

Important: The test lamp may momentarily ﬂash when testing

these circuits. This is considered normal.

1. Connect the engine control module connector.

2. Disconnect the throttle body harness connector.

3. Turn ON the ignition, with the engine OFF.

4. Probe the TAC motor control 1 and 2 circuits with the test

lamp connected to ground.

Did the test lamp illuminate and remain illuminated on either

circuit? Go to

Step 13

Go to

Step 10

Important: The test lamp may momentarily ﬂash when testing

these circuits. This is considered normal.

Probe the TAC motor control 1 and 2 circuits with the test lamp

connected to battery positive.

Did the test lamp illuminate and remain illuminated on either

circuit? Go to

Step 14

Go to

Step 11

1. Turn OFF the ignition.

2. Connect the test lamp between the TAC motor control 1 and

battery ground.

3. Observe the test lamp as you turn ON the ignition.

Does the test lamp ﬂash ON and then turn OFF? Go to

Step 12

Go to

Step 15

1. Turn OFF the ignition.

2. Connect a test lamp between the TAC motor control 2 circuit

and battery ground.

3. Observe the test lamp as you turn ON the ignition.

Does the test lamp ﬂash ON and then OFF? Go to

Step 19

Go to

Step 15

1. Turn OFF the ignition.

2. Disconnect the ECM connector that contains the TAC motor

control circuits.

3. Turn ON the ignition, with the engine OFF.

4. Probe the TAC motor control 1 and 2 circuits with the test

lamp connected to ground.

Does the test lamp illuminate? Go to

Step 21

Go to

Step 20

1. Turn OFF the ignition.

2. Disconnect the ECM connector that contains the TAC motor

control circuits.

3. Probe the TAC motor control 1 and 2 circuits with the test

lamp connected to battery positive.

Does the test lamp illuminate? Go to

Step 22

Go to

Step 20

1. Turn OFF the ignition.

2. Disconnect the ECM connector that contains the TAC motor

controls circuits.

3. Test TAC motor control 1 and 2 circuits for an open or high

resistance.

4. Repair the circuit as necessary. Refer to

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 27

Go to

Step 20

EngineEngineControls-6.0L

DTC P2176 (cont’d)

Step Action Yes No

16 Test the ETC ignition 1 voltage circuit for a short to ground. Refer

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 27

Go to

Step 17

17 Test the motor control 1 circuit for a short to ground. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 27

Go to

Step 25

1. Turn OFF the ignition.

2. Disconnect the ECM connector that contains the TAC motor

control circuits.

3. Test the TAC motor control 1 and 2 circuits for an open or

high resistance.

4. Repair the circuit as necessary. Refer to

Wiring Repairs

Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 27

Go to

Step 19

Test for a poor connection or terminal tension at the throttle body

connector. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 27

Go to

Step 25

Test for a poor connection or terminal tension at the ECM. Refer

Testing for Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 27

Go to

Step 25

21 Repair the short to voltage on the circuit where the test lamp

remained illuminated. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 27

—

22 Repair the short to ground on the circuit where the test lamp

remained illuminated. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 27

—

23 Repair the short to voltage on the ETC ignition 1 voltage circuit.

Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 27

—

24 Repair the open or high resistance in the ETC ignition 1 voltage

circuit. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? Go to

Step 27

—

25 Replace the throttle body assembly. Refer to

Throttle Body

Installation

Did you complete the replacement? Go to

Step 27

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement? Go to

Step 27

—

1.CleartheDTCswithaTech 2 .

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for Running the

DTC. You may also operate the vehicle within the conditions

that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition? Go to

Step 2

Go to

Step 28

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

Symptoms - Engine Controls

EngineControls-6.0LEngine

Important Preliminary Inspections Before

Beginning

Before using this section, perform the

Diagnostic

System Check - Vehicle

in Vehicle DTC Information

and verify all of the following conditions:

• The engine control module (ECM) and the

malfunction indicator lamp (MIL) are operating

correctly. Refer to

Malfunction Indicator

Lamp (MIL) Inoperative

• Diagnostic trouble codes (DTCs) are not stored.

•TheTech 2 dataiswithinthenormaloperating

range.Referto

Tech 2 DataList

• Verify the customer concern and locate the

correct symptom table. Inspect the items indicated

in that symptom table.

• Several of the symptom procedures ask for a

careful visual/physical inspection. This step

is extremely important, and can lead to correcting

a condition without further inspections and can

save valuable time.

• If the intermittent condition exists as a start and

then stall, inspect for any DTCs related to the

theft deterrent system. Refer to

Diagnostic Trouble

Code (DTC) List - Vehicle

in Vehicle

DTC Information.

• Verify the proper installation of any of the following

aftermarket accessories:

− Lights

− Cellular phone

− Remote starter system

− Aftermarket installed alarm

• Use the following tables when diagnosing a

symptom concern:

−

Poor Fuel Fill Quality

−

Hard Start

−

Surges/Chuggles

−

Lack of Power, Sluggishness, or Sponginess

−

Detonation/Spark Knock

−

Hesitation, Sag, Stumble

−

Cuts Out, Misses

−

Poor Fuel Economy

−

Rough, Unstable, or Incorrect Idle and

Stalling

−

Dieseling, Run-On

−

Backﬁre

• If the condition cannot be isolated using the

appropriate table, refer to

Intermittent Conditions

for further diagnosis.

Intermittent Conditions

Inspection/Test Action

DEFINITION: The problem is not currently present but is indicated in DTC History.

There is a customer complaint, but the symptom can not currently be duplicated, if the problem is not DTC related.

Preliminary Refer to

Symptoms - Engine Controls

before starting.

Harness/Connector Many intermittent open or shorted circuits are affected by harness/connector

movement that is caused by vibration, engine torque, bumps/rough pavement, etc.

Test for this type of condition by performing the applicable procedure from the

following list:

•MoverelatedconnectorsandwiringwhilemonitoringtheappropriateTech 2

tool data.

• Move related connectors and wiring with the component commanded ON, and

OFF,withtheTech 2 .Observethecomponentoperation.

• With the engine running, move related connectors and wiring while monitoring

engine operation.

If harness or connector movement affects the data displayed, component/system

operation, or engine operation, inspect and repair the harness/connections as

necessary.

Refer to Electrical Connections or Wiring.

EngineEngineControls-6.0L

Intermittent Conditions (cont’d)

Inspection/Test Action

Electrical Connections or Wiring Poor electrical connections, terminal tension or wiring problems cause most

intermittents. Refer to

Testing for Intermittent Conditions and Poor Connections

Circuit Testing

Connector Repairs

,or

Wiring Repairs

in Wiring Systems to perform

the following inspections:

• Inspect for poor mating of the connector halves, or terminals improperly seated in

the connector body.

• Inspect for improperly formed or damaged terminals. Test for poor terminal

tension.

• Inspect for poor terminal to wire connections including terminals crimped over

insulation. This requires removing the terminal from the connector body.

• Inspect for corrosion/water intrusion. Pierced or damaged insulation can allow

moisture to enter the wiring. The conductor can corrode inside the insulation,

with little visible evidence. Look for swollen and stiff sections of wire in the

suspect circuits.

• Inspect for wires that are broken inside the insulation.

• Inspect the harness for pinched, cut or rubbed through wiring.

• Ensure that the wiring does not come in contact with hot exhaust components.

Control Module Power and Grounds

Component Power and Grounds Poor power or ground connections can cause widely varying symptoms.

• Test all control module power supply circuits. Many vehicles have multiple

circuits supplying power to the control module. Other components in the system

may have separate power supply circuits that may also need to be tested.

Inspect connections at the module/component connectors, fuses, and any

intermediate connections between the power source and the module/component.

A test lamp or a DMM may indicate that voltage is present, but neither tests the

ability of the circuit to carry sufficient current. Ensure that the circuit can carry the

current necessary to operate the component. Refer to

Circuit Testing

and

Power

Distribution Schematics

in Wiring Systems.

• Test all control module ground and system ground circuits. The control module

may have multiple ground circuits. Other components in the system may have

separate grounds that may also need to be tested. Inspect grounds for clean and

tight connections at the grounding point. Inspect the connections at the

component and in splice packs, where applicable. Ensure that the circuit can

carry the current necessary to operate the component. Refer to

Circuit Testing

and

Ground Distribution Schematics

in Wiring Systems.

Temperature Sensitivity • An intermittent condition may occur when a component/connection reaches

normal operating temperature. The condition may occur only when the

component/connection is cold, or only when the component/connection is hot.

• Freeze Frame, Failure Records, Snapshot, or Vehicle Data Recorder data may

help with this type of intermittent condition, where applicable.

• If the intermittent is related to heat, review the data for a relationship with the

following:

− High ambient temperatures

− Underhood/engine generated heat

− Circuit generated heat due to a poor connection, or high electrical load

− Higher than normal load conditions, towing, etc.

• If the intermittent is related to cold, review the data for the following:

− Low ambient temperatures—In extremely low temperatures, ice may form in a

connection or component. Test for water intrusion.

− The condition only occurs on a cold start.

− The condition goes away when the vehicle warms up.

• Information from the customer may help to determine if the trouble follows a

pattern that is temperature related.

EngineControls-6.0LEngine

Intermittent Conditions (cont’d)

Inspection/Test Action

Electromagnetic Interference (EMI)

and Electrical Noise Some electrical components/circuits are sensitive to EMI or other types of electrical

noise. Inspect for the following conditions:

• A misrouted harness that is too close to high voltage/high current devices such

as secondary ignition components, motors, generator etc. These components

may induce electrical noise on a circuit that could interfere with normal circuit

operation.

• Electrical system interference caused by a malfunctioning relay, or an engine

control module (ECM) driven solenoid or switch. These conditions can cause a

sharp electrical surge. Normally, the problem will occur when the malfunctioning

component is operating.

• Improper installation of non-factory or aftermarket add on accessories such as

lights, 2-way radios, ampliﬁers, electric motors, remote starters, alarm systems,

cell phones, etc. These accessories may lead to an emission related OBD II

failure while in use, but do not fail when the accessories are not in use. Refer to

Checking Aftermarket Accessories

in Wiring Systems.

• Test for an open diode across the A/C compressor clutch and for other open

diodes. Some relays may contain a clamping diode.

• Test the generator for a bad rectiﬁer bridge that may be allowing AC noise into

the electrical system. Refer to

Symptoms - Engine Electrical

in Engine Electrical.

Incorrect PCM Programming • There are only a few situations where reprogramming an ECM is appropriate:

− A new service ECM is installed.

− An ECM from another vehicle is installed.

− Revised software/calibration ﬁles have been released for this vehicle.

Important: DO NOT re-program the ECM with the SAME software/calibration ﬁles

that are already present in the ECM. This is not an effective repair for any type of

driveability problem.

• Verify that the ECM contains the correct software/calibration. If incorrect

programming is found, reprogram the ECM with the most current

software/calibration. Refer to

Control Module References

in Computer/Integrating

Systems for replacement, setup, and programming.

Duplicating Failure Conditions • If none of the previous tests are successful, attempt to duplicate and/or capture

the failure conditions.

• Freeze Frame/Failure Records data, where applicable, contains the conditions

that were present when the DTC set.

1. Review and record Freeze Frame/Failure Records data

2.CleartheDTCsusingtheTech 2 .

3. Turn the key to OFF and wait 15 seconds.

4. Operate the vehicle under the same conditions that were noted in Freeze

Frame/Failure Records data, as closely as possible. The vehicle must also

be operating within the Conditions for Running the DTC. Refer to

Conditions for Running the DTC in the supporting text of the DTC being

diagnosed.

5.MonitorDTCStatusfortheDTCbeingtested.TheTech 2 willindicate

Ran, when the enabling conditions have been satisﬁed long enough for the

DTCtorun.TheTech 2 willalsoindicatewhethertheDTCpassedor

failed.

• An alternate method is to drive the vehicle with the DMM connected to a

suspected circuit. An abnormal reading on the DMM when the problem occurs,

may help you locate the problem.

Tech 2 SnapshotTheTech 2 canbesetuptotakeaSnapshotoftheparametersavailableviaserial

data. The Snapshot function records live data over a period of time. The recorded

datacanbeplayedbackandanalyzed.TheTech 2 canalsographparameters

singly or in combinations of parameters for comparison. The Snapshot can be

triggered manually at the time the symptom is noticed, or set up in advance to trigger

when a DTC sets.

An abnormal value captured in the recorded data may point to a system or

component that needs to be investigated further.

RefertotheTech 2 userinstructionsformoreinformationontheSnapshotfunction.

EngineEngineControls-6.0L

Intermittent Conditions (cont’d)

Inspection/Test Action

Vehicle Data Recorder The

J 42598

Vehicle Data Recorder is connected to the data link connector (DLC)

and sent with the customer. The

J 42598

captures data for later retrieval and analysis

by the technician. Refer to the vehicle data recorder user instructions for more

information.

Hard Start

Inspection/Test Action

DEFINITION: Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately dies.

Preliminary • Refer to Important Preliminary Inspections Before Starting in

Symptoms - Engine

Controls

• Verify that the engine control module (ECM) grounds are clean, tight, and in the

proper locations. Refer to

Power and Grounding Component Views

in Wiring

Systems, and

Engine Controls Schematics

• Search for bulletins.

Sensor/System • Verify that the engine coolant temperature (ECT) sensor is not shifted in value.

ConnectaTech 2 .Comparetheenginecoolanttemperaturetotheintakeair

temperature (IAT) on a cold engine. The ECT and IAT sensor values should be

within ±3°C (5°F) of each other. If the ECT sensor is out of range with the IAT

sensor, measure the resistance of the ECT sensor. Refer to

Temperature vs

Resistance

for resistance speciﬁcations.

Important: The embossed arrows on the mass air ﬂow (MAF) sensor indicate the

direction of the intake air ﬂow. The arrows must point toward the engine.

• Inspect the MAF sensor installation. A MAF sensor that is incorrectly installed

may cause a hard start. Install the MAF in the proper direction. Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor Replacement

• Inspect the camshaft position (CMP) sensor for proper mounting and/or a bad

connection. An extended crank occurs if the ECM does not receive a CMP

signal.

Fuel System • Inspect the fuel pump relay operation. The fuel pump should turn ON for

2 seconds when you turn ON the ignition. Refer to

Fuel Pump Electrical Circuit

Diagnosis

• Verify that both fuel injector fuses are not open. An open fuel injector fuse

causes 4 injectors and 4 ignition coils not to operate. Inspect the injector circuits

and the ignition coil circuits for an intermittent short to ground. Replace the fuse.

Refer to

Circuit Testing

in Wiring Systems.

• Inspect for incorrect fuel pressure. Refer to

Fuel System Diagnosis

• Inspect for a contaminated fuel condition. Refer to

Alcohol/Contaminants-in-Fuel

Diagnosis (without Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with

Special Tool)

EngineControls-6.0LEngine

Hard Start (cont’d)

Inspection/Test Action

Ignition System • Verify that both fuel injector fuses are not open. An open fuel injector fuse

causes 4 ignition coils and 4 fuel injectors not to operate. Inspect the ignition coil

circuits and the fuel injector circuits for an intermittent short to ground. Refer to

Circuit Testing

in Wiring Systems. Replace the fuse.

• Inspect for proper ignition voltage output with the

J 26792

Spark Tester. Refer to

Electronic Ignition (EI) System Diagnosis

• Remove the spark plugs and inspect for the following:

− Correct heat range

− Wet plugs

− Cracks

− Wear

− Improper gap

− Burned electrodes

− Heavy deposits

Refer to

Spark Plug Inspection

• Determine the cause of the conditions before replacing the spark plugs.

• Inspect for bare or shorted ignition wires. Refer to

Spark Plug Wire Inspection

• Inspect for loose ignition coil grounds. Refer to

Electronic Ignition (EI) System

Diagnosis

Engine Mechanical Inspect for the following conditions:

• Excessive oil in combustion chamber or leaking valve seals—Refer to

Oil

Consumption Diagnosis

in Engine Mechanical.

• Low cylinder compression—Refer to

Engine Compression Test

in Engine

Mechanical.

• Combustion chambers for excessive carbon buildup—Clean the chambers using

top engine cleaner. Follow the instructions on the can.

• Incorrect basic engine parts—Inspect the following:

− Cylinder heads—Refer to

Cylinder Head Cleaning and Inspection

in Engine

Mechanical.

− Camshaft—Refer to

Camshaft and Bearings Cleaning and Inspection

Engine Mechanical.

− Pistons, etc.—Refer to

Piston, Connecting Rod, and Bearings Cleaning and

Inspection

in Engine Mechanical.

• Inspect for excessive crankshaft endplay that will cause the crankshaft

position (CKP) sensor reluctor wheel to move out of alignment with the CKP

sensor. Refer to

Crankshaft and Bearings Cleaning and Inspection

in Engine

Mechanical. This could result in any of the following conditions:

− A no start

− A start and stall

− Erratic performance

Surges/Chuggles

Inspection/Tests Action

DEFINITION: Engine power variation under steady throttle or cruise. Feels like the vehicle speeds up and slows down with

no change in the accelerator pedal position.

Preliminary • Refer to Important Preliminary Inspections Before Starting in

Symptoms - Engine

Controls

• Search for bulletins.

• Inspect the engine control module (ECM) grounds for being clean, tight, and in

the proper locations. Refer to

Power and Grounding Component Views

in Wiring

Systems and

Engine Controls Schematics

• Verify the driver understands the operation of the transmission torque converter

clutch (TCC) and A/C compressor operation as explained in the owners manual.

Inform the customer how the TCC and the A/C clutch operates.

EngineEngineControls-6.0L

Surges/Chuggles (cont’d)

Inspection/Tests Action

Sensor/System • Inspect the heated oxygen sensors (HO2S). The HO2S should respond quickly

to different throttle positions. If they do not, inspect the HO2S for silicon or other

contaminates from fuel or the use of improper RTV sealant. The sensors may

have a white, powdery coating and result in a high but false signal voltage rich

exhaust indication. The ECM will then reduce the amount of fuel delivered to the

engine causing a severe driveability problem.

• Inspect the mass air ﬂow (MAF) sensor connections. Repair or replace damaged

terminals. Refer to

Connector Repairs

in Wiring Systems.

Fuel System • Test for incorrect fuel pressure. Refer to

Fuel System Diagnosis

• Inspect for a contaminated fuel condition. Refer to

Alcohol/Contaminants-in-Fuel

Diagnosis (without Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with

Special Tool)

• Verify that each injector harness is connected to the correct injector or cylinder.

Relocate injector harnesses as necessary.

• Inspect for the following that may cause the engine to run rich:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the HO2S connector

− Engine oil contaminated by fuel

− An evaporative emission (EVAP) canister purge condition

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Leaking fuel injectors—Refer to

Fuel System Diagnosis

− An inaccurate MAF sensor

− Blockage on the inlet screen of the MAF sensor—Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor Replacement

− Vacuum hoses that are split, kinked, or improperly connected

− An air intake duct that is collapsed or restricted

− An air ﬁlter that is dirty or restricted—Refer to

Air Cleaner Element

Replacement

• Inspect for the following conditions that may cause the engine to run lean:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the HO2S connector

− An exhaust leak between the HO2S and the engine—Refer to

Exhaust

Leakage

in Engine Exhaust.

− Vacuum leaks

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Restricted fuel injectors—Refer to

Fuel Injector Balance Test with Special Tool

Fuel Injector Balance Test with Tech 2

− An inaccurate MAF sensor

− Fuel contamination—Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without

Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool)

− Vacuum hoses that are split, kinked, or improperly connected

EngineControls-6.0LEngine

Surges/Chuggles (cont’d)

Inspection/Tests Action

Ignition System • Soak the secondary ignition system with water from a spray bottle. Soaking the

secondary ignition system may help locate damaged or deteriorated components.

Look and listen for arcing or misﬁring as you apply the water.

• Test for proper ignition voltage output with the

J 26792

Spark Tester. Refer to

Electronic Ignition (EI) System Diagnosis

• Remove the spark plugs and inspect for the following:

− Correct heat range

− Wet plugs

− Cracks

− Wear

− Improper gap

− Burned electrodes

− Heavy deposits

Refer to

Spark Plug Inspection

• An improper spark plug gap will cause a driveability problem. Gap the spark

plugs using a wire gage gap tool. Refer to

Spark Plug Replacement

• Determine the cause of the fouling before replacing the spark plugs.

• Monitor the Misﬁre Current Counters while driving the vehicle within the

conditions that the misﬁre occurred. If a misﬁring cylinder can be located, use the

DTC P0300 table for diagnosis. Refer to

DTC P0300

• Inspect for loose ignition coil grounds. Refer to

Electronic Ignition (EI) System

Diagnosis

Engine Mechanical • Verify that the engine coolant temperature (ECT) is not above 130°C (266°F).

This condition causes the ECM to operate in Engine Coolant Over

Temperature-Fuel Disabled Mode. While in Engine Coolant Over

Temperature-Fuel Disabled Mode, the ECM turns fuel OFF to 4 cylinders at a

time to keep engine temperatures from reaching damaging levels. The driver

may perceive Engine Coolant Over Temperature–Fuel Disabled Mode as a lack

of power, miss, or rough idle. If the vehicle operates in Engine Coolant Over

Temperature-Fuel Disabled Mode, refer to

Engine Overheating

in Engine Cooling

for diagnosis.

• Inspect for excessive crankshaft endplay that will cause the crankshaft

position (CKP) sensor reluctor wheel to move out of alignment with the CKP

sensor. Refer to

Crankshaft and Bearings Cleaning and Inspection

in Engine

Mechanical. This could result in any of the following conditions:

− A no start

− A start and stall

− Erratic performance

Additional Inspections • Visually and physically inspect vacuum hoses for splits, kinks, and proper

connections and routing as shown on the Vehicle Emission Control

Information label.

• Inspect the transmission torque converter clutch (TCC) operation. A TCC

applying too soon can cause the engine to spark knock.

Lack of Power, Sluggishness, or Sponginess

Inspection/Tests Action

DEFINITION: Engine delivers less than expected power. Little or no increase in speed when the accelerator pedal is pushed

down part way.

Preliminary Inspections • Refer to Important Preliminary Inspections Before Starting in

Symptoms - Engine

Controls

• Search for bulletins.

• Verify that the engine control module (ECM) grounds are clean, tight, and in the

proper locations. Refer to

Power and Grounding Component Views

in Wiring

Systems and

Engine Controls Schematics

• Remove the air ﬁlter element and inspect for dirt or for restrictions. Refer to

Air

Cleaner Element Replacement

and replace as necessary.

EngineEngineControls-6.0L

Lack of Power, Sluggishness, or Sponginess (cont’d)

Inspection/Tests Action

Fuel System • Inspect both injector fuses for being open. An open injector fuse causes

4 ignition coils and 4 injectors not to operate. Replace the fuse. Inspect the

ignition coil circuits and the injector circuits for an intermittent short to ground.

• Inspect for incorrect fuel pressure. Refer to

Fuel System Diagnosis

• Inspect for a contaminated fuel condition. Refer to

Alcohol/Contaminants-in-Fuel

Diagnosis (without Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with

Special Tool)

• Inspect the fuel injectors. Refer to

Fuel Injector Coil Test

• Inspect for the following that may cause the engine to run rich:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the heated oxygen sensor (HO2S) connector

− Engine oil contaminated by fuel

− An evaporative emission (EVAP) canister purge condition

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Leaking fuel injectors—Refer to

Fuel System Diagnosis

− An inaccurate mass air ﬂow (MAF) sensor

− Blockage on the inlet screen of the MAF sensor—Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor Replacement

− Vacuum hoses that are split, kinked, or improperly connected

− An air intake duct that is collapsed or restricted

− An air ﬁlter that is dirty or restricted—Refer to

Air Cleaner Element

Replacement

• Inspect for the following conditions that may cause the engine to run lean:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the HO2S connector

− An exhaust leak between the HO2S and the engine—Refer to

Exhaust

Leakage

in Engine Exhaust.

− Vacuum leaks

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Restricted fuel injectors—Refer to

Fuel Injector Balance Test with Special Tool

Fuel Injector Balance Test with Tech 2

− An inaccurate MAF sensor

− Fuel contamination—Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without

Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool)

− Vacuum hoses that are split, kinked, or improperly connected

Sensor/SystemUseaTech 2 inordertomonitortheknocksensor(KS)systemforexcessivespark

retard activity. Refer to

Knock Sensor (KS) System Description

EngineControls-6.0LEngine

Lack of Power, Sluggishness, or Sponginess (cont’d)

Inspection/Tests Action

Ignition System • Verify that both fuel injector fuses are not open. An open fuel injector fuse

causes 4 ignition coils and 4 fuel injectors not to operate. Inspect the ignition coil

circuit and the injector circuits for an intermittent short to ground. Refer to

Circuit

Testing

in Wiring Systems. Replace the fuse.

• Soak the secondary ignition system with water from a spray bottle. Soaking the

secondary ignition system may help locate damaged or deteriorated components.

Look and listen for arcing or misﬁring as water is applied.

• Inspect for proper ignition voltage output with the

J 26792

Spark Tester.

• Remove the spark plugs and inspect for the following:

− Correct heat range

− Wet plugs

− Cracks

− Wear

− Improper gap

− Burned electrodes

− Heavy deposits

Refer to

Spark Plug Inspection

• An improper spark plug gap will cause a driveability problem. Gap the spark

plugs using a wire gage gap tool. Refer to

Spark Plug Replacement

• Determine the cause of the fouling before replacing the spark plugs.

• Monitor the Misﬁre Current Counters while driving the vehicle within the

conditions that the misﬁre occurred. If a misﬁring cylinder can be located with a

misﬁre, use the DTC P0300 table for diagnosis. Refer to

DTC P0300

• Inspect for loose ignition coil grounds. Refer to

Electronic Ignition (EI) System

Diagnosis

Engine Mechanical • Verify that the engine coolant temperature (ECT) is not above 130°C (266°F).

This condition causes the ECM to operate in Engine Coolant Over

Temperature-Fuel Disabled Mode. While in Engine Coolant Over

Temperature-Fuel Disabled Mode, the ECM will disable the fuel injectors to

4 cylinders at a time to keep engine temperatures from reaching damaging

levels. The driver may perceive the Engine Coolant Over Temperature-Fuel

Disabled Mode as a lack of power, miss, or rough idle. If the vehicle operates in

Engine Coolant Over Temperature–Fuel Disabled Mode, refer to

Engine

Overheating

in Engine Cooling for diagnosis.

• Inspect for excessive oil in the combustion chambers and leaking valve seals.

Refer to

Oil Consumption Diagnosis

in Engine Mechanical.

• Test for low cylinder compression. Refer to

Engine Compression Test

in Engine

Mechanical.

• Inspect for incorrect basic engine parts, including the following:

− The camshaft—Refer to

Camshaft and Bearings Cleaning and Inspection

Engine Mechanical.

− The cylinder heads—Refer to

Cylinder Head Cleaning and Inspection

Engine Mechanical.

− The pistons, etc.—Refer to

Piston, Connecting Rod, and Bearings Cleaning

and Inspection

in Engine Mechanical.

• Inspect for excessive crankshaft endplay that will cause the crankshaft

position (CKP) sensor reluctor wheel to move out of alignment with the CKP

sensor. Refer to

Crankshaft and Bearings Cleaning and Inspection

in Engine

Mechanical. This could result in any of the following conditions:

− A no start

− A start and stall

− Erratic performance

Additional Inspections • Inspect the exhaust system for possible restrictions. Perform the following:

− Inspect the exhaust system for damaged or collapsed pipes.

− Inspect the mufflers for heat distress or internal failure.

− Inspect for plugged catalytic converters. Refer to

Restricted Exhaust

in Engine

Exhaust.

• Inspect the transmission torque converter clutch (TCC) for proper operation.

EngineEngineControls-6.0L

Detonation/Spark Knock

Inspection/Tests Action

DEFINITION: A mild to severe ping, usually worse under acceleration. The engine makes sharp metallic knocks that change

with throttle opening.

Preliminary Inspections • Refer to Important Preliminary Inspections Before Starting in

Symptoms - Engine

Controls

• Search for bulletins.

• Verify that the engine control module (ECM) grounds are clean, tight, and in the

proper locations. Refer to

Power and Grounding Component Views

in Wiring

Systems and

Engine Controls Schematics

• If there are no engine mechanical faults, ﬁll the fuel tank with a known high

quality fuel that meets the vehicles minimum octane requirements. Road test the

vehicle and re-evaluate the vehicles performance.

Fuel System • Inspect for incorrect fuel pressure. Refer to

Fuel System Diagnosis

• Inspect for a restricted fuel ﬁlter. Refer to

Fuel System Diagnosis

• Inspect for a contaminated fuel condition. Refer to

Alcohol/Contaminants-in-Fuel

Diagnosis (without Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with

Special Tool)

• Inspect for the following conditions that may cause the engine to run lean:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the heated oxygen sensor (HO2S) connector

− An exhaust leak between the HO2S and the engine—Refer to

Exhaust

Leakage

in Engine Exhaust.

− Vacuum leaks

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Restricted fuel injectors—Refer to

Fuel Injector Balance Test with Special Tool

Fuel Injector Balance Test with Tech 2

− An inaccurate mass air ﬂow (MAF) sensor

− Fuel contamination—Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without

Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool)

− Vacuum hoses that are split, kinked, or improperly connected

Ignition System Verify that the spark plugs are of the proper heat range. Refer to

Spark Plug

Inspection

Engine Cooling System Inspect for obvious overheating problems:

• Low engine coolant—Refer to

Loss of Coolant (Automatic Transmission)

Loss

of Coolant (Manual Transmission)

in Engine Cooling for the type and amount of

engine coolant to be used.

• Restricted air ﬂow to the radiator or restricted coolant ﬂow through the radiator.

• Inoperative cooling fan—Refer to

Cooling Fan Inoperative

in Engine Cooling.

Engine Mechanical Inspect for the following engine mechanical problems:

• Excessive oil in combustion chamber—Leaking valve seals. Refer to

Oil

Consumption Diagnosis

in Engine Mechanical.

• Low cylinder compression—Refer to

Engine Compression Test

in Engine

Mechanical.

• Combustion chambers for excessive carbon buildup—Clean the combustion

chamber by using top engine cleaner. Follow the instructions on the can.

• Inspect for incorrect basic engine parts. Inspect the following:

− The camshaft—Refer to

Camshaft and Bearings Cleaning and Inspection

Engine Mechanical.

− The cylinder heads—Refer to

Cylinder Head Cleaning and Inspection

Engine Mechanical.

− The pistons, etc.—Refer to

Piston, Connecting Rod, and Bearings Cleaning

and Inspection

in Engine Mechanical.

• Refer to

Symptoms - Engine Mechanical

in Engine Mechanical.

EngineControls-6.0LEngine

Detonation/Spark Knock (cont’d)

Inspection/Tests Action

Additional Inspections • Inspect the park/neutral position (PNP) switch operation.

• Inspect the transmission torque converter clutch (TCC) operation. The TCC

applying too soon can cause the engine to spark knock. Refer to

Torque

Converter Diagnosis Procedure

in Automatic Transmission–4L60-E.

Hesitation, Sag, Stumble

Inspection/Tests Action

DEFINITION: Momentary lack of response as the accelerator is pushed down. Can occur at any vehicle speed. Usually more

pronounced when ﬁrst trying to make the vehicle move, as from a stop. May cause the engine to stall if severe enough.

Preliminary • Refer to Important Preliminary Inspections Before Starting in

Symptoms - Engine

Controls

• Search for bulletins.

• Verify that the engine control module (ECM) grounds are clean, tight, and in the

proper locations. Refer to

Engine Controls Schematics

Sensor/System Inspect the manifold absolute pressure (MAP) sensor operation.

Fuel System • Inspect for incorrect fuel pressure. Refer to

Fuel System Diagnosis

• Inspect for a contaminated fuel condition. Refer to

Alcohol/Contaminants-in-Fuel

Diagnosis (without Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with

Special Tool)

• Verify that both fuel injector fuses are not open. An open fuel injector fuse

causes 4 ignition coils and 4 fuel injectors not to operate. Inspect the ignition coil

circuits and the fuel injector circuits for an intermittent short to ground. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems. Replace the fuse.

• Inspect for the following that may cause the engine to run rich:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the heated oxygen sensor (HO2S) connector

− Engine oil contaminated by fuel

− An evaporative emission (EVAP) canister purge condition

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Leaking fuel injectors—Refer to

Fuel System Diagnosis

− An inaccurate mass air ﬂow (MAF) sensor

− Blockage on the inlet screen of the MAF sensor—Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor Replacement

− Vacuum hoses that are split, kinked, or improperly connected

− An air intake duct that is collapsed or restricted

− An air ﬁlter that is dirty or restricted—Refer to

Air Cleaner Element

Replacement

• Inspect for the following conditions that may cause the engine to run lean:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the HO2S connector

− An exhaust leak between the HO2S and the engine—Refer to

Exhaust

Leakage

in Engine Exhaust.

− Vacuum leaks

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Restricted fuel injectors—Refer to

Fuel Injector Balance Test with Special Tool

Fuel Injector Balance Test with Tech 2

− An inaccurate MAF sensor

− Fuel contamination—Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without

Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool)

− Vacuum hoses that are split, kinked, or improperly connected

EngineEngineControls-6.0L

Hesitation, Sag, Stumble (cont’d)

Inspection/Tests Action

Ignition System • Soak the secondary ignition system with water from a spray bottle. Soaking the

secondary ignition system may help locate damaged or deteriorated components.

Look and listen for arcing or misﬁring as you apply water.

• Test for proper ignition voltage output with the

J 26792

Spark Tester. Refer to

Electronic Ignition (EI) System Diagnosis

for the procedure.

• Remove the spark plugs and check for the following:

− Correct heat range

− Wet plugs

− Cracks

− Wear

− Improper gap

− Burned electrodes

− Heavy deposits

Refer to

Spark Plug Inspection

• An improper spark plug gap will cause a driveability problem. Gap the spark

plugs using a wire gage gap tool. Refer to

Spark Plug Replacement

• Determine the cause of the fouling before replacing the spark plugs.

• Monitor the Misﬁre Current Counters while driving the vehicle in the conditions

that the misﬁre occurred. If a misﬁring cylinder can be located, use the

DTC P0300 table for diagnosis. Refer to

DTC P0300

• Inspect for loose ignition coil grounds. Refer to

Electronic Ignition (EI) System

Diagnosis

Engine Cooling System Inspect the engine thermostat for proper operation and for proper heat range. Refer

Thermostat Diagnosis

in Engine Cooling.

Engine Mechanical Inspect for excessive crankshaft endplay that will cause the crankshaft position (CKP)

sensor reluctor wheel to move out of alignment with the CKP sensor. Refer to

Crankshaft and Bearings Cleaning and Inspection

in Engine Mechanical. This could

result in any of the following conditions:

• A no start

• A start and stall

• Erratic performance

Additional Inspections Inspect the generator output voltage. Refer to

Charging System Test

in Engine

Electrical for the procedure. Repair the charging system if the generator output

voltage is less than 9 volts or more than 16 volts.

Cuts Out, Misses

Inspections Action

DEFINITION: Steady pulsation or jerking that follows engine speed, usually more pronounced as engine load increases. This

condition is not normally felt above 1,500 RPM or 48 km/h (30 mph). The exhaust has a steady spitting sound at idle or

low speed.

Preliminary • Refer to Important Preliminary Inspections Before Starting in

Symptoms - Engine

Controls

• Search for bulletins.

• Verify that the engine control module (ECM) grounds are clean, tight, and in the

proper locations. Refer to

Power and Grounding Component Views

in Wiring

Systems and

Engine Controls Schematics

• Remove the air ﬁlter element and inspect for dirt and for restrictions. Refer to

Air

Cleaner Element Replacement

. Replace as necessary.

EngineControls-6.0LEngine

Cuts Out, Misses (cont’d)

Inspections Action

Fuel System • Inspect the fuel injectors. Refer to

Fuel Injector Coil Test

• Inspect for incorrect fuel pressure. Refer to

Fuel System Diagnosis

• Inspect for a restricted fuel ﬁlter. Refer to

Fuel System Diagnosis

• Inspect for a contaminated fuel condition. Refer to

Alcohol/Contaminants-in-Fuel

Diagnosis (without Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with

Special Tool)

• Inspect for the following that may cause the engine to run rich:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the heated oxygen sensor (HO2S) connector

− Engine oil contaminated by fuel

− An evaporative emission (EVAP) canister purge condition

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− A leaking fuel pressure regulator—Refer to

Fuel System Diagnosis

− Leaking fuel injectors—Refer to

Fuel System Diagnosis

− An inaccurate mass air ﬂow (MAF) sensor

− Blockage on the inlet screen of the MAF sensor—Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor Replacement

− Vacuum hoses that are split, kinked, or improperly connected

− An air intake duct that is collapsed or restricted

− An air ﬁlter that is dirty or restricted—Refer to

Air Cleaner Element

Replacement

• Inspect for the following conditions that may cause the engine to run lean:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the HO2S connector

− An exhaust leak between the HO2S and the engine—Refer to

Exhaust

Leakage

in Engine Exhaust.

− Vacuum leaks

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Restricted fuel injectors—Refer to

Fuel Injector Balance Test with Special Tool

Fuel Injector Balance Test with Tech 2

− An inaccurate MAF sensor

− Fuel contamination—Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without

Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool)

− Vacuum hoses that are split, kinked, or improperly connected

Sensor/SystemUseaTech 2 inordertomonitortheknocksensor(KS)systemforexcessivespark

retard activity. Refer to

Knock Sensor (KS) System Description

EngineEngineControls-6.0L

Cuts Out, Misses (cont’d)

Inspections Action

Ignition System • Soak the secondary ignition system with water from a spray bottle. Soaking the

secondary ignition system may help locate damaged or deteriorated components.

Look and listen for arcing or misﬁring as you apply water.

• Test for proper ignition voltage output with the

J 26792

Spark Tester.

• Remove the spark plugs and inspect for the following:

− Correct heat range

− Wet plugs

− Cracks

− Wear

− Improper gap

− Burned electrodes

− Heavy deposits

Refer to

Spark Plug Inspection

• An improper spark plug gap will cause a driveability problem. Refer to

Spark

Plug Inspection

. Gap the spark plugs using a wire gage gap tool. Refer to

Spark

Plug Replacement

• Determine the cause of the fouling before replacing the spark plugs.

• Visually and physically inspect the secondary ignition for the following:

− The ignition wires arcing to ground

− The ignition wires for proper engagement to spark plug

− The ignition coils for cracks or carbon tracking

• Monitor the Misﬁre Current Counters while driving the vehicle in the conditions

that the misﬁre occurred. If a misﬁring cylinder can be located, use the

DTC P0300 table for diagnosis. Refer to

DTC P0300

Engine Mechanical • Inspect engine mechanical for the following:

− Inspect compression—Refer to

Engine Compression Test

in Engine

Mechanical.

− Sticking or leaking valves

− Worn camshaft lobes

− Valve timing

− Bent push rods

− Worn rocker arms

− Broken valve springs

− Excessive oil in combustion chamber—Leaking valve seals. Refer to

Oil

Consumption Diagnosis

in Engine Mechanical.

• For incorrect basic engine parts inspect the following:

− The camshaft—Refer to

Camshaft and Bearings Cleaning and Inspection

Engine Mechanical.

− The cylinder heads—Refer to

Cylinder Head Cleaning and Inspection

Engine Mechanical.

− The pistons, etc.—Refer to

Piston, Connecting Rod, and Bearings Cleaning

and Inspection

in Engine Mechanical.

• Inspect for excessive crankshaft endplay that will cause the crankshaft

position (CKP) sensor reluctor wheel to move out of alignment with the CKP

sensor. Refer to

Crankshaft and Bearings Cleaning and Inspection

in Engine

Mechanical. This could result in any of the following conditions:

− A no start

− A start and stall

− Erratic performance

Refer to

Symptoms - Engine Mechanical

in Engine Mechanical for diagnostic

procedures.

EngineControls-6.0LEngine

Cuts Out, Misses (cont’d)

Inspections Action

Additional Inspections • Inspect the exhaust system for possible restrictions. Inspect for the following:

− Inspect the exhaust system for damaged or collapsed pipes.

− Inspect the mufflers for heat distress or possible internal failure.

− Inspect for possible plugged catalytic converters. Refer to

Restricted Exhaust

in Engine Exhaust.

• Electromagnetic interference (EMI) on the reference circuit can cause an engine

misﬁre condition. A sudden increase in indicated RPM with little change in actual

engine RPM change indicates EMI is present. Inspect for high voltage

components near ignition control circuits if a condition exists.

• Inspect the intake manifold and the exhaust manifold passages for casting ﬂash.

Poor Fuel Economy

Inspections Action

DEFINITION: Fuel economy, as measured by an actual road test, is noticeably lower than expected. Also, fuel economy is

noticeably lower than the economy was on this vehicle at one time, as previously shown by an actual road test.

Preliminary • Refer to Important Preliminary Inspections Before Starting in

Symptoms - Engine

Controls

• Search for bulletins.

• Verify that the engine control module (ECM) grounds are clean, tight, and in the

proper locations. Refer to

Power and Grounding Component Views

in Wiring

Systems and

Engine Controls Schematics

• Inspect the owners driving habits.

− Is the A/C ON or the Defroster mode ON full time?

− Are the tires at the correct pressure?

− Are the wheels and tires the correct size?

− Is the acceleration rate too much, too often?

• Remove the air ﬁlter element and inspect for dirt or for restrictions. Refer to

Air

Cleaner Element Replacement

. Replace as necessary.

EngineEngineControls-6.0L

Poor Fuel Economy (cont’d)

Inspections Action

Fuel System • Inspect the type, quality, and alcohol content of the fuel. Oxygenated fuels have

lower energy and may deliver reduced fuel economy. Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool)

• Inspect the fuel injectors. Refer to

Fuel Injector Coil Test

Fuel Injector Balance

Test with Special Tool

Fuel Injector Balance Test with Tech 2

• Inspect for incorrect fuel pressure. Refer to

Fuel System Diagnosis

• Inspect for a contaminated fuel condition. Refer to

Alcohol/Contaminants-in-Fuel

Diagnosis (without Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with

Special Tool)

• Inspect that each fuel injector harness is connected to the correct injector and

cylinder. Relocate the injector harnesses as necessary.

• Inspect for foreign material accumulation in the throttle bore, coking on the

throttle valve, or on the throttle shaft.

• Inspect for the following that may cause the engine to run rich:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the heated oxygen sensor (HO2S) connector

− Engine oil contaminated by fuel

− An evaporative emissions (EVAP) canister purge condition

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Leaking fuel injectors—Refer to

Fuel System Diagnosis

− An inaccurate mass air ﬂow (MAF) sensor

− Blockage on the inlet screen of the MAF sensor—Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor Replacement

− Vacuum hoses that are split, kinked, or improperly connected

− An air intake duct that is collapsed or restricted

− An air ﬁlter that is dirty or restricted—Refer to

Air Cleaner Element

Replacement

Sensor/System • Inspect the air intake system and crankcase for air leaks.

• Inspect the crankcase ventilation valve for proper operation. Refer to

Crankcase

Ventilation System Inspection/Diagnosis

in Engine Mechanical.

• Inspect for an inaccurate speedometer. Refer to

Symptoms - Instrument Panel,

Gages and Console

in Instrument Panel, Gages, and Console.

•UseaTech 2 inordertomonitortheknocksensor(KS)systemforexcessive

spark retard activity. Refer to

Knock Sensor (KS) System Description

Ignition System • Inspect for proper ignition voltage output with the

J 26792

Spark Tester.

• Remove the spark plugs and inspect for the following:

− Wet plugs

− Cracks

− Wear

− Improper gap

− Burned electrodes

− Heavy deposits

Refer to

Spark Plug Inspection

• An improper spark plug gap will cause a driveability problem. Refer to

Spark

Plug Inspection

. Gap the spark plugs using a wire gage gap tool. Refer to

Spark

Plug Replacement

• Determine the cause of the fouling before replacing the spark plugs. Refer to

Spark Plug Inspection

• Visually and physically inspect the secondary ignition for the following:

− Ignition wires arcing to ground

− Ignition wires for proper routing

• Soaking the secondary ignition system with water from a spray bottle may help

locate damaged or deteriorated components. Look and listen for arcing or

misﬁring as you apply water.

• Inspect for loose ignition coil grounds. Refer to

Electronic Ignition (EI) System

Diagnosis

EngineControls-6.0LEngine

Poor Fuel Economy (cont’d)

Inspections Action

Engine Cooling System • Inspect the engine coolant level for being low. Refer to

Loss of Coolant

(Automatic Transmission)

Loss of Coolant (Manual Transmission)

in Engine

Cooling.

• Inspect the engine thermostat for proper operation and for the correct heat

range. Refer to

Thermostat Diagnosis

in Engine Cooling.

Engine Mechanical • Inspect engine mechanical for the following:

− Compression—Refer to

Engine Compression Test

in Engine Mechanical.

− Sticking or leaking valves

− Worn camshaft lobes

− Valve timing

− Bent push rods

− Worn rocker arms

− Broken valve springs

− Excessive oil in combustion chamber—Leaking valve seals. Refer to

Oil

Consumption Diagnosis

in Engine Mechanical.

• For incorrect basic engine parts inspect for the following:

− The camshaft—Refer to

Camshaft and Bearings Cleaning and Inspection

Engine Mechanical.

− The cylinder heads—Refer to

Cylinder Head Cleaning and Inspection

Engine Mechanical.

− The pistons, etc.—Refer to

Piston, Connecting Rod, and Bearings Cleaning

and Inspection

in Engine Mechanical.

Refer to

Symptoms - Engine Mechanical

in Engine Mechanical for diagnostic

procedures.

Additional Inspections • Visually and physically check the vacuum hoses for splits, kinks, and proper

connections and routing as shown on Vehicle Emission Control Information label.

•Inspectthetransmissiontorqueconverterclutch(TCC)operation.TheTech 2

should indicate a RPM drop, when the system commands the TCC ON. Refer to

Torque Converter Diagnosis Procedure

in Automatic Transmission – 4L60-E.

• Inspect the exhaust system for a possible restriction. Inspect for the following:

− Inspect the exhaust system for damaged or collapsed pipes.

− Inspect the mufflers for heat distress or possible internal failure.

− Inspect for possible plugged catalytic converters. Refer to

Restricted Exhaust

in Engine Exhaust.

• Electromagnetic interference (EMI) on the reference circuit can cause an engine

misscondition.ATech 2 canusuallydetectEMIbymonitoringtheengine

RPM. A sudden increase in RPM with little change in actual engine RPM change

indicates EMI is present. Inspect for high voltage components, near ignition

control circuits, if a condition exists.

• Inspect the park neutral position (PNP) switch circuit.

• Inspect the intake and the exhaust manifold passages for casting ﬂash.

• Inspect the brake system for dragging or improper operation. Refer to

Brakes

Drag

in Hydraulic Brakes. Verify that the vehicle operator does not drive with a

foot on the brake pedal.

Poor Fuel Fill Quality

Problem Causes

DEFINITION: Difficulty when refueling the vehicle.

EngineEngineControls-6.0L

Poor Fuel Fill Quality (cont’d)

Problem Causes

Difficult to ﬁll • The check valve is stuck closed.

• The ﬁll limiter vent valve is stuck closed.

• The evaporative emission (EVAP) canister is restricted.

• The EVAP canister vent solenoid is stuck closed.

• Restricted EVAP pipes

• High Reid vapor pressure

• High fuel temperature

• The fuel ﬁller hose/pipe is pinched, kinked or blocked.

• The fuel feed hose, or crossover hose, is pinched, kinked or blocked.

• The ignition switch is ON.

Over ﬁll • The pressure relief valve in the ﬁll limiter vent valve is stuck open.

• The pressure relief valve in the ﬁll limiter vent is valve leaking.

• The ﬁll limiter vent valve is stuck open.

• The ﬁll limiter vent valve is leaking.

Pre-mature shut-off of the fuel

dispensing nozzle • The check valve is stuck closed.

• The ﬁll limiter vent valve is stuck closed.

• The EVAP canister is restricted.

• The EVAP canister vent solenoid is stuck closed.

• Restricted EVAP pipes

• High Reid vapor pressure

• High fuel temperature

• The fuel ﬁller hose/pipe is pinched, kinked or blocked.

• The fuel feed hose, or crossover hose, is pinched, kinked or blocked.

• The ignition switch is ON.

Fuel spit back • The check valve is stuck open.

• The check valve is stuck closed.

• The check valve is leaking.

• High Reid vapor pressure

• High fuel temperature

Liquid fuel in the EVAP canister • The ﬁll limiter vent valve is stuck open.

• The ﬁll limiter vent valve is leaking.

Liquid fuel leak • The pressure relief valve in the ﬁll limiter vent valve is stuck open.

• The pressure relief valve in the ﬁll limiter vent valve is leaking.

• The fuel ﬁller hose is loose or torn.

• The fuel feed hose, or crossover hose, is loose or torn.

• The ﬁll limiter vent valve is stuck open.

Fuel odor • The pressure relief valve in the ﬁll limiter vent valve is stuck open.

• The pressure relief valve in the ﬁll limiter vent valve is leaking.

• The EVAP canister is saturated.

Rough, Unstable, or Incorrect Idle and Stalling

Inspections Action

DEFINITION: Engine runs unevenly at idle. If severe, the engine or vehicle may shake. Engine idle speed may vary in RPM.

Either condition may be severe enough to stall the engine.

EngineControls-6.0LEngine

Rough, Unstable, or Incorrect Idle and Stalling (cont’d)

Inspections Action

Preliminary Inspections • Refer to Important Preliminary Inspections Before Starting in

Symptoms - Engine

Controls

• Search for bulletins.

• Verify that the engine control module (ECM) grounds are clean, tight, and in the

proper locations. Refer to

Power and Grounding Component Views

in Wiring

Systems and

Engine Controls Schematics

• Remove and inspect the air ﬁlter element for dirt or for restrictions. Refer to

Air

Cleaner Element Replacement

. Replace as necessary.

Fuel System • Inspect the fuel injectors. Refer to

Fuel Injector Coil Test

Fuel Injector Balance

Test with Special Tool

Fuel Injector Balance Test with Tech 2

• Inspect for incorrect fuel pressure. Refer to

Fuel System Diagnosis

• Inspect for a contaminated fuel condition. Refer to

Alcohol/Contaminants-in-Fuel

Diagnosis (without Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with

Special Tool)

• Inspect that each fuel injector harness is connected to the correct

injector/cylinder. Relocate fuel injector harnesses as necessary.

• Inspect for the following that may cause the engine to run rich:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the heated oxygen sensor (HO2S) connector

− Engine oil contaminated by fuel

− An evaporative emissions (EVAP) canister purge condition

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Leaking fuel injectors—Refer to

Fuel System Diagnosis

− An inaccurate mass air ﬂow (MAF) sensor

− Blockage on the inlet screen of the MAF sensor—Refer to

Mass Air

Flow (MAF)/Intake Air Temperature (IAT) Sensor Replacement

− Vacuum hoses that are split, kinked, or improperly connected

− An air intake duct that is collapsed or restricted

− An air ﬁlter that is dirty or restricted—Refer to

Air Cleaner Element

Replacement

• Inspect for the following conditions that may cause the engine to run lean:

Notice:

Refer to

Heated Oxygen and Oxygen Sensor Notice

in Cautions and Notices.

− Water intrusion in the HO2S connector

− An exhaust leak between the HO2S and the engine—Refer to

Exhaust

Leakage

in Engine Exhaust.

− Vacuum leaks

− Incorrect fuel pressure—Refer to

Fuel System Diagnosis

− Restricted fuel injectors—Refer to

Fuel Injector Balance Test with Special Tool

Fuel Injector Balance Test with Tech 2

− An inaccurate MAF sensor

− Fuel contamination—Refer to

Alcohol/Contaminants-in-Fuel Diagnosis (without

Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool)

− Vacuum hoses that are split, kinked, or improperly connected

Sensor/System • Inspect the crankcase ventilation valve for proper operation. Refer to

Crankcase

Ventilation System Inspection/Diagnosis

in Engine Mechanical.

•UseaTech 2 inordertomonitortheknocksensor(KS)systemforexcessive

spark retard activity.

EngineEngineControls-6.0L

Rough, Unstable, or Incorrect Idle and Stalling (cont’d)

Inspections Action

Ignition System • Inspect for proper ignition voltage output with the

J 26792

Spark Tester. Refer to

Electronic Ignition (EI) System Diagnosis

for procedure.

• Remove spark plugs and check for the following:

− Wet plugs

− Cracks

− Wear

− Improper gap

− Burned electrodes

− Heavy deposits

Refer to

Spark Plug Inspection

• An improper spark plug gap will cause a driveability problem. Refer to

Spark

Plug Inspection

. Gap the spark plugs using a wire gage gap tool. Refer to

Spark

Plug Replacement

• Determine the cause of the fouling before replacing the spark plugs.

• Visually and physically inspect secondary ignition for the following:

− Ignition wires arcing to ground

− Ignition wires for proper routing

• Soak the secondary ignition system with water from a spray bottle. Soaking the

secondary ignition system may help locate damaged or deteriorated components.

Look and listen for arcing or misﬁring as you apply water.

• Monitor the Misﬁre Current Counters while driving the vehicle in the conditions

that the misﬁre occurred. If a misﬁring cylinder can be located, use the

DTC P0300 table for diagnosis. Refer to

DTC P0300

• Inspect for loose ignition coil grounds. Refer to

Electronic Ignition (EI) System

Diagnosis

Engine Mechanical • Inspect engine mechanical for the following:

− Compression—Refer to

Engine Compression Test

in Engine Mechanical.

− Sticking or leaking valves

− Worn camshaft lobes

− Valve timing

− Bent push rods

− Worn rocker arms

− Broken valve springs

− Excessive oil in combustion chamber or leaking valve seals—Refer to

Oil

Consumption Diagnosis

in Engine Mechanical.

• For incorrect basic engine parts. Inspect the following:

− The camshaft—Refer to

Camshaft and Bearings Cleaning and Inspection

Engine Mechanical.

− The cylinder heads—Refer to

Cylinder Head Cleaning and Inspection

Engine Mechanical.

− The pistons, etc.—Refer to

Piston, Connecting Rod, and Bearings Cleaning

and Inspection

in Engine Mechanical.

• Inspect for excessive crankshaft endplay that will cause the crankshaft

position (CKP) sensor reluctor wheel to move out of alignment with the CKP

sensor. Refer to

Crankshaft and Bearings Cleaning and Inspection

in Engine

Mechanical. This could result in any of the following conditions:

− A no start

− A start and stall

− Erratic performance

Refer to

Symptoms - Engine Mechanical

in Engine Mechanical for diagnosis

procedures.

EngineControls-6.0LEngine

Rough, Unstable, or Incorrect Idle and Stalling (cont’d)

Inspections Action

Additional Inspections • Inspect the exhaust system for possible restrictions. Inspect for the following:

− Inspect the exhaust system for damaged or collapsed pipes.

− Inspect the mufflers for heat distress or possible internal failure.

− Inspect for possible plugged catalytic converters. Refer to

Restricted Exhaust

in Engine Exhaust.

• Electromagnetic interference (EMI) on the reference circuit can cause an engine

misscondition.ATech 2 canusuallydetectEMIbymonitoringtheengine

RPM. A sudden increase in RPM with little change in actual engine RPM change

indicates that EMI is present. If a problem exists, inspect routing of secondary

ignition wires or high voltage components near the ignition control circuits.

• Inspect the park neutral position (PNP) switch circuit.

• Inspect for faulty motor mounts. Refer to

Engine Mount Inspection

in Engine

Mechanical.

• Inspect the intake manifold and the exhaust manifold passages for casting ﬂash.

Dieseling, Run-On

Inspections Action

DEFINITION: Engine continues to run after key is turned OFF, but runs very rough. If the engine runs smooth, inspect the

ignition switch and the ignition switch adjustment.

Preliminary Inspections • Refer to Important Preliminary Inspections Before Starting in

Symptoms - Engine

Controls

• Search for bulletins.

• Verify that the engine control module (ECM) grounds are clean, tight, and in the

proper locations. Refer to

Power and Grounding Component Views

in Wiring

Systems and

Engine Controls Schematics

Fuel System Inspect the fuel injectors for a leaking condition. Refer to

Fuel System Diagnosis

for

the proper procedure.

Backﬁre

Inspections Actions

DEFINITION: Fuel ignites in the intake manifold or in the exhaust system, making a loud popping noise.

Preliminary Inspections • Refer to Important Preliminary Inspections Before Starting in

Symptoms - Engine

Controls

• Search for bulletins.

• Verify that the engine control module (ECM) grounds are clean, tight, and in the

proper locations. Refer to

Power and Grounding Component Views

in Wiring

Systems and

Engine Controls Schematics

Fuel System • Inspect for incorrect fuel pressure. Refer to

Fuel System Diagnosis

• Inspect for a contaminated fuel condition. Refer to

Alcohol/Contaminants-in-Fuel

Diagnosis (without Special Tool)

Alcohol/Contaminants-in-Fuel Diagnosis (with

Special Tool)

• Inspect the fuel injectors. Refer to

Fuel Injector Coil Test

Fuel Injector Balance

Test with Special Tool

Fuel Injector Balance Test with Tech 2

• Verify that each injector harness is connected to the correct injector or cylinder.

Relocate injector harnesses as necessary.

Sensor/System • Inspect the air intake system and crankcase for air leaks.

• Inspect the crankcase ventilation valve for proper operation. Refer to

Crankcase

Ventilation System Inspection/Diagnosis

in Engine Mechanical.

• Inspect for an inaccurate speedometer. Refer to

Symptoms - Instrument Panel,

Gages and Console

in Instrument Panel, Gages, and Console.

•UseaTech 2 inordertomonitortheknocksensor(KS)systemforexcessive

spark retard activity. Refer to

Knock Sensor (KS) System Description

EngineEngineControls-6.0L

Backﬁre (cont’d)

Inspections Actions

Ignition System • Inspect for proper ignition voltage output with

J 26792

Spark Tester.

• Remove spark plugs and inspect for the following:

− Wet plugs

− Cracks

− Wear

− Improper gap

− Burned electrodes

− Heavy deposits

Refer to

Spark Plug Inspection

• An improper spark plug gap will cause a driveability problem. Refer to

Spark

Plug Inspection

. Gap the spark plugs using a wire gage gap tool. Refer to

Spark

Plug Replacement

• Determine the cause of the fouling before replacing the spark plugs. Refer to

Spark Plug Inspection

for diagnosis.

• Visually and physically inspect secondary ignition for the following:

− Ignition wires arcing to ground

− Ignition coils arcing to ground

• Soak the secondary ignition system with water from a spray bottle. Soaking the

secondary ignition system may help locate damaged or deteriorated components.

Look and listen for arcing or misﬁring as you apply the water.

• Monitor the Misﬁre Current Counters while driving the vehicle in the conditions

that the misﬁre occurred. If a misﬁring cylinder can be located, use the

DTC P0300 table for diagnosis. Refer to

DTC P0300

• Inspect for loose ignition coil grounds. Refer to

Electronic Ignition (EI) System

Diagnosis

Engine Cooling System • Inspect the engine coolant level for being low. Refer to

Loss of Coolant

(Automatic Transmission)

Loss of Coolant (Manual Transmission)

in Engine

Cooling.

• Inspect the engine thermostat for proper operation and for the correct heat

range. Refer to

Thermostat Diagnosis

in Engine Cooling.

Engine Mechanical • Inspect engine mechanical for the following:

− Compression—Refer to

Engine Compression Test

in Engine Mechanical.

− Sticking or leaking valves

− Worn camshaft lobes

− Valve timing

− Bent push rods

− Worn rocker arms

− Broken valve springs

− Excessive oil in combustion chamber or leaking valve seals—Refer to

Oil

Consumption Diagnosis

in Engine Mechanical.

• For incorrect basic engine parts. Inspect the following:

− The camshaft—Refer to

Camshaft and Bearings Cleaning and Inspection

Engine Mechanical.

− The cylinder heads—Refer to

Cylinder Head Cleaning and Inspection

Engine Mechanical.

− The pistons, etc.—Refer to

Piston, Connecting Rod, and Bearings Cleaning

and Inspection

in Engine Mechanical.

• Refer to

Symptoms - Engine Mechanical

in Engine Mechanical for diagnosis

procedures.

EngineControls-6.0LEngine

Backﬁre (cont’d)

Inspections Actions

Additional Inspections • Visually and physically inspect the vacuum hoses for splits, kinks, and proper

connections and routing as shown on the Vehicle Emission Control

Information label.

• Inspect the intake manifold and the exhaust manifold passages for casting ﬂash.

•Inspectthetransmissiontorqueconverterclutch(TCC)operation.TheTech 2

should indicate an RPM drop when the TCC is commanded ON. Refer to

Torque

Converter Diagnosis Procedure

in Automatic Transmission.

• Inspect the exhaust system for possible restrictions. Inspect the following:

− Inspect the exhaust system for damaged or collapsed pipes.

− Inspect the mufflers for heat distress or possible internal failure.

− Inspect for possible plugged catalytic converters. Refer to

Restricted Exhaust

in Engine Exhaust.

• Electromagnetic interference (EMI) on the reference circuit can cause an engine

misscondition.ATech 2 canusuallydetectEMIbymonitoringtheengine

RPM. A sudden increase in RPM with little change in actual engine RPM change

may indicate that EMI is present. If a problem exists, inspect for high voltage

components near the ignition control circuits.

• Inspect the park/neutral position (PNP) switch operation.

• Inspect for faulty motor mounts. Refer to

Engine Mount Inspection

in Engine

Mechanical.

• Inspect the intake manifold and the exhaust manifold passages for casting ﬂash

Malfunction Indicator Lamp (MIL)

Inoperative

Circuit Description

Ignition voltage is supplied to the malfunction indicator

lamp (MIL). The engine control module (ECM) turns

the MIL ON by grounding the MIL control circuit. There

should be a steady MIL with the ignition ON and the

engine OFF.

MIL Operation

The MIL is located on the instrument panel

cluster (IPC).

MIL Function

• The MIL informs the driver that a malfunction has

occurred and the vehicle should be taken in for

service as soon as possible.

• The MIL illuminates during a bulb test and a

system test.

• A DTC will be stored if a MIL is requested by

the ECM.

MIL Illumination

• The MIL will illuminate with ignition switch ON and

the engine not running.

• The MIL will turn OFF when the engine is started.

• The MIL will remain ON if the self-diagnostic

system has detected a malfunction.

• The MIL may turn OFF if the malfunction is not

present.

• If the MIL is illuminated and then the engine stalls,

the MIL will remain illuminated so long as the

ignition switch is ON.

• If the MIL is not illuminated and the engine stalls,

the MIL will not illuminate until the ignition switch

is cycled OFF, then ON.

Test Description

The number below refers to the step number on the

diagnostic table.

4. This step tests for a short to voltage on the MIL

control circuit. With the fuse removed there

should be no voltage on the MIL control circuit.

Malfunction Indicator Lamp (MIL) Inoperative

Step Action Values Yes No

Schematic Reference:

Instrument Cluster Schematics

in Instrument Panel, Gages, and Console or

Engine Controls

Schematics

Connector End View Reference:

Instrument Panel, Gages, and Console Connector End Views

in Instrument Panel, Gages,

and Console or

Engine Control Module (ECM) Connector End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

EngineEngineControls-6.0L

Malfunction Indicator Lamp (MIL) Inoperative (cont’d)

Step Action Values Yes No

Command the malfunction indicator lamp (MIL) ON and

OFFwithaTech 2 .

Does the MIL turn ON and OFF when commanded with a

Tech 2 ?

—Go to

Intermittent

Conditions

Go to

Step 3

3Inspect the fuse that supplies ignition voltage to the cluster.

Is the fuse open? —Go to

Step 11

Go to

Step 4

1. Turn OFF the ignition.

2. Remove the fuse that supplies voltage to the cluster.

3. Disconnect the engine control module (ECM). Refer to

Control Module References

in Computer/Integrating

Systems.

4. Turn ON the ignition with the engine OFF.

5. Measure the voltage from the MIL control circuit in the

ECM harness connector to a good ground.

Is the voltage less than the speciﬁed value?

0.3 V

Go to

Step 5

Go to

Step 10

1. Turn OFF the ignition.

2. Install the fuse that supplies voltage to the cluster.

3. Turn ON the ignition with the engine OFF.

4. Connect a 3-amp fused jumper wire between the MIL

control circuit in the ECM harness connector and a

good ground.

Is the MIL illuminated?

—

Go to

Step 9

Go to

Step 6

1. Turn OFF the ignition.

2. Remove the instrument panel cluster (IPC). Refer to

Instrument Panel Cluster (IPC) Replacement

Instrument Panel, Gages, and Console.

3. Turn ON the ignition.

4. Probe the ignition voltage circuit of the IPC harness

connector with a test lamp that is connected to a good

ground.

Does the test lamp illuminate?

—

Go to

Step 7

Go to

Step 12

Test the MIL control circuit for an open or high resistance.

Refer to

Circuit Testing

and

Wiring Repairs

in Wiring

Systems.

Did you ﬁnd and correct a condition?

—

Go to

Step 15

Go to

Step 8

Test for an intermittent and for a poor connection at the

IPC. Refer to

Testing for Intermittent Conditions and Poor

Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 13

Test for an intermittent and for a poor connection at the

ECM. Refer to Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 15

Go to

Step 14

10 Repair the short to voltage in the MIL control circuit. Refer

Wiring Repairs

in Wiring Systems

Did you complete the repair? —Go to

Step 15

—

11 Repair the short to ground in the ignition voltage circuit.

Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 15

—

12 Repair the open in the ignition voltage circuit. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 15

—

13 Replace the IPC. Refer to

Instrument Panel Cluster (IPC)

Replacement

in Instrument Panel, Gages, and Console.

Did you complete the replacement? —Go to

Step 15

—

EngineControls-6.0LEngine

Malfunction Indicator Lamp (MIL) Inoperative (cont’d)

Step Action Values Yes No

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 15

—

15 CommandtheMILONandOFFwiththeTech 2 .

Does the MIL turn ON and OFF when commanded with a

Tech 2 ?—Go to

Step 16

Go to

Step 2

ObservetheCaptureInfowithaTech 2 .

Are there any DTCs that have not been diagnosed? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

Malfunction Indicator Lamp (MIL) Always

Circuit Description

Battery positive voltage is supplied directly to the

malfunction indicator lamp (MIL). The engine control

module (ECM) turns the MIL ON by grounding the MIL

control circuit.

MIL Operation

The MIL is located on the instrument panel (IPC).

MIL Function

• The MIL informs the driver that a malfunction has

occurred and the vehicle should be taken in for

service as soon as possible.

• The MIL illuminates during a bulb test and a

system test.

• A DTC will be stored if a MIL is requested by the

diagnostic.

MIL Illumination

• The MIL will illuminate with ignition switch ON and

the engine not running.

• The MIL will turn OFF when the engine is started.

• The MIL will remain ON if the self-diagnostic

system has detected a malfunction.

• The MIL may turn OFF if the malfunction is not

present.

• If the MIL is illuminated and then the engine stalls,

the MIL will remain illuminated so long as the

ignition switch is ON.

• If the MIL is not illuminated and the engine stalls,

the MIL will not illuminate until the ignition switch

is cycled OFF, then ON.

Diagnostic Aids

If the problem is intermittent, refer to

Intermittent

Conditions

Test Description

The number below refers to the step number on the

diagnostic table.

2. This step determines if the condition is with the

MIL control circuit or the ECM.

Malfunction Indicator Lamp (MIL) Always On

Step Action Yes No

Schematic Reference:

Instrument Cluster Schematics

in Instrument Panel, Gages, and Console or

Engine Controls

Schematics

Connector End View Reference:

Instrument Panel, Gages, and Console Connector End Views

in Instrument Panel, Gages,

and Console or

Engine Control Module (ECM) Connector End Views

1Did you perform the Diagnostic System Check – Vehicle?

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

1. Turn OFF the ignition.

2. Disconnect the engine control module (ECM). Refer to

Control Module References

in Computer/Integrating Systems.

3. Turn ON the ignition, with the engine OFF.

4. Observe the malfunction indicator lamp (MIL).

Is the MIL illuminated? Go to

Step 3

Go to

Step 5

EngineEngineControls-6.0L

Malfunction Indicator Lamp (MIL) Always On (cont’d)

Step Action Yes No

1. Remove the instrument panel cluster (IPC). Refer to

Instrument Panel Cluster (IPC) Replacement

in Instrument

Panel, Gages, and Console.

2. Test the MIL control circuit for a short to ground. Refer to

Circuit Testing

and

Wiring Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition? Go to

Step 6

Go to

Step 4

4Replace the IPC. Refer to

Instrument Panel Cluster (IPC)

Replacement

in Instrument Panel, Gages, and Console.

Did you complete the replacement? Go to

Step 6

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement? Go to

Step 6

—

1. Turn the ignition OFF for 30 seconds.

2. Start the engine.

Does the vehicle operate correctly without any MIL illumination,

and without any stored DTCs? System OK

Go to

Diagnostic

System Check -

Vehicle

in Vehicle

DTC Information

Engine Cranks but Does Not Run

Description

The Engine Cranks but Does Not Run diagnostic table

is an organized approach to identifying a condition

that causes an engine to not start. The diagnostic table

directs the service technician to the appropriate

system diagnosis. The diagnostic table assumes the

following conditions are met:

• The battery is completely charged. Refer to

Battery Inspection/Test

in Engine Electrical.

• The engine cranking speed is acceptable. Refer to

Engine Cranks Slowly

in Engine Electrical.

• There is adequate fuel in the fuel tank.

Engine Cranks but Does Not Run

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

1. Turn ON the ignition, with the engine OFF.

2.ObservetheDTCinformationwithaTech 2 .

DoestheTech 2 displayDTCsP0101,P0108,P0230,

P0335, P0336, P0601, P0602, P0604, P0606, P0641,

P0651, P0685, P0689, P0690, P1630, P1631, or P1682?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

DoestheTech 2 displayanybodycontrolmodule(BCM)

or vehicle theft deterrent (VTD) DTCs? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 4

EngineControls-6.0LEngine

Engine Cranks but Does Not Run (cont’d)

Step Action Values Yes No

1. Turn ON the ignition, with the engine OFF.

2. Probe both sides of the fuses located in the

underhood electrical center listed below using a test

lamp connected to ground.

• Fuel fuse

• O2 Sensor fuse

• ETC fuse

• Emission fuse

• Even INJ fuse

• Odd INJ fuse

Does the test lamp illuminate on at least one side of

each fuse?

—

Go to

Step 5

Go to

Powertrain

Relay Diagnosis

5CommandthefuelpumpONwithaTech 2 .

Does the fuel pump operate? —Go to

Step 6

Go to

Fuel Pump

Electrical Circuit

Diagnosis

1. Turn OFF the ignition.

2. Disconnect a spark plug wire.

3. Install

J 26792

Spark Tester.

4. Attempt to start the engine.

Does the spark tester spark?

—

Go to

Step 7

Go to

Electronic

Ignition (EI)

System

Diagnosis

1. Turn OFF the ignition.

2. Install a fuel pressure gage. Refer to

Fuel Pressure

Gage Installation and Removal

Important: You may need to command the fuel pump ON

a few times to obtain the highest possible fuel pressure.

3. Turn ON the ignition, with the engine OFF.

4.CommandthefuelpumpONwithaTech 2 .

5. Observe the fuel pressure while the fuel pump is

operating.

Is the fuel pressure within the speciﬁed range?

379–427 kPa

(55–62 psi)

Go to

Step 8

Go to

Fuel

System

Diagnosis

Inspect for the following conditions:

• Collapsed air intake duct

• Restricted air ﬁlter element—Refer to

Air Cleaner

Element Replacement

• Spark plugs for being fouled—Refer to

Spark Plug

Inspection

. If the spark plugs are fouled, determine

what caused the condition.

• Engine mechanical condition, for example, broken

timing chain, low compression—Refer to

Engine

Compression Test

in Engine Mechanical.

• Restricted exhaust system—Refer to

Restricted

Exhaust

in Engine Exhaust

• An engine coolant temperature (ECT) sensor that has

shifted in value—Refer to

Temperature vs Resistance

• Compare the MAP parameter to another vehicle. The

parameters should be close in value. Refer to

DTC P0106

Did you complete the action?

—

Go to

Step 9

Go to

Hard Start

91.CleartheDTCswithaTech 2 .

2. Attempt to start the engine.

Does the engine start and continue to operate? —Go to

Step 10

Go to

Step 2

EngineEngineControls-6.0L

Engine Cranks but Does Not Run (cont’d)

Step Action Values Yes No

1. Idle the engine.

2. Allow the engine to reach operating temperature.

3.ObservetheDTCinformationwithaTech 2 .

Are any DTCs displayed?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

Powertrain Relay Diagnosis

Circuit Description

The powertrain relay is a normally open relay. The

relay armature is held in the open position by spring

tension. Battery positive voltage is supplied directly

to the powertrain relay coil and the armature contact at

all times. The engine control module (ECM) supplies

the ground path to the relay coil control circuit via

an internal integrated circuit called an output driver

module (ODM). When the ECM commands the

relay ON, the relay coil creates an electromagnetic

ﬁeld. This electromagnetic ﬁeld overcomes the spring

tension and pulls the armature contact into the

stationary contact of the relay load circuit. The closing

of the relay contacts allows current to ﬂow from the

battery to the following fuses and relay.

• Fuel Fuse

• O2 Sensor Fuse

• ETC fuse

• Emission Fuse

• Even INJ Fuse

• Odd INJ Fuse

• A/C Comp Relay – Relay coil side

When the ignition switch is turned to the OFF position,

power is interrupted to the ODM in the ECM and

the powertrain relay electromagnetic ﬁeld collapses.

This action allows the spring tension pulling on

the armature to separate from the relay load circuit

contact, which interrupts current ﬂow to the fuses and

relay. The underhood fuse block features an

alphanumeric grid system for the terminals of the

relays and the mini fuses. Along the top forward edge

of the underhood fuse block the letters A, B, C, D,

E, F, G, H, J, K, L, and M are used. Along the top right

edge of the underhood fuse block the numbers 1

through 20 are used. If the powertrain relay fails to

close, the engine will crank but will not run. The

GMLAN and class II data communications will be

availablewiththeuseofaCANdimoduleandaTech 2

tool. The powertrain relay will remain powered up

for 5 seconds after the ignition switch is turned OFF.

The powertrain relay system diagnosis table assumes

that the vehicle battery is fully charged. Refer to

Battery Inspection/Test

in Engine Electrical.

Powertrain Relay Diagnosis

Step Action Values Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector End

Views

, and

Electrical Center Identiﬁcation Views

in Wiring Systems

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

Are DTCs P0685, P0689, or P0690 also set?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 3

EngineControls-6.0LEngine

Powertrain Relay Diagnosis (cont’d)

Step Action Values Yes No

1. Turn ON the ignition, with the engine OFF.

2. Remove the underhood fuse block cover.

3. Probe the following fuses with a test lamp that is

connected to a good ground:

• Fuel Fuse

• O2 Sensor Fuse

• ECT Fuse

• Emission Fuse

• Even INJ Fuse

• Odd INJ Fuse

Refer to

Troubleshooting with a Test Lamp

Wiring Systems.

Does the test lamp illuminate on at least one test point of

each fuse?

—

Go to

Step 6

Go to

Step 4

1. Turn OFF the ignition.

2. Remove the powertrain ignition 1 relay from the

underhood fuse block with the

J 43244

Relay Puller

Pliers. Refer to

Relay Replacement (Within an

Electrical Center)

Relay Replacement (Attached to

Wire Harness)

in Wiring Systems.

3. Connect a 20-amp fused jumper wire from the battery

positive voltage terminal H14 for the powertrain

ignition 1 relay armature at the underhood fuse block,

to the relay load circuit terminal F13 at the underhood

fuse block. Refer to

Using Fused Jumper Wires

Wiring Systems.

4. Probe the following fuses with a test lamp that is

connected to a good ground:

• Fuel Fuse

• O2 Sensor Fuse

• ECT Fuse

• Emission Fuse

• Even INJ Fuse

• Odd INJ Fuse

Does the test lamp illuminate on at least one test point of

each fuse?

—

Go to

Intermittent

Conditions

Go to

Step 5

Replace the underhood fuse block. Refer to

Underhood

Electrical Center or Junction Block Replacement

in Wiring

Systems.

Did you complete the replacement?

—

Go to

Step 6

—

1. Replace any open fuses.

2. Turn OFF the ignition for 30 seconds.

3. Attempt to start the engine.

Does the engine start and run?

—

Go to

Step 7

Go to

Engine

Cranks but Does

Not Run

1.CleartheDTCswithaTech 2 .

2. Operate the vehicle for 5 minutes.

Does a DTC set during this ignition cycle? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

Fuel Pump Electrical Circuit Diagnosis

For all information on Fuel Pump Diagnosis refer to Holden VZ Service Information

EngineEngineControls-6.0L

Fuel Injector Balance Test with Tech 2

Description

TheTech 2 isﬁrstusedtoenergizethefuelpump.

TheTech 2 isthenusedtopulseeachinjector

for a precise amount of time, allowing a measured

amount of fuel into the manifold. This causes a drop in

system fuel pressure that can be recorded and used

to compare the ﬂow through each injector.

Fuel Injector Balance Test Example (Typical)

Cylinder 1 2 3 4

1st Reading 380 kPa (55 psi) 380 kPa (55 psi) 380 kPa (55 psi) 380 kPa (55 psi)

2nd Reading 215 kPa (31 psi) 201 kPa (29 psi) 208 kPa (30 psi) 229 kPa (33 psi)

Amount of Drop 165 kPa (24 psi) 179 kPa (26 psi) 172 kPa (25 psi) 151 kPa (22 psi)

Average Range:

156–176 kPa (22.5–

25.5 psi) Injector OK Replace fuel injector -

too much fuel

pressure drop Injector OK Replace fuel injector -

too little fuel

pressure drop

Fuel Injector Balance Test with Tech 2

Step Action Values Yes No

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

2Did you perform the Fuel Injector Coil Test? —Go to

Step 3

Go to

Fuel

Injector Coil Test

Important: DO NOT perform this test if the ECT is above

94°C (201°F).

Important: Verify that adequate fuel is in the fuel tank

before proceeding with this diagnostic.

1. Install the fuel pressure gage. Refer to

Fuel Pressure

Gage Installation and Removal

2. Turn ON the ignition, with the engine OFF.

Important: The fuel pump relay may need to be

commanded ON a few times in order to obtain the highest

possible fuel pressure.

3.CommandthefuelpumprelayONwithaTech 2 .

4. Observe the fuel pressure gage, with the fuel pump

operating.

Is the fuel pressure within the speciﬁed value?

380–

427 kPa (55–

62 psi)

Go to

Step 4

Go to

Fuel

System

Diagnosis

Important: The fuel pressure will decrease when the fuel

pump stops operating. After the fuel pump stops operating,

the fuel pressure should stabilize and remain constant.

Monitor the fuel pressure gage for 5 minutes.

Does the fuel pressure decrease to less than the

speciﬁed value?

350 kPa (51 psi)

Go to

Fuel

System Diagnosis

Go to

Step 5

EngineControls-6.0LEngine

Alcohol/Contaminants-in-Fuel Diagnosis

(without Special Tool)

Description

Water contamination in the fuel system may cause

driveability conditions such as hesitation, stalling, no

start, or misﬁres in one or more cylinders. Water

may collect near a single fuel injector at the lowest

point in the fuel injection system, and cause a misﬁre

in that cylinder. If the fuel system is contaminated

with water, inspect the fuel system components

for rust, or deterioration.

Alcohol concentrations of 10 percent or greater in fuel

can be detrimental to fuel system components.

Alcohol contamination may cause fuel system

corrosion, deterioration of rubber components, and

subsequent fuel ﬁlter restriction. Some types of alcohol

are more detrimental to fuel system components

than others. Ethanol is commonly used in gasoline,

but in concentrations of no more than 10 percent.

Some fuels, such as E85, contain a very high

percentage of ethanol. Fuel with more than 10 percent

ethanol may cause driveability conditions such as

hesitation, lack of power, stalling, or no start.

EngineEngineControls-6.0L

Alcohol in Fuel Testing Procedure

The fuel sample should be drawn from the bottom of

the tank so that any water present in the tank will

be detected. The sample should be bright and clear. If

alcohol contamination is suspected then use the

following procedure to test the fuel quality.

1. Using a 100 ml (3.4 oz) speciﬁed cylinder with

1 ml (0.03 oz) graduation marks, ﬁll the cylinder

with fuel to the 90 ml (3.04 oz) mark.

2. Add 10 ml (0.34 oz) of water in order to bring the

total ﬂuid volume to 100 ml (3.4 oz) and install a

stopper.

3. Shake the cylinder vigorously for 10–15 seconds.

4. Carefully loosen the stopper in order to release

the pressure.

5. Re-install the stopper and shake the cylinder

vigorously again for 10–15 seconds.

6. Put the cylinder on a level surface for

approximately 5 minutes in order to allow

adequate liquid separation.

If alcohol is present in the fuel, the volume of the

lower layer, which would now contain both alcohol and

water, will be more than 10 ml (0.34 oz). For

example, if the volume of the lower layer is increased

to 15 ml (0.51 oz), this indicates at least 5 percent

alcohol in the fuel. The actual amount of alcohol may

be somewhat more because this procedure does

not extract all of the alcohol from the fuel.

Particulate Contaminants in Fuel Testing

Procedure

The fuel sample should be drawn from the bottom of

the tank so that any water present in the tank will

be detected. The sample should be bright and clear. If

the sample appears cloudy, or contaminated with

water, as indicated by a water layer at the bottom of

the sample, use the following procedure to diagnose

the fuel.

1. Using an approved fuel container, draw

approximately 0.5 liter (0.13 gal) of fuel.

2. Place the cylinder on a level surface for

approximately 5 minutes in order to allow settling

of the particulate contamination.

Particulate contamination will show up in various

shapes and colors. Sand will typically be identiﬁed by

a white or light brown crystals. Rubber will appear

as black and irregular particles. If particles are found

clean the entire fuel system thoroughly.

Alcohol/Contaminants-in-Fuel Diagnosis

(with Special Tool)

Description

Water contamination in the fuel system may cause

driveability conditions such as hesitation, stalling, no

start, or misﬁres in one or more cylinders. Water

may collect near a single fuel injector at the lowest

point in the fuel injection system, and cause a misﬁre

in that cylinder. If the fuel system is contaminated

with water, inspect the fuel system components for rust

or deterioration.

Ethanol concentrations of greater than 10 percent can

cause driveability conditions and fuel system

deterioration. Fuel with more than 10 percent ethanol

could result in driveability conditions such as

hesitation, lack of power, stalling, or no start.

Excessive concentrations of ethanol used in vehicles

not designed for it may cause fuel system corrosion,

deterioration of rubber components, and fuel ﬁlter

restriction.

Test Procedure

1. Test the fuel composition using

J 44175

Fuel

Composition Tester and J44175-3 Instruction

Manual.

2. Subtract 50 from the reading on the DMM in order

to obtain the percentage of alcohol in the fuel

sample. Refer to the examples in the Fuel

Composition Test Examples table.

3. If the fuel sample contains more than 15 percent

ethanol, add fresh, regular gasoline to the

vehicle’s fuel tank.

4. Test the fuel composition.

5. If testing shows the ethanol percentage is still

more than 15 percent, replace the fuel in the

vehicle.

Fuel Composition Test Examples

— Frequency (Hz) Subtract 50 Ethanol Percent

Example A 50 Hz -50 0

Example B 65 Hz -50 15

Example C 129 Hz -50 79

Electronic Ignition (EI) System Diagnosis

Circuit Description

The electronic ignition system uses an individual

ignition coil for each cylinder. The engine control

module (ECM) controls the ignition operation through

eight individual ignition control (IC) circuits. Each bank

of four ignition coils is connected to the ECM,

power, or ground by the following circuits:

• A low reference circuit

• A chassis ground circuit

• An ignition 1 voltage circuit

• The appropriate IC circuit

EngineControls-6.0LEngine

The ECM triggers an ignition coil by grounding the

appropriate IC circuit using information from the

crankshaft position (CKP) and camshaft position (CMP)

sensors.

Diagnostic Aids

Important: A missing CMP sensor signal may cause

a long crank condition.

The CKP signal must be available for the engine to

start. The CMP signal is not needed to start and

operate the engine. The ECM can determine when a

cylinder is on either the ﬁring or the exhaust stroke

by the 24X signal.

Remove any debris from the ECM connector surfaces

before servicing the ECM. Inspect the ECM connector

gaskets when diagnosing or replacing the ECM.

Ensure that the gaskets are installed correctly. The

gaskets prevent water intrusion into the ECM.

For an intermittent condition, refer to

Intermittent

Conditions

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

5. Monitoring the misﬁre current counters determines

if a fault is present.

12. A good indication that the fuse is open is all off

the misﬁre current counters are incrementing

on one side of the engine. Inspect the ignition

positive voltage circuit for a grounded circuit. If the

fuse is open and the ignition coil circuits are

OK, inspect the injector circuits for being

grounded.

Electronic Ignition (EI) System Diagnosis

Step Action Value(s) Yes No

Schematic Reference:

Engine Controls Schematics

Connector End View Reference:

Engine Control Module (ECM) Connector End Views

Engine Controls Connector

End Views

Did you perform the Diagnostic System Check – Vehicle?

—

Go to

Step 2

Go to

Diagnostic

System Check -

Vehicle

DTC Information

2Attempt to start the engine.

Does the engine start and run? —Go to

Step 5

Go to

Step 3

1. Observe the Engine Speed parameter with a

Tech 2 .

2. Crank the engine.

DoestheTech 2 toolindicateRPMispresent?

—

Go to

Step 7

Go to

Step 4

Is DTC P0335, P0336, or P0351–P0358 also set?

—

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 16

1. Idle the engine.

2.ObservethemisﬁrecurrentcountersontheTech 2 .

DoestheTech 2 displayanymisﬁrecurrentcounters

incrementing?

—

Go to

Step 6

Go to

Diagnostic Aids

6Do the misﬁre current counters increment for most

cylinders on one bank of the engine? —Go to

Step 12

Go to

Step 7

1. Inspect the spark plug wire for open circuits, cracks,

or improper seating of terminals at the spark plug or

coil before proceeding with test. Refer to

Spark Plug

Wire Inspection

2. Inspect for spark at the plug with the

J 26792

Spark

Tester or equivalent while cranking. A few sparks,

then nothing is considered no spark.

Is adequate spark present?

—

Go to

Step 33

Go to

Step 8

8Measure the spark plug wire resistance. Refer to

Spark

Plug Wire Inspection

Does the resistance measure within the speciﬁed range? 188–312 ΩGo to

Step 32

Go to

Step 9

EngineEngineControls-6.0L

Electronic Ignition (EI) System Diagnosis (cont’d)

Step Action Value(s) Yes No

1. Turn OFF the ignition.

2. Disconnect the inoperative ignition coil.

3. Turn ON the ignition, with the engine OFF.

4. Probe the ignition 1 voltage circuit of the ignition coil

with a test lamp connected to a good ground. Refer to

Probing Electrical Connectors

in Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 10

Go to

Step 13

Probe the ignition 1 voltage circuit at the ignition coil with a

test lamp connected to the ground circuit of the ignition

coil. Refer to

Probing Electrical Connectors

in Wiring

Systems.

Does the test lamp illuminate?

—

Go to

Step 11

Go to

Step 14

Probe the ignition 1 voltage circuit at the ignition coil with a

test lamp connected to the low reference circuit of the

ignition coil. Refer to

Probing Electrical Connectors

Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 20

Go to

Step 15

Inspect for an open even INJ fuse or odd INJ fuse.

Is the fuse open? —Go to

Step 29

Go to

Step 23

1. Disconnect the main ignition coil 8-way connector.

2. Probe the ignition 1 voltage circuit at the ignition coil

main 8-way connector using the test lamp connected

to battery ground. Refer to

Probing Electrical

Connectors

in Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 24

Go to

Step 23

1. Disconnect the main ignition coil 8-way connector.

2. Probe the ignition 1 voltage circuit on the harness side

with a test lamp connected to the ground circuit of the

ignition coil. Refer to

Probing Electrical Connectors

Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 18

Go to

Step 26

1. Disconnect the main ignition coil 8-way connector.

2. Probe the ignition 1 voltage circuit on the harness side

with a test lamp connected to the low reference circuit

of the ignition coil. Refer to

Probing Electrical

Connectors

in Wiring Systems.

Does the test lamp illuminate?

—

Go to

Step 19

Go to

Step 28

1. Turn ON the ignition, with the engine OFF.

2. Disconnect the crankshaft position (CKP) sensor.

3. Measure the voltage from the CKP sensor 12-volt

reference circuit and a good ground with the DMM.

4. Compare the measured voltage with the system

voltage.

Is the difference in the voltage more than the

speciﬁed value?

0.5 V

Go to

Step 17

Go to

Step 30

Test for a short to ground in the CKP 12-volt reference

circuit or the camshaft position (CMP) sensor 12-volt

reference circuit. Refer to

Circuit Testing

and

Wiring

Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 35

Go to

Step 22

Test for an intermittent and for a poor connection at the

ignition coil 8-way connector. Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 35

Go to

Step 25

EngineControls-6.0LEngine

Electronic Ignition (EI) System Diagnosis (cont’d)

Step Action Value(s) Yes No

Test for an intermittent and for a poor connection at the

ignition coil 8-way connector. Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 35

Go to

Step 27

Test for an intermittent and for a poor connection at the

ignition coil. Refer to

Testing for Intermittent Conditions and

Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 35

Go to

Step 31

Test for an intermittent and for a poor connection at the

CKP sensor. Refer to

Testing for Intermittent Conditions

and Poor Connections

and

Connector Repairs

in Wiring

Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 35

Go to

Step 30

Test for an intermittent and for a poor connection at the

engine control module (ECM). Refer to

Testing for

Intermittent Conditions and Poor Connections

and

Connector Repairs

in Wiring Systems.

Did you ﬁnd and correct the condition?

—

Go to

Step 35

Go to

Step 34

Repair the open or high resistance in the ignition 1 voltage

circuit between the fuse block and the splice. Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 35

—

Repair the open or high resistance in the ignition 1 voltage

circuit between the splice and the ignition coil connector.

Refer to

Wiring Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 35

—

Repair the open in the ground circuit between the main

8-way connector and the ignition coil. Refer to

Wiring

Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 35

—

26 Repair the open in the ground circuit. Refer to

Wiring

Repairs

in Wiring Systems.

Did you complete the repair? —Go to

Step 35

—

Repair the open in the low reference circuit between the

main 8-way connector and the ignition coil. Refer to

Wiring

Repairs

in Wiring Systems.

Did you complete the repair?

—

Go to

Step 35

—

Repair the open in the low reference circuit between the

ECM and the splice. Refer to

Wiring Repairs

in Wiring

Systems.

Did you complete the repair?

—

Go to

Step 35

—

1. Repair the ignition 1 voltage for a short to ground.

Refer to

Wiring Repairs

in Wiring Systems.

2. Replace the fuse.

Did you complete the repair?

—

Go to

Step 35

—

30 Replace the CKP sensor. Refer to

Crankshaft

Position (CKP) Sensor Replacement

Did you complete the replacement? —Go to

Step 35

—

31 Replace the ignition coil. Refer to

Ignition Coil(s)

Replacement

Did you complete the replacement? —Go to

Step 35

—

32 Replace the spark plug wire. Refer to

Spark Plug Wire

Replacement

Did you complete the replacement? —Go to

Step 35

—

EngineEngineControls-6.0L

Electronic Ignition (EI) System Diagnosis (cont’d)

Step Action Value(s) Yes No

33 Replace the spark plug. Refer to

Spark Plug Replacement

Did you complete the replacement? —Go to

Step 35

—

Replace the ECM. Refer to

Control Module References

Computer/Integrating Systems for replacement, setup, and

programming.

Did you complete the replacement?

—

Go to

Step 35

—

35 Attempt to start the engine.

Does the engine start and continue to run? —Go to

Step 36

Go to

Step 3

1.CleartheDTCswithaTech 2 .

2. Turn OFF the engine for 30 seconds.

3. Start the engine.

4. Allow the engine to reach operating temperature.

Are there any DTCs that have not been diagnosed?

—

System OK

Go to

Diagnostic

Trouble

Code (DTC) List

- Vehicle

Vehicle

DTC Information

Inspection/Maintenance (I/M) System

Check

Description

Several states require that a vehicle pass on-board

diagnostic (OBD) system tests and the

inspection/maintenance (I/M) emission inspection in

order to renew license plates. This is accomplished by

viewingtheI/MSystemStatusdisplayonaTech 2

tool.UsingaTech 2 ,thetechniciancanobservethe

I/M System Status in order to verify that the vehicle

meets the criteria that comply with the local area

requirements.

Conditions for Updating the I/M System

Status

Each system monitor requires at least one, and

sometimes several diagnostic tests. The result of each

test is reported by a diagnostic trouble code (DTC).

A system monitor is complete when either all of

the DTCs comprising the monitor have Run and

Passed, or when any one of the DTCs comprising the

monitor has illuminated the malfunction indicator

lamp (MIL). Once the system monitor is complete, the

I/M System Status display will indicate YES in the

Completed column.

For example, when the HO2S Heater Status indicates

YES, either all of the oxygen sensor heater tests

have passed or one of the tests has illuminated the

MIL. If the vehicle has four heated oxygen sensors,

either all four heater circuit tests have passed or one of

the heater circuit tests has illuminated the MIL. The

I/M System Status will indicate NO under the

Completed column when any of the required tests for

that system have not run. The following is a list of

conditions that would set the I/M System Status

indicator to NO:

• The vehicle is new from the factory and has not

yet been driven through the necessary drive

conditions to complete the tests.

• The battery has been disconnected or discharged

below operating voltage.

• The control module power or ground has been

interrupted.

• The control module has been reprogrammed.

• The control module DTCs have been cleared.

Monitored Emission Control Systems

The OBD II System monitors all emission control

systems that are on-board. Not all vehicles have a full

complement of emission control systems. For

example, a vehicle may not be equipped with

secondary air injection (AIR) or exhaust gas

recirculation (EGR). The OBD II regulations require

monitoring of the following:

• The air conditioning system

• The catalytic converter efficiency

• Comprehensive component monitoring—Emission

related inputs and outputs

• The evaporative emissions (EVAP) system

• The EGR System

• The fuel delivery system

• Heated catalyst monitoring

• Misﬁre monitoring

• The oxygen sensor system (O2S or HO2S)

• The oxygen sensor heater system (HO2S heater)

• The AIR system

For the speciﬁc DTCs required for each system, refer

Inspection/Maintenance (I/M) System DTC Table

Systems such as fuel delivery, misﬁre, and

comprehensive components may not be listed in a

system status list. These tests run continuously and do

not require an I/M System Status indicator.

EngineControls-6.0LEngine

Inspection/Maintenance (I/M) System Check

Step Action Value(s) Yes No

1. Perform the

Diagnostic System Check - Vehicle

Vehicle DTC Information.

Important: Many DTC related repairs will instruct the

technician to clear the DTC information. This procedure will

reset ALL of the I/M System Status indicators to NO, and

require performing the I/M Complete System Set

Procedure.

2. Repair any DTCs or driveability concerns that would

prevent the I/M System Status tests from completing.

Did you ﬁnd and repair a DTC or driveability concern?

—

Go to

Step 3

Go to

Step 2

1. Review any service bulletins for software updates that

may prevent inspection/maintenance (I/M) readiness.

2. Perform any reprogramming or repairs indicated by

the service bulletins.

Was a reprogramming or repair service required?

—

Go to

Inspection/Maintenance

(I/M) Complete

System Set

Procedure

Go to

Step 3

ObservetheI/MSystemStatusdisplaywithaTech 2 .

Is more than one test indicating a NO status? —Go to

Inspection/Maintenance

(I/M) Complete

System Set

Procedure

Go to the I/M

System Set

Procedure for the

indicated

systems that

have not updated

Inspection/Maintenance (I/M) Complete

System Set Procedure

Description

The purpose of the Inspection/Maintenance (I/M)

Complete System Set Procedure is to satisfy

the enable criteria necessary to execute all of the I/M

readiness diagnostics, and to complete the trips

for those particular diagnostics. When all diagnostic

tests are completed, the I/M System Status indicators

are set to YES. Perform this test when more than

one or all of the I/M System Status indicators are set

to NO.

Conditions for Running

Cold Start

• The barometric pressure (BARO) is more than

75 kPa.

• The engine coolant temperature (ECT) is between

4–30°C (39–86°F).

• The intake air temperature (IAT) is between 4–

30°C (39–86°F).

• The difference between the IAT and the ECT is

8°C (14°F) or less.

• The battery voltage is between 10–18 volts.

• The fuel level is between 15–85 percent.

Diagnostic Aids

Rough road conditions may prevent some of the tests

from running. Extreme high or low ambient

temperatures may prevent tests such as for the

heated oxygen sensor (HO2S) heater and the

evaporative emission (EVAP) system from initiating. If

a step is interrupted before completion, perform the

remaining portion of the set procedures. Any portion of

the set procedure that requires the engine at operating

temperature may be repeated. This allows most of

the diagnostics to run and the remaining tests can be

performed using the individual System Set

Procedures.

TheTech 2 canbeusedinordertomonitoreachof

the I/M System Status indicators during the I/M

Complete System Set Procedure. When all of the

indicators for a test step have updated to YES, testing

can move on to the next step even if the remaining

portion of the test is not complete. For example, step 3

is designed to run the EVAP, AIR, and HO2S tests.

The procedure instructs the technician to operate

the vehicle in the enable conditions for 6 minutes. If all

3 tests have updated to YES within 4 minutes, you

do not need to continue with the enable conditions and

testing can advance to the next step.

Test Description

The numbers below refer to the step numbers on the

diagnostic table.

2. This step is to run the HO2S heater tests and

initiate the EVAP System Test.

PreprogrammingtheTech 2 willreducethe

amount of time the oxygen sensor heaters operate

while verifying the enable criteria.

3. This step is to run the EVAP, the AIR, and the

oxygen sensor tests. The EVAP test begins

once the engine coolant reaches a calibrated

temperature. The AIR test, if equipped, begins

shortly after Closed Loop and the indicated speed

is achieved. The oxygen sensor tests begin

once the engine is at operating temperature, in

Closed Loop fuel control, and a calibrated amount

of time has elapsed.

EngineEngineControls-6.0L

4. This step is to run the Catalyst Tests. This test

runs during the idle period immediately following

a cruise period that meets a minimum calibrated

RPM and time period.

Inspection/Maintenance (I/M) Complete System Set Procedure

Step Action Value(s) Yes No

Caution: Refer to Road Test Caution in Cautions and Notices.

1Did you perform the Inspection/Maintenance (I/M)

System Check? —Go to

Step 2

Go to

Inspection/Maintenance

(I/M)

System Check

Important: Whenever the ignition is turned ON, ignition

positive voltage is supplied to the heated oxygen sensor

(HO2S) heaters. After verifying the enable criteria, turn

OFF the ignition for approximately 5 minutes in order to

allow the sensors to cool before continuing with the test.

Once the engine is started, DO NOT turn the engine OFF

for the remaining portion of the set procedure.

1.PreprogramtheTech 2 withthevehicleinformation

before the ignition is turned ON.

2. Ensure that the vehicle is within the Conditions for

Running speciﬁed in the supporting text.

3. Turn OFF all of the accessories, including the A/C,

and blower fan.

4. Set the vehicle parking brake.

5. Verify the transmission is in Park for automatic

transmissions and Neutral for manual transmissions.

6. Start the engine and allow it to idle for the

speciﬁed time.

Is the action complete?

2 minutes

Go to

Step 3

—

In order for the next group of tests to run, the vehicle must

operate in the following conditions:

1. Acceleration at part throttle to 90 km/h (55 mph), with

this speed maintained until the engine reaches

operating temperature. This may be up to 10 minutes

depending on the start up coolant temperature.

2. Continue operation under these conditions for an

additional 6 minutes.

Is the action complete?

—

Go to

Step 4

—

In order for the next group of tests to run, the vehicle must

operate in the following conditions:

1. Acceleration at part throttle to 75–89 km/h (45–

55 mph) with this speed maintained for 2 minutes.

2. Brake safely to a stop.

3. Engine idling for 2 minutes while the following criteria

are maintained:

• Service brake depressed

• Automatic transmission in drive

• Manual transmission in neutral with the clutch

pedal depressed

Is the action complete?

—

Go to

Step 5

—

ObservetheI/MSystemStatusdisplaywithaTech 2 .

Did all of the I/M System Status indicators update to YES? —

Go to

Step 6

Go to the I/M

System Set

Procedure for the

systems that

have not updated

EngineControls-6.0LEngine

Inspection/Maintenance (I/M) Complete System Set Procedure (cont’d)

Step Action Value(s) Yes No

Observe the emission related DTC portion of the I/M

SystemStatusdisplaywithaTech 2 .

DoestheTech 2 ndicateanyemissionrelated

DTCs set? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

Inspection/Maintenance (I/M) System DTC Table

System DTCs Required to Set System Status to YES

Catalyst

DTC P0420 or P0430

EVAP

DTC P0442

DTC P0446

DTC P0451

DTC P0454

DTC P0455

DTC P0496

Oxygen Sensor

DTC P0133 or P0153

DTC P0140 or P0160

DTC P0136 or P0156

DTC P1133 or P1153

DTC P1134 or P1154

Oxygen Sensor Heater

DTC P0135, P0141, P0155, or P0161

Inspection/Maintenance (I/M) Catalyst System Set Procedure

Description

The purpose of this test is to satisfy the enable criteria

necessary to execute inspection/maintenance (I/M)

readiness diagnostics for the catalyst system. The test

may be used to set the I/M System Status indicators

to YES. The I/M System Status display on the

Tech 2 providesanindicationofwhetherthecontrol

module has completed the required tests. The I/M

System Status does not indicate that the tests have

passed or failed. When all of the diagnostics for a

speciﬁc system have run and passed, the I/M System

Status will update to YES. If a test for a speciﬁc

system has failed, the I/M System Status will update

to YES, indicating a determination was made even if all

of the other tests for that system have not run.

Conditions for Running

• The barometric pressure is more than 70 kPa.

• The engine coolant temperature (ECT) is between

70–125.5°C (158–258°F).

• The battery voltage is more than 11 volts.

• The fuel alcohol content is less than 87 percent.

Diagnostic Aids

The control module runs a maximum of 6 catalyst

tests per trip until the Catalyst System Status updates

to YES. If the status does not update, the test

outlined in this procedure can be repeated until the

I/M System Status updates to YES.

If there is an impending failure, the system may

require more time to run the diagnostic than was

allotted in the set procedure. If the test does not run

after numerous attempts and no DTC is set, review the

appropriateTech 2 datalistandtheservice

information for an indication of why the test does not

complete. Some tests may abort due to changes

in the conditions while the test is running. For example,

changes in engine load such as a cooling fan or

A/C compressor clutch turning ON may cause the test

to abort.

Inspection/Maintenance (I/M) Catalyst System Set Procedure

Step Action Yes No

1Did you perform the Inspection/Maintenance (I/M) System Check?

Go to

Step 2

Go to

Inspection/Maintenance

(I/M) System Check

EngineEngineControls-6.0L

Inspection/Maintenance (I/M) Catalyst System Set Procedure (cont’d)

Step Action Yes No

1. Ensure the vehicle is within the Conditions for Running

speciﬁed in the supporting text.

2. Turn OFF all of the accessories, e.g., A/C, blower fan, etc.

3. Start the engine and allow it to idle for 2 minutes.

Caution: Refer to Road Test Caution in Cautions and Notices.

4. Accelerate at part throttle to 90 km/h (55 mph) with this

speed maintained for 8 minutes

5. Brake safely to a stop.

6. Engine idling for 2 minutes while the following criteria is

maintained:

• Service brake depressed

• Automatic transmission in Drive

7.ObservetheI/MSystemStatusdisplaywithaTech 2 .

Did the catalyst System Status update to YES? Go to

Step 5

Go to

Step 3

ObservetheDTCInformationwithaTech 2

DoestheTech 2 indicateanyfailedDTCs? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

Step 4

1. Refer to the

Inspection/Maintenance (I/M) System DTC Table

to determine which DTCs are required to run in order to

complete this test.

2. Observe the Not Ran Since Code Cleared display with a

Tech 2 .

3. Determine which of the DTCs required for a YES status has

not run.

4. Enter the DTC number in the speciﬁc DTC menu of the

Tech 2 .

5. Operate the vehicle within the Conditions for Running the

DTC, located in the supporting text for the diagnostic table of

the DTC.

6. Repeat steps 4 and 5 for any additional required DTCs that

have not run.

7.ObservetheI/MSystemStatusdisplaywithaTech 2 .

Did the catalyst System Status update to YES? Go to

Step 5

Go to Diagnostic Aids

Observe the emission related DTC portion of the I/M System

StatusdisplaywithaTech 2 .

DoestheTech 2 indicateanyemissionrelatedDTCsset?

Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

Inspection/Maintenance (I/M) Evaporative Emission (EVAP) System Set Procedure

Description

The purpose of this procedure is to satisfy the enable

criteria necessary to execute inspection/maintenance

(I/M) readiness diagnostics for the Evaporative

Emission (EVAP) System. The procedure may be

used to set the EVAP I/M System Status display on

theTech 2 toYES.TheEVAPI/MSystem

Status display indicates whether or not the control

module has completed the readiness diagnostics. The

readiness diagnostics complete when all DTCs

comprising the diagnostics run and pass, or any DTC

comprising the diagnostics illuminates the malfunction

indicator lamp (MIL). If the diagnostics pass during

one drive cycle, seventeen hours must elapse,

regardless of whether the vehicle is driven or not.

Then, the diagnostics will run again during the

next drive cycle in which the conditions for running are

met. Once the diagnostics have passed during the

third drive cycle, the EVAP I/M System Status display

will be updated to YES. A failed or aborted diagnostic

will require the vehicle to cool down in order to

meet the enable criteria for another drive cycle.

Therefore, performing a visual inspection prior to

running the EVAP test may prevent having to repeat

the drive cycle.

Conditions for Running

• At least 17 hours have elapsed since the last

drive cycle met the Conditions for Running.

EngineControls-6.0LEngine

• The difference between the startup engine coolant

temperature (ECT) and the startup intake air

temperature (IAT) is less than 8°C (14.4°F).

• The barometric pressure (BARO) is more than

74 kPa.

• The startup ECT is between 4–30°C (39–86°F).

• The startup IAT is between 4–30°C (39–86°F).

• The fuel level is between 15–85 percent.

• The battery voltage is between 10–18 volts.

• The fuel level does not increase more than

9 percent during this drive cycle.

• The engine run time is at least 10 minutes.

• The vehicle has been driven at least 5 km

(3.15 miles) this drive cycle.

• The estimated ambient temperature at the end of

this drive cycle is between 2–32°C (36–89°F).

• The shutdown ECT is at least 70°C (158°F).

• The ignition is turned OFF for at least 1 hour after

this drive cycle.

Diagnostic Aids

Extreme high or low ambient temperatures may

prevent the EVAP System Tests from initiating. A loose

fuel cap may cause a test to abort or fail and prevent

the I/M System Status from updating. A failed or

aborted diagnostic will require the vehicle to cool down

in order to meet the enable criteria for another

drive cycle.

If there is an impending failure, the system may

require more time to run the diagnostic than was

allotted in the set procedure. If the diagnostic does not

run after numerous attempts and no DTC is set,

reviewtheappropriateTech 2 datalistandthe

service information. This will give an indication of why

the test does not complete. Some diagnostics may

abort due to changes in the conditions while the test is

running. For example, changes in engine load, such

as a cooling fan or an A/C compressor clutch

turning ON, may cause the diagnostic to abort.

Inspection/Maintenance (I/M) Evaporative Emission (EVAP) System Set Procedure

Step Action Yes No

1Did you perform the Inspection/Maintenance (I/M) System Check?

Go to

Step 2

Go to

Inspection/Maintenance

(I/M) System Check

Important: At least 3 drive cycles, with a minimum of 17 hours

between drive cycles, are required for the EVAP System Status to

update to YES. Repeat steps 1–9 until the minimum requirement

of drive cycles is met.

1. Ensure the vehicle is within the Conditions for Running

speciﬁed in the supporting text.

2. Turn OFF all of the accessories, e.g., A/C, blower fan, etc.

Important: Once the engine is started, DO NOT turn the engine

OFF for the remainder of the procedure.

3. Start the engine and idle for 2 minutes.

Caution: Refer to Road Test Caution in Cautions and Notices.

4. Accelerate at part throttle to 72 km/h (45 mph) with this

speed maintained until the engine reaches operating

temperature. This may be up to 10 minutes depending on the

start up coolant temperature.

5. Continue the operating conditions for an additional 6 minutes

after the engine reaches operating temperature.

6. Decelerate to 0 km/h (0 mph).

7. Allow the engine to idle for 2 minutes.

Important: Ensure that the ignition remains OFF for 1 hour in

order for the control module to perform vacuum testing.

8. Turn OFF the ignition for 1 hour.

9. Turn ON the ignition after 1 hour.

Did the EVAP System Status update to YES? Go to

Step 5

Go to

Step 3

ObservetheDTCInformationwithaTech 2 .

DoestheTech 2 indicateanyfailedDTCs? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

Step 4

EngineEngineControls-6.0L

Inspection/Maintenance (I/M) Evaporative Emission (EVAP) System Set Procedure (cont’d)

Step Action Yes No

1. Refer to the

Inspection/Maintenance (I/M) System DTC Table

to determine which DTCs are required to run in order to

complete this diagnostic.

2. Observe the Not Ran Since Code Cleared display with a

Tech 2 .

3. Determine which of the DTCs required for a YES status has

not run.

4. Enter the DTC number in the Speciﬁc DTC menu of the

Tech 2 .

5. Ensure that the vehicle is within the Conditions for Running

the DTC, located in the supporting text for the diagnostic

table of the DTC.

6. Repeat the procedure in step 2 of the inspection/maintenance

(I/M) evaporative emission (EVAP) system set procedure until

theTech 2 indicatestheDTChasrun.

7. Repeat steps 4–6 for any additional required DTCs that have

not run.

8.ObservetheI/MSystemStatusdisplaywithaTech 2 .

Did the EVAP System Status update to YES? Go to

Step 5

Go to Diagnostic Aids

Observe the Emission Related DTC portion of the I/M System

StatusdisplaywithaTech 2

DoestheTech 2 indicateanyEmissionRelatedDTCsset?

Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

Inspection/Maintenance (I/M) Heated Oxygen Sensor/Oxygen Sensor (HO2S/O2S) System

Set Procedure

Description

The purpose of this test is to satisfy the enable criteria

necessary to execute inspection/maintenance (I/M)

readiness diagnostics for the oxygen sensor

(O2S, HO2S) system. The test may be used to set the

I/M System Status to YES. The I/M System Status

displayontheTech 2 providesanindication

of whether the control module has completed the

required tests. The I/M System Status does not

indicate that the tests have passed or failed. When all

of the diagnostics for a speciﬁc system have run

and passed, the I/M System Status will update to YES.

If a test for a speciﬁc system has failed, the I/M

System Status will update to YES, indicating a

determination was made, even if all of the other tests

for that system have not run.

Conditions for Running

• The fuel level is more than 10 percent.

• The engine coolant temperature (ECT) is more

than 55°C (131°F).

• The battery voltage is between 10–18 volts.

• The fuel alcohol content is less than 90 percent.

Diagnostic Aids

If there is an impending failure, the system may

require more time to run the diagnostic than was

allotted in the set procedure. If the test does not run

after numerous attempts and no DTC is set, review the

appropriateTech 2 datalistandtheservice

information for an indication of why the test does not

complete. Some tests may abort due to changes

in the conditions while the test is running. For example,

changes in engine load such as a cooling fan or

A/C compressor clutch turning ON may cause the test

to abort.

Inspection/Maintenance (I/M) Heated Oxygen Sensor/Oxygen Sensor (HO2S/O2S) System Set

Procedure

Step Action Yes No

1Did you perform the Inspection/Maintenance (I/M) System Check?

Go to

Step 2

Go to

Inspection/Maintenance

(I/M) System Check

EngineControls-6.0LEngine

Inspection/Maintenance (I/M) Heated Oxygen Sensor/Oxygen Sensor (HO2S/O2S) System Set

Procedure (cont’d)

Step Action Yes No

1. Ensure the vehicle is within the Conditions for Running

speciﬁed in the supporting text.

2. Turn OFF all of the accessories, e.g., A/C, blower fan, etc.

3. Start the engine and allow it to idle for 1 minute.

Caution: Refer to Road Test Caution in Cautions and Notices.

4. Accelerate at part throttle to 75–90 km/h (45–55 mph) with

this speed maintained for 6 minutes or until the I/M System

Status updates to YES.

Manual transmissions, either 5 or 6 speed, may require

operation in 4th or 5th gear respectively, in order for this test

to run.

5.ReviewtheI/MSystemStatusdisplaywithaTech 2 .

Did the HO2S/O2S System Status update to YES? Go to

Step 5

Go to

Step 3

ObservetheDTCInformationwithaTech 2 .

DoestheTech 2 indicateanyfailedDTCs? Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information Go to

Step 4

1. Refer to the

Inspection/Maintenance (I/M) System DTC Table

to determine which DTCs are required to run in order to

complete this test.

2. Observe the Not Ran Since Code Cleared display with a

Tech 2 .

3. Determine which of the DTCs required for a YES status has

not run.

4. Enter the DTC number in the Speciﬁc DTC menu of the

Tech 2 .

5. Operate the vehicle within the Conditions for Running the

DTC, located in the supporting text for the diagnostic table of

the DTC.

6. Repeat steps 4 and 5 for any additional required DTCs that

have not run.

7.ObservetheI/MSystemStatusdisplaywithaTech 2 .

Did the HO2S/O2S System Status update to YES? Go to

Step 5

Go to Diagnostic Aids

Observe the Emission Related DTC portion of the I/M System

StatusdisplaywithaTech 2 .

DoestheTech 2 indicateanyEmissionRelatedDTCsset?

Go to

Diagnostic

Trouble Code (DTC)

List - Vehicle

Vehicle

DTC Information System OK

Inspection/Maintenance (I/M) Heated Oxygen Sensor (HO2S) Heater System Set

Procedure

Description

The purpose of this test is to satisfy the enable criteria

necessary to execute inspection/maintenance (I/M)

readiness diagnostics for the heated oxygen sensor

(HO2S) system. The test may be used to set the

I/M System Status to YES. The I/M System Status

displayontheTech 2 providesanindication

of whether the control module has completed the

required tests. The I/M System Status does not

indicate that the tests have passed or failed. When all

of the diagnostics for a speciﬁc system have run

and passed, the I/M System Status will update to YES.

If a test for a speciﬁc system has failed, the I/M

System Status will update to YES, indicating a

determination was made, even if all of the other tests

for that system have not run.

Conditions for Running

• The intake air temperature (IAT) is between 30–

45°C (22–113°F).

• The difference between the IAT and the ECT is

less than 8°C (14°F).

• The battery voltage is between 11–18 volts.

EngineEngineControls-6.0L

Diagnostic Aids

The HO2S Heater Tests will normally run within the

2 minutes allotted in the procedure. If there is an

indeterminate condition, the test may take up

to 8 minutes on some vehicles before a decision of

pass or fail is made. If the test does not update

to YES, it may have failed or aborted due to the loss

of enabling conditions. Extremely high ambient

temperatures may prevent the HO2S Heater Test from

initiating.

If there is an impending failure, the system may

require more time to run the diagnostic than was

allotted in the set procedure. If the test does not run

after numerous attempts and no DTC is set, review

theappropriateTech 2 datalistandtheservice

information for an indication of why the test does not

complete. Some tests may abort due to changes

in the conditions while the test is running. For example,

changes in engine load such as a cooling fan or

A/C compressor clutch turning ON may cause the test

to abort.

Inspection/Maintenance (I/M) Heated Oxygen Sensor (HO2S) Heater System Set Procedure

Step Action Value(s) Yes No

1Did you perform the Inspection/Maintenance (I/M)

System Check? —Go to

Step 2

Go to

Inspection/Maintenance

(I/M)

System Check

Important: Whenever the ignition is turned ON, ignition

positive voltage is supplied to the heated oxygen sensor

(HO2S) heaters. After verifying the enable criteria, turn

OFF the ignition for approximately 5 minutes to allow the

sensors to cool before continuing with the test.

1.PreprogramtheTech 2 withthevehicleinformation

before the ignition is turned ON.

2. Ensure the vehicle is within the Conditions for

Running as speciﬁed in the supporting text.

3. Set the vehicle parking brake.

4. Verify the transmission is in Park for automatic

transmissions and Neutral for manual transmissions.

5. Turn OFF all of the accessories, e.g., A/C, blower

fan, etc.

6. Start the engine and allow it to idle for the speciﬁed

time or until the I/M System Status indicator updates

to YES.

Did the HO2S Heater System Status update to YES?

2 minutes

Go to

Step 5

Go to

Step 3

ObservetheDTCinformationwithaTech 2 .

DoestheTech 2 indicateanyfailedDTCs? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information Go to

Step 4

1. Refer to the

Inspection/Maintenance (I/M) System

DTC Table

to determine which DTCs are required to

run in order to complete this test.

2. Observe the Not Ran Since Code Cleared display with

aTech 2 .

3. Determine which of the DTCs required for a YES

status has not run.

4. Enter the DTC number in the Speciﬁc DTC menu of

theTech 2 .

5. Operate the vehicle within the Conditions for Running

the DTC, located in the supporting text for the

diagnostic table of the DTC.

6. Repeat steps 4–5 for any additional required DTCs

that have not run.

7. Observe the I/M System Status display with a

Tech 2 .

Did the HO2S Heater System Status update to YES?

—

Go to

Step 5

Go to

Diagnostic Aids

EngineControls-6.0LEngine

Inspection/Maintenance (I/M) Heated Oxygen Sensor (HO2S) Heater System Set Procedure

(cont’d)

Step Action Value(s) Yes No

Observe the Emission Related DTC portion of the I/M

SystemStatusdisplaywithaTech 2 .

DoestheTech 2 indicateanyEmissionRelated

DTCs set? —

Go to

Diagnostic

Trouble

Code (DTC) List -

Vehicle

in Vehicle

DTC Information System OK

EngineEngineControls-6.0L

Repair Instructions

Engine Control Module (ECM)

Replacement

Engine control module (ECM) service should normally

consist of either ECM replacement or electrically

erasable programmable read only memory (EEPROM)

programming. If the diagnostic procedures require

ECM replacement, check the ECM ﬁrst to see if

the correct part is being used.

Important: In order to prevent internal ECM damage,

the ignition must be OFF when you disconnect or

reconnect the power to the ECM. For example,

disconnect the power when you work with the following

components:

• A battery cable

• The ECM pigtail

• The ECM fuse

• The jumper cables

Important: When you diagnose or replace the ECM,

remove any debris from the ECM connector

surfaces before servicing the ECM module connector

gaskets. Ensure that the gaskets are installed

correctly. The gaskets prevent intrusion into the ECM.

Important: The replacement ECM MUST be

programmed.

Removal Procedure

Important: It is necessary to record the remaining

engine oil life. If the replacement module is not

programed with the remaining engine oil life, the

engine oil life will default to 100%. If the replacement

module is not programmed with the remaining

engine oil life, the engine oil will need to be changed

at 5000 km (3,000 mi) from the last engine oil

change.

1.UsingaTech 2 ,retrievethepercentageof

remaining engine oil. Record the remaining

engine oil life.

2. Remove the wheelhouse ﬁller panel. Refer to

Fender, Insulator, Liner, Brake Caliper Cooling

Duct Replacement - Front

in Body Front End.

3. Remove the throttle actuator control (TAC)

module. Refer to

Transmission Control

Module (TCM) Replacement

in Automatic

Transmission – 4L60-E/4L65-E.

4. Disconnect the ECM electrical harness

connectors.

5. Loosen but do not remove the ECM rear retaining

fastener. Use the rear retaining fastener as an

anchor for the outer bracket.

6. Remove the front retaining fastener from the ECM.

7. Reposition the ECM outer bracket.

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8. Remove the ECM from the bracket and the

vehicle.

Installation Procedure

1. Install the ECM to the ECM rear bracket.

2. Position the ECM front bracket.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

3. Install the ECM front retaining fasteners.

Tighten

Tighten the ECM retaining fasteners to

2.0 N·m (17 lb in).

4. Connect the electrical connectors to the ECM.

Tighten

Tighten the ECM electrical connectors to

8 N·m (70 lb in).

5. Install the TAC module. Refer to

Transmission

Control Module (TCM) Replacement

in Automatic

Transmission – 4L60-E/4L65-E.

6. Install the wheelhouse ﬁller panel. Refer to

Fender, Insulator, Liner, Brake Caliper Cooling

Duct Replacement - Front

in Body Front End.

7. If a new ECM is being installed, program the

ECM. Refer to

Control Module References

Computer/Integrating Systems.

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CKP System Variation Learn Procedure

1.InstallaTech 2 .

2. Monitor the engine control module (ECM) for

DTCswithaTech 2 .IfotherDTCsareset,

except DTC P0315, refer to

Diagnostic Trouble

Code (DTC) List - Vehicle

in Vehicle

DTC Information for the applicable DTC that set.

3. Select the crankshaft position (CKP) variation

learnprocedurewithaTech 2 .

4.TheTech 2 instructsyoutoperformthe

following:

4.1. Accelerate to wide open throttle (WOT).

4.2. Release throttle when fuel cut-off occurs.

4.3. Observe fuel cut-off for applicable engine.

4.4. Engine should not accelerate beyond

calibrated RPM value.

4.5. Release throttle immediately if value is

exceeded.

4.6. Block drive wheels.

4.7. Set parking brake.

4.8. DO NOT apply brake pedal.

4.9. Cycle ignition from OFF to ON.

4.10. Apply and hold brake pedal.

4.11. Start and idle engine.

4.12. Turn A/C OFF.

4.13. Vehicle must remain in Park or Neutral.

4.14.TheTech 2 monitorscertaincomponent

signals to determine if all the conditions are

met to continue with the procedure. The

Tech 2 onlydisplaysthecondition

thatinhibitstheprocedure.TheTech 2

monitors the following components:

• CKP sensors activity—If there is a CKP

sensor condition, refer to the applicable

DTC that set.

• Camshaft position (CMP) sensor

activity—If there is a CMP sensor

condition, refer to the applicable DTC

that set.

• Engine coolant temperature (ECT)—If

the ECT is not warm enough, idle

the engine until the engine coolant

temperature reaches the correct

temperature.

5. Enable the CKP system variation learn procedure

withaTech 2 .

Important: While the learn procedure is in progress,

release the throttle immediately when the engine starts

to decelerate. The engine control is returned to the

operator and the engine responds to throttle position

after the learn procedure is complete.

6. Accelerate to WOT.

7. Release when the fuel cut-off occurs.

8. Test in progress

9.TheTech 2 displaysLearnStatus:Learnedthis

ignition.IftheTech 2 indicatesthatDTCP0315

ran and passed, the CKP variation learn

procedureiscomplete.IftheTech 2 indicates

DTC P0315 failed or did not run, refer to

DTC P0315

. If any other DTCs set, refer to

Diagnostic Trouble Code (DTC) List - Vehicle

Vehicle DTC Information for the applicable

DTC that set.

10. Turn OFF the ignition for 30 seconds after the

learn procedure is completed successfully.

11. The CKP system variation learn procedure is also

required when the following service procedures

have been performed, regardless of whether

DTC P0315 is set:

• A CKP sensor replacement

• An engine replacement

• An ECM replacement

• A harmonic balancer replacement

• A crankshaft replacement

• Any engine repairs which disturb the CKP

sensor relationship

EngineControls-6.0LEngine

Engine Coolant Temperature (ECT) Sensor

Replacement

Removal Procedure

1. Turn OFF the ignition.

Caution: Refer to Vehicle Lifting Caution in

Cautions and Notices.

2. Raise the vehicle. Refer to

Lifting and Jacking the

Vehicle

in General Information.

3. Drain the engine coolant below the level of the

engine coolant temperature (ECT) sensor. Refer

Draining and Filling Cooling System

Engine Cooling.

4. Lower the vehicle.

5. Disconnect the harness connector from the ECT

sensor.

Notice:

SIO-ID = 5367 LMD = 18-aug-1995 Use care when

handling the coolant sensor. Damage to the coolant

sensor will affect the operation of the fuel control

system.

6. Remove the ECT sensor.

Installation Procedure

Notice:

Replacement

components must be the correct part number for

the application. Components requiring the use of the

thread locking compound, lubricants, corrosion

inhibitors, or sealants are identiﬁed in the service

procedure. Some replacement components may come

with these coatings already applied. Do not use

these coatings on components unless speciﬁed. These

coatings can affect the ﬁnal torque, which may

affect the operation of the component. Use the correct

torque speciﬁcation when installing components in

order to avoid damage.

Notice:

Usecarewhen

handling the coolant sensor. Damage to the coolant

sensor will affect the operation of the fuel control

system.

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1. Coat the ECT sensor threads with sealer

P/N 12346004 (Canadian P/N 10953480) or the

equivalent.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

2. Install the ECT sensor.

Tighten

Tighten the ECT sensor to 20 N·m (15 lb ft).

3. Connect the ECT sensor electrical connector.

4. Reﬁll the engine coolant. Refer to

Draining and

Filling Cooling System

in Engine Cooling.

Mass Air Flow (MAF)/Intake Air

Temperature (IAT) Sensor Replacement

Removal Procedure

1. Disconnect the electrical connector 1 for the mass

airﬂow/airintaketemperature(MAF/IAT)sensor

2.Removethelines2fromtheairduct.

3.Loosentheairintakeductclamps.

4.Removetheairintakeductfromthe

throttle body.

5.RemovetheMAF/IATsensorfromtheair

cleanerhousing.

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Installation Procedure

Important: Ensure that the arrow on the MAF/IAT

sensor is pointing to the front, radiator, indicate

the proper air ﬂow direction. The arrow must point

toward the engine.

1.InstalltheMAF/IATsensor5intheaircleaner

housing.

2.Installtheairintakeduct.

3.Positiontheclampsontheairintakeduct.

Notice:

Refer to

Fastener Notice

in Cautions

and Notices.

4.Tightentheclamps.

Tighten

TightenairintakeductandMAF/IATsensorto

4 N·m (35 lb in).

5.ReconnecttheMAF/IATelectricalconnector.

6.Reconnecttheelectricalconnector.

Manifold Absolute Pressure (MAP) Sensor

Replacement

Removal Procedure

1.Removetheoilﬁllercap.

2.Removetheenginecover.

3.Removethemanifoldabsolutepressure(MAP)

sensor.

4.Disconnecttheelectricalconnectorforthe

MAP sensor.

EngineEngineControls-6.0L

Installation Procedure

1. Reconnect the MAP sensor electrical

connectortotheenginewiringharness.

2.InstalltheMAPsensor.

3.Installenginecover.

4.Installtheoilﬁllercap.

Heated Oxygen Sensor (HO2S)

Replacement Bank 1 Sensor 1

Removal Procedure

1. Raise the vehicle. Refer to

Lifting and Jacking the

Vehicle

in General Information.

Notice:

Refer to

Heated Oxygen and Oxygen Sensor

Notice

in Cautions and Notices.

Notice:

Refer to

Excessive Force and Oxygen Sensor

Notice

in Cautions and Notices.

2. Disconnect the bank 1, oxygen sensor 1 (1)

electrical connector, from the engine wiring

harness electrical connector.

3. Remove the bank 1, oxygen sensor 1 (1) from the

exhaust manifold.

Installation Procedure

Important: Use special anti-seize compound on the

heated oxygen sensor threads. The compound

consists of graphite suspended in ﬂuid and glass

beads. The graphite burns away, but the glass beads

remain, making the sensor easier to remove. New

or service sensors already have the compound applied

to the threads. If you remove an oxygen sensor and

if for any reason you must reinstall the same

oxygen sensor, apply the anti-seize compound to the

threads before reinstallation.

1. Coat the threads of the heated oxygen sensor

with the anti-seize compound P/N 5613695, or

the equivalent if necessary.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

2. Install the heated oxygen sensor (1).

Tighten

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Tighten the HO2S to 41 N·m (30 lb ft).

3. Reconnect the bank 1, oxygen sensor (4),

electrical connector to the engine wiring harness

electrical connector.

4. Lower the vehicle.

Heated Oxygen Sensor (HO2S)

Replacement Bank 1 Sensor 2

Removal Procedure

1. Raise the vehicle. Refer to

Lifting and Jacking the

Vehicle

in General Information.

Notice:

Refer to

Heated Oxygen and Oxygen Sensor

Notice

in Cautions and Notices.

Notice:

Refer to

Excessive Force and Oxygen Sensor

Notice

in Cautions and Notices.

2. Disconnect the bank 1, oxygen sensor 2 (2),

electrical connector from the engine harness.

3. Remove the bank 1, oxygen sensor 2 (2), in the

catalytic convertor.

Installation Procedure

Important: Use special anti-seize compound on the

heated oxygen sensor threads. The compound

consists of graphite suspended in ﬂuid and glass

beads. The graphite burns away, but the glass beads

remain, making the sensor easier to remove. New

or service sensors already have the compound applied

to the threads. If you remove an oxygen sensor and

if for any reason you must reinstall the same

oxygen sensor, apply the anti-seize compound to the

threads before reinstallation.

1. Coat the threads of the heated oxygen sensor

with the anti-seize compound P/N 5613695, or

the equivalent if necessary.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

2. Install the bank 1, oxygen sensor 2 (2), in the

catalytic convertor.

Tighten

Tighten the oxygen sensor to 41 N·m (30 lb ft).

3. Reconnect the bank 1, oxygen sensor 2 (2),

electrical connector to the engine wiring

harness electrical connector.

4. Lower the vehicle.

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EngineEngineControls-6.0L

Heated Oxygen Sensor (HO2S)

Replacement Bank 2 Sensor 1

Removal Procedure

1. Raise the vehicle. Refer to

Lifting and Jacking the

Vehicle

in General Information.

2. Disconnect bank 2, oxygen sensor 1 (3), electrical

connector from the engine harness electrical

connector.

Notice:

Refer to

Heated Oxygen and Oxygen Sensor

Notice

in Cautions and Notices.

Notice:

Refer to

Excessive Force and Oxygen Sensor

Notice

in Cautions and Notices.

3. Remove the bank 2, oxygen sensor 1 (3), from the

catalytic convertor.

Installation Procedure

Important: Use special anti-seize compound on the

heated oxygen sensor threads. The compound

consists of graphite suspended in ﬂuid and glass

beads. The graphite burns away, but the glass beads

remain, making the sensor easier to remove. New

or service sensors already have the compound applied

to the threads. If you remove an oxygen sensor and

if for any reason you must reinstall the same

oxygen sensor, apply the anti-seize compound to the

threads before reinstallation.

1. Coat the threads of the bank 2, oxygen sensor

1 (3) with the anti-seize compound P/N 5613695,

or the equivalent if necessary.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

2. Install the bank 2, oxygen sensor 1 (3), in the

exhaust manifold.

Tighten

Tighten the oxygen sensor to 41 N·m (30 lb ft).

3. Reconnect the bank 2, oxygen sensor 1 (3),

electrical connector to the engine wiring

harness electrical connector.

4. Lower the vehicle.

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Heated Oxygen Sensor (HO2S)

Replacement Bank 2 Sensor 2

Removal Procedure

1. Raise the vehicle. Refer to

Lifting and Jacking the

Vehicle

in General Information.

2. Disconnect the bank 2, oxygen sensor 2 (4),

electrical connector from the engine wiring

harness connector.

Notice:

Refer to

Heated Oxygen and Oxygen Sensor

Notice

in Cautions and Notices.

Notice:

Refer to

Excessive Force and Oxygen Sensor

Notice

in Cautions and Notices.

3. Remove the bank 2, oxygen sensor 2 (4), from

the catalytic converter.

Installation Procedure

Important: Use special anti-seize compound on the

heated oxygen sensor threads. The compound

consists of graphite suspended in ﬂuid and glass

beads. The graphite burns away, but the glass beads

remain, making the sensor easier to remove. New

or service sensors already have the compound applied

to the threads. If you remove an oxygen sensor and

if for any reason you must reinstall the same

oxygen sensor, apply the anti-seize compound to the

threads before reinstallation.

1. Coat the threads of the oxygen sensor 2 with the

anti-seize compound P/N 5613695, or the

equivalent if necessary.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

2. Install the bank 2, oxygen sensor 2 (4), in the

catalytic converter.

Tighten

Tighten the bank 2, oxygen senor 2 to 41

N·m (30 lb ft).

3. Reconnect the bank 2, oxygen sensor 2 (4),

electrical connector to the engine wiring

harness electrical connector.

4. Lower the vehicle.

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EngineEngineControls-6.0L

Accelerator Pedal Position (APP) Sensor

Replacement

Removal Procedure

Notice:

Handlethe

electronic throttle control components carefully.

Use cleanliness in order to prevent damage. Do not

drop the electronic throttle control components. Do not

roughly handle the electronic throttle control

components. Do not immerse the electronic throttle

control components in cleaning solvents of any type.

1. Remove the left instrument panel (I/P) on the

lower closeout insulator panel. Refer to

Closeout/Insulator Panel Replacement -

Instrument Panel (I/P) Lower

in Instrument Panel,

Gages and Console.

2. Disconnect the electrical connector of the

accelerator pedal sensor module.

3. Remove the accelerator pedal mounting bolts.

4. Remove the accelerator pedal.

Installation Procedure

1. Install the accelerator pedal to the steering

column support bracket.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

Important: Always use a torque wrench in order to

obtain the proper torque.

2. Install the accelerator pedal mounting bolts.

Tighten

Tighten the accelerator pedal mounting bolts to

20 N·m (15 lb ft).

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3. Connect the accelerator pedal sensor module

electrical connector.

4. Inspect for complete throttle opening, and throttle

closing positions by operating the accelerator

pedal. Monitor the throttle angles using a

Tech 2 .Theacceleratorpedalshouldoperate

freely without binding between full closed

throttle, and wide open throttle.

5. Inspect for an incorrect carpet ﬁt under the

accelerator pedal.

6. Install the left I/P on the lower closeout insulator

panel. Refer to

Closeout/Insulator Panel

Replacement - Instrument Panel (I/P) Lower

Instrument Panel, Gages and Console.

Throttle Body Assembly Replacement

Removal Procedure

Notice:

Handlethe

electronic throttle control components carefully.

Use cleanliness in order to prevent damage. Do not

drop the electronic throttle control components. Do not

roughly handle the electronic throttle control

components. Do not immerse the electronic throttle

control components in cleaning solvents of any type.

1. An 8-digit part identiﬁcation number is stamped on

the throttle body casting. Refer to this number if

servicing, or if a part replacement is required.

Important: Cover or plug any openings when servicing

the throttle body in order to prevent possible

contamination.

2. Disconnect the intake air temperature sensor

electrical connector.

3. Remove the air intake duct.

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EngineEngineControls-6.0L

4. Disconnect the air control valve electrical

connector.

5. Disconnect the throttle position (TP) sensor

electrical connector.

6. Disconnect the crankcase ventilation hose from

the throttle body.

7. Remove the throttle body attaching bolts.

8. Remove the throttle body and the gasket.

Important: Do not reuse the throttle body gasket.

Install a new gasket during assembly.

9. Discard the throttle body gasket.

10. Inspect the crankcase ventilation hose and the

tube. Replace any damaged components.

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Installation Procedure

1. Install a new throttle body gasket.

2. Install the throttle body assembly.

Notice:

Refer to the

Fastener Notice

in Cautions and

Notices.

Important: Always use a torque wrench in order to

obtain the proper torque.

3. Install the throttle body attaching bolts.

Tighten

Tighten the throttle body bolts to 10 N·m (89 lb in).

4. Connect the TP sensor electrical connector.

5. Connect the crankcase ventilation hose to the

throttle body.

Important: Ensure that the air control valve electrical

connector and the connector seal are properly

installed and not damaged.

6. Connect the air control valve electrical connector.

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7. Install the air intake duct.

8. Connect the intake air temperature sensor

electrical connector.

9. Check for complete throttle opening and closing

positions by operating the accelerator pedal.

Monitorthethrottleangles,usingaTech 2 .The

accelerator pedal should operate freely without

binding between full closed throttle and wide open

throttle.

10. Start the engine.

Throttle Body Cleaning Procedure

Caution:TurnOFF

the ignition before inserting ﬁngers into the throttle

bore. Unexpected movement of the throttle

blade could cause personal injury.

1. Remove the air intake duct.

Notice:

Donotinsert

any tools into the throttle body bore in order to

avoid damage to the throttle valve plate.

2. Inspect the throttle body bore and the throttle

valve plate for deposits. If necessary, open the

throttle valve to inspect all surfaces.

Notice:

Donotuseany

solvent that contains Methyl Ethyl Ketone (MEK).

This solvent may damage fuel system components.

3. Clean the throttle body bore and the throttle valve

plate using a clean shop towel with an appropriate

cleaning substance, such one of the following:

• GM Top Engine Cleaner

• P/N 1052626

• AC-Delco Carburetor Tune-Up Conditioner

• P/N X66–P

4. Install the air intake duct.

EngineControls-6.0LEngine

Fuel Pressure Relief Procedure

Tool Required

J 34730-1A

Fuel Pressure Gage

Caution:Removethe

fuel tank cap and relieve the fuel system pressure

before servicing the fuel system in order to

reduce the risk of personal injury. After you relieve

the fuel system pressure, a small amount of fuel

may be released when servicing the fuel lines, the

fuel injection pump, or the connections. In order

to reduce the risk of personal injury, cover the fuel

system components with a shop towel before

disconnection. This will catch any fuel that may

leak out. Place the towel in an approved container

when the disconnection is complete.

1. Turn the ignition OFF.

Caution: Refer to the Battery Disconnect Caution

in Cautions and Notices.

2. Disconnect the negative battery cable in order to

avoid possible fuel discharge if an accidental

attempt is made to start the engine.

3. Loosen the fuel ﬁller cap in order to relieve the

fuel tank vapor pressure.

4. Remove the left fuel rail cover.

5. Connect the

J 34730-1A

to the fuel pressure

connection. Wrap a shop towel around the ﬁtting

while connecting the gauge in order to avoid

spillage.

6. Install the bleed hose of the gauge into an

approved container.

7. Open the valve on the gauge to bleed the system

pressure. The fuel connections are now safe for

servicing.

8. Drain any fuel remaining in the gauge into an

approved container.

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Fuel Pressure Gage Installation and

Removal

Installation Procedure

Caution: Refer to Gasoline/Gasoline Vapors

Caution in Cautions and Notices.

1. Remove the left fuel rail cover.

Caution: Refer to Fuel Gage Leak Caution in

Cautions and Notices.

Notice:

Refer to

Fuel and Evaporative

Emission (EVAP) Hose/Pipe Connection Cleaning

Notice

in Cautions and Notices.

2. Install the fuel pressure gage to the fuel pressure

service connection, located on the fuel rail.

3. Turn ON the ignition.

Caution: Refer to Fuel Storage Caution in Cautions

and Notices.

4. Place the bleed hose of the fuel pressure gage

into an approved gasoline container.

5. Open the bleed valve on the fuel pressure gage in

order to bleed the air from the fuel pressure gage.

6.CommandthefuelpumpONwithaTech 2 .

7. Close the bleed valve on the fuel pressure gage.

8. Inspect for fuel leaks.

Quick Connect Fitting(s) Service (Metal

Collar)

Tools Required

•

J 34730-1A

Fuel Pressure Gage

•

J 37088-A

Tool Set, Fuel Line Quick-Connect

Separator

Removal Procedure

1. Relieve the fuel system pressure before servicing

any fuel system connection. Refer to the

Fuel

Pressure Relief Procedure

2. Slide the dust cover from the quick-connect ﬁtting.

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Caution:Wearsafety

glasses when using compressed air in order to

prevent eye injury.

3. Blow any dirt out of the ﬁtting, using

compressed air.

4. Choose the correct tool from the

J 37088-A

Tool

Set for the size of the ﬁtting. Insert the tool into

the female connector, then push inward in order to

release the locking tabs.

5. Pull the connection apart.

Notice:

Ifnecessary,

remove rust or burrs from the fuel pipes with an emery

cloth. Use a radial motion with the fuel pipe end in

order to prevent damage to the O-ring sealing surface.

Use a clean shop towel in order to wipe off the

male tube ends. Inspect all the connections for dirt

and burrs. Clean or replace the components and

assemblies as required.

6. Using a clean shop towel, wipe off the male

pipe end.

7. Inspect both ends of the ﬁtting for dirt and burrs.

Clean or replace the components as required.

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Installation Procedure

Caution:Always

apply a few drops of clean engine oil to the male

pipe ends before connecting the fuel pipe

ﬁttings in order to reduce the risk of ﬁre and

personal injury. This will ensure proper

reconnection and prevent a possible fuel leak.

During normal operation, the O-rings located in the

female connector will swell and may prevent

proper reconnection if not lubricated.

1. Apply a few drops of clean engine oil to the male

pipe end.

2. Push both sides of the ﬁtting together in order to

cause the retaining tabs to snap into place.

3. Once installed, pull on both sides of the ﬁtting in

order to make sure the connection is secure.

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4. Reposition the dust cover over the quick-connect

ﬁtting.

Quick Connect Fitting(s) Service (Plastic

Collar)

Tool Required

J 34730-1A

Fuel Pressure Gage

Removal Procedure

1. Relieve the fuel system pressure before servicing

any fuel system connection. Refer to the

Fuel

Pressure Relief Procedure

Caution:Wearsafety

glasses when using compressed air in order to

prevent eye injury.

2. Using compressed air, blow any dirt out of the

quick-connect ﬁtting.

Important: Plastic quick connect ﬁttings can be

released either by squeezing the plastic retainer

release tabs (step 3) or by using the appropriate

J 37088-A

Fuel Line Quick Connect Separator Tool

(step 4).

3. Squeeze the plastic retainer release tabs.

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4. Choose the correct tool from the

J 37088-A

Tool

Set for the size of the ﬁtting. Insert the tool into

the female connector, then push inward in order to

release the locking tabs. The plastic retainer will

remain on the female connector.

5. Pull the connection apart.

Installation Procedure

Caution:Always

apply a few drops of clean engine oil to the male

pipe ends before connecting the fuel pipe

ﬁttings in order to reduce the risk of ﬁre and

personal injury. This will ensure proper

reconnection and prevent a possible fuel leak.

During normal operation, the O-rings located in the

female connector will swell and may prevent

proper reconnection if not lubricated.

1. Apply a few drops of clean engine oil to the male

fuel pipe end.

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2. Push both sides of the quick-connect ﬁtting

together in order to cause the retaining

tabs/ﬁngers to snap into place.

3. Once installed, pull on both sides of the

quick-connect ﬁtting in order to make sure the

connection is secure.

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Fuel Tank Draining Procedure

For all information on HSV VZ Fuel Tank refer to Holden VZ Service Information

EngineControls-6.0LEngine

Fuel Pulse Dampener Replacement

Tool Required

J 34730-1A

Fuel Pressure Gage

Removal Procedure

Caution: Refer to Battery Disconnect Caution in

Cautions and Notices.

1. Disconnect the negative battery cable.

2. Remove the left fuel rail cover.

3. Relieve the fuel system pressure. Refer to

Fuel

Pressure Relief Procedure

4. Clean any dirt from the fuel pulse dampener

retaining ring.

5. Remove the fuel pulse dampener retaining ring.

6. Remove the fuel pulse dampener from the fuel rail.

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Installation Procedure

1. Install the new O-ring on the fuel pulse dampener.

2. Lubricate the fuel pulse dampener O-ring with

clean engine oil.

3. Push the fuel pulse dampener into the fuel rail.

4. Install the new fuel pulse dampener retaining ring.

5. Tighten the fuel ﬁller cap.

6. Connect the negative battery cable.

7. Inspect for leaks.

7.1. Turn the ignition switch ON for 2 seconds.

7.2. Turn the ignition switch OFF for

10 seconds.

7.3. Turn the ignition switch ON.

7.4. Inspect for fuel leaks.

8. Install the left fuel rail cover.

9. Program the transmitters. Refer to

Transmitter

Programming (Domestic)

Transmitter

Programming (Export - Including Canada)

Keyless Entry.

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EngineEngineControls-6.0L

Fuel Hose/Pipes Replacement - Engine

Compartment

Tools Required

•

J 34730-1A

Fuel Pressure Gage

•

J 37088-A

Tool Set, Fuel Line Quick-Connect

Separator

Removal Procedure

Caution: Refer to Battery Disconnect Caution in

Cautions and Notices.

Notice:

• Do not repair the fuel feed or return pipes.

• Replace the fuel feed and return pipes with original

equipment or with parts that meet the GM

speciﬁcations for those parts. The replacement

pipe must have the same type of ﬁttings as

the original pipe in order to ensure the integrity of

the connection.

1. Disconnect the negative battery cable. Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

2. Remove the left fuel rail cover.

3. Relieve the fuel system pressure. Refer to the

Fuel Pressure Relief Procedure

EngineEngineControls-6.0L

4. Disconnect the quick-connect ﬁtting at the fuel

rail (1). Refer to

Quick Connect Fitting(s) Service

(Metal Collar)

5. Disconnect the quick-connect ﬁtting at the chassis

fuel pipe (3). Refer to

Quick Connect Fitting(s)

Service (Metal Collar)

6. Remove the fuel feed hose (2).

7. Cap the chassis fuel pipe and the fuel rail pipe in

order to prevent possible fuel system

contamination.

8. Inspect the hose for bends, for kinks, for chaﬁng,

and for cracks. Replace the hose as required.

Installation Procedure

1. Remove the caps from the chassis fuel pipe and

the fuel rail pipe.

2. Connect the fuel feed hose (2) to the chassis fuel

pipe (3). Refer to

Quick Connect Fitting(s) Service

(Metal Collar)

3. Connect the fuel feed hose (2) to the fuel rail (1).

Refer to

Quick Connect Fitting(s) Service (Metal

Collar)

4. Tighten the fuel ﬁller cap.

5. Connect the negative battery cable. Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

6. Perform the following procedure in order to

inspect for leaks:

6.1. Turn the ignition switch ON for 2 seconds.

6.2. Turn the ignition switch OFF for

10 seconds.

6.3. Turn the ignition switch ON.

6.4. Inspect for fuel leaks.

7. Install the left fuel rail cover.

8. Program the transmitters. Refer to

Transmitter

Programming (Domestic)

Transmitter

Programming (Export - Including Canada)

Keyless Entry.

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Fuel System Cleaning

Tools Required

•

J 34730-1A

Fuel Pressure Gage

•

J 37088-A

Tool Set, Fuel Line Quick Connect

Separator

Caution: Refer to Battery Disconnect Caution in

Cautions and Notices.

1. Disconnect the negative battery cable. Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

2. Relieve the fuel system pressure. Refer to the

Fuel Pressure Relief Procedure

3. Drain the fuel tanks. Refer to

Fuel Tank Draining

Procedure

4.Removethefueltank.

5.Removethefuelsenderassemblie.

6. Inspect the left fuel sender strainer. Replace a

contaminated strainer for the left fuel sender

only, and inspect the fuel pump.

7. Inspect the left fuel sender fuel pump inlet for

debris. Replace the left fuel sender assembly if

you ﬁnd debris in the fuel pump inlet.

8. Inspect the right fuel sender strainers. Replace

the right fuel sender assembly if you ﬁnd a

contaminated strainer. The right fuel sender

strainers are not serviced separately.

Important: When ﬂushing the fuel tanks, handle the

fuel and water mixture as a hazardous material.

Handle the fuel and water mixture in accordance with

all applicable local, state, and federal laws and

regulations.

9. Flush the fuel tanks with hot water.

10. Pour the water out of the fuel sender assembly

openings. Rock the tanks to be sure that removal

of the water from the tanks is complete.

11. Install the fuel sender assemblies. Refer to

Fuel

Sender Assembly Replacement (Right )

Fuel

Sender Assembly Replacement (Left)

12.Installthefueltank.

13. Reﬁll the fuel system.

14. Install the fuel ﬁller cap.

15. Connect the negative battery cable. Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

16. Perform the following procedure in order to

inspect for leaks:

16.1. Turn the ignition switch ON for 2 seconds.

16.2. Turn the ignition switch OFF for

10 seconds.

16.3. Turn the ignition switch ON.

16.4. Inspect for fuel leaks.

17. Program the transmitters. Refer to

Transmitter

Programming (Domestic)

Transmitter

Programming (Export - Including Canada)

Keyless Entry.

EngineEngineControls-6.0L

Fuel Rail Assembly Replacement

Tools Required

•

J 34730-1A

Fuel Pressure Gage

•

J 37088-A

Tool Set, Fuel Line Quick Connect

Separator

Removal Procedure

Caution: Refer to Battery Disconnect Caution in

Cautions and Notices.

1. Disconnect the negative battery cable. Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

2. Remove the engine sight covers. Refer to

Engine

Sight Shield Replacement

in Engine Mechanical –

6.0L.

3. Relieve the fuel system pressure. Refer to

Fuel

Pressure Relief Procedure

4. Using compressed air, clean the fuel injector and

intake manifold.

5. Disconnect the fuel feed line (1) from the fuel

rail (2).

Important: Before disconnecting the electrical

connectors, mark the relationship of the electrical

connector to the fuel rail injector ﬁtting. This will ensure

the proper electrical connector sequence for

reassembly.

6. Mark the fuel injector to the electrical connector.

Disconnect the electrical connectors.

7. Remove the intake manifold bolts (3).

8. Remove the mounting bolts for the fuel rail (4).

9. Remove the fuel rail assembly (2) from the intake

manifold (10).

10. Remove the fuel injectors (7) from the fuel rail.

Refer to

Fuel Injector Replacement

Installation Procedure

Important: When installing the fuel injectors, apply a

small amount of clean motor oil to the O-rings.

1. Install the fuel injectors (7) in the fuel rail (2).

Refer to

Fuel Injector Replacement

2. Install the fuel rail (2) to the intake manifold (10).

3. Apply a 5 mm (0.020 in) band of

GM P/N 12345382 (Canadian P/N 10953489)

threadlock or equivalent to the threads of the fuel

rail and intake manifold bolts.

Caution:Thefuelrail

stop bracket must be installed onto the engine

assembly. The stop bracket serves as a protective

shield for the fuel rail in the event of a vehicle

frontal crash. If the fuel rail stop bracket is

not installed and the vehicle is involved in a frontal

crash, fuel could be sprayed possibly causing a

ﬁre and personal injury from burns.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

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4. Install the intake mounting bolts (3).

Tighten

Tighten the intake manifold bolts to

10 N·m (89 lb in).

5. Install the fuel rail (4) mounting bolts.

Tighten

Tighten the intake manifold bolts to

10 N·m (89 lb in).

Important: Ensure that the electrical connectors are

attached to the proper fuel injector.

6. Reconnect the electrical connectors (5) for the

fuel injectors (7).

7. Reconnect the fuel feed hose (1) to the fuel

rail (2).

8. Reconnect the negative battery cable.

9. Perform the following procedure in order to

inspect for leaks:

9.1. Turn the ignition switch ON for 2 seconds.

9.2. Turn the ignition switch OFF for

10 seconds.

9.3. Turn the ignition switch ON.

9.4. Inspect for fuel leaks.

10. Install the engine sight covers. Refer to

Engine

Sight Shield Replacement

in Engine Mechanical

– 6.0L.

11. Program the transmitters. Refer to

Transmitter

Programming (Domestic)

Transmitter

Programming (Export - Including Canada)

Keyless Entry.

Fuel Injector Cleaning Procedure

Tools Required

•

J 37287

Fuel Line Shut-Off Adapters

•

J 35800-A

Fuel Injector Cleaner

•

J 42873-1

3/8 Fuel Line Shut-Off Valve

•

J 42873-2

5/16 Return Pipe Shut-Off Valve

•

J 42964-1

3/8 Fuel Pipe Shut-Off Valve

•

J 42964-2

5/16 Fuel Pipe Shut-Off Valve

Notice:

• GM Top-Engine Cleaner is the only injector

cleaning agent recommended. Do not use other

cleaning agents, as they may contain methanol

which can damage fuel system components.

• Under NO circumstances should the top engine

cleaner be added to the vehicles fuel tank, as

it may damage the fuel pump and other system

components.

• Do not exceed a 10 percent cleaning solution

concentration. Higher concentrations may damage

fuel system components. Testing has

demonstrated that exceeding the 10 percent

cleaning solution concentration does not improve

the effectiveness of this procedure.

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Important: Vehicles with less than 160 km (100 mi)

on the odometer should not have the injectors cleaned.

These vehicles should have the injectors replaced.

Important: During this procedure you will need a total

of 960 ml (32.4 oz) of cleaning solution. That is

2 tanks of solution for the

J 35800-A

. Other brands of

tools may have a different capacity and would

therefore require more or less tanks to complete the

procedure. You must use all 960 ml (32.4 oz) of

solution to ensure complete injector cleaning.

1. Obtain

J 35800-A

(2).

Important: Make sure the valve at the bottom of the

canister (3) is closed.

2. For US dealers, empty 2 pre-measured GM

Top-Engine Cleaner containers, 24 ml (0.812 oz)

each, GM P/N 12346535, into the

J 35800-A

3. For Canadian dealers, measure and dispense

48 ml (1.62 oz) of Top-Engine Cleaner,

Canadian P/N 992872, into the

J 35800-A

4. If you are using any other brand of tank you will

need a total of 96 ml (3.24 oz) of Top-Engine

Cleaner mixed with 864 ml (29.16 oz) of regular

unleaded gasoline.

5. Fill the injector cleaning tank with regular unleaded

gasoline. Be sure to follow all additional

instructions provided with the tool.

6. Electrically disable the vehicle fuel pump by

removing the fuel pump relay and disconnecting

the oil pressure switch connector, if equipped.

7. Disconnect the fuel feed and return line, if

equipped, at the fuel rail. Plug the fuel feed

and return line, if equipped, coming off the fuel rail

with

J 37287

,or

J 42964-1

, and

J 42964-2

J 42873-1

, and

J 42873-2

as appropriate for the

fuel system.

8. Connect the

J 35800-A

to the vehicle fuel rail.

9. Pressurize the

J 35800-A

to 510 kPa (75 psi).

10. Start and idle the engine until it stalls due to lack

of fuel. This should take approximately 15–

20 minutes.

11. Disconnect

J 35800-A

from the fuel rail.

12. Reconnect the vehicle fuel pump relay and oil

pressure switch connector, if equipped.

13. Remove

J 37287

J 42964-1

, and

J 42964-2

J 42873-1

, and

J 42873-2

and reconnect the

vehicle fuel feed and return lines.

14. Start and idle the vehicle for an additional

2 minutes to ensure residual injector cleaner

is ﬂushed from the fuel rail and fuel lines.

15. Repeat steps 1–5 of the Injector Balance Test,

and record the fuel pressure drop from each

injector.

16. Subtract the lowest fuel pressure drop from the

highest fuel pressure drop. If the value is

15 kPa (2 psi) or less, no additional action is

required. If the value is greater than 15 kPa (2 psi),

replace the injector with the lowest fuel

pressure drop.

EngineControls-6.0LEngine

17. Add one ounce of Port Fuel Injector Cleaner,

GM P/N 12345104 (Canadian P/N 10953467),

to the vehicle fuel tank for each gallon of gasoline

estimated to be in the fuel tank. Instruct the

customer to add the reminder of the bottle of Port

Fuel Injector Cleaner to the vehicle fuel tank at

the next ﬁll-up.

18. Advise the customer to change brands of fuel and

to add GM Port Fuel Injector Cleaner every

5 000 km (3,000 mi). GM Port Fuel Injector

Cleaner contains the same additives that the fuel

companies are removing from the fuel to

reduce costs. Regular use of GM Port Fuel

Injector Cleaner should keep the customer from

having to repeat the injector cleaning procedure.

19. Road test the vehicle to verify that the customer

concern has been corrected.

Fuel Injector Replacement

Tools Required

•

J 34730-1A

Fuel Pressure Gage

•

J 37088-A

Tool Set, Fuel Line Quick Connect

Separator

Removal Procedure

1. Remove the fuel rail assembly. Refer to

Fuel Rail

Assembly Replacement

2. Disconnect the electrical connector (5) for the fuel

injector (7).

3. Remove the retaining clip (6) for the fuel

injector (7).

Notice:

Usecarein

removing the fuel injectors in order to prevent damage

to the fuel injector electrical connector pins or the

fuel injector nozzles. Do not immerse the fuel injector

in any type of cleaner. The fuel injector is an

electrical component and may be damaged by this

cleaning method.

4. Remove the fuel injector (7) from the fuel rail (2).

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EngineEngineControls-6.0L

Installation Procedure

Important: If the fuel injectors are being removed for

the replacement of the fuel rail, it is not necessary

to replace the O-rings on the fuel injector. Replace the

O-rings only if they are damage.

1. Apply a small amount of clean motor oil to the

O-rings (8) and (9), before installing the new

fuel injector.

2. Install the fuel injector (7) in the fuel rail (2).

3. Install the retaining clips for the fuel injector (6).

4. Reconnect the electrical connector (50 for the fuel

injector (7).

5. Install the fuel rail assembly (2). Refer to

Fuel Rail

Assembly Replacement

6. Inspect for leaks:

6.1. Turn the ignition switch ON for 2 seconds.

6.2. Turn the ignition switch OFF for

10 seconds.

6.3. Turn the ignition switch ON.

6.4. Inspect for fuel leaks.

Evaporative Emission (EVAP) Canister

Purge Solenoid Valve Replacement

Removal Procedure

1. Remove the left fuel rail cover.

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2. Disconnect the engine vacuum pipe from the

EVAP canister purge solenoid valve to intake

manifold EVAP pipe.

3. Disconnect the engine purge pipe from the EVAP

canister purge valve.

4. Disconnect the EVAP canister purge valve

harness connector.

5. Remove the EVAP canister purge valve from the

purge bracket.

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Installation Procedure

1. Install the EVAP canister purge valve to the purge

bracket.

2. Connect the harness connector to the EVAP

canister purge valve.

3. Connect the engine purge pipe to the chassis

purge pipe.

4. Connect the engine vacuum pipe to the EVAP

canister purge valve.

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5. Install the left fuel rail cover.

Evaporative Emission (EVAP) Canister

Vent Solenoid Valve Replacement

Removal Procedure

1. Raise the vehicle. Refer to

Lifting and Jacking the

Vehicle

in General Information.

2. Lower the right muffler for automatic transmission

equipped vehicles only. Refer to

Muffler

Replacement - Right

in Engine Exhaust.

3. Disconnect the EVAP canister valve harness

connector.

4. Disconnect the vent hose (2) from the EVAP

canister vent valve (1).

5. Remove the EVAP canister vent valve (2) from

the vent bracket (1).

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Installation Procedure

1. Install the EVAP canister vent valve (2) to the

vent bracket (1).

2. Connect the vent hose (2) to the EVAP canister

vent valve (1).

3. Connect the EVAP vent valve electrical connector.

4. For automatic transmission– equipped vehicles

only, raise the right muffler. Refer to

Muffler

Replacement - Right

in Engine Exhaust.

5. Lower the vehicle.

Evaporative Emission (EVAP) System

Hoses/Pipes Replacement (Vacuum

Supply)

Removal Procedure

Caution: Refer to Fuel and EVAP Pipe Caution in

Cautions and Notices.

1.Removetheenginecover.

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2. Disconnect the quick-connect ﬁttings at the

throttle body (6) and the evaporative

emission (EVAP) canister purge valve (7). Refer

Quick Connect Fitting(s) Service (Plastic

Collar)

3. Remove the EVAP pipe (3).

Installation Procedure

1. Reconnect the EVAP pipe (3) to the throttle

body (6).

2. Reconnect the EVAP pipe (3) to EVAP canister

purge valve (7).

3.Installtheenginecover.

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Evaporative Emission (EVAP) System

Hoses/Pipes Replacement (Engine

Purge Pipe)

Removal Procedure

Caution: Refer to Fuel and EVAP Pipe Caution in

Cautions and Notices.

1. Remove the left engine sight cover.

2. Disconnect the quick-connect ﬁttings at the

evaporative emission (EVAP) canister purge

valve (7). Refer to

Quick Connect Fitting(s)

Service (Plastic Collar)

3. Remove the EVAP pipe (2).

Installation Procedure

1. Install the EVAP pipe (2) to the EVAP canister

purge valve (7).

2. Connect the EVAP pipe (2) to the connection for

the canister at the left rear of the engine.

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3.Installtheenginecover.

Evaporative Emission (EVAP) Hoses/Pipes

Replacement - Engine (Chassis)

For information on replacement of EVAP hoses

refer to Holden VZ Service Information

EngineEngineControls-6.0L

Spark Plug Wire Inspection

Spark plug wire integrity is vital for proper engine

operation. A thorough inspection will be necessary to

accurately identify conditions that may affect engine

operation. Inspect for the following conditions:

1. Correct routing of the spark plug wires. Incorrect

routing may cause cross-ﬁring.

2. Any signs of cracks or splits in the wires.

3. Inspect each boot for the following conditions:

• Tearing

• Piercing

• Arcing

• Carbon tracking

• Corroded terminal

If corrosion, carbon tracking, or arcing are indicated

on a spark plug wire boot or on a terminal, replace the

wire and the component connected to the wire.

EngineEngineControls-6.0L

Spark Plug Wire Replacement

Removal Procedure

1. Disconnect the spark plug wires at each

spark plug:

• Twist each spark plug boot 1/2 turn.

• Pull only on the boot in order to remove the

wire from each spark plug.

2. Disconnect the spark plug wires from the

ignition coil:

• Twist each spark plug boot 1/2 turn.

• Pull only on the boot in order to remove the

wires from the ignition coil.

Installation Procedure

1. Install the spark plug wires at the ignition coil.

2. Install the spark plug wire to each spark plug.

3. Inspect the wires for proper installation:

• Push sideways on each boot in order to inspect

the seating.

• Reinstall any loose boot.

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Spark Plug Inspection

Spark Plug Usage

• Verify that the correct spark plug is installed. An

incorrect spark plug causes driveability conditions.

Refer to

Ignition System Speciﬁcations

for the

correct spark plug.

• Ensure that the spark plug has the correct heat

range. An incorrect heat range causes the

following conditions:

− Spark plug fouling — colder plug

− Pre-ignition causing spark plug and/or engine

damage — hotter plug

Spark Plug Inspection

• Inspect the terminal post (1) for damage.

− Inspect for a bent or broken terminal post (1).

− Test for a loose terminal post (1) by

twisting and pulling the post. The

terminal post (1) should NOT move.

• Inspect the insulator (2) for ﬂashover or carbon

tracking, soot. This is caused by the electrical

charge traveling across the insulator (2) between

the terminal post (1) and ground. Inspect for

the following conditions:

− Inspect the spark plug boot for damage.

− Inspect the spark plug recess area of

the cylinder head for moisture, such as oil,

coolant, or water. A spark plug boot that

is saturated causes arcing to ground.

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EngineEngineControls-6.0L

• Inspect the insulator (2) for cracks. All or part of

the electrical charge may arc through the crack

instead of the electrodes (3, 4).

• Inspect for evidence of improper arcing.

− Measure the gap between the center

electrode (4) and the side electrode (3)

terminals. Refer to

Ignition System

Speciﬁcations

. An excessively-wide electrode

gap can prevent correct spark plug

operation.

− Inspect for the correct spark plug torque.

Refer to

Ignition System Speciﬁcations

Insufficient torque can prevent correct spark

plug operation. An over-torqued spark

plug, causes the insulator (2) to crack.

− Inspect for signs of tracking that occurred

near the insulator tip instead of the center

electrode (4).

− Inspect for a broken or worn side

electrode (3).

− Inspect for a broken, worn, or loose center

electrode (4) by shaking the spark plug.

• A rattling sound indicates internal

damage.

• A loose center electrode (4) reduces the

spark intensity.

− Inspect for bridged electrodes (3, 4). Deposits

on the electrodes reduce or eliminates

the gap.

− Inspect for worn or missing platinum pads on

the electrodes (3, 4), if equipped.

− Inspect for excessive fouling.

• Inspect the spark plug recess area of the cylinder

head for debris. Dirty or damaged threads can

cause the spark plug not to seat correctly during

installation.

Spark Plug Visual Inspection

• Normal operation — Brown to grayish-tan with

small amounts of white powdery deposits are

normal combustion by-products from fuels

with additives.

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• Carbon Fouled — Dry, ﬂuffy black carbon, or soot

caused by the following conditions:

− Rich fuel mixtures

• Leaking fuel injectors

• Excessive fuel pressure

• Restricted air ﬁlter element

• Incorrect combustion

− Reduced ignition system voltage output

• Weak coils

• Worn ignition wires

• Incorrect spark plug gap

− Excessive idling or slow speeds under light

loads can keep spark plug temperatures so

low that normal combustion deposits

may not burn off.

• Deposit Fouling — Oil, coolant, or additives that

include substances such as silicone, very white

coating, reduces the spark intensity. Most powdery

deposits will not effect spark intensity unless

they form into a glazing over the electrode.

Spark Plug Replacement

Removal Procedure

1. Remove the fuel rail covers.

Notice:

Allowthe

engine to cool before removing the spark plugs.

Attempting to remove the spark plugs from a hot

engine may cause the plug threads to seize, causing

damage to cylinder head threads.

Notice:

Cleanthe

spark plug recess area before removing the spark

plug. Failure to do so could result in engine damage

because of dirt or foreign material entering the cylinder

head, or by the contamination of the cylinder head

threads. The contaminated threads may prevent

the proper seating of the new plug. Use a thread

chaser to clean the threads of any contamination.

2. Remove the spark plug wires. Refer to

Spark Plug

Wire Replacement

3. Loosen each spark plug 1 or 2 turns.

4. Brush or use compressed air to remove any dirt

around the spark plugs.

5. Remove the spark plugs one at a time and place

each plug in a tray marked with the corresponding

cylinder numbers.

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EngineEngineControls-6.0L

Installation Procedure

1. Inspect each spark plug gap. Adjust each plug as

needed.

Speciﬁcation

Spark plug gap: 1.016 mm (0.040 in)

2. Hand start the spark plugs in the corresponding

cylinders.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

3. Tighten the spark plugs.

Tighten

• For cylinder head-new: Tighten the spark plugs

to 20 N·m (15 lb ft).

• For cylinder head-all subsequent installations:

Tighten the spark plugs to 15 N·m (11 lb ft).

4. Install the spark plug wires. Refer to

Spark Plug

Wire Replacement

5. Install the fuel rail covers.

Crankshaft Position (CKP) Sensor

Replacement

Removal Procedure

Caution: Refer to Battery Disconnect Caution in

Cautions and Notices.

1. Disconnect the negative battery cable. Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

Caution: Refer to Vehicle Lifting Caution in

Cautions and Notices.

2. Raise the vehicle. Refer to

Lifting and Jacking the

Vehicle

in General Information.

3. Remove the starter. Refer to

Starter Motor

Replacement

in Engine Electrical.

4. Disconnect the crankshaft position (CKP) sensor

electrical connector.

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Important: Clean the area around the CKP before

removal in order to avoid debris from entering the

engine.

5. Remove the CKP sensor retaining bolt.

6. Remove the CKP sensor.

Installation Procedure

1. Install the CKP sensor.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

2. Install the CKP sensor retaining bolt.

Tighten

Tighten the CKP sensor to 25 N·m (18 lb ft).

3. Connect the CKP sensor electrical connector.

4. Install the starter. Refer to

Starter Motor

Replacement

in Engine Electrical.

5. Lower the vehicle.

6. Connect the negative battery cable.

7. Program the transmitters. Refer to

Transmitter

Programming (Domestic)

Transmitter

Programming (Export - Including Canada)

Keyless Entry.

8. Perform the CKP System Variation Learn

Procedure. Refer to

CKP System Variation Learn

Procedure

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Camshaft Position (CMP) Sensor

Replacement

Removal Procedure

1. Remove the generator bracket assembly. Refer to

Generator Bracket Replacement

in Engine

Electrical.

2. Remove the camshaft position sensor mounting

bolts (1).

3. Remove the camshaft position sensor

assembly (4, 5, 6) from the front cover (7).

4. Disconnect the camshaft position sensor jumper

harness (2) and the engine harness (3) electrical

connectors.

5. Remove the camshaft sensor assembly (4, 5, 6).

6. Disconnect camshaft position sensor (5) from

the jumper harness (4).

Installation Procedure

1. Reconnect the camshaft sensor (5) and the

jumper harness (4).

2. Install the O-ring (6) on the camshaft sensor

assembly (4 and 5).

3. Reconnect the camshaft position sensor

assembly (4, 5 and 6) and the engine harness

connector (3).

Important: Before installing the camshaft sensor

assembly, apply a small amount of clean motor oil to

the O-ring (6).

4. Install the camshaft position sensor assembly (4,

5 and 6) in the front cover (7).

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

5. Install the camshaft position sensor

mounting bolts.

Tighten

Tighten the camshaft position mounting bolts

25 N·m (18 lb ft).

6. Install the generator assembly. Refer to

Generator

Bracket Replacement

in Engine Electrical.

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Knock Sensor (KS) Replacement (Left)

Removal Procedure

1. Disconnect the negative battery cable. Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

2. Remove the left exhaust manifold. Refer to

Muffler

Replacement - Left

in Engine Exhaust.

3. Remove the left catalytic convertor. Refer to

Catalytic Converter Replacement (Left)

Catalytic Converter Replacement (Right)

in Engine

Exhaust.

4. Remove the mounting bolt for the knock sensor 1.

5. Disconnect the electrical connector of the knock

sensor from the engine harness (3).

6. Remove the knock sensor (2) from the engine

block (4).

Installation Procedure

1. Reconnect the engine harness (3) and the knock

sensor (2) electrical connectors.

2. Position the knock sensor 2 on the engine

block (4).

3. Install the mounting bolt (1) for the knock sensor 2.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

4. Tighten the knock sensor mounting bolt (1).

Tighten

Tighten the knock sensor mounting bolt to

20 N·m (15 lb ft).

5. Install the left catalytic convertor. Refer to

Catalytic

Converter Replacement (Left)

Catalytic

Converter Replacement (Right)

in Engine Exhaust.

6. Install the left exhaust manifold. Refer to

Muffler

Replacement - Left

in Engine Exhaust.

7. Connect the negative battery cable. Refer to

Battery Negative Cable Disconnect/Connect

Procedure

in Engine Electrical.

8. Program the transmitters. Refer to

Transmitter

Programming (Domestic)

Transmitter

Programming (Export - Including Canada)

Keyless Entry.

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Knock Sensor (KS) Replacement (Right)

Removal Procedure

1. Remove the negative battery cable. Refer to

Battery Negative Cable Replacement

in Engine

Electrical.

2. Remove the right exhaust manifold. Refer to

Exhaust Manifold Replacement - Right

Engine Exhaust.

3. Remove the right catalytic convertor. Refer to

Catalytic Converter Replacement (Left)

Catalytic Converter Replacement (Right)

in Engine

Exhaust.

Important: In the following service procedure, it

maybe necessary to remove the starter assembly to

gain enough clearance to remove the knock sensor.

4. Remove the starter assembly (4), ONLY IF

NEEDED. Refer to

Starter Motor Replacement

Engine Electrical.

5. Remove the knock sensor mounting (1).

6. Remove the knock sensor 2 from the engine

block (5).

7. Disconnect the engine electrical connector (3)

from the knock sensor 2.

8. Remove the knock sensor 2.

Installation Procedure

1. Reconnect electrical connector (3) for the engine

harness to the knock sensor 2.

2. Position the knock sensor 2 on the engine

block (5).

3. Install the mounting bolt (1) for the knock sensor 2.

Notice:

Refer to

Fastener Notice

in Cautions and

Notices.

4. Tighten the knock sensor mounting bolt (1).

Tighten

Tighten the knock sensor mounting

bolt 1 to 20 N·m (15 lb ft).

5. Install the starter assembly (4), ONLY IF

REMOVED. Refer to

Starter Motor Replacement

in Engine Electrical.

6. Install the catalytic convertor. Refer to

Catalytic

Converter Replacement (Left)

Catalytic

Converter Replacement (Right)

in Engine Exhaust.

7. Install the right exhaust manifold. Refer to

Exhaust

Manifold Replacement - Right

in Engine Exhaust.

Important: Perform the following procedure only if the

battery has been disconnected.

8. Program the transmitters. Refer to

Transmitter

Programming (Domestic)

Transmitter

Programming (Export - Including Canada)

Keyless Entry.

9. Install the negative battery cable. Refer to

Battery

Negative Cable Replacement

in Engine Electrical.

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Description and Operation

Engine Control Module (ECM) Description

The powertrain has electronic controls to reduce

exhaust emissions while maintaining excellent

driveability and fuel economy. The engine control

module (ECM) is the control center of this system. The

ECM monitors numerous engine and vehicle

functions. The ECM constantly monitors at the

information from various sensors and other inputs, and

controls the systems that affect vehicle performance

and emissions. The ECM also performs the diagnostic

tests on various parts of the system. The ECM can

recognize operational problems and alert the driver via

the malfunction indicator lamp (MIL). When the

ECM detects a malfunction, the ECM stores a

diagnostic trouble code (DTC). The problem area is

identiﬁed by the particular DTC that is set. The control

module supplies a buffered voltage to various

sensors and switches. Review the components and

wiring diagrams in order to determine which systems

are controlled by the ECM.

Malfunction Indicator Lamp (MIL) Operation

The malfunction indicator lamp (MIL) is located in the

instrument panel cluster. The MIL will display as

either SERVICE ENGINE SOON or one of the

following symbols when commanded ON:

SIO-ID = 801183 LMD = 02-aug-2001

The MIL indicates that an emissions related fault has

occurred and vehicle service is required.

The following is a list of the modes of operation for

the MIL:

• The MIL illuminates when the ignition is turned

ON, with the engine OFF. This is a bulb test

to ensure the MIL is able to illuminate.

• The MIL turns OFF after the engine is started if a

diagnostic fault is not present.

• The MIL remains illuminated after the engine is

started if the control module detects a fault. A

diagnostic trouble code (DTC) is stored any time

the control module illuminates the MIL due to

an emissions related fault. The MIL turns

OFF after three consecutive ignition cycles in

which a Test Passed has been reported for the

diagnostic test that originally caused the MIL

to illuminate.

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• The MIL ﬂashes if the control module detects a

misﬁre condition which could damage the

catalytic converter.

• When the MIL is illuminated and the engine stalls,

the MIL will remain illuminated as long as the

ignition is ON.

• When the MIL is not illuminated and the engine

stalls, the MIL will not illuminate until the ignition

is cycled OFF and then ON.

Throttle Actuator Control (TAC) System

Description

Purpose

The throttle actuator control (TAC) system delivers

improved throttle response and greater reliability and

eliminates the need for mechanical cable. The

TAC system performs the following functions:

• Accelerator pedal position sensing

• Throttle positioning to meet driver and engine

demands

• Throttle position sensing

• Internal diagnostics

• Cruise control functions

• Manage TAC electrical power consumption

The TAC system includes the following components:

• The accelerator pedal position (APP) sensors

• The throttle body assembly

• The engine control module (ECM)

Accelerator Pedal Position (APP) Sensor

The accelerator pedal contains 2 individual APP

sensors within the assembly. The APP sensors 1 and

2 are potentiometer type sensors each with 3 circuits:

• A 5-volt reference circuit

• A low reference circuit

• A signal circuit

The APP sensors are used to determine the pedal

angle. The ECM provides each APP sensor a

5-volt reference circuit and a low reference circuit. The

APP sensors provide the ECM with signal voltage

proportional to the pedal movement. The APP sensor 1

signal voltage at rest position is less than 1 volt and

increases to above 2.5 volts as the pedal is actuated.

The APP sensor 2 signal voltage at rest position is

near the 4 volts and decreases to less than 1 volt as

the pedal is actuated.

Throttle Body Assembly

The throttle assembly contains the following

components:

• The throttle blade

• The throttle actuator motor

• The throttle position (TP) sensor 1 and 2

The throttle body functions similar to a conventional

throttle body with the following exceptions:

• An electric motor opens and closes the

throttle valve.

• The throttle blade is spring loaded in both

directions and the default position is slightly open.

• There are 2 individual TP sensors within the

throttle body assembly.

The TP sensors are used to determine the throttle

plate angle. The TP sensors provide the ECM with a

signal voltage proportional to throttle plate movement.

The TP sensor 1 signal voltage at closed throttle is

above 4 volts and decreases as the throttle plate

is opened. The TP sensor 2 signal voltage at closed

throttle is below 1 volt and increases as the throttle

plate is opened.

Engine Control Module

The ECM is the control center for the TAC system.

The ECM determines the drivers intent and then

calculates the appropriate throttle response. The ECM

achieves throttle positioning by providing a pulse

width modulated voltage to the TAC motor.

Modes of Operation

Normal Mode

During the operation of the TAC system, several

modes or functions are considered normal. The

following modes may be entered during normal

operation:

• Minimum pedal value—At key-up the ECM

updates the learned minimum pedal value.

• Minimum TP values—At key-up the ECM updates

the learned minimum TP value. In order to learn

the minimum TP value, the throttle blade is moved

to the closed position.

• Ice break mode—If the throttle is not able to reach

a predetermined minimum throttle position, the ice

break mode is entered. During the ice break

mode, the ECM commands the maximum pulse

width several times to the throttle actuator motor in

the closing direction.

• Battery saver mode—After a predetermined time

without engine RPM, the ECM commands the

battery saver mode. During the battery saver

mode, the TAC module removes the voltage from

the motor control circuits, which removes the

current draw used to maintain the idle position and

allows the throttle to return to the spring loaded

default position.

Reduced Engine Power Mode

When the ECM detects a condition with the TAC

system, the ECM may enter a reduced engine power

mode. Reduced engine power may cause one or

more of the following conditions:

• Acceleration limiting—The ECM will continue to

use the accelerator pedal for throttle control;

however, the vehicle acceleration is limited.

• Limited throttle mode—The ECM will continue to

use the accelerator pedal for throttle control;

however, the maximum throttle opening is limited.

EngineControls-6.0LEngine

• Throttle default mode—The ECM will turn off the

throttle actuator motor and the throttle will

return to the spring loaded default position.

• Forced idle mode—The ECM will perform the

following actions:

− Limit engine speed to idle by positioning the

throttle position, or by controlling the fuel

and spark if the throttle is turned off.

− Ignore the accelerator pedal input.

• Engine shutdown mode—The ECM will disable

fuel and de-energize the throttle actuator.

Fuel System Description

System Overview

Legend

(1) Fuel Fill Hose

(2) Left Fuel Tank Grade Vent Valve

(3) Fuel Feed Pipe to Engine

(4) 5/16 Inch Auxiliary Fuel Feed Pipe

(5) 3/8 Inch Auxiliary Fuel Return Pipe

(6) Right Fuel Tank Grade Vent Valve

(7) Fill Limiter Vent Valve (FLVV)

(8) Secondary Fuel Pressure Regulator

(9) Siphon Jet Pump

(10) Convoluted Crossover Hose

(11) Anti-siphon Hole

(12) Fuel Sender Reservoir

(13) Turbine Fuel Pump

(14) Venturi Pump

(15) Primary Fuel Pressure Regulator

(16) Reverse Flow Check Valve

(17) Fuel Filter

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EngineEngineControls-6.0L

The fuel system is a returnless on-demand design.

The fuel pressure regulator is a part of the fuel sender

assembly, eliminating the need for a return pipe

from the engine. A returnless fuel system reduces the

internal temperature of the fuel tank by not returning

hot fuel from the engine to the fuel tank. Reducing the

internal temperature of the fuel tank results in lower

evaporative emissions.

Two fuel tanks store the fuel supply. An electric

turbine style fuel pump (13) attaches to the fuel sender

assembly inside the left fuel tank. The fuel pump

supplies high pressure fuel through the fuel ﬁlter (17)

and the fuel feed pipe (3) to the fuel injection

system. The fuel pump provides fuel at a higher rate

of ﬂow than is needed by the fuel injection system. The

fuel pump also supplies fuel to the venturi pump

(14) located on the bottom of the left fuel sender

assembly. The function of the venturi pump is to ﬁll the

fuel sender assembly reservoir (12). The primary

fuel pressure regulator (15), a part of the left

fuel sender assembly, maintains the correct fuel

pressure to the fuel injection system. The fuel pump

and sender assembly contains a reverse ﬂow

check valve (16). The check valve, the primary fuel

pressure regulator, and the secondary fuel pressure

regulator maintain fuel pressure in the fuel feed

pipe and the fuel rail in order to prevent long

cranking times.

The fuel pump also supplies a small amount of

pressurized fuel through the auxiliary fuel feed pipe (4)

to the siphon jet pump (9) inside the right fuel tank.

The pressurized fuel creates a venturi action inside the

siphon jet pump. The venturi action causes the fuel

to be drawn out of the right fuel tank. The fuel transfers

from the right fuel tank to the left fuel tank through

the auxiliary fuel return pipe (5). The auxiliary

fuel return pipe inside the left fuel tank contains an

anti-siphon hole (11) in order to prevent fuel from

siphoning from the left fuel tank into the right fuel tank.

Both the auxiliary fuel feed pipe and the auxiliary

fuel return pipe are located inside the convoluted

stainless steel crossover hose (10).

The right fuel sender assembly contains a secondary

fuel pressure regulator (8). The secondary fuel

pressure regulator has a lower set point than the

primary regulator in order to allow fuel to ﬂow to the

siphon jet pump on the right fuel sender. When

the engine is shut off, the pressure in the feed pipes

immediately drops to the secondary regulator set point.

This prevents the siphon jet pump from operating

and in turn prevents the equalization of the left and

right fuel tanks. The secondary fuel pressure regulator

maintains fuel pressure in the auxiliary fuel feed

pipe which reduces the time to prime the siphon jet

pump. The pressurization also reduces fuel

vaporization and boiling in the auxiliary fuel feed pipe.

Fuel Tanks

The fuel tanks (6, 8) store the fuel for the vehicle. The

fuel tanks are located on the left and right side of

the vehicle in front of the rear wheels. The fuel tanks

are molded from high density polyethylene.

Fuel Tank Fill Pipe and Hose

The fuel tank ﬁll pipe is positioned at the rear of the

vehicle on the left side. A built in restrictor in the

fuel tank ﬁll pipe prevents refueling with leaded fuel.

The fuel tank ﬁll pipe connects to the left fuel tank with

a rubber hose. Fuel transfers to the right fuel tank

during fueling by a stainless steel convoluted crossover

tube/hose which connects the left fuel tank to the

right fuel tank.

Fuel Filler Cap

Notice:

Ifafueltank

ﬁller cap requires replacement, use only a fuel

tank ﬁller cap with the same features. Failure to use

the correct fuel tank ﬁller cap can result in a

serious malfunction of the fuel and EVAP system.

The fuel tank ﬁller pipe has a tethered fuel tank ﬁller

cap. The fuel tank ﬁller cap requires a quarter of a turn

in order to be removed. A torque limiting device

prevents the cap from being over tightened.

Fuel Sender Assembly

A fuel sender assembly is located inside each fuel

tank. The fuel sender assembly attaches to the top of

each fuel tank. The left fuel sender assembly

consists of the following major components:

• The fuel level sensor

• The fuel pump and reservoir assembly

• The fuel pump strainer

• The fuel ﬁlter (4)

• The primary fuel pressure regulator (9)

The right fuel sender assembly consists of the

following major components:

• The fuel level sensor (7)

• The siphon jet pump (5)

• The secondary fuel pressure regulator (2)

• The ﬁll limiter vent valve (FLVV)

Fuel Level Sensor

The fuel level sensor consists of a ﬂoat, a wire ﬂoat

arm, and a variable resistor. The position of the

ﬂoat arm indicates the fuel level. The fuel level sensor

contains a variable resistor, which changes the

resistance corresponding to the amount of fuel in the

fuel tanks. The PCM uses inputs from both fuel

level sensors in order to calculate the total fuel

remaining in both fuel tanks. This information is sent

via a Class 2 message to the instrument panel

cluster (IPC) to be displayed on the fuel gage.

Fuel Pump

An electric turbine style fuel pump attaches to the fuel

sender assembly inside the left fuel tank. The fuel

pump supplies fuel to the fuel rail assembly at

a speciﬁed ﬂow and pressure. The fuel pump delivers

a constant ﬂow of fuel to the engine even during

low fuel conditions and aggressive vehicle maneuvers.

The PCM controls the electric fuel pump operation

through a fuel pump relay.

The fuel pump also supplies a small amount of

pressurized fuel to the right fuel tank siphon jet pump

through the auxiliary fuel feed pipe. The pressurized

fuel creates a venturi action inside the siphon jet pump.

The venturi action causes the fuel to be drawn out

of the right fuel tank. Fuel is then transferred from the

right fuel tank to the left fuel tank through the

auxiliary fuel return pipe. The fuel pump also supplies

fuel to a venturi pump located on the bottom of the

left fuel sender assembly. The function of the venturi

pump is to ﬁll the fuel sender assembly reservoir.

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Fuel Strainer

The fuel strainer is made of woven plastic. The

functions of the fuel strainer are to ﬁlter the

contaminants and to wick the fuel. The fuel strainer

attaches to the bottom of the fuel pump inside of

the fuel sender reservoir. The fuel strainer normally

requires no maintenance. Fuel stoppage at this

point indicates that the fuel tanks contain an abnormal

amount of sediment. If the fuel strainer is plugged,

refer to

Fuel System Cleaning

Fuel Filter

The fuel ﬁlter is contained in the fuel sender assembly

inside the left fuel tank. The paper ﬁlter element of

the fuel ﬁlter traps particles in the fuel that may

damage the fuel injection system. The fuel ﬁlter

housing is made to withstand maximum fuel system

pressure, exposure to fuel additives, and changes

in temperature. There is no service interval for

fuel ﬁlter replacement.

Primary Fuel Pressure Regulator

The primary fuel pressure regulator is contained in the

left fuel sender assembly. The fuel pressure regulator

is a diaphragm relief valve. The diaphragm has

fuel pressure on one side and regulator spring

pressure on the other side. A software bias

compensates the injector on-time because the fuel

pressure regulator is not referenced to the manifold

vacuum. The primary fuel pressure regulator

keeps fuel available to the injectors at a regulated

pressure.

Secondary Fuel Pressure Regulator

The right fuel sender assembly contains a secondary

fuel pressure regulator. The secondary fuel pressure

regulator has a lower set point than the primary

regulator in order to allow fuel to ﬂow to the siphon jet

pump on the right fuel sender. When the engine is

shut off, the pressure in the feed pipes immediately

drops to the secondary regulator set point. This

prevents the siphon jet pump from operating and in

turn prevents the equalization of the left and right fuel

tanks. The secondary fuel pressure regulator

maintains fuel pressure in the auxiliary fuel feed pipe

which reduces the time to prime the siphon jet

pump. The pressurization also reduces fuel

vaporization and boiling in the auxiliary fuel feed pipe.

Fuel Feed and Return Pipes

The engine compartment connecting fuel pipe

connects the chassis fuel pipe to the fuel rail assembly.

The engine compartment fuel pipe is constructed of

Teﬂon

with a braided stainless steel covering.

The chassis fuel pipe is located under the vehicle on

the left side of the tunnel. The chassis fuel pipe

connects the rear fuel feed pipe from the left fuel

sender assembly to the engine compartment

connecting fuel pipe. The chassis fuel pipe is

constructed of aluminum with a plastic coating.

The rear fuel feed pipe connects the left fuel sender

fuel pipe to the chassis fuel pipe. The rear fuel

feed pipe is constructed of nylon with a covering of

heat resistant rubber hose.

The auxiliary fuel feed pipes and the auxiliary fuel

return pipes are located inside of the fuel crossover

hose and inside of each fuel tank. The fuel pump

supplies fuel through the auxiliary fuel feed pipe to the

siphon jet pump inside the right fuel tank. The

siphon jet pump transfers fuel from the right fuel tank

to the left fuel tank through the auxiliary fuel return

pipe. The return pipe feeds returning fuel from the right

fuel tank directly into the left fuel sender reservoir.

The auxiliary fuel feed and return pipes are

constructed of nylon.

The fuel tank crossover tube/hose is comprised of a

convoluted stainless steel outer tubing. The crossover

tube/hose internally houses the auxiliary fuel feed

pipe and the auxiliary fuel return pipe. The crossover

tube/hose has the following functions:

• Fuel liquid and vapor transfer during refueling

• High pressure siphon jet pump feed

• Low pressure siphon jet pump return

• Electrostatic discharge ground to body

Nylon Fuel Pipes

Caution:Inorderto

reduce the risk of ﬁre and personal injury observe

the following items:

•

Replace all nylon fuel pipes that are nicked,

scratched or damaged during installation,

do not attempt to repair the sections of

the nylon fuel pipes

•

Do not hammer directly on the fuel harness

body clips when installing new fuel pipes.

Damage to the nylon pipes may result in

a fuel leak.

•

Always cover nylon vapor pipes with a wet

towel before using a torch near them. Also,

never expose the vehicle to temperatures

higher than 115°C (239°F) for more than

one hour, or more than 90°C (194°F) for any

extended period.

•

Apply a few drops of clean engine oil to the

male pipe ends before connecting fuel pipe

ﬁttings. This will ensure proper reconnection

and prevent a possible fuel leak. (During

normal operation, the O-rings located in the

female connector will swell and may prevent

proper reconnection if not lubricated.)

Nylon pipes are constructed to withstand maximum

fuel system pressure, exposure to fuel additives, and

changes in temperature. There are 2 sizes of nylon

fuel pipes used. A 9.53 mm (3/8 in) ID pipe is used for

the fuel feed pipe and the auxiliary fuel return pipe.

A 7.94 mm (5/16 in) ID pipe is used for the auxiliary

fuel feed pipe. Heat resistant rubber hose protects the

section of the rear fuel feed pipe that is exposed to

chaﬁng, high temperature or vibration.

Nylon fuel pipes are somewhat ﬂexible and can be

formed around gradual turns under the vehicle.

However, if nylon fuel pipes are forced into sharp

bends, the pipes will kink and restrict the fuel

ﬂow. Also, once exposed to the fuel, nylon pipes may

become stiffer and are more likely to kink if bent

too far. Take special care when working on a vehicle

with nylon fuel pipes.

Quick-Connect Fittings

Quick-connect ﬁttings provide a simpliﬁed means of

installing and connecting fuel system components. The

ﬁttings consist of a unique female connector and a

compatible male pipe end. O-rings located inside the

female connector provide the fuel seal. Integral

locking tabs located inside the female connector hold

the ﬁttings together.

On-Board Refueling Vapor Recovery

System (ORVR)

The on-board refueling vapor recovery system (ORVR)

is an on board vehicle system designed to recover

fuel vapors during the vehicle refueling operation. The

ﬂow of liquid fuel down the fuel ﬁller pipe provides

a liquid seal which prevents vapor from leaving the fuel

ﬁller pipe. An EVAP pipe transports the fuel vapor to

the EVAP canister for use by the engine. Listed below

are the ORVR system components with a brief

description of their operation:

• The EVAP canister (1)—the EVAP canister

receives refueling vapor from the fuel system,

stores the vapor and releases the vapor to

the engine upon demand.

• The EVAP pipes (2)—transports fuel vapor from

the fuel tank to the EVAP canister.

• The fuel ﬁller pipe (3)—the pipe which carries fuel

from the fuel nozzle to the fuel tank.

• The check valve (4)—the check valve limits fuel

“spit back” from the fuel tank during the refueling

operation by allowing fuel ﬂow only into the

fuel tank. This check valve is located at the bottom

of the fuel ﬁller pipe.

• The modular fuel sender assembly (5)—this

assembly pumps fuel to the engine from the

fuel tank.

• The ﬁll limiter vent valve (FLVV) (6)—this valve

acts as a shut off valve. The FLVV is located

on the right fuel sender. This valve is not serviced

separately. The FLVV has the following functions:

− Controls the fuel tank ﬁll level by closing the

primary vent from the fuel tank.

− Prevents the fuel from exiting the fuel tank

via the EVAP pipe to the canister.

− Provides fuel-spillage protection in the event

of a vehicle rollover by closing the vapor

path from the fuel tank to the EVAP canister.

Fuel Rail Assembly

The fuel rail assembly attaches to the engine intake

manifold. The fuel rail assembly performs the following

functions:

• Positions the injectors (1) in the intake manifold

• Distributes the fuel evenly to the injectors

• Integrates the fuel pulse dampener (2) into the

fuel metering system

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Fuel Injectors

The fuel injector assembly is a solenoid device,

controlled by the PCM, that meters pressurized fuel to

a single engine cylinder. The PCM energizes the

injector solenoid to open a normally closed ball valve.

This allows the fuel to ﬂow into the top of the

injector, past the ball valve, and through a director

plate at the injector outlet. The director plate has

machined holes that control the fuel ﬂow, generating a

spray of ﬁnely-atomized fuel at the injector tip. Fuel

from the injector tip is directed at the intake valve,

causing the fuel to become further atomized and

vaporized before entering the combustion chamber.

This ﬁne atomization improves fuel economy and

emissions.

Fuel Metering Modes of Operation

The PCM monitors voltages from several sensors in

order to determine how much fuel to give the

engine. The PCM controls the amount of fuel delivered

to the engine by changing the fuel injector pulse

width. The fuel is delivered under one of

several modes.

Starting Mode

When the ignition is ﬁrst turned ON, the PCM

energizes the fuel pump relay for 2 seconds. This

allows the fuel pump to build pressure in the fuel

system. The PCM calculates the air/fuel ratio based

on inputs from the engine coolant temperature (ECT),

mass air ﬂow (MAF), manifold absolute

pressure (MAP), and throttle position (TP) sensors.

The system stays in starting mode until the engine

speed reaches a predetermined RPM.

Clear Flood Mode

If the engine ﬂoods, clear the engine by pressing the

accelerator pedal down to the ﬂoor and then crank

the engine. When the TP sensor is at wide open

throttle (WOT), the PCM reduces the fuel injector pulse

width in order to increase the air to fuel ratio. The

PCM holds this injector rate as long as the throttle

stays wide open and the engine speed is below

a predetermined RPM. If the throttle is not held wide

open, the PCM returns to the starting mode.

Run Mode

The run mode has 2 conditions called Open Loop and

Closed Loop. When the engine is ﬁrst started and

the engine speed is above a predetermined RPM, the

system begins Open Loop operation. The PCM

ignores the signal from the heated oxygen sensors

(HO2S). The PCM calculates the air/fuel ratio

based on inputs from the ECT, MAF, MAP, and TP

sensors. The system stays in Open Loop until meeting

the following conditions:

• Both front HO2S have varying voltage output,

showing that both HO2S are hot enough to

operate properly.

• The ECT sensor is above a speciﬁed temperature.

• A speciﬁc amount of time has elapsed after

starting the engine.

Speciﬁc values for the above conditions exist for each

different engine, and are stored in the electrically

erasable programmable read-only memory (EEPROM).

The system begins Closed Loop operation after

reaching these values. In Closed Loop, the PCM

calculates the air/fuel ratio, injector ON time, based

upon the signal from various sensors, but mainly from

the HO2S. This allows the air/fuel ratio to stay very

close to 14.7:1.

Acceleration Mode

When the driver pushes on the accelerator pedal, air

ﬂow into the cylinders increases rapidly. To prevent

possible hesitation, the PCM increases the pulse width

to the injectors to provide extra fuel during

acceleration. This is also known as power enrichment.

The PCM determines the amount of fuel required

based upon the TP, the ECT, the MAP, the MAF, and

the engine speed.

Deceleration Mode

When the driver releases the accelerator pedal, air

ﬂow into the engine is reduced. The PCM monitors the

corresponding changes in the TP, the MAP, and the

MAF. The PCM shuts OFF fuel completely if the

deceleration is very rapid, or for long periods, such as

long, closed-throttle coast-down. The fuel shuts

OFF in order to prevent damage to the catalytic

converters.

Battery Voltage Correction Mode

When the battery voltage is low, the PCM

compensates for the weak spark delivered by the

ignition system in the following ways:

• Increasing the amount of fuel delivered

• Increasing the idle RPM

• Increasing the ignition dwell time

Fuel Cutoff Mode

The PCM cuts OFF fuel from the fuel injectors when

the following conditions are met in order to protect the

powertrain from damage and improve driveability:

• The ignition is OFF. This prevents engine run-on.

• The ignition is ON but there is no ignition

reference signal. This prevents ﬂooding or

backﬁring.

• The engine speed is too high, above red line.

• The vehicle speed is too high, above rated

tire speed.

• During an extended, high speed, closed throttle

coast down—This reduces emissions and

increases engine braking.

• During extended deceleration, in order to prevent

damage to the catalytic converters

Fuel Trim

The PCM controls the air/fuel metering system in

order to provide the best possible combination

of driveability, fuel economy, and emission control.

The PCM monitors the HO2S signal voltage while in

Closed Loop and regulates the fuel delivery by

adjusting the pulse width of the injectors based on this

signal. The ideal fuel trim values are around 0 percent

for both short and long term fuel trim. A positive

fuel trim value indicates the PCM is adding fuel in

EngineControls-6.0LEngine

order to compensate for a lean condition by increasing

the pulse width. A negative fuel trim value indicates

that the PCM is reducing the amount of fuel in order to

compensate for a rich condition by decreasing the

pulse width. A change made to the fuel delivery

changes the long and short term fuel trim values. The

short term fuel trim values change rapidly in

response to the HO2S signal voltage. These changes

ﬁne tune the engine fueling. The long term fuel trim

makes coarse adjustments to fueling in order to

re-center and restore control to short term fuel trim. A

Tech 2 canbeusedtomonitortheshortand

long term fuel trim values. The long term fuel trim

diagnostic is based on an average of several of the

long term speed load learn cells. The PCM selects the

cells based on the engine speed and engine load. If

the PCM detects an excessively lean or rich condition,

the PCM will set a fuel trim diagnostic trouble

code (DTC).

Evaporative Emission (EVAP) Control

System Description

EVAP System Operation

The evaporative emission (EVAP) control system limits

fuel vapors from escaping into the atmosphere. Fuel

tank vapors are allowed to move from the fuel

tank, due to pressure in the tank, through the vapor

pipe, into the EVAP canister. Carbon in the canister

absorbs and stores the fuel vapors. Excess pressure is

vented through the vent line and EVAP vent solenoid

valve to the atmosphere. The EVAP canister stores

the fuel vapors until the engine is able to use them. At

an appropriate time, the control module will command

the EVAP purge solenoid valve ON, allowing engine

vacuum to be applied to the EVAP canister. With

the EVAP vent solenoid valve OFF, fresh air is drawn

through the vent solenoid valve and the vent line to

the EVAP canister. Fresh air is drawn through

the canister, pulling fuel vapors from the carbon. The

air/fuel vapor mixture continues through the EVAP

purge pipe and EVAP purge solenoid valve into

the intake manifold to be consumed during normal

combustion. The control module uses several tests to

determine if the EVAP system is leaking.

Large Leak Test

This tests for large leaks and blockages in the

evaporative emission (EVAP) system. The control

module commands the EVAP vent solenoid valve ON

and commands the EVAP purge solenoid valve

ON, with the engine running, allowing engine vacuum

into the EVAP system. The control module monitors

the fuel tank pressure (FTP) sensor voltage to

verify that the system is able to reach a predetermined

level of vacuum within a set amount of time. The

control module then commands the EVAP purge

solenoid valve OFF, sealing the system, and monitors

the vacuum level for decay. If the control module

does not detect that the predetermined vacuum level

was achieved, or the vacuum decay rate is more

than a calibrated level on 2 consecutive tests,

DTC P0455 will set.

Small Leak Test

The engine off natural vacuum (EONV) diagnostic is

the small-leak detection diagnostic for the evaporative

emission (EVAP) system. While previous leak

detection methods were performed with the engine

running, the EONV diagnostic monitors the EVAP

system pressure or vacuum with the ignition OFF.

Because of this, it may be normal for the control

module to remain active for up to 40 minutes after the

ignition is turned OFF. This is important to remember

when performing a parasitic draw test on vehicles

equipped with EONV.

The EONV utilizes the temperature changes in the

fuel tank immediately following a drive cycle to use the

naturally occurring vacuum or pressure in the fuel

tank. When the vehicle is driven, the temperature rises

in the tank. After the vehicle is parked, the temperature

in the tank continues to rise for a period of time,

then starts to drop. The EONV diagnostic relies on

this temperature change and the corresponding

pressure change in a sealed system, to determine if

an EVAP system leak is present.

The EONV diagnostic is designed to detect leaks as

small as 0.51 mm (0.020 in). The diagnostic can

determine if a small leak is present based on vacuum

or pressure readings in the EVAP system. When

the system is sealed, a ﬁnite amount of pressure or

vacuum will be observed. When a 0.51 mm (0.020 in)

leak is present, often little or no pressure or vacuum

is observed. If the test reports a failing value,

DTC P0442 will set.

Canister Vent Restriction Test

If the evaporative emission (EVAP) vent system is

restricted, fuel vapors will not be properly purged from

the EVAP canister. The control module tests this by

commanding the EVAP purge solenoid valve ON,

commanding the EVAP vent solenoid valve OFF, and

monitoring the fuel tank pressure (FTP) sensor for

an increase in vacuum. If the vacuum increases more

than a calibrated value, DTC P0446 will set.

Purge Solenoid Valve Leak Test

If the evaporative emission (EVAP) purge solenoid

valve does not seal properly fuel vapors could

enter the engine at an undesired time, causing

driveability concerns. The control module tests for this

by commanding the EVAP purge solenoid valve

OFF and the vent solenoid valve ON, sealing the

system, and monitors the fuel tank pressure (FTP) for

an increase in vacuum. If the control module detects

that the EVAP system vacuum increases above a

calibrated value, DTC P0496 will set.

Check Gas Cap Message

The powertrain control module (PCM) sends a class 2

message to the driver information center (DIC)

illuminating the Check Gas Cap message when any of

the following occur:

• A malfunction in the evaporative emission (EVAP)

system and a large leak test fails

• A malfunction in the EVAP system and a small

leak test fails

EngineEngineControls-6.0L

EVAP System Components

The evaporative emission (EVAP) system consists of

the following components:

EVAP Canister

The canister is ﬁlled with carbon pellets used to

absorb and store fuel vapors. Fuel vapor is stored in

the canister until the control module determines

that the vapor can be consumed in the normal

combustion process.

EVAP Purge Solenoid Valve

The EVAP purge solenoid valve controls the ﬂow of

vapors from the EVAP system to the intake manifold.

The purge solenoid valve opens when commanded

ON by the control module. This normally closed valve

is pulse width modulated (PWM) by the control

module to precisely control the ﬂow of fuel vapor to

the engine. The valve will also be opened during some

portions of the EVAP testing, allowing engine

vacuum to enter the EVAP system.

EVAP Vent Solenoid Valve

The EVAP vent solenoid valve controls fresh airﬂow

into the EVAP canister. The valve is normally

open. The control module commands the valve ON,

closing the valve during some EVAP tests, allowing the

system to be tested for leaks.

Fuel Tank Pressure Sensor

The fuel tank pressure (FTP) sensor measures the

difference between the pressure or vacuum in the fuel

tank and outside air pressure. The control module

provides a 5-volt reference and a ground to the FTP

sensor. The FTP sensor provides a signal voltage back

to the control module that can vary between 0.1–

4.9 volts. A high FTP sensor voltage indicates a low

fuel tank pressure or vacuum. A low FTP sensor

voltage indicates a high fuel tank pressure.

EVAP Service Port

The EVAP service port is located in the EVAP purge

pipe between the EVAP purge solenoid valve and

the EVAP canister. The service port is identiﬁed by a

green colored cap.

Electronic Ignition (EI) System Description

The electronic ignition (EI) system is responsible for

producing and controlling a high energy secondary

spark. This spark is used to ignite the compressed

air/fuel mixture at precisely the correct time. This

provides optimal performance, fuel economy,

and control of exhaust emissions. This ignition system

consists of a separate ignition coil connected to

each spark plug by a short secondary wire. The driver

modules within each coil assembly are commanded

ON/OFF by the engine control module (ECM).

The ECM primarily uses engine speed and position

information from the crankshaft and camshaft

position (CMP) sensors to control the sequence, dwell,

and timing of the spark event. The EI system

consists of the following components:

Crankshaft Position (CKP) Sensor

The crankshaft position (CKP) sensor is a three wire

sensor based on the magneto resistive principle.

A magneto resistive sensor uses two magnetic pickups

between a permanent magnet. As an element such

as a reluctor wheel passes the magnets the resulting

change in the magnetic ﬁeld is used by the sensor

electronics to produce a digital output pulse. The ECM

supplies a 12-volt, low reference, and signal circuit

to the CKP sensor. The sensor returns a digital

ON/OFF pulse 24 times per crankshaft revolution.

Crankshaft Reluctor Wheel

The crankshaft reluctor wheel is mounted on the rear

of the crankshaft. The wheel is comprised of

four 90 degree segments. Each segment represents a

pair of cylinders at TDC, and is further divided into

six 15 degree segments. Within each 15 degree

segment is a notch of 1 of 2 different sizes. Each

90 degree segment has a unique pattern of notches.

This is known as pulse width encoding. This pulse

width encoded pattern allows the ECM to quickly

recognize which pair of cylinders are at top dead

center (TDC). The reluctor wheel is also a dual track-or

mirror image-design. This means there is an

additional wheel pressed against the ﬁrst, with a gap

of equal size to each notch of the mating wheel.

When one sensing element of the CKP sensor is

reading a notch, the other is reading a set of teeth. The

resulting signals are then converted into a digital

square wave output by the circuitry within the CKP

sensor.

Camshaft Position (CMP) Sensor

The CMP sensor is also a magneto resistive sensor,

with the same type of circuits as the CKP sensor. The

CMP sensor signal is a digital ON/OFF pulse, output

once per revolution of the camshaft. The CMP

sensor information is used by the ECM to determine

the position of the valve train relative to the CKP.

Camshaft Reluctor Wheel

The camshaft reluctor wheel is either pressed onto the

camshaft or part of the camshaft gear depending on

the application. The feature-or target- is read in a radial

or axial fashion respectively. The wheel is a smooth

track, half of which is of a lower proﬁle than the other

half. This feature allows the CMP sensor to supply

a signal as soon as the key is turned ON, since

the CMP sensor reads the track proﬁle, instead of

a notch.

Ignition Coils

Each ignition coil has an ignition 1 voltage feed and a

ground. The ECM supplies a low reference and an

ignition control (IC) circuit. Each ignition coil contains a

solid state driver module. The ECM will command

the IC circuit ON, this allows the current to ﬂow

through the primary coil windings for the appropriate

time or dwell. When the ECM commands the IC circuit

OFF, this will interrupt current ﬂow through the

primary coil windings. The magnetic ﬁeld created by

EngineControls-6.0LEngine

the primary coil windings will collapse across the

secondary coil windings, which induces a high voltage

across the spark plug electrodes. The coils are

current limited to prevent overloading if the IC current

is held high too long. The spark plugs are connected

to their respective coils by a short secondary wire. The

spark plugs are tipped with iridium for long life and

efficiency.

Engine Control Module (ECM)

The ECM controls all ignition system functions, and

constantly corrects the basic spark timing. The

ECM monitors information from various sensor inputs

that include the following:

• The throttle position (TP) sensor

• The engine coolant temperature (ECT) sensor

• The mass air ﬂow (MAF) sensor

• The intake air temperature (IAT) sensor

• The vehicle speed sensor (VSS)

• The transmission gear position or range

information sensors

• The engine knock sensors (KS)

Modes of Operation

There is one normal mode of operation, with the spark

under ECM control. If the CKP pulses are lost the

engine will not run. The loss of a CMP signal

may result in a longer crank time since the ECM

cannot determine which stroke the pistons are

on. Diagnostic trouble codes are available to

accurately diagnose the ignition system with a

Tech 2 .

Knock Sensor (KS) System Description

Purpose

The knock sensor (KS) system enables the control

module to control the ignition timing for the best

possible performance while protecting the engine from

potentially damaging levels of detonation. The

control module uses the KS system to test for

abnormal engine noise that may indicate detonation,

also known as spark knock.

Sensor Description

This knock sensor (KS) system uses one or two ﬂat

response 2-wire sensors. The sensor uses

piezo-electric crystal technology that produces an AC

voltage signal of varying amplitude and frequency

based on the engine vibration or noise level. The

control module receives the KS signal through a signal

circuit. The KS ground is supplied by the control

module through a low reference circuit.

The control module learns a minimum noise level, or

background noise, at idle from the KS and uses

calibrated values for the rest of the RPM range. The

control module uses the minimum noise level to

calculate a noise channel. A normal KS signal will ride

within the noise channel. As engine speed and load

change, the noise channel upper and lower parameters

will change to accommodate the normal KS signal,

keeping the signal within the channel. In order

to determine which cylinders are knocking, the control

module only uses KS signal information when each

cylinder is near top dead center (TDC) of the

ﬁring stroke. If knock is present, the signal will range

outside of the noise channel.

If the control module has determined that knock is

present, it will retard the ignition timing to attempt to

eliminate the knock. The control module will always try

to work back to a zero compensation level, or no

spark retard. An abnormal KS signal will stay outside

of the noise channel or will not be present. KS

diagnostics are calibrated to detect faults with the KS

circuitry inside the control module, the KS wiring,

or the KS voltage output. Some diagnostics are also

calibrated to detect constant noise from an outside

inﬂuence such as a loose/damaged component

or excessive engine mechanical noise.

Air Intake System Description

The primary function of the air intake system is to

provide ﬁltered air to the engine. The system uses a

cleaner element mounted in a housing. The cleaner

housing is remotely mounted and uses intake ducts to

route the incoming air into the throttle body. The

secondary function of the air intake system is to muffle

air induction noise. This is achieved through the use

of resonators attached to the air intake ducts. The

resonators are tuned to the speciﬁc powertrain. The

mas air ﬂow (MAF) sensor is used to measure

the air entering the engine.

EngineEngineControls-6.0L

Special Tools and Equipment

Illustration Tool Number/Description

82243

J 22610

Service Boot Clamp

5386

J 23738-A

Vacuum Pump

5381

J 26792

Spark Tester

5382

J 34142-B

Test Light

5389

J 34730-1A

Fuel Pressure Gauge

Illustration Tool Number/Description

5390

J 34730-2C

Injector Test Light (EFI Lite)

8917

J 35616-A

Connector Test Adapter Kit

821470

J 35800-A

Fuel Injector Cleaner

1025

J 36169–A

Fused Jumper Wire

12366

J 37088-A

Fuel Line Quick Connect

Separator

EngineControls-6.0LEngine

Illustration Tool Number/Description

13541

J 37287

Inlet and Return Fuel Line

Shut off Adapters

5380

J 39021

Fuel Injector Coil/Balance

Tester

3430

J 39200

Digital Multimeter

16891

J 39765

Fuel Sender Lock Nut

Wrench

825000

J 41413–200

Evaporative Emissions

System Tester (EEST)

Illustration Tool Number/Description

829182

J 41413–SPT

High Intensity White Light

1161160

J 41413–306

EVAP Plug

1161161

J 41413–307

EVAP Plug

1174862

J 41413–311

EVAP Plug

829198

J 41413–VLV

EVAP Service Port Vent

Fitting

EngineEngineControls-6.0L

Illustration Tool Number/Description

254302

J 41415–40

Fuel Tank Cap Adapter

69758

J 41416

Ultrasonic Leak Detector

208072

J 42236-A

Serial Data Link Test

624560

J 42598

Vehicle Data Recorder

Illustration Tool Number/Description

696431

J 43244

Relay Puller Pliers

677554

J 44175

Fuel Composition Tester

793709

J 45004

Fuel Tank Drain Hose

50062

Tech 2 Kit

7000081

EngineControls-6.0LEngine