SECTION 6D1 - 3.5L ENGINE DRIVEABILITY AND

EMISSIONS

Specifications

Tightening Specifications

Diagrams and Schematics

PCM Wiring Diagram (1 of 7)

PCM Wiring Diagram (2 of 7)

PCM Wiring Diagram (3 of 7)

PCM Wiring Diagram (4 of 7)

PCM Wiring Diagram (5 of 7)

PCM Wiring Diagram (6 of 7)

PCM Wiring Diagram (7 of 7)

PCM Pinouts

PCM Pinout Table, 32-Way Red Connector –

Row “A”

PCM Pinout Table, 32-Way Red Connector –

Row “B”

PCM Pinout Table, 32-Way White Connector –

Row “C”

PCM Pinout Table, 32-Way White Connector –

Row “D”

PCM Pinout Table, 32-Way Blue Connector –

Row “E”

PCM Pinout Table, 32-Way Blue Connector –

Row “F”

Component Locators

Engine Component Locator

Undercarriage Component Locator

Fuse and Relay Panel (Underhood Electrical Center)

Sensors and Miscellaneous Component Locator

Diagnosis

Strategy-Based Diagnostics

DTC Stored

No DTC

No Matching Symptom

Intermittents

No Trouble Found

Verifying Vehicle Repair

General Service Information

OBD Serviceablity Issues

Maintenance Schedule

Visual / Physical Engine Compartment

Inspection

Basic Knowledge of Tools Required

Serial Data Communications

Class II Serial Data Communications

On-Board Diagnostic (OBD)

On-Board Diagnostic Tests

Comprehensive Component Monitor Diagnostic

Operation

Common OBD Terms

The Diagnostic Executive

DTC Types

Verifying Vehicle Repair

Reading Diagnostic Trouble Codes Using A

Tech 2

Using Tech 2 On The Vehicle

Connecting TECH 2 To The Vehicle

Powertrain Application Menu

3.2l V6 6VE1 Engine Functions

Primary System-Based Diagnostic

Fuel Control Heated Oxygen Sensor

HO2S Heater

Fuel Trim System Monitor Diagnostic Operation

Fuel Trim Cell Diagnostic Weights

On-Board Diagnostic (OBD) System Check

A/C Clutch Control Circuit Diagnosis

Electronic Ignition System Diagnosis

Fuel Metering System Check

Idle Air Control (IAC) Valve

Fuel System Pressure Test

Fuel Injector Coil Test Procedure and Fuel Injector

Balance Test Procedure

Injector Coil Test Procedure (Steps 1-6) and Injector

Balance Test Procedure (Steps 7-11)

Knock Sensor Diagnosis

Powertrain Control Module (PCM) Diagnosis

Multiple PCM Information Sensor DTCS Set

Exhaust Gas Recirculation (EGR) Diagnosis

Engine Tech 2 Data Definitions and Ranges

Typical Scan Data Values

No Malfunction Indicator Lamp (MIL)

Malfunction Indicator Lamp (MIL) “ON”Steady

Engine Cranks But Will Not Run

Fuel System Electrical Test

Fuel System Diagnosis

Idle Air Control (IAC) System Check

Knock Sensor (KS) System Check (Engine Knock, Poor

Performance, or Poor Economy)

Exhaust Gas Recirculation (EGR) System Check

Manifold Absolute Pressure (MAP) Output Check

PCM Diagnostic Trouble Codes

Diagnostic Trouble Code (DTC) P0101 MAF

System Performance

Diagnostic Trouble Code (DTC) P0102 MAF

Sensor Circuit Low Frequency

Diagnostic Trouble Code (DTC) P0103 MAF

Sensor Circuit High Frequency

Diagnostic Trouble Code (DTC) P0107 MAP

Sensor Circuit Low Voltage

Diagnostic Trouble Code (DTC) P0108 MAP

Sensor Circuit High Voltage

Diagnostic Trouble Code (DTC) P0112 IAT

Sensor Circuit Low Voltage

Diagnostic Trouble Code (DTC) P0113 IAT

Sensor Circuit High Voltage

Diagnostic Trouble Code (DTC) P0117 ECT

Sensor Circuit Low Voltage

Diagnostic Trouble Code (DTC) P0118 ECT

Sensor Circuit High Voltage

Diagnostic Trouble Code (DTC) P0121 TP

System Performance

Diagnostic Trouble Code (DTC) P0122 TP

Sensor Circuit Low Voltage

Diagnostic Trouble Code (DTC) P0123 TP

Sensor Circuit High Voltage

Diagnostic Trouble Code (DTC) P0131

HO2S Circuit Low Voltage Bank 1 Sensor 1

Diagnostic Trouble Code (DTC) P0132 HO2S

Circuit High Voltage Bank 1 Sensor 1

Diagnostic Trouble Code (DTC) P0134 HO2S

Circuit Insufficient Activity Bank 1 Sensor 1

Diagnostic Trouble Code (DTC) P0151 HO2S

Circuit Low Voltage Bank 2 Sensor 1

Diagnostic Trouble Code (DTC) P0152 HO2S

Circuit HIGH Voltage Bank 2 Sensor 1

Diagnostic Trouble Code (DTC) P0171 Fuel

Trim System Lean Bank 1

Diagnostic Trouble Code (DTC) P0172 Fuel

Trim System Rich Bank 1

Diagnostic Trouble Code (DTC) P0174 Fuel

Trim System Lean Bank 2

Diagnostic Trouble Code (DTC) P0175 Fuel

Trim System Rich Bank 2

Diagnostic Trouble Code (DTC) P0201

Injector 1 Control Circuit

Diagnostic Trouble Code (DTC) P0202

Injector 2 Control Circuit

Diagnostic Trouble Code (DTC) P0203

Injector 3 Control Circuit

Diagnostic Trouble Code (DTC) P0204

Injector 4 Control Circuit

Diagnostic Trouble Code (DTC) P0205

Injector 5 Control Circuit

Diagnostic Trouble Code (DTC) P0206

Injector 6 Control Circuit

Diagnostic Trouble Code (DTC) P0325

KS Module Circuit

Diagnostic Trouble Code (DTC) P0327

KS Sensor Circuit

Diagnostic Trouble Code (DTC) P0336

58X Reference Signal Circuit

Diagnostic Trouble Code (DTC) P0337

CKP Sensor Circuit Low Frequency

Diagnostic Trouble Code (DTC) P0341

CMP Sensor Circuit Performance

Diagnostic Trouble Code (DTC) P0342

CMP Sensor Circuit Low

Diagnostic Trouble Code (DTC) P0351

Ignition 1 Control Circuit

Diagnostic Trouble Code (DTC) P0352

Ignition 2 Control Circuit

Diagnostic Trouble Code (DTC) P0353

Ignition 3 Control Circuit

Diagnostic Trouble Code (DTC) P0354

Ignition 4 Control Circuit

Diagnostic Trouble Code (DTC) P0355

Ignition 5 Control Circuit

Diagnostic Trouble Code (DTC) P0356

Ignition 6 Control Circuit

Diagnostic Trouble Code (DTC) P0402

EGR Pintle Crank Error

Diagnostic Trouble Code (DTC) P0404

EGR Open Stuck

Diagnostic Trouble Code (DTC) P0405

EGR Low Voltage

Diagnostic Trouble Code (DTC) P0406

EGR High Voltage

Diagnostic Trouble Code (DTC) P0502

VSS Circuit Low Input

Diagnostic Trouble Code (DTC) P0562

System Voltage Low

Diagnostic Trouble Code (DTC) P0563

System Voltage High

Diagnostic Trouble Code (DTC) P0601

PCM Memory

Diagnostic Trouble Code (DTC) P1154 HO2S

Circuit Transition Time Ratio Bank 2 Sensor 1

Diagnostic Trouble Code (DTC) P1171

Fuel System Lean During Acceleration

Diagnostic Trouble Code (DTC) P1380

ABS Rough Road ABS System Fault

Diagnostic Trouble Code (DTC) P1404

EGR Closed Stuck

Diagnostic Trouble Code (DTC) P1508

IAC System Low RPM

Diagnostic Trouble Code (DTC) P1509

IAC System High RPM

Diagnostic Trouble Code (DTC) P1618

Serial Peripheral Interface (SPI) PCM

Interprocessor Communication Error

Diagnostic Trouble Code (DTC) P1625

PCM Unexpected Reset

Diagnostic Trouble Code (DTC) P1626 -

No Response From Immobiliser

Diagnostic Trouble Code (DTC) P1631 -

Received Response Was Not Correct

Diagnostic Trouble Code (DTC) P1640

Driver-1-Input High Voltage

Diagnostic Trouble Code (DTC) P1648 -

Received Incorrect Security Code

Diagnostic Trouble code (DTC) P1649 - Security

Code & Security Key Not Programmed

Symptom Diagnosis

Hard Start Symptom

Surges and/or Chuggles Symptom

Lack of Power, Sluggish or Spongy Symptom

Detonation/Spark Knock Symptom

Rough, Unstable, or Incorrect Idle, Stalling Symptom

Poor Fuel Economy Symptom

Excessive Exhaust Emissions or Odors Symptom

Dieseling, Run-On Symptom

Backfire Symptom

Cuts Out, Misses Symptom

Hesitation, Sag, Stumble Symptom

Default Matrix Table

Camshaft Position (CMP) Sensor

Crankshaft Position (CKP) Sensor

Engine Coolant Temperature (ECT) Sensor

Heated Oxygen Sensor (HO2S)

Intake Air Temperature (IAT) Sensor

Knock Sensor (KS)

Mass Air Flow (MAF) Sensor

Manifold Absolute Pressure (MAP) Sensor

Malfunction Indicator Lamp (MIL)

Powertrain Control Module (PCM)

Electrostatic Discharge (ESD) Damage

EEPROM

Power Steering Pressure (PSP) Switch

Throttle Position (TP) Sensor

Vehicle Speed Sensor (VSS)

Air Cleaner/Air Filter

Idle Air Control (IAC) Valve

Common Chamber

Accelerator Cable Assembly

Accelerator Pedal Replacement

Fuel Filter Cap

Fuel Filter

Fuel Gauge Unit

Fuel Injectors

Fuel Pressure Regulator

Fuel Metering System

Fuel Pump Assembly

Fuel Pump Relay

Fuel Rail Assembly

Fuel Tank

Throttle Body (TB)

Electronic Ignition System

Catalytic Converter

Air Conditioning Relay

EVAP Canister Hoses

EVAP Canister

EVAP Canister Purge Solenoid

Fuel Tank Vent Valve

Linear Exhaust Gas Recirculation (EGR) Valve

Positive Crankcase Ventilation (PCV) Valve

Wiring and Connectors

PCM Connectors and Terminals

Wire Harness Repair: Twisted Shielded Cable

Twisted Leads

Weather-Pack Connector

Com-Pack III

Metri-Pack

General Description (PCM and Sensors)

58X Reference PCM Input

A/C Request Signal

Crankshaft Position (CKP) Sensor

Camshaft Position (CMP) Sensor and Signal

Engine Coolant Temperature (ECT) Sensor

Electrically Erasable Programmable Read Only

Memory (EEPROM)

Fuel Control Heated Oxygen Sensors

Intake Air Temperature (IAT) Sensor

Knock Sensor

Linear Exhaust Gas Recirculation (EGR) Control

Mass Air Flow (MAF) Sensor

Manifold Absolute Pressure (MAP) Sensor

Powertrain Control Module (PCM)

PCM Function

PCM Components

PCM Voltage Description

PCM Input/Outputs

PCM Service Precautions

Reprogramming The PCM

Throttle Position (TP) Sensor

Transmission Fluid Temperature (TFT) Sensor

Transmission Range Switch

Vehicle Speed Sensor (VSS)

Use of Circuit Testing Tools

Aftermarket Electrical and Vacuum Equipment

Electrostatic Discharge Damage

Upshift Lamp

General Description (Air Induction)

Air Induction System

General Description (Fuel Metering)

Acceleration Mode

Accelerator Controls

Battery Voltage Correction Mode

CMP Signal

Clear Flood Mode

Deceleration Mode

Engine Speed Fuel Disable Mode

Fuel Cutoff Mode

Fuel Injector

Fuel Metering System Components

Fuel Metering System Purpose

Fuel Pressure Regulator

Fuel Pump Electrical Circuit

Fuel Rail

Idle Air Control (IAC) Valve

Run Mode

Starting Mode

Throttle Body Unit

General Description (Electronic Ignition System)

Camshaft Position (CMP) Sensor

Crankshaft Position (CKP) Sensor

Ignition Coils

Ignition Control

Ignition Control PCM Output

Knock Sensor (KS) PCM Input

Powertrain Control Module (PCM)

Spark Plug

A/C Clutch Diagnosis

A/C Clutch Circuit Operation

A/C Clutch Circuit Purpose

A/C Request Signal

General Description (Exhaust Gas Recirculation

(EGR) System)

EGR Purpose

Linear EGR Valve

Linear EGR Control

Linear EGR Valve Operation and Results of

Incorrect Operation

EGR Pintle Position Sensor

General Description (Positive Crankcase

Ventilation (PCV) System)

Crankcase Ventilation System Purpose

Crankcase Ventilation System Operation

Special Tools

Specifications

Tightening Specifications

Application N·m Lb Ft. Lb In.

Camshaft Position Sensor Retaining Screw 9 — 78

Crankshaft Position Sensor Mounting Bolt 10 — 87

EGR Bolt 28 21 —

EGR Nut 28 21 —

Engine Coolant Temperature Sensor 20 7.7 —

Fuel Drain Plug 29 22 —

Fuel Pressure Regulator Attaching Screw 6.5 — 60

Fuel Rail Bolts 25 18 —

Fuel Tank Undercover Retaining Bolts 36 27 —

Heated Oxygen Sensor 42 31 —

Lower Intake Manifold to Engine Block Bolts 25 18 —

Lower Intake Manifold to Engine Block Nuts 25 18 —

Spark Plugs 18 13 —

Throttle Body Mounting Bolts 25 18 —

Upper Intake Manifold to Lower Intake Manifold Bolts 25 18 —

VSS Retaining Bolt 13 — 120

Diagrams and Schematics

PCM Wiring Diagram (1 of 7)

D06RW00005

PCM Wiring Diagram (2 of 7)

D06RW134

D06RW140

PCM Wiring Diagram (3 of 7)

D06RX0 0003

PCM Wiring Diagram (4 of 7)

D06RW138

PCM Wiring Diagram (5 of 7)

D06RW137

PCM Wiring Diagram (6 of 7)

D06RW099

PCM Wiring Diagram (7 of 7)

D06RW136

PCM Pinouts

PCM Pinout Table, 32-Way Red Connector – Row “A”

TS23344

PIN PIN Function Wire Color IGN ON ENG RUN

A1 5 Volt Reference “A” RED 5.0 V 5.0 V

A2 Knock Sensor YEL 0.0 V DC

2mV AC

0.0 V DC

18mV AC (at

idle)

A3 Not Used — — —

A4 Battery Feed WHT B+ B+

A5 Idle Air Control (IAC)

“A”High

BLU B+/0.8 V B+/0.8 V

A6 IAC “A” Low BLU/WHT B+/0.8 V B+/0.8 V

A7 IAC “B” Low BLU/BLK B+/0.8 V B+/0.8 V

A8 IAC “B” High BLU/RED B+/0.8 V B+/0.8 V

A9 Automatic Transmission

Fluid (ATF) Lamp

ORN/BLU B+ B+

A10 Winter Lamp PNK/GRN B+ B+

A11 Power Lamp GRY/WHT B+ B+

A12 Antilock Brake System

(ABS)

GRY B+ B+

A13 Malfunction Indicator

(Check Engine or MIL)

Lamp/Immobiliser

BLU 0.0 V B+

A14 “Check Transmission”

Lamp Driver (AT)

ORN/BLK B+ B+

A15 EVAP RED/BLU B+ 5.0 V

A16 Band Apply (AT) BRN/YEL B+ B+

PCM Pinout Table, 32-Way Red Connector – Row “B”

TS23344

PIN PIN Function Wire Color IGN ON ENG RUN

B1 5 Volt Reference “B” RED/YEL 5.0 V 5.0 V

B2 lgnition coil RED/WHT 0.0 V 0.1 V

B3 lgnition coil RED/BLK 0.0 V 0.1 V

B4 lgnition coil RED/GRN 0.0 V 0.1 V

B5 Not Used — — —

B6 Not Used — — —

B7 Exhaust Gas Recirculation

(EGR)

YEL/RED 0.6 V 0.6 V

B8 Intake Air Temperature

(IAT) Sensor

YEL/GRN 0.5-4.9 V

(depends on

temperature)

0.5-4.9 V

(depends on

temperature)

B9 Not Used — — —

B10 Not Used — — —

B11 Power Steering Pressure

(PSP) Switch

GRN/YEL B+ B+

B12 Illuminated Switch GRN B+ B+

B13 Class 2 Data ORN/GRN 0.0 V 0.0 V

B14 A/C Clutch GRN/BLK B+ (A/C OFF) B+ (A/C OFF)

B15 ECM to ECU

Communication

Violet 0.0 V 0.1 V

B16 Not Used — — —

PCM Pinout Table, 32-Way White Connector – Row “C”

TS23345

PIN PIN Function Wire Color IGN ON ENG RUN

C1 Injector Cylinder #4 GRN/RED B+ B+

C2 Shift “B” Solenoid BRN/BLK 0.0 V 0.0 V

C3 Injector Cylinder #6 GRN/YEL B+ B+

C4 Ignition Control (IC)

Cylinder #1

RED 0.0 V 0.1 V

C5 Crankshaft Position

Sensor, “A”Circuit

YEL 0.3 V to 5 V 2.2 V

C6 Not Used — — —

C7 PCM Ground BLK/BLU 0.0 V 0.0 V

C8 PCM Ground BLK/PNK 0.0 V 0.0 V

C9 PCM Ground BLK/BLU 0.0 V 0.0 V

C10 Tachometer BLK/RED 8.8 V 10.0 V (at

idle)

C11 Variable Intake Manifold YEL/BLK 0.0 V B+ (rpm 3600

over)

C12 Not Used — — —

C13 Not Used — — —

C14 Not Used — — —

C15 Not Used — — —

C16 Not Used — — —

PCM Pinout Table, 32-Way White Connector – Row “D”

TS23345

PIN PIN Function Wire Color IGN ON ENG RUN

D1 Injector Cylinder #2 GRN/ORN B+ B+

D2 Torque Converter Clutch

(TCC)

BRN/BLU 0.0 V 0.0 V

D3 Injector Cylinder #1 GRN/WHT B+ B+

D4 Serial Data (8192) ORN 5.0 V 5.0 V

D5 Ignition Control, Cylinder

RED/YEL 0.0 V 0.1 V

D6 Ignition Control, Cylinder

RED/BLUE 0.0 V 0.0 V

D7 VSS Input / IMOB

Response

WHT/BLK 0.0 V 0.1 V (at rest)

D8 Sensor Ground 5V

Reference A Return

GRN 0.0 V 0.0 V

D9 Sensor Ground 5 V

Reference B Return

GRY 0.0 V 0.0 V

D10 Mass Air Flow (MAF) YEL 4.9 V 4.2 V

D11 Camshaft Position Sensor WHT 5.0 V or less

than 1.0 V

4.6 V

D12 Not Used — — —

D13 Not Used — — —

D14 Bank 1 HO2S 1 Low GRN 0.0 V 0.1 V

D15 Bank 1 HO2S 1 Signal RED 0.4 V 0.1-0.9 V

D16 Not Used — — —

PCM Pinout Table, 32-Way Blue Connector – Row “E”

TS23346

PIN PIN Function Wire Color IGN ON ENG RUN

E1 Transmission Output Shaft

Sensor (TOSS) High

RED 0.0 V 0.1 V

E2 Transmission Output Shaft

Sensor (TOSS) Low

WHT 0.0 V 0.0 V

E3 Pressure Control Solenoid

Low

PPL/RED 0.0 V 1.1 V

E4 Pressure Control Solenoid

High

PPL/WHT 0.0 V 4.9 V

E5 Exhaust Gas Recirculation

(EGR) Control High

BLK/YEL B+ B+

E6 Exhaust Gas Recirculation

(EGR) Control Low

YEL B+ B+

E7 Transmission Range Signal

“B”

BLU/YEL 0.0 V 0.0 V

E8 Throttle Position (TP)

Sensor

BLU 0.5-0.8 V 0.5-0.8 V (at

idle)

E9 Engine Coolant

Temperature (ECT) Sensor

BLU/RED 0.5-4.9 V

(depends on

temperature)

0.5-4.9 V

(depends on

temperature)

E10 Not Used — — —

E11 Crankshaft Position (CKP)

Sensor +5 Volt Reference

YEL/RED 5.0 V or less

than 1.0 V

5.0 V

E12 Transmission Range Signal

“A”

BLU/WHT B+ B+

E13 Fuel Pump (FP) Relay RED/WHT 0.0 V B+

E14 Shift High (BAND APPLY) BRN/WHT B+ B+

E15 A/C Request GRN/ORN 0.0 V 0.0 V

E16 Ignition Feed (1 of 2 F16) RED/BLU B+ B+

PCM Pinout Table, 32-Way Blue Connector – Row “F”

TS23346

PIN PIN Function Wire Color IGN ON ENG RUN

F1 Not Used — — —

F2 Transmission Range Signal

“C”

BLU/BLK 0.0 V 0.0 V

F3 Transmission Range Signal

“P”

YEL/GRN B+ 0.0 V

F4 Brake Switch GRN/YEL 0.0 V 0.0 V

F5 Power Switch PPL/RED B+ B+

F6 Winter Switch PPL/GRN B+ B+

F7 Transmission Fluid

Temperature

RED/BLK 0.5-4.9 V

(depends on

temperature)

0.5-4.9 V

(depends on

temperature)

F8 Manifold Absolute Pressure

(MAP)

GRY/BLK 3.5-4.9 V

(depends on

altitude and

barometric

pressure)

0.6-1.3 V

F9 Not Used — — —

F10 Cruise Control GRY/BLU B+ B+

F11 Kickdown Switch LT BLU B+ B+

F12 DIAG ORN/BLU B+ B+

F13 Injector “C” Cylinder #3 GRN B+ B+

F14 Shift “A” Solenoid BRN/RED B+ B+

F15 Injector Cylinder #5 GRN/BLK B+ B+

F16 Ignition Feed (1 of 2 E16) RED/BLU B+ B+

Component Locators

Engine Component Locator

060RW210

Engine Component Locator Table

Number Name Location

1 Linear Exhaust Gas Recirculation (EGR) Valve Rear right side of the engine

2 Throttle Position (TP) Sensor On the rear of the throttle body

3 Intake Air Temperature (IAT) Sensor On the intake air duct near the throttle body

4 Check Engine (MIL) Light On the instrument panel beneath the tachometer

5 Positive Crankcase Ventilation (PCV) Valve On the left of the cylinder head cover

6 Air Cleaner Left front of the engine bay

7 Mass Air Flow (MAF) Sensor Attached to the air filter box

8 Camshaft Position (CMP) Sensor On the rear right side at the left of the cylinder

head cover

9 Fuel Pressure Regulator Rear right side of the engine

10 Idle Air Control (IAC) Valve On the left of the throttle body

11 Upper Intake Manifold Top of the engine

12 Fuse/Relay Box Along the inside of the right fender

13 Manifold Absolute Pressure (MAP) Sensor Bolted to the top of the upper intake manifold

14 Throttle Body Between the intake air duct and the upper intake

manifold

15 Engine Coolant Temperature Sensor On the coolant crossover pipe at the front of the

engine, near the throttle body

Undercarriage Component Locator

F00RW040

Undercarriage Component Locator Table (Automatic Transmission)

Number Name Location

1 Fuel Pump Assembly Installed in the top of the fuel tank

2 Fuel Gauge Unit Installed in the front edge of the fuel tank, on the

right side

3 Fuel Filter Located along the inside of the right frame rail,

ahead of the rear axle

4 Vehicle Speed Sensor (VSS) Protrudes from the rear output shaft housing of

the transfer case.

5 Heated Oxygen Sensor (Bank 1, HO2S 1) Threaded into the exhaust pipe ahead of the

right-hand catalytic converter

6 Heated Oxygen Sensor (Bank 2, HO2S 1) Threaded into the exhaust pipe ahead the

left-hand catalytic converter

Undercarriage Component Locator Table (Manual Transmission)

Fuse and Relay Panel (Underhood Electrical Center)

TS23336

Number Name Location

1 Fuel Pump Assembly Installed in the top of the fuel tank

2 Fuel Gauge Unit Installed in the front edge of the right frame rail,

ahead of the rear axle

3 Fuel Filter Located along the inside of the right frame rail,

ahead of the rear axle

4 Vehicle Speed Sensor (VSS) Protrudes from the rear output shaft housing of

the transfer case.

5 Heated Oxygen Sensor (Bank 1, HO2S 1) Threaded into the exhaust pipe ahead of the

right-hand catalytic converter

6 Heated Oxygen Sensor (Bank 2, HO2S 1) Threaded into the exhaust pipe ahead of the

left-hand catalytic converter

Sensors and Miscellaneous Component

Locator

150RW101

T321066

T321067

140RW032

014RW125

T321070

055RW003

041RW004

025RW005

T321078

060RW007

028RW001

Diagnosis

Strategy-Based Diagnostics

The strategy-based diagnostic is a uniform approach to

repair all Electrical/Electronic (E/E) systems. The

diagnostic flow can always be used to resolve an E/E

system problem and is a starting point when repairs are

necessary. The following steps will instruct the

technician how to proceed with a diagnosis:

1.Verify the customer complaint.

•To verify the customer complaint, the technician

should know the normal operation of the system.

2.Perform preliminary checks.

•Conduct a thorough visual inspection.

•Review the service history.

•Detect unusual sounds or odors.

•Gather diagnostic trouble code information to

achieve an effective repair.

3.Check bulletins and other service information.

•This includes videos, newsletters, etc.

4.Refer to service information (manual) system

check(s).

•“System checks” contain information on a system

that may not be supported by one or more DTCs.

System checks verify proper operation of the

system. This will lead the technician in an

organized approach to diagnostics.

5.Refer to service diagnostics.

DTC Stored

Follow the designated DTC chart exactly to make an

effective repair.

No DTC

Select the symptom from the symptom tables. Follow

the diagnostic paths or suggestions to complete the

repair. You may refer to the applicable component/

system check in the system checks.

No Matching Symptom

1.Analyze the complaint.

2.Develop a plan for diagnostics.

3.Utilize the wiring diagrams and the theory of

operation.

Call technical assistance for similar cases where repair

history may be available. Combine technician

knowledge with efficient use of the available service

information.

Intermittents

Conditions that are not always present are called

intermittents. To resolve intermittents, perform the

following steps:

1.Observe history DTCs, DTC modes, and

freezeframe data.

2.Evaluate the symptoms and the conditions

described by the customer.

3.Use a check sheet or other method to identify the

circuit or electrical system component.

4.Follow the suggestions for intermittent diagnosis

found in the service documentation.

Most Tech 2s, such as the Tech II and the 5–8840–

0285–0 (Fluke model 87 DVOM), have data-capturing

capabilities that can assist in detecting intermittents.

No Trouble Found

This condition exists when the vehicle is found to

operate normally. The condition described by the

customer may be normal. Verify the customer

complaint against another vehicle that is operating

normally. The condition may be intermittent. Verify the

complaint under the conditions described by the

customer before releasing the vehicle.

1.Re-examine the complaint.

When the Complaint cannot be successfully found

or isolated, a re-evaluation is necessary. The

complaint should be re-verified and could be

intermittent as defined in Intermittents, or could be

normal.

2.Repair and verify.

After isolating the cause, the repairs should be

made. Validate for proper operation and verify that

the symptom has been corrected. This may involve

road testing or other methods to verify that the

complaint has been resolved under the following

conditions:

•Conditions noted by the customer.

•If a DTC was diagnosed, verify a repair by

duplicating conditions present when the DTC was

set as noted in the Failure Records or Freeze

Frame data.

Verifying Vehicle Repair

Verification of the vehicle repair will be more

comprehensive for vehicles with OBD system

diagnostics. Following a repair, the technician should

perform the following steps:

Important: Follow the steps below when you verify

repairs on OBD systems. Failure to follow these steps

could result in unnecessary repairs.

1. Review and record the Failure Records and the

Freeze Frame data for the DTC which has been

diagnosed (Freeze Frame data will only be stored

for an A or B type diagnostic and only if the

MIL("Check Engine" lamp) has been requested).

2. Clear the DTC(S).

3. Operate the vehicle within conditions noted in the

Failure Records and Freeze Frame data.

4. Monitor the DTC status information for the specific

DTC which has been diagnosed until the diagnostic

test associated with that DTC runs.

General Service Information

OBD Serviceablity Issues

The list of non-vehicle faults that could affect the

performance of the OBD system has been compiled.

These non-vehicle faults vary from environmental

conditions to the quality of fuel used.

The illumination of the MIL (“Check Engine”lamp) due to

a non-vehicle fault could lead to misdiagnosis of the

vehicle, increased warranty expense and customer

dissatisfaction. The following list of non-vehicle faults

does not include every possible fault and may not apply

equally to all product lines.

Fuel Quality

Using fuel with the wrong octane rating for your vehicle

may cause driveability problems. Many of the major

fuel companies advertise that using “premium” gasoline

will improve the performance of your vehicle. Most

premium fuels use alcohol to increase the octane rating

of the fuel. Although alcohol-enhanced fuels may raise

the octane rating, the fuel's ability to turn into vapor in

cold temperatures deteriorates. This may affect the

starting ability and cold driveability of the engine.

Low fuel levels can lead to fuel starvation, lean engine

operation, and eventually engine misfire.

Non-OEM Parts

All of the OBD diagnostics have been calibrated to run

with OEM parts. Something as simple as a

high-performance exhaust system that affects exhaust

system back pressure could potentially interfere with the

operation of the EGR valve and thereby turn on the MIL

(“Check Engine”lamp). Small leaks in the exhaust

system near the post catalyst oxygen sensor can also

cause the MIL (“Check Engine”lamp) to turn on.

Aftermarket electronics, such as cellular phones,

stereos, and anti-theft devices, may radiate EMI into the

control system if they are improperly installed. This may

cause a false sensor reading and turn on the MIL

(“Check Engine”lamp).

Environment

Temporary environmental conditions, such as localized

flooding, will have an effect on the vehicle ignition

system. If the ignition system is rain-soaked, it can

temporarily cause engine misfire and turn on the MIL

(“Check Engine”lamp).

Poor Vehicle Maintenance

The sensitivity of OBD diagnostics will cause the MIL

(“Check Engine”lamp) to turn on if the vehicle is not

maintained properly. Restricted air filters, fuel filters,

and crankcase deposits due to lack of oil changes or

improper oil viscosity can trigger actual vehicle faults

that were not previously monitored prior to OBD. Poor

vehicle maintenance can not be classified as

a“non-vehicle fault”, but with the sensitivity of OBD

diagnostics, vehicle maintenance schedules must be

more closely followed.

Related System Faults

Many of the OBD system diagnostics will not run if the

PCM detects a fault on a related system or component.

One example would be that if the PCM detected a

Misfire fault, the diagnostics on the catalytic converter

would be suspended until Misfire fault was repaired. If

the Misfire fault was severe enough, the catalytic

converter could be damaged due to overheating and

would never set a Catalyst DTC until the Misfire fault

was repaired and the Catalyst diagnostic was allowed to

run to completion. If this happens, the customer may

have to make two trips to the dealership in order to

repair the vehicle.

Maintenance Schedule

Refer to the Maintenance Schedule.

Visual / Physical Engine Compartment

Inspection

Perform a careful visual and physical engine

compartment inspection when performing any

diagnostic procedure or diagnosing the cause of an

emission test failure. This can often lead to repairing a

problem without further steps. Use the following

guidelines when performing a visual/physical

inspection:

• Inspect all vacuum hoses for punches, cuts,

disconnects, and correct routing.

• Inspect hoses that are difficult to see behind other

components.

• Inspect all wires in the engine compartment for

proper connections, burned or chafed spots, pinched

wires, contact with sharp edges or contact with hot

exhaust manifolds or pipes.

Basic Knowledge of Tools Required

NOTE: Lack of basic knowledge of this powertrain

when performing diagnostic procedures could result in

an incorrect diagnosis or damage to powertrain

components. Do not attempt to diagnose a powertrain

problem without this basic knowledge.

A basic understanding of hand tools is necessary to

effectively use this section of the Service Manual.

Serial Data Communications

Class II Serial Data Communications

This vehicle utilizes the “Class II” communication

system. Each bit of information can have one of two

lengths: long or short. This allows vehicle wiring to be

reduced by transmitting and receiving multiple signals

over a single wire. The messages carried on Class II

data streams are also prioritized. If two messages

attempt to establish communications on the data line at

the same time, only the message with higher priority will

continue. The device with the lower priority message

must wait. The most significant result of this regulation

is that it provides Tech 2 manufacturers with the

capability to access data from any make or model

vehicle that is sold.

The data displayed on the other Tech 2 will appear the

same, with some exceptions. Some Tech 2s will only be

able to display certain vehicle parameters as values that

are a coded representation of the true or actual value.

For more information on this system of coding, refer to

Decimal/Binary/Hexadecimal Conversions. On this

vehicle Tech 2 displays the actual values for vehicle

parameters. It will not be necessary to perform any

conversions from coded values to actual values.

On-Board Diagnostic (OBD)

On-Board Diagnostic Tests

A diagnostic test is a series of steps, the result of which

is a pass or fail reported to the diagnostic executive.

When a diagnostic test reports a pass result, the

diagnostic executive records the following data:

• The diagnostic test has been completed since the

last ignition cycle.

• The diagnostic test has passed during the current

ignition cycle.

• The fault identified by the diagnostic test is not

currently active.

When a diagnostic test reports a fail result, the

diagnostic executive records the following data:

• The diagnostic test has been completed since the

last ignition cycle.

• The fault identified by the diagnostic test is currently

active.

• The fault has been active during this ignition cycle.

• The operating conditions at the time of the failure.

Remember, a fuel trim DTC may be triggered by a list of

vehicle faults. Make use of all information available

(other DTCs stored, rich or lean condition, etc.) when

diagnosing a fuel trim fault.

Comprehensive Component Monitor

Diagnostic Operation

Input Components:

Input components are monitored for circuit continuity

and out-of-range values. This includes rationality

checking. Rationality checking refers to indicating a

fault when the signal from a sensor does not seem

reasonable, i.e. Throttle Position (TP) sensor that

indicates high throttle position at low engine loads or

MAP voltage. Input components may include, but are

not limited to the following sensors:

• Vehicle Speed Sensor (VSS)

• Crankshaft Position (CKP) sensor

• Knock Sensor (KS)

• Throttle Position (TP) sensor

• Engine Coolant Temperature (ECT) sensor

• Camshaft Position (CMP) sensor

• Manifold Absolute Pressure (MAP) sensor

• Mass Air Flow (MAF) sensor

In addition to the circuit continuity and rationality check,

the ECT sensor is monitored for its ability to achieve a

steady state temperature to enable closed loop fuel

control.

Output Components:

Output components are diagnosed for proper response

to control module commands. Components where

functional monitoring is not feasible will be monitored for

circuit continuity and out-of-range values if applicable.

Output components to be monitored include, but are not

limited to, the following circuits:

• Idle Air Control (IAC) Motor

• Electronic Transmission controls

•A/C relays

• Cooling fan relay

• VSS output

• MIL control

• Cruise control inhibit

Refer to PCM and Sensors in General Descriptions.

Passive and Active Diagnostic Tests

A passive test is a diagnostic test which simply monitors

a vehicle system or component. Conversely, an active

test, actually takes some sort of action when performing

diagnostic functions, often in response to a failed

passive test. For example, the EGR diagnostic active

test will force the EGR valve open during closed throttle

decel and/or force the EGR valve closed during a

steady state. Either action should result in a change in

manifold pressure.

Intrusive Diagnostic Tests

This is any on-board test run by the Diagnostic

Management System which may have an effect on

vehicle performance or emission levels.

Warm-Up Cycle

A warm-up cycle means that engine at temperature

must reach a minimum of 70°C (160°F) and rise at least

22°C (40°F) over the course of a trip.

Freeze Frame

Freeze Frame is an element of the Diagnostic

Management System which stores various vehicle

information at the moment an emissions-related fault is

stored in memory and when the MIL is commanded on.

These data can help to identify the cause of a fault.

Refer to Storing And Erasing Freeze Fame Data for

more detailed information.

Failure Records

Failure Records data is an enhancement of the OBD

Freeze Frame feature. Failure Records store the same

vehicle information as does Freeze Frame, but it will

store that information for any fault which is stored in

on-board memory, while Freeze Frame stores

information only for emission-related faults that

command the MIL on.

Common OBD Terms

Diagnostic

When used as a noun, the word diagnostic refers to any

on-board test run by the vehicle's Diagnostic

Management System. A diagnostic is simply a test run

on a system or component to determine if the system or

component is operating according to specification.

There are many diagnostics, shown in the following list:

• Oxygen sensors

• Oxygen sensor heaters

•EGR

• Catalyst monitoring

Enable Criteria

The term “enable criteria” is engineering language for

the conditions necessary for a given diagnostic test to

run. Each diagnostic has a specific list of conditions

which must be met before the diagnostic will run.

“Enable criteria”is another way of saying“conditions

required”.

The enable criteria for each diagnostic is listed on the

first page of the DTC description under the

heading“Conditions for Setting the DTC”. Enable criteria

varies with each diagnostic, and typically includes, but

is not limited to the following items:

• engine speed

• vehicle speed

•ECT

•MAF/MAP

• barometric pressure

•IAT

•TP

• fuel trim

• TCC enabled

•A/C on

Trip

Technically, a trip is a key on-run-key off cycle in which

all the enable criteria for a given diagnostic are met,

allowing the diagnostic to run. Unfortunately, this

concept is not quite that simple. A trip is official when all

the enable criteria for a given diagnostic are met. But

because the enable criteria vary from one diagnostic to

another, the definition of trip varies as well. Some

diagnostic are run when the vehicle is at operating

temperature, some when the vehicle first start up; some

require that the vehicle be cruising at a steady highway

speed, some run only when the vehicle is idle; some

diagnostics function with the TCC disables. Some run

only immediately following a cold engine start-up.

A trip then, is defined as a key on-run-key off cycle in

which the vehicle was operated in such a way as to

satisfy the enables criteria for a given diagnostic, and

this diagnostic will consider this cycle to be one trip.

However, another diagnostic with a different set of

enable criteria (which were not met) during this driving

event, would not consider it a trip. No trip will occur for

that particular diagnostic until the vehicle is driven in

such a way as to meet all the enable criteria.

The Diagnostic Executive

The Diagnostic Executive is a unique segment of

software which is designed to coordinate and prioritize

the diagnostic procedures as well as define the protocol

for recording and displaying their results. The main

responsibilities of the Diagnostic Executive are listed as

following:

• Commanding the MIL (“Check Engine”lamp) on and

off

• DTC logging and clearing

• Freeze Frame data for the first emission related DTC

recorded

• Non-emission related Service Lamp (future)

• Operating conditions Failure Records buffer, (the

number of records will vary)

• Current status information on each diagnostic

The Diagnostic Executive records DTCs and turns on

the MIL when emission-related faults occur. It can also

turn off the MIL if the conditions cease which caused

the DTC to set.

Diagnostic Information

The diagnostic charts and functional checks are

designed to locate a faulty circuit or component through

a process of logical decisions. The charts are prepared

with the requirement that the vehicle functioned

correctly at the time of assembly and that there are not

multiple faults present.

There is a continuous self-diagnosis on certain control

functions. This diagnostic capability is complemented

by the diagnostic procedures contained in this manual.

The language of communicating the source of the

malfunction is a system of diagnostic trouble codes.

When a malfunction is detected by the control module, a

diagnostic trouble code is set and the Malfunction

Indicator Lamp (MIL) (“Check Engine”lamp) is

illuminated.

Malfunction Indicator Lamp (MIL)

The Malfunction Indicator Lamp (MIL) looks the same

as the MIL you are already familiar with (“Check

Engine”lamp). However, OBD requires that the it

illuminate under a strict set of guide lines.

Basically, the MIL is turned on when the PCM detects a

DTC that will impact the vehicle emissions.

The MIL is under the control of the Diagnostic

Executive. The MIL will be turned on if an

emissions-related diagnostic test indicates a

malfunction has occurred. It will stay on until the system

or component passes the same test, for three

consecutive trips, with no emissionsrelated faults.

Extinguishing the MIL

When the MIL is on, the Diagnostic Executive will turn

off the MIL after three consecutive trips that a “test

passed” has been reported for the diagnostic test that

originally caused the MIL to illuminate.

Although the MIL has been turned off, the DTC will

remain in the PCM memory (both Freeze Frame and

Failure Records) until forty(40) warm-up cycles after no

faults have been completed.

If the MIL was set by either a fuel trim or misfire-related

DTC, additional requirements must be met. In addition

to the requirements stated in the previous paragraph,

these requirements are as follows:

• The diagnostic tests that are passed must occur with

375 RPM of the RPM data stored at the time the last

test failed.

• Plus or minus ten (10) percent of the engine load that

was stored at the time the last failed.

• Similar engine temperature conditions (warmed up or

warming up ) as those stored at the time the last test

failed.

Meeting these requirements ensures that the fault which

turned on the MIL has been corrected.

The MIL (“Check Engine”lamp) is on the instrument

panel and has the following function:

• It informs the driver that a fault affects vehicle

emission levels has occurred and that the vehicle

should be taken for service as soon as possible.

• As a bulb and system check, the MIL will come “ON”

with the key “ON” and the engine not running. When

the engine is started, the MIL will turn “OFF.”

• When the MIL remains “ON” while the engine is

running, or when a malfunction is suspected due to a

driveability or emissions problem, a Powertrain

On-Board Diagnostic (OBD ll) System Check must be

performed. The procedures for these checks are

given in On-Board Diagnostic (OBD) System Check.

These checks will expose faults which may not be

detected if other diagnostics are performed first.

DTC Types

Each DTC is directly related to a diagnostic test. The

Diagnostic Management System sets DTC based on

the failure of the tests during a trip or trips. Certain

tests must fail two (2) consecutive trips before the DTC

is set. The following are the four (4) types of DTCs and

the characteristics of those codes:

•Type A

• Emissions related

• Requests illumination of the MIL of the first trip with

a fail

• Stores a History DTC on the first trip with a fail

• Stores a Freeze Frame (if empty)

• Stores a Fail Record

• Updates the Fail Record each time the diagnostic

test fails

•Type B

• Emissions related

• “Armed” after one (1) trip with a fail

• “Disarmed” after one (1) trip with a pass

• Requests illumination of the MIL on the second

consecutive trip with a fail

• Stores a History DTC on the second consecutive

trip with a fail (The DTC will be armed after the first

fail)

• Stores a Freeze Frame on the second consecutive

trip with a fail (if empty)

• Stores a Fail Record when the first test fails (not

dependent on consecutive trip fails)

• Updates the Fail Record each time the diagnostic

test fails

• Type C (if the vehicle is so equipped)

• Non-Emissions related

• Requests illumination of the Service Lamp or the

service message on the Drive Information Center

(DIC) on the first trip with a fail

• Stores a History DTC on the first trip with a fail

•Does not store a Freeze Frame

• Stores Fail Record when test fails

• Updates the Fail Record each time the diagnostic

test fails

•Type D (Type D non-emissions related are not

utilized on certain vehicle applications).

• Non-Emissions related

• Dose not request illumination of any lamp

• Stores a History DTC on the first trip with a fail

•Does not store a Freeze Frame

• Stores Fail Record when test fails

• Updates the Fail Record each time the diagnostic

test fails

Important: Only four Fail Records can be stored. Each

Fail Record is for a different DTC. It is possible that

there will not be Fail Records for every DTC if multiple

DTCs are set.

Storing and Erasing Freeze Frame Data and Failure

Records

The data captured is called Freeze Frame data. The

Freeze Frame data is very similar to a single record of

operating conditions. Whenever the MIL is illuminated,

the corresponding record of operating conditions is

recorded to the Freeze Frame buffer.

Data from these faults take precedence over data

associated with any other fault. The Freeze Frame data

will not be erased unless the associated history DTC is

cleared.

Each time a diagnostic test reports a failure, the current

engine operating conditions are recorded in the Failure

Records buffer. A subsequent failure will update the

recorded operating conditions. The following operating

conditions for the diagnostic test which failed typically

include the following parameters:

•Air Fuel Ratio

•Air Flow Rate

•Fuel Trim

•Engine Speed

•Engine Load

•Engine Coolant Temperature

•Vehicle Speed

•TP Angle

•MAP/BARO

•Injector Base Pulse Width

•Loop Status

Intermittent Malfunction Indicator Lamp

In the case of an “intermittent” fault, the MIL (“Check

Engine”lamp) may illuminate and then (after three trips)

go“OFF”. However, the corresponding diagnostic

trouble code will be stored in the memory. When

unexpected diagnostic trouble codes appear, check for

an intermittent malfunction.

A diagnostic trouble code may reset. Consult the

“Diagnostic Aids” associated with the diagnostic trouble

code. A physical inspection of the applicable

sub-system most often will resolve the problem.

Data Link Connector (DLC)

The provision for communication with the control

module is the Data Link Connector (DLC). The DLC is

used to connect to Tech 2. Some common uses of Tech

2 are listed below:

•Identifying stored Diagnostic Trouble Codes (DTCs).

•Clearing DTCs.

•Performing output control tests.

•Reading serial data.

TS24064

Verifying Vehicle Repair

Verification of vehicle repair will be more

comprehensive for vehicles with OBD system

diagnostic. Following a repair, the technician should

perform the following steps:

1.Review and record the Fail Records and/or Freeze

Frame data for the DTC which has been diagnosed

(Freeze Frame data will only be stored for an A or B

type diagnostic and only if the MIL has been

requested).

2.Clear DTC(s).

3.Operate the vehicle within conditions noted in the

Fail Records and/or Freeze Frame data.

4.Monitor the DTC status information for the specific

DTC which has been diagnosed until the diagnostic

test associated with that DTC runs.

Following these steps are very important in verifying

repairs on OBD systems. Failure to follow these steps

could result in unnecessary repairs.

Reading Diagnostic Trouble Codes Using A

Tech 2

The procedure for reading diagnostic trouble code(s) is

to used a diagnostic Tech 2. When reading DTC(s),

follow instructions supplied by Tech 2 manufacturer.

Clearing Diagnostic Trouble Codes

Important: Do not clear DTCs unless directed to do so

by the service information provided for each diagnostic

procedure. When DTCs are cleared, the Freeze Frame

and Failure Record data which may help diagnose an

intermittent fault will also be erased from memory.

If the fault that caused the DTC to be stored into

memory has been corrected, the Diagnostic Executive

will begin to count the “warm-up” cycles with no further

faults detected, the DTC will automatically be cleared

from the PCM memory.

To clear Diagnostic Trouble Codes (DTCs), use the

diagnostic Tech 2“clear DTCs”. When clearing DTCs

follow instructions supplied by the tool manufacturer.

When Tech 2 is not available, DTCs can also be cleared

by disconnecting one of the following sources for at

least thirty (30) seconds.

NOTE: To prevent system damage, the ignition key

must be “OFF” when disconnecting or reconnecting

battery power.

• The power source to the control module. Examples:

fuse, pigtail at battery PCM connectors etc.

• The negative battery cable. (Disconnecting the

negative battery cable will result in the loss of other

on-board memory data, such as preset radio tuning).

Using Tech 2 On The Vehicle

NOTE: Due to the constant evolution of TECH 2

software, the screens shown in this section may

differ slightly from those displayed for the vehicle

being tested.

Connecting TECH 2 To The Vehicle

1. Connect Tech 2 to the vehicle DLC, with the DLC

cable and the 16/19 pin adapter.

2. Switch the unit on by pressing the power button (2).

A green light (1) should come on indicating that the

tool is receiving power.

NOTE: At this time the technician should see the Power

On Self Test (POST) run. The POST is a built in

diagnostic self test for the TECH 2 that should find most

common system faults. The POST is run on every

power up to ensure the best operation of the tool. After

the completion of the POST, the TECH 2 unit will briefly

show the POST results. If POST passes, the tool will

continue onto the title screen. If POST fails, results of all

tests will be displayed, and this should show which test

failed. POST failures may be classified as fatal or non-

fatal. A fatal error will not allow the user to continue

using the tool. Failure of the keypad would be an

example of a fatal error. Non-fatal errors found during

the POST will allow continued use of the TECH 2, but

with some limitations. If either a fatal or non-fatal error

occurs, refer to the Troubleshooting section of the

TECH 2 User's Guide.

1. Power Status Indicator Light

2. PWR (Power) Key

3. SHIFT Key

4. SHIFT Key Status Indicator Light

3. At the Tech 2 title screen press the ENTER key to

continue.

PWR

TECH 2

Tech

10 Megabyte

Press [ENTER] to continue

Software Version 11.010

Holden 1997 - 2002

4. A selection can be made from the Main Menu,

either by using a function key or by using the arrow

keys to highlight a menu choice and pressing

ENTER.

•NOTE: You will then need to supply some additional

information to the TECH 2. This requires navigation

through a series of lists (called picklists). On some

menus or picklists, the user can use a function key to

make a menu selection, but most of the picklists

require using the selection and action keys. If a

mistake is made in the selection process, or if a

different application or function is desired, press EXIT

to back up one level. Within an application, there may

be soft keys which are available for use. These soft

keys allow access to additional tool functions without

exiting a current tool function. Soft keys are made up

of sets which will appear together. To see the next set

of soft keys, select the More soft key.

The TECH 2 Main Menu contains the following:

F0: Diagnostics

Contains all functions to test, diagnose, monitor and

program the different vehicle systems.

F1: Service Programming System (SPS)

SPS is used in conjunction with Technical

Information System (TIS) 2000 to program vehicle

control units.

F2: View Capture Data

Contains all functions to work with one or two

previously recorded snapshots on one or two

vehicles. This function is to enable the viewing of

captured data without a vehicle.

F3: Tool Options

Contains the TECH 2 self test, set clock, set units,

set screen contrast and Getting Started.

F4: Download/Upload Help

Contains help information on the downloading and

uploading from the TECH 2 to the TIS 2000 CD-

ROM.

Main Menu

UBS2000a

F0: Diagnostics

F1: Service Programming System (SPS)

F2: View Capture Data

F3: Tool Options

F4: Download/Upload Help

5. Select the correct Model Year with the arrow keys

and the press ENTER. The Vehicle identification

screen will then be displayed.

6. Select the correct Vehicle Type with the arrow keys

and the press ENTER. The System Select Menu

will then be displayed.

7. The desired system can be selected from the

System Select Menu with the function keys or with

arrow keys and then press ENTER.

F0:Powertrain contains all functions to test,

diagnose, and monitor the engine and transmission

systems that communicate with the Tech 2 via the

Powertrain Control Module (PCM).

F1: Chassis contains all functions to test,

diagnose, monitor the vehicles chassis systems;

TOD and ABS modules.

F2: Body contains all functions to test, diagnose,

monitor the instruments and Supplemental

Restraint System.

Main Menu

Select one of the following

Model Year(s)

UBS2001a

(2)

(1)

(Y)

(X)

(W)

(2)

2002

2001

2000

1999

1998

1 / 5

2002

Main Menu

Select one of the following

Vehicle Type(s)

Frontera

Jackaroo

Rodeo

VX Commodore

VU Utility

WH Statesman & Caprice

Corsa-B

Corsa-C

Astra-F

Astra-G

Jackaroo 2 / 10

UBS2001

System Select Menu

(2) 2002 Jackaroo

F0: Powertrain

F1: Chassis

F2: Body

UBS2002

Powertrain Application Menu

1. Select the correct engine from the Vehicle

Identification menu with the arrow keys, then

press ENTER.

2. Turn on the ignition and press the Confirm soft key.

3. The Engine identification screen will then display

the PCM identification information, which will vary

depending upon engine type and software level.

Press the Confirm soft key, the engine application

menu will then be displayed.

NOTE: If Tech 2 is able to communicate with the

PCM the Engine identification information will be

displayed. If Tech 2 is unable to communicate with

the PCM, Tech 2 will display “Waiting for Data”.

The following functions can be selected from the

engine application menu:

F0: Diagnostic Trouble Codes

F1: Data Display

F2: Snapshot

F3: Miscellaneous Tests

F4: Programming

Vehicle Identification

Select one of the following

Powertrain

3.0L L4 4JX1

3.5L V6 6VE1

4L30E

AW30-40LE

3.5L V6 6VE1

2 / 4

UBS2004

Powertrain

(2) 2002 Jackaroo

Electronic System: 3.0L L4 4JX1

Turn Ignition On!

UBS2004h

Confirm

Powertrain

(2) 2002 Jackaroo

Electronic System: 3.0L L4 4JX1

Part Number

Broadcast Code

Identifier

9383459

DJWD

40C

Part Number

UBS2004j

Confirm

3.2L V6 6VE1 ENGINE FUNCTIONS

F0: Diagnostic Trouble Codes

In this test mode, DTCs stored by the PCM can be displayed or cleared. When F0: Diagnostic Trouble Codes is

selected, there are an additional four modes:

F0: Read Current DTC: All current DTC(s) will be displayed.

F1: Clear Current DTC: Clears all current DTC(s) in the PCM memory.

F2: DTC Information: All current DTC(s) will be displayed in numerical order.

F3: Freeze Frame/Failure Records: Freeze Frame is an element of the Diagnostic Management Ssytem which

stores various items of vehicle information at the moment an emissions related DTC is logged in memory and

the MIL is commanded ON.

Failure Records data is an enhancement of Freeze Frame. Failure Records store the same vehicle information

as Freeze Frame, but will store the information when DTC is logged in memory.

F1: Data Display

This mode displays data parameters for the system being diagnosed. When entering this mode, there are three

modes:

F0: Engine Data: In this test mode, the TECH 2 continuously monitors and displays all engine data parameters.

F1: Misfire Data: In this test mode, the TECH 2 continuously monitors the PCM’s “mis-fire counters”. A current and

history misfire counter are maintained for each cylinder. Engine data parameters relevant to the misfire are

displayed along with the misfire counters.

F2: O2 Sensor Data: The Tech 2 continuously monitors and displays engine data parameters.

F2:Snapshot

In this mode, the TECH 2 scan tool captures data before and after a selected snapshot triggering condition which may

or may not set a DTC.

F3:Miscellaneous Tests

In this test mode, the Tech 2 performs software override commands of the PCM, to assist in problem isolation during

diagnostics.

F0: Lamps: The MIL (Malfunction Indicator Lamp) can be commanded on and off.

F1: Relays: The A/C Compressor Clutch relay and the Fuel Pump relay can be commanded on and off.

F2: EVAP: The Cannister Purge Solenoid operation can be commanded between 0% and 99%.

F3: Fuel System: Fuel Trim can be enabled or reset and O2 loop status monitored.

F4: Instruments: Tachometer Control allows the basic operation of the tachometer to be tested.

F5: EGR Control: The EGR Valve operation can be commanded between 0% and 99% in 10% increments.

F6: Variable Intake Manifold Solenoid: Used to command the Variable Intake Manifold Solenoid ON and OFF.

F7:Injector Balance Test: Allows individual injectors to be disabled and the resultant drop in engine RPM to be

monitored.

F4:System Information

In this mode, the TECH 2 displays the status of the Malfunction Indicator Lamp (MIL) and the number of emission

related DTC’s set.

Primary System-Based Diagnostic

There are primary system-based diagnostics which

evaluate system operation and its effect on vehicle

emissions. The primary system-based diagnostics are

listed below with a brief description of the diagnostic

function:

Oxygen Sensor Diagnosis

The fuel control heated oxygen sensors (Bank 1 HO2S

1 and Bank 2 HO2S 1) are diagnosed for the following

conditions:

•Inactive signal (output steady at bias voltage –

approx. 450 mV)

•Signal fixed high

•Signal fixed low

If the oxygen sensor pigtail wiring, connector or terminal

are damaged, the entire oxygen sensor assembly must

be replaced. DO NOT attempt to repair the wiring,

connector or terminals. In order for the sensor to

function properly, it must have clean reference air

provided to it. This clean air reference is obtained by

way of the oxygen sensor wire(s). Any attempt to repair

the wires, connector or terminals could result in the

obstruction of the reference air and degrade oxygen

sensor performance. Refer to On-Vehicle Service,

Heated Oxygen Sensors.

Fuel Control Heated Oxygen Sensor

The main function of the fuel control heated oxygen

sensors is to provide the control module with exhaust

stream oxygen content information to allow proper

fueling and maintain emissions within mandated levels.

After it reaches operating temperature, the sensor will

generate a voltage, inversely proportional to the amount

of oxygen present in the exhaust gases. The control

module uses the signal voltage from the fuel control

heated oxygen sensors while in closed loop to adjust

fuel injector pulse width. While in closed loop, the PCM

can adjust fuel delivery to maintain an air/fuel ratio

which allows the best combination of emission control

and driveability.

HO2S Heater

Heated oxygen sensors are used to minimize the

amount of time required for closed loop fuel control to

begin operation and to allow accurate catalyst

monitoring. The oxygen sensor heater greatly

decreases the amount of time required for fuel control

sensors (Bank 1 HO2S 1 and Bank2 HO2S 1) to

become active. Oxygen sensor heaters are required to

maintain a sufficiently high temperature which allows

accurate exhaust oxygen content readings further away

from the engine.

Fuel Trim System Monitor Diagnostic

Operation

Fuel Trim System Monitor Diagnostic

Operation

This system monitors the averages of short-term and

long-term fuel trim values. If these fuel trim values stay

at their limits for a calibrated period of time, a

malfunction is indicated. The fuel trim diagnostic

compares the averages of short-term fuel trim values

and long-term fuel trim values to rich and lean

thresholds. If either value is within the thresholds, a

pass is recorded. If both values are outside their

thresholds, a rich or lean DTC will be recorded.

The fuel trim system diagnostic also conducts an

intrusive test. This test determines if a rich condition is

being caused by excessive fuel vapor from the EVAP

canister. In order to meet OBD requirements, the

control module uses weighted fuel trim cells to

determine the need to set a fuel trim DTC. A fuel trim

DTC can only be set if fuel trim counts in the weighted

fuel trim cells exceed specifications. This means that

the vehicle could have a fuel trim problem which is

causing a problem under certain conditions (i.e., engine

idle high due to a small vacuum leak or rough idle due

to a large vacuum leak) while it operates fine at other

times. No fuel trim DTC would set (although an engine

idle speed DTC or HO2S DTC may set). Use a Tech 2

to observe fuel trim counts while the problem is

occurring.

A fuel trim DTC may be triggered by a number of vehicle

faults. Make use of all information available (other

DTCs stored, rich or lean condition, etc.) when

diagnosing a fuel trim fault.

Fuel Trim Cell Diagnostic Weights

No fuel trim DTC will set regardless of the fuel trim

counts in cell 0 unless the fuel trim counts in the

weighted cells are also outside specifications. This

means that the vehicle could have a fuel trim problem

which is causing a problem under certain conditions (i.e.

engine idle high due to a small vacuum leak or rough

due to a large vacuum leak) while it operates fine at

other times. No fuel trim DTC would set (although an

engine idle speed DTC or HO2S DTC may set). Use a

Tech 2 to observe fuel trim counts while the problem is

occurring.

On-Board Diagnostic (OBD) System Check

TS321119

Circuit Description

The on-board diagnostic system check is the starting

point for any driveability complaint diagnosis. Before

using this procedure, perform a careful visual/physical

check of the PCM and engine grounds for cleanliness

and tightness.

The on-board diagnostic system check is an organized

approach to identifying a problem created by an

electronic engine control system malfunction.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation or a wire broken inside

the insulation. Check for poor connections or a

damaged harness. Inspect the PCM harness and

connector for improper mating, broken locks,

improperly formed or damaged terminals, poor

terminal-to-wire connection, and damaged harness.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart:

1. The MIL (“Check Engine”lamp) should be “ON”

steady with the ignition “ON”/engine “OFF.” If not,

Chart A-1 should be used to isolate the malfunction.

2. Checks the Class 2 data circuit and ensures that the

PCM is able to transmit serial data.

3. This test ensures that the PCM is capable of

controlling the MIL (“Check Engine”lamp) and the

MIL (“Check Engine”lamp) driver circuit is not

shorted to ground.

4. If the engine will not start, the Cranks But Will Not

Run chart should be used to diagnose the condition.

7. A Tech 2 parameter which is not within the typical

range may help to isolate the area which is causing

the problem.

Important: 10. This vehicle is equipped with a PCM

which utilizes an electrically erasable programmable

read only memory (EEPROM). The replacement PCM

must be programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

On-Board Diagnostic (OBD) System Check

StepActionValue(s)YesNo

1 1.Ignition “ON,” engine “OFF.”

2.Observe the malfunction indicator lamp (MIL or

“Check Engine” lamp).

Is the MIL (“Check Engine”lamp)“ON?” —Go to Step 2

Go to No MIL

(“Check

Engine”lamp)

2 1.Ignition “OFF.”

2.Install a Tech 2.

3.Ignition “ON.”

4.Attempt to display PCM engine data with the Tech

Does the Tech 2 display PCM data?—Go to Step 3Go to Step 8

3 1.Using the Tech 2 output tests function, select MIL

(“Check Engine”lamp) dash lamp control and

command the MIL (“Check Engine”lamp) “OFF.”

2.Observe the MIL (“Check Engine”lamp).

Did the MIL (“Check Engine”lamp) turn “OFF?”

3.Push the QUIT softkey to exit the test. (see

Note 1)—Go to Step 4

Go to MIL

(“Check

Engine”lamp)

On Steady

4 Attempt to start the engine.

Did the engine start and continue to run?

—Go to Step 5

Go to Cranks

But Will Not

Run

5 Select “Display DTCs” with the Tech 2.

Are any DTCs stored?—Go to Step 6Go to Step 7

6 Are two or more of the following DTCs stored?

P0107, P0108, P0113, P0118, P0122, P0123,

P0712.?

—

Go to “Multiple

PCM

Information

Sensor DTCs

Set”

Go to

applicable DTC

table

7 Compare PCM data values displayed on the Tech 2 to

the typical engine scan data values.

Are the displayed values normal or close to the typical

values?—

Refer toTypical

scan data value

Refer to

indicated

Component

System Checks

8 1.Ignition “OFF,” disconnect the PCM.

2.Ignition “ON,” engine “OFF.”

3.Check the Class 2 data circuit for an open, short

to ground, or short to voltage. Also, check the

DLC ignition feed circuit for an open or short to

ground and the DLC ground circuit for an open.

4.If a problem is found, repair as necessary.

Was a problem found?—Go to Step 2Go to Step 9

9 Attempt to display PCM data with the Tech 2.

Does the Tech 2 display PCM engine data?—Go to Step 2Go to Step 10

10 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Important: Is the action complete?—Go to Step 2 —

Note 1

Failure to exit the MIL test at Step 3 with the “QUIT” softkey may result in a false DTC P1850 -

“Band Apply Solenoid Failure” being set in the PCM.

A/C Clutch Control Circuit Diagnosis

D06RW085

Circuit Description

When air conditioning and blower fan are selected, and

if the system has a sufficient refrigerant charge, a

12-volt signal is supplied to the A/C request input of the

powertrain control module (PCM). The A/C request

signal may be temporarily canceled during system

operation by the electronic thermostat in the evaporator

case. The electronic thermostat may intermittently

remove the control circuit ground for the A/C thermostat

relay to prevent the evaporator from forming ice. When

the A/C request signal is received by the PCM, the PCM

supplies a ground from the compressor clutch relay if

the engine operating conditions are within acceptable

ranges. With the A/C compressor relay energized,

voltage is supplied to the compressor clutch coil.

The PCM will enable the compressor clutch to engage

whenever A/C has been selected with the engine

running, unless any of the following conditions are

present:

• The throttle is greater than 90%.

• The ignition voltage is below 10.5 volts.

• The engine speed is greater than 4500 RPM for 5

seconds or 5400 RPM.

• The engine coolant temperature (ECT) is greater

than 125 °C (257 °F).

• The intake air temperature (IAT) is less than 5°C

(41°F).

• The power steering pressure switch signals a

cramped position.

Diagnostic Aids

To diagnose an the intermittent fault, check for the

following conditions:

• Poor connection at the PCM–Inspect connections for

backed-out terminals, improper mating, broken locks,

improperly formed or damaged terminals, and poor

terminal-to-wire connection.

•Damaged harness–Inspect the wiring harness for

damage. If the harness appears to OK, observe the

A/C clutch while moving connectors and wiring

harnesses related to the A/C. A sudden clutch

malfunction will indicate the source of the intermittent

fault.

A/C Clutch Diagnosis

This chart should be used for diagnosing the electrical

portion of the A/C compressor clutch circuit. A Tech 2

will be used in diagnosing the system. The Tech 2 has

the ability to read the A/C request input to the PCM.

The Tech 2 can display when the PCM has commanded

the A/C clutch “ON.” The Tech 2 should have the ability

to override the A/C request signal and energize the A/C

compressor relay.

Test Description

Important: Do not engage the A/C compressor clutch

with the engine running if an A/C mode is not selected

at the A/C control switch.

The numbers below refer to the step numbers on the

Diagnostic Chart:

3. This a test determine is the problem is with the

refrigerant system. If the switch is open, A/C

pressure gauges will be used to determine if the

pressure switch is faulty or if the system is partially

discharged or empty.

4. Although the normal complaint will be the A/C clutch

failing to engage, it is possible for a short circuit to

cause the clutch to run when A/C has not been

selected. This step is a test for that condition.

7. There is an extremely low probability that both relays

will fail at the same time, so the substitution process

is one way to check the A/C Thermostat relay. Use a

known good relay to do a substitution check.

9. The blower system furnishes a ground for the A/C

control circuit, and it also shares a power source

through the Heater and A/C Relay. The blower must

be “ON” in order to test the A/C system.

A/C Clutch Control Circuit Diagnosis

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 Are any other DTCs stored?

—

Go to the other

DTC chart(s)

firstGo to Step 3

3 1.Disconnect the electrical connector at the

pressure switch located on the receiver/drier.

2.Use an ohmmeter to check continuity across the

pressure switch.

Is the pressure switch open? —

Go to Air

Conditioning to

diagnose the

cause of the

open pressure

switchGo to Step 4

4 Important: Before continuing with the diagnosis, the

following conditions must be met:

• The intake air temperature must be greater than

15°C. (60°F).

• The engine coolant temperature must be less than

119°C (246°F).

1. A/C “OFF.”

2. Start the engine and idle for 1 minute.

3. Observe the A/C compressor.

Is the A/C compressor clutch engaged even though A/

C has not been requested? — Go to Step 45 Go to Step 5

5 1. Idle the engine.

2. A/C“ON”.

3. Blower“ON”.

4. Observe the A/C compressor.

Is the A/C compressor magnetic clutch engaged? —

Refer to

Diagnostic Aids Go to Step 6

6 1. Engine idling.

2. A/C“ON”.

3. Blower“ON”.

4. Observe the “A/C Request” display on the Tech 2.

Does the tool “A/C Request” display indicate “Yes?” — Go to Step 34 Go to Step 7

7 Temporarily substitute the A/C compressor relay in

place of the A/C thermostat relay, then repeat Step 5.

Did the “A/C Request” display indicate “Yes?” — Go to Step 8 Go to Step 9

8 Replace the original A/C thermostat relay.

Is the action complete? — Verify repair —

9 Dose the blower operate? — Go to Step 10 Go to Step 11

10 Repair the blower.

Is the action complete? — Verify repair —

11 Check for a faulty 10a A/C fuse in the underdash fuse

panel.

Was the 10A fuse OK? — Go to Step 13 Go to Step 12

12 Check for short circuit and make repairs if necessary.

Replace the 10A A/C fuse.

Is the action complete? — Verify repair —

13 1. Ignition “ON.”

2. Use a DVM to check voltage at the positive A/C

switch wire (BRN).

Was voltage equal to the specified value? +B Go to Step 15 Go to Step 14

14 Repair the open wire (BRN) between the A/C switch

and the A/C fuse.

Is the action complete? — Verify repair —

15 1. Remove the glove box to gain access to the A/C

thermostat.

2. Disconnect the thermostat connector.

3. Attach a fused jumper between ground and the

PNK/GRN wire at the thermostat.

4. A/C “ON.”

5. Blower “ON.”

Dose A/C request indicate “YES” on the Tech 2? — Go to Step 16 Go to Step 23

16 1. Ignition “ON.”

2. Use a DVM to check voltage at the electronic A/C

thermostat.

Was voltage equal to the specified value? +B Go to Step 20 Go to Step 17

17 Check for an open (LT GRN) between the thermostat

and the A/C switch.

Was the wire open? — Go to Step 18 Go to Step 19

18 Repair the open wire (LT GRN) between the

thermostat and the A/C switch.

Is the action complete? — Verify repair —

19 Replace the A/C switch.

Is the action complete? — Verify repair —

20 Use an ohmmeter to check continuity between the

electronic A/C thermostat and the blower switch.

Was there an open circuit? — Go to Step 21 Go to Step 22

Step Action Value(s) Yes No

21 Repair the open wire (GRN/YEL) between the

thermostat and the blower switch.

Is the action complete?—Verify repair—

22 Replace the electronic A/C thermostat.

Is the an action complete?—Verify repair—

23 Check for an open circuit between A/C thermostat

relay and PCM A/C request terminal (E-15).

Was there an open circuit?—Go to Step 24Go to Step 25

24 Repair the open circuit between the PCM and A/C

thermostat relay.

Is the action complete?—Verify repair—

25 Check for an open circuit between the A/C switch (LT

GRN) and the A/C thermostat relay (LT GRN).

Was there an open circuit?—Go to Step 26Go to Step 27

26 Repair the open circuit between the A/C switch and

the A/C thermostat relay.

Is the action complete?—Verify repair—

27 1.Ignition “ON.”

2.Use a DVM to check voltage at the A/C pressure

switch (BRN).

Was voltage equal to the specified value?+BGo to Step 29Go to Step 28

28 Repair the open circuit between the 10A A/C fuse and

the pressure switch.

Is the action complete?—Verify repair—

29 Use an ohmmeter to check continuity between the

pressure switch (GRN/WHT) and the A/C thermostat

relay (GRN/WHT).

Was the circuit open?—Go to Step 30Go to Step 31

30 Repair the open circuit between the pressure switch

and the A/C thermostat relay.

Is the action complete?—Verify repair—

31 Check for damaged pin or terminal at E-15 of the

PCM.

Was a damaged pin or terminal found?—Go to Step 32Go to Step 33

32 Repair the damaged pin or terminal.

Is the action complete?—Verify repair—

33 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

34 1. Remove the A/C compressor relay.

2. Ignition “ON.”

3. Use a DVM to check voltage at both of the BRN

wires at the A/C compressor relay socket.

Is the voltage equal to the specified value? +B Go to Step 36 Go to Step 35

35 Repair the faulty BRN wire between the A/C fuse and

the A/C compressor relay .

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

36 1. A/C compressor relay removed.

2. Engine idling.

3. A/C “ON.”

4. Blower “ON.”

5. Use a DVM to measure voltage between the GRN/

BLK wire at the A/C compressor relay socket and

battery±.

Did the DVM indicate the specified value? +B Go to Step 40 Go to Step 37

37 Check for an open GRN/BLK wire between PCM

terminal B-14 and the A/C compressor relay.

Was the wire open? — Go to Step 38 Go to Step 39

38 Repair the open GRN/BLK wire between the PCM and

the A/C compressor relay.

Is the action complete? — Verify repair —

39 Check for a damaged pin or terminal at B-14 of the

PCM.

Was a damaged pin or a terminal found? — Go to Step 32 Go to Step 33

40 1. A/C compressor relay removed.

2. Connect a fused jumper at the A/C compressor

relay socket between either BRN wire and the

BRN/YEL wire.

3. Engine idling.

4. A/C “ON.”

5. Blower “ON.”

Did the compressor magnetic clutch engage? — Go to Step 41 Go to Step 42

41 Repair the A/C compressor relay.

Is the action complete? — Verify repair —

42 Check for an open circuit between the A/C

compressor relay and the A/C clutch.

Was an open circuit found? — Go to Step 43 Go to Step 44

43 Repair the open circuit between the compressor

Clutch and the A/C compressor relay.

Is the action complete? — Verify repair —

44 Service the compressor clutch or replace the

compressor due to a faulty internal overheat switch.

Is the action complete? — Verify repair —

45 1. Remove the A/C compressor relay.

2. Idle the engine.

Is the compressor clutch still engaged when A/C is not

selected? — Go to Step 46 Go to Step 47

46 Repair the short to voltage between the A/C clutch

and A/C compressor relay.

Is the action complete? — Verify repair —

47 1. Reinstall the A/C compressor relay.

2. Remove the A/C thermostat relay.

3. Engine idling.

Is the compressor clutch still engaged when A/C is not

selected? — Go to Step 48 Go to Step 50

48 Use a DVM to check for a short to ground between the

A/C compressor relay and B-14 of the PCM.

Was a short detected? — Go to Step 49 Go to Step 33

Step Action Value(s) Yes No

49 Repair the short to ground between the PCM and A/C

compressor relay.

Is the action complete? — Verify repair —

50 Repair the short to ground between the A/C

thermostat relay and the electronic thermostat.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Electronic Ignition System Diagnosis

If the engine cranks but will not run or immediately

stalls, the Engine Cranks But Will Not Start chart must

be used to determine if the failure is the ignition system

or the fuel system. If DTC P0341, or P0336 is set, the

appropriate diagnostic trouble code chart must be used

for diagnosis.

If a misfire is being experienced with no DTC set, refer

to the Symptoms section for diagnosis.

Fuel Metering System Check

Some failures of the fuel metering system will result in

an “Engine Cranks But Will Not Run” symptom. If this

condition exists, refer to the Cranks But Will Not Run

chart. This chart will determine if the problem is caused

by the ignition system, the PCM, or the fuel pump

electrical circuit.

Refer to Fuel System Electrical Test for the fuel system

wiring schematic.

If there is a fuel delivery problem, refer to Fuel System

Diagnosis, which diagnoses the fuel injectors, the fuel

pressure regulator, and the fuel pump. If a malfunction

occurs in the fuel metering system, it usually results in

either a rich HO2S signal or a lean HO2S signal. This

condition is indicated by the HO2S voltage, which

causes the PCM to change the fuel calculation (fuel

injector pulse width) based on the HO2S reading.

Changes made to the fuel calculation will be indicated

by a change in the long term fuel trim values which can

be monitored with a Tech 2. Ideal long term fuel trim

values are around 0%; for a lean HO2S signal, the PCM

will add fuel, resulting in a fuel trim value above 0%.

Some variations in fuel trim values are normal because

all engines are not exactly the same. If the fuel trim

values are greater than +23%, refer to DTC P0131,

DTC P0151, DTC P0171, and DTC 1171 for items

which can cause a lean HO2S signal.

Idle Air Control (IAC) Valve

The Tech 2 displays the IAC pintle position in counts. A

count of “0” indicates the PCM is commanding the IAC

pintle to be driven all the way into a fully-seated

position. This is usually caused by a large vacuum leak.

The higher the number of counts, the more air is being

commanded to bypass the throttle blade. Refer to IAC

System Check in order to diagnose the IAC system.

Refer to Rough, Unstable, or Incorrect Idle, Stalling in

Symptoms for other possible causes of idle problems.

Fuel System Pressure Test

A fuel system pressure test is part of several of the

diagnostic charts and symptom checks. To perform this

test, refer to Fuel Systems Diagnosis.

Fuel Injector Coil Test Procedure and

Fuel Injector Balance Test Procedure

T32003

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart:

2. Relieve the fuel pressure by connecting the

5-8840-0378-0 Fuel Pressure Gauge to the fuel

pressure connection on the fuel rail.

CAUTION: In order to reduce the risk of fire and

personal injury, wrap a shop towel around the fuel

pressure connection. The towel will absorb any

fuel leakage that occurs during the connection of

the fuel pressure gauge. Place the towel in an

approved container when the connection of the fuel

pressure gauge is complete.

Place the fuel pressure gauge bleed hose in an

approved gasoline container.

With the ignition switch “OFF,” open the valve on the

fuel pressure gauge.

3. Record the lowest voltage displayed by the DVM

after the first second of the test. (During the first

second, voltage displayed by the DVM may be

inaccurate due to the initial current surge.)

Injector Specifications:

• The voltage displayed by the DVM should be

within the specified range.

• The voltage displayed by the DVM may increase

throughout the test as the fuel injector windings

warm and the resistance of the fuel injector

windings changes.

• An erratic voltage reading (large fluctuations in

voltage that do not stabilize) indicates an

intermittent connection within the fuel injector.

Resistance Ohms Voltage Specification at

10°C-35°C (50°F-95°F)

11.8 – 12.6 5.7 – 6.6

5. Injector Specifications: 7. The Fuel Injector Balance Test portion of this chart

(Step 7 through Step 11) checks the mechanical (fuel

delivery) portion of the fuel injector. An engine

cool-down period of 10 minutes is necessary in order

to avoid irregular fuel pressure readings due to “Hot

Soak” fuel boiling.

Injector Coil Test Procedure (Steps 1-6) and Injector Balance Test Procedure

(Steps 7-11)

R262001

NOTE: These figures are examples only.

Highest Acceptable

Voltage Reading Above/

Below 35°C/10°C (95°F/

50°F)

Acceptable Subtracted

Value

9.5 Volts 0.6 Volts

CYLINDER 1 2 3 4 5 6

1st Reading (1) 296kPa

(43psi)

296kPa

(43psi)

296kPa

(43psi)

296kPa

(43psi)

296kPa

(43psi)

296kPa

(43psi)

2nd Reading (2) 131kPa

(19psi)

117 kPa

(17psi)

124kPa

(18psi)

145kPa

(21psi)

131kPa

(19psi)

130kPa

(19psi)

Amount of Drop (1st

Reading–2nd Reading)

165kPa

(24psi)

179kPa

(26psi)

172kPa

(25psi)

151kPa

(22psi)

165kPa

(24psi)

166kPa

(24psi)

Av.drop = 166 kPa/24 psi ±

10 kPa/1.5 psi

= 156–176 kPa or 22.5–

25.5psi

OK Faulty, Rich

(Too Much

Fuel Drop)

OK Faulty, Lean

(Too Little

Fuel Drop)

OK OK

Injector Coil Test Procedure (Steps 1-6) and Injector Balance Test Procedure (Steps 7-11)

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 1.Turn the engine “OFF.”

NOTE: In order to prevent flooding of a single cylinder

and possible engine damage, relieve the fuel pressure

before performing the fuel injector coil test procedure.

2.Relieve the fuel pressure. Refer to Test

Description Number 2.

3.Connect the 5-8840-2638-0 Fuel Injector Tester to

B+ and ground, and to the 5-8840-2619-0 Injector

Switch Box.

4.Connect the injector switch box to the grey fuel

injector harness connector located on the front of

the EVAP canister bracket.

5.Set the amperage supply selector switch on the

fuel injector tester to the “Coil Test” 0.5 amp

position.

6.Connect the leads from the 5-8840-0285-0 Digital

Voltmeter (DVM) to the injector tester. Refer to

the illustrations associated with the test

description.

7.Set the DVM to the tenths scale (0.0).

8.Observe the engine coolant temperature.

Is the engine coolant temperature within the specified

values?

10°C (50°F)

to 35°C

(95°F)Go to Step 3Go to Step 5

3 1.Set injector switch box injector #1.

2.Press the “Push to Start Test” button on the fuel

injector tester.

3.Observe the voltage reading on the DVM.

Important: The voltage reading may rise during the

test.

4. Record the lowest voltage observed after the first

second of the test.

5. Set the injector switch box to the next injector and

repeat steps 2, 3, and 4.

Did any fuel injector have an erratic voltage reading

(large fluctuations in voltage that did not stabilize) or a

voltage reading outside of the specified values? 5.7-6.6 V Go to Step 4 Go to Step 7

4 Replace the faulty fuel injector(s). Refer to Fuel

Injector.

Is the action complete? — Go to Step 7 —

5 1.Set injector switch box injector #1.

2.Press the “Push to Start Test” button on the fuel

injector tester.

3.Observe the voltage reading on the DVM.

Important: The voltage reading may rise during the

test.

4.Record the lowest voltage observed after the first

second of the test.

5.Set the injector switch box to the next injector and

repeat steps 2, 3, and 4.

Did any fuel injector have an erratic voltage reading

(large fluctuations in voltage that did not stabilize) or a

voltage reading above the specified value?9.5 VGo to Step 4Go to Step 6

6 1.Identify the highest voltage reading recorded

(other than those above 9.5 V).

2.Subtract the voltage reading of each injector from

the highest voltage selected in step 1. Repeat

until you have a subtracted value for each injector.

For any injector, is the subtracted Value in step 2

greater than the specified value?0.6 VGo to Step 4Go to Step 7

7 CAUTION: In order to reduce the risk of fire and

personal injury, wrap a shop towel around the fuel

pressure connection. The towel will absorb any

fuel leakage that occurs during the connection of

the fuel pressure gauge. Place the towel in an

approved container when the connection of the

fuel pressure gauge is complete.

1. Connect the 5-8840-0378-0 Fuel Pressure Gauge

to the fuel pressure test port.

2. Energize the fuel pump using the scan tool.

3. Place the bleed hose of the fuel pressure gauge

into an approved gasoline container.

4. Bleed the air out of the fuel pressure gauge.

5. With the fuel pump running, observe the reading

on the fuel pressure gauge.

Is the fuel pressure within the specified values?

296-376kPa

(43-55psi) Go to Step 8

Go to Fuel

System

Diagnosis

8 Turn the fuel pump “OFF.”

Does the fuel pressure remain constant?

—Go to Step 9

Go to Fuel

System

Diagnosis

Step Action Value(s) Yes No

9 1. Connect the 5-8840-2638-0 Fuel Injector Tester

and 5-8840-2619-0 Injector Switch Box the fuel

injector harness connector.

2. Set the amperage supply selector switch on the

fuel injector tester to the “Balance Test” 0.5–2.5

amp position.

3. Using the scan tool turn the fuel pump “ON” then

“OFF” in order to pressurize the fuel system.

4. Record the fuel pressure indicated by the fuel

pressure gauge after the fuel pressure stabilizes.

This is the first pressure reading.

5. Energize the fuel injector by depressing the “Push

to Start Test” button on the fuel injector tester.

6. Record the fuel pressure indicated by the fuel

pressure gauge after the fuel pressure gauge

needle has stopped moving. This is the second

pressure reading.

7. Repeat steps 1 through 6 for each fuel injector.

8. Subtract the second pressure reading from the

first pressure reading for one fuel injector. The

result is the pressure drop value.

9. Obtain a pressure drop value for each fuel injector.

10. Add all of the individual pressure drop values.

This is the total pressure drop.

11. Divide the total pressure drop by the number of

fuel injectors. This is the average pressure drop.

Does any fuel injector have a pressure drop value that

is either higher than the average pressure drop or

lower than the average pressure drop by the specified

value?

10kPa

(1.5psi) Go to Step 10

Go to OBD

System Check

10 Re-test any fuel injector that does not meet the

specification. Refer to the procedure in step 11.

NOTE: Do not repeat any portion of this test before

running the engine in order to prevent the engine from

flooding.

Does any fuel injector still have a pressure drop value

that is either higher than the average pressure drop or

lower than the average pressure drop by the specified

value?

10kPa

(1.5psi) Go to Step 11

Go to

Symptoms

11 Replace the faulty fuel injector(s). Refer to Fuel

Injector.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Knock Sensor Diagnosis

The Tech 2 has two data displays available for

diagnosing the knock sensor (KS) system. The two

displays are described as follows:

•“Knock Retard” indicates the number of degrees that

the spark timing is being retarded due to a knock

condition.

•“KS Noise Channel” indicates the current voltage

level being monitored on the noise channel.

DTCs P0325 and P0327 are designed to diagnose the

KS module, the knock sensor, and the related wiring.

The problems encountered with the KS system should

set a DTC. However, if no DTC was set but the KS

system is suspect because of a detonation complaint,

refer to Detonation/Spark Knock in Symptoms.

Powertrain Control Module (PCM)

Diagnosis

To read and clear diagnostic trouble codes, use a Tech

Important: Use of a Tech 2 is recommended to clear

diagnostic trouble codes from the PCM memory.

Diagnostic trouble codes can also be cleared by turning

the ignition “OFF” and disconnecting the battery power

from the PCM for 30 seconds. Turning off the ignition

and disconnecting the battery power from the PCM will

cause all diagnostic information in the PCM memory to

be cleared. Therefore, all the diagnostic tests will have

to be re-run.

Since the PCM can have a failure which may affect only

one circuit, following the diagnostic procedures in this

section will determine which circuit has a problem and

where it is.

If a diagnostic chart indicates that the PCM connections

or the PCM is the cause of a problem, and the PCM is

replaced, but this does not correct the problem, one of

the following may be the reason:

•There is a problem with the PCM terminal

connections. The terminals may have to be removed

from the connector in order to check them properly.

•The problem is intermittent. This means that the

problem is not present at the time the system is being

checked. In this case, refer to the Symptoms portion

of the manual and make a careful physical inspection

of all component and wiring associated with the

affected system.

•There is a shorted solenoid, relay coil, or harness.

Solenoids and relays are turned “ON” and “OFF” by

the PCM using internal electronic switches called

drivers. A shorted solenoid, relay coil, or harness will

not damage the PCM but will cause the solenoid or

relay to be inoperative.

Multiple PCM Information Sensor

DTCS Set

Circuit Description

The powertrain control module (PCM) monitors various

sensors to determine the engine operating conditions.

The PCM controls fuel delivery, spark advance,

transmission operation, and emission control device

operation based on the sensor inputs.

The PCM provides a sensor ground to all of the

sensors. The PCM applies 5 volts through a pull-up

resistor, and determines the status of the following

sensors by monitoring the voltage present between the

5-volt supply and the resistor:

•The engine coolant temperature (ETC) sensor

•The intake air temperature (IAT) sensor

•The transmission fluid temperature (TFT) sensor

The PCM provides the following sensors with a 5-volt

reference and a sensor ground signal:

•The exhaust gas recirculating (EGR) pintle position

sensor

•The throttle position (TP) sensor

•The manifold absolute pressure (MAP) sensor

The PCM monitors the separate feedback signals from

these sensors in order to determine their operating

status.

Diagnostic Aids

Important: Be sure to inspect PCM and engine

grounds for being secure and clean.

A short to voltage in one of the sensor input circuits may

cause one or more of the following DTCs to be set:

•P0108

•P0113

•P0118

•P0123

•P0560

•P0712

•P0406

Important: If a sensor input circuit has been shorted to

voltage, ensure that the sensor is not damaged. A

damaged sensor will continue to indicate a high or low

voltage after the affected circuit has been repaired. If

the sensor has been damaged, replace it.

An open in the sensor ground circuit between the PCM

and the splice will cause one or more of the following

DTCs to be set:

• P0108

•P0113

•P0118

• P0123

• P0712

• P0406

A short to ground in the 5-volt reference A or B circuit

will cause one or more of the following DTCs to be set:

•P0107

•P0122

In the 5-volt reference circuit A, between the PCM and

the splice, will cause one or more of the following DTCs

to be set:

•P0122

In the 5-volt reference circuit B, between the PCM and

the splice, will cause one or more of the following DTCs

to be set:

•P0107

Check for the following conditions:

•Poor connection at PCM.

Inspect the harness connectors for backed-out

terminals, improper mating, broken locks, improperly

formed or damage terminals, and a poor

terminal-to-wire connection.

•Damaged harness.

Inspect the wiring harness for damage. If the

harness is not damaged, observe an affected

sensor's displayed value on the Tech 2 with the

ignition “ON” and the engine “OFF” while you move

the connectors and the wiring harnesses related to

the following sensors:

•IAT

•ECT

•TP

•MAP

•EGR

•TFT

Multiple PCM Information Sensor DTCs Set

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Turn the ignition “OFF,” disconnect the PCM.

2. Turn the ignition “ON,” check the 5 volt reference

A circuit for the following conditions:

• A poor connection at the PCM.

• An open between the PCM connector and the

splice.

• A short to ground.

• A short to voltage.

Is there an open or short? — Go to Step 3 Go to Step 4

3 Repair the open or short.

Is the action complete? — Verify repair —

4 Check the sensor ground circuit for the following

conditions:

• A poor connection at the PCM or the affected

sensors.

• An open between the PCM connector and the

affected sensors.

Is there an open or a poor connection? — Go to Step 5 Go to Step 6

5 Repair the open or the poor connection.

Is the action complete? — Verify repair —

6 Measure the voltage between the EGR pintle position

sensor signal circuit at the PCM harness connector

and ground.

Does the voltage measure near the specified value? 0 V Go to Step 7 Go to Step 12

7 Measure the voltage between the MAP sensor signal

circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value? 0 V Go to Step 8 Go to Step 15

8 Measure the voltage between the TP sensor signal

circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value? 0 V Go to Step 9 Go to Step 16

9 Measure the voltage between the IAT sensor signal

circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value? 0 V Go to Step 10 Go to Step 17

10 Measure the voltage between the ECT sensor signal

circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?0 VGo to Step 11Go to Step 18

11 1.Disconnect the EGR valve.

2.Measure the voltage between the EGR pintle

position sensor signal circuit at the PCM harness

connector and ground.

Does the voltage measure near the specified value?0 VGo to Step 13Go to Step 18

12 Measure the voltage between the TFT sensor signal

circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?0 VGo to Step 20Go to Step 19

13 Replace the EGR valve.

Is the action complete?—Verify repair—

14 Locate and repair the short to voltage in the MAP

sensor signal circuit.

Is the action complete?—Verify repair—

15 Locate and repair the short to voltage in the TP sensor

signal circuit.

Is the action complete?—Verify repair—

16 Locate and repair the short to voltage in the IAT

sensor signal circuit.

Is the action complete?—Verify repair—

17 Locate and repair the short to voltage in the ECT

sensor signal circuit.

Is the action complete?—Verify repair—

18 Locate and repair the short to voltage in the EGR

pintle position sensor signal circuit.

Is the action complete?—Verify repair—

19 Locate and repair the short to voltage in the TFT

sensor signal circuit.

Is the action complete?—Verify repair—

20 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? —

Go to OBD

System Check —

Step Action Value(s) Yes No

Exhaust Gas Recirculation (EGR)

Diagnosis

Pintle position error diagnosis is covered by DTC

P0402, P0404, P1404, P0405, P0406. If EGR

diagnostic trouble codes P0402, P0404, P1404, P0405,

P0406 are encountered, refer to the DTC charts.

Engine Tech 2 Data Definitions and

Ranges

A/C CLUTCH – Tech 2 Displays ON or OFF –

Indicates whether the PCM has commanded the A/C

clutch ON. Used in A/C system diagnostic.

A/C REQUEST — Tech 2 Displays YES or NO —

Indicates the state of the A/C request input circuit from

the HVAC controls. The PCM uses the A/C request

signal to determine whether A/C compressor operation

is being requested.

AIR/FUEL RATIO — Tech 2 Range 0.0-25.5 —

Air/fuel ratio indicates the PCM commanded value. In

closed loop, the air/fuel ratio should normally be

displayed around “14.2-14.7.” A lower air/fuel ratio

indicates a richer commanded mixture, which may be

seen during power enrichment or TWC protection

modes. A higher air/fuel ratio indicates a leaner

commanded mixture. This can be seen during

deceleration fuel mode.

BAROMETRIC PRESSURE — Tech 2 Range 10-105

kPa/0.00-5.00 Volts —

The barometric pressure reading is determined from the

MAP sensor signal monitored during key up and wide

open throttle (WOT) conditions. The barometric

pressure is used to compensate for altitude differences

and is normally displayed around “61-104” depending

on altitude and barometric pressure.

CHECK TRANS LAMP — AUTO TRANSMISSION —

Indicates the need to check for a DTC with the Tech 2

when the lamp is flashing 0.2 seconds ON and 0.2

seconds OFF.

CMP ACT. COUNTER – Cam Position Activity

DECEL FUEL MODE — Tech 2 Display ACTIVE or

INACTIVE —

“ACTIVE” displayed indicates that the PCM has

detected conditions appropriate to operate in

deceleration fuel mode. The PCM will command the

deceleration fuel mode when it detects a closed throttle

position while the vehicle is traveling over 20 mph.

While in the deceleration fuel delivered by entering

open loop and decreasing the injector pulse width.

DESIRED EGR POS. — Tech 2 Range 0%-100% —

Represents the EGR pintle position that the PCM is

commanding.

DESIRED IDLE — Tech 2 Range 0-3187 RPM —

The idle speed that the PCM is commanding. The PCM

will compensate for various engine loads based on

engine coolant temperature, to keep the engine at the

desired speed.

ECT — (Engine Coolant Temperature) Tech 2 Range

–40°C to 151°C (–40°F to 304°F) —

The engine coolant temperature (ECT) is mounted in

the coolant stream and sends engine temperature

information to the PCM. The PCM applies 5 volts to the

ECT sensor circuit. The sensor is a thermistor which

changes internal resistance as temperature changes.

When the sensor is cold (high resistance), the PCM

monitors a high signal voltage and interprets that as a

cold engine. As the sensor warms (decreasing

resistance), the voltage signal will decrease and the

PCM will interpret the lower voltage as a warm engine.

EGR DUTY CYCLE — Tech 2 Range 0%-100% —

Represents the EGR valve driver PWM signal from the

PCM. A duty cycle of 0% indicates that no EGR flow is

being commanded; a 100% duty cycle indicates

maximum EGR flow commanded.

EGR FEEDBACK — Tech 2 Range 0.00-5.00 Volts —

Indicates the EGR pintle position sensor signal voltage

being monitored by the PCM. A low voltage indicates a

fully extended pintle (closed valve); a voltage near 5

volts indicates a retracted pintle (open valve).

ENGINE LOAD — Tech 2 Range 0%-100% —

Engine load is calculated by the PCM from engine

speed and MAF sensor readings. Engine load should

increase with an increase in RPM or air flow.

ENGINE RUN TIME — Tech 2 Range

00:00:00-99:99:99 Hrs:Min:Sec —

Indicates the time elapsed since the engine was started.

If the engine is stopped, engine run time will be reset to

00:00:00.

ENGINE SPEED — Range 0-9999 RPM —

Engine speed is computed by the PCM from the 58X

reference input. It should remain close to desired idle

under various engine loads with engine idling.

FUEL PUMP — Tech 2 Displays ON or OFF —

Indicates the PCM commanded state of the fuel pump

relay driver circuit.

FUEL TRIM CELL — Tech 2 Range 0-21 —

The fuel trim cell is dependent upon engine speed and

MAF sensor readings. A plot of RPM vs. MAF is

divided into 22 cells. Fuel trim cell indicates which cell

is currently active.

FUEL TRIM LEARN — Tech 2 Displays NO or YES —

When conditions are appropriate for enabling long term

fuel trim corrections, fuel trim learn will display “YES.”

This indicates that the long term fuel trim is responding

to the short term fuel trim. If the fuel trim learn displays

“NO,” then long term fuel trim will not respond to

changes in short term fuel trim.

HO2S BANK 1, SEN. 1 — Tech 2 Range 0-1132 mV —

Represents the fuel control exhaust oxygen sensor

output voltage. Should fluctuate constantly within a

range between 10 mV (lean exhaust) and 1000 mV (rich

exhaust) while operating in closed loop.

HO2S BANK2, SEN. 1—Tech 2 Range 0-1132 mV—

Represents the fuel control exhaust oxygen sensor

output voltage. Should fluctuate constantly within a

range between 10mV (lean exhaust) and 1000 mV (rich

exhaust) while operating in closed loop.

HO2S BANK 1, SEN. 1—Tech 2 Displays NOT

READY or READY—

Indicates the status of the exhaust oxygen sensor. The

Tech 2 will indicate that the exhaust oxygen sensor is

ready when the PCM detects a fluctuating HO2S

voltage sufficient to allow closed loop operation. This

will not occur unless the exhaust oxygen sensor is

warmed up.

HO2S BANK 2, SEN. 1 — Tech 2 Displays NOT

READY or READY —

Indicates the status of the exhaust oxygen sensor. The

Tech 2 will indicate that the exhaust oxygen sensor is

ready when the PCM detects a fluctuating HO2S

voltage sufficient to allow closed loop operation. This

will not occur unless the exhaust oxygen sensor is

warmed up.

HO2S WARM UP TIME BANK 1, SEN. 1/BANK 2 SEN.

1 — Tech 2 Range 00:00:00-99:99:99 HRS:MIN:SEC

—

Indicates warm-up time for each HO2S. The HO2S

warm-up time is used for the HO2S heater test. The

PCM will run the heater test only after a cold start

(determined by engine coolant and intake air

temperature at the time of start-up) and only once

during an ignition cycle. When the engine is started the

PCM will monitor the HO2S voltage. When the HO2S

voltage indicates a sufficiently active sensor, the PCM

looks at how much time has elapsed since start-up. If

the PCM determines that too much time was required

for the HO2S to become active, a DTC will set. If the

engine was warm when started, HO2S warm-up will the

display“00:00:00”.

IAC POSITION — Tech 2 Range 0-255 Counts —

Displays the commanded position of the idle air control

pintle in counts. A larger number of counts means that

more air is being commanded through the idle air

passage. Idle air control should respond fairly quickly to

changes in engine load to maintain desired idle RPM.

IAT (INTAKE AIR TEMPERATURE) — Tech 2 Range –

40°C to 151°C (–40°F to 304°F) —

The PCM converts the resistance of the intake air

temperature sensor to degrees. Intake air temperature

(IAT) is used by the PCM to adjust fuel delivery and

spark timing according to incoming air density.

IGNITION 1 — Tech 2 Range 0-25.5 Volts —

This represents the system voltage measured by the

PCM at its ignition feed.

INJ. PULSE BANK 1/INJ. PULSE BANK 2 — Tech 2

Range 0-1000 msec. —

Indicates the amount of time the PCM is commanding

each injector “ON” during each engine cycle. A longer

injector pulse width will cause more fuel to be delivered.

Injector pulse width should increase with increased

engine load.

KS NOISE CHANNEL (Knock Sensor) —

Indicates the output from the KS noise channel. There

is always some electrical noise in an engine

compartment and to avoid mistaking this as engine

knock, the output from the knock sensor is compared to

the output from the noise channel. A knock condition is

not set unless t he knock sensor output is greater than

the noise channel output.

LONG TERM FUEL TRIM BANK 1/BANK 2 —

The long term fuel trim is derived from the short term

fuel trim values and represents a long term correction of

fuel delivery for the bank in question. A value of 0%

indicates that fuel delivery requires no compensation to

maintain the PCM commanded air/fuel ratio. A negative

value significantly below 0% indicates that the fuel

system is rich and fuel delivery is being reduced

(decreased injector pulse width). A positive value

significantly greater than 0% indicates that a lean

condition exists and the PCM is compensating by

adding fuel (increased injector pulse width). Because

long term fuel trim tends to follow short term fuel trim, a

value in the negative range due to canister purge at idle

should not be considered unusual. Fuel trim values at

maximum authority may indicate an excessively rich or

lean system.

LOOP STATUS — Tech 2 Displays OPEN or CLOSED

—

“CLOSED” indicates that the PCM is controlling fuel

delivery according to oxygen sensor voltage. In “OPEN”

the PCM ignores the oxygen sensor voltage and bases

the amount of fuel to be delivered on TP sensor, engine

coolant, and MAF sensor inputs only.

MAF — Tech 2 Range 0.0-512 gm/s —

MAF (mass air flow) is the MAF input frequency

converted to grams of air per second. This indicates the

amount of air entering the engine.

MAP — Tech 2 Range 10-105 kPa (0.00-4.97 Volts) —

The manifold absolute pressure (MAP) sensor

measures the change in the intake manifold pressure

from engine load, EGR flow, and speed changes. As

intake manifold pressure increases, intake vacuum

decreases, resulting in a higher MAP sensor voltage

and kPa reading. The MAP sensor signal is used to

monitor intake manifold pressure changes during the

EGR flow test, to update the BARO reading, and as an

enabling factor for several of the diagnostics.

MIL — Tech 2 Displays ON or OFF —

Indicates the PCM commanded state of the malfunction

indicator lamp.

POWER ENRICHMENT — Tech 2 Displays ACTIVE

or INACTIVE —

“ACTIVE” displayed indicates that the PCM has

detected conditions appropriate to operate in power

enrichment mode. The PCM will command power

enrichment mode when a large increase in throttle

position and load is detected. While in power

enrichment mode, the PCM will increase the amount of

fuel delivered by entering open loop and increasing the

injector pulse width. This is done to prevent a possible

sag or hesitation from occurring during acceleration.

SPARK — Tech 2 Range –64° to 64° —

Displays the amount of spark advance being

commanded by the PCM on the IC circuit.

START-UP ECT — Tech 2 Range –40°C to 151°C (–

40°F to 304°F) —

Indicates the engine coolant temperature at the time

that the vehicle was started. Used by the HO2S

diagnostic to determine if the last start-up was a cold

start.

START-UP IAT — Tech 2 Range –40°C to 151°C (–

40°F to 304°F) —

Indicates the intake air temperature at the time that the

vehicle was started. Used by the HO2S diagnostic to

determine if the last start-up was a cold start.

TP — Tech 2 Range 0%-100% —

TP (throttle position) angle is computed by the PCM

from the TP sensor voltage. TP angle should display

“0%” at idle and “100%” at wide open throttle.

TP SENSOR — Tech 2 Range 0.00-5.00 Volts —

The voltage being monitored by the PCM on the TP

sensor signal circuit.

CATALYST PROTECTION MODE — Tech 2 Displays

YES or NO —

“YES” displayed indicates that the PCM has detected

conditions appropriate to operate in TWC protection

mode. The PCM will decrease the air/fuel ratio to a

value that depends on mass air flow (higher mass air

flow = lower air/fuel ratio).

UPSHIFT LAMP (MANUAL TRANSMISSION)

VEHICLE SPEED — Tech 2 Range 0-255 km/h (0-155

mph) —

The vehicle speed sensor signal is converted into km/h

and mph for display.

WEAK CYLINDER — Tech 2 Displays Cylinder

Number —

This indicates that the PCM has detected crankshaft

speed variations that indicate 2% or more cylinder firing

events are misfires.

Typical Scan Data Values

Use the Typical Scan Data Values Table only after the

On-Board Diagnostic System Check has been

completed, no DTC(s) were noted, and you have

determined that the on-board diagnostics are

functioning properly. Tech 2 values from a

properly-running engine may be used for comparison

with the engine you are diagnosing. The typical scan

data values represent values that would be seen on a

normally-running engine.

NOTE: A Tech 2 that displays faulty data should not be

used, and the problem should be reported to the Tech 2

manufacturer. Use of a faulty Tech 2 can result in

misdiagnosis and unnecessary replacement of parts.

Only the parameters listed below are referred to in this

service manual for use in diagnosis. For further

information on using the Tech 2 to diagnose the PCM

and related sensors, refer to the applicable reference

section listed below. If all values are within the typical

range described below, refer to the Symptoms section

for diagnosis.

Test Conditions

Engine running, lower radiator hose hot, transmission in

park or neutral, closed loop, accessaries off, brake not

applied and air conditioning off.

3.2/3.5L V-6 Engine

Tec h 2

Parameter

Data List Units

Displayed

Typical Data

Values (IDLE)

Typical Data

Values

(2500RPM)

Refer To

A/C Clutch Engine On/Off Off Off General Description and

Operation, A/C Clutch

Circuit Operation

A/C Request Engine Yes/No No No General Description and

Operation, A/C Request

Signal

Air/Fuel Ratio Engine Ratio: _ to 1 14.7 14.7 General Description and

Operation, Fuel System

Metering Purpose

Barometric

Pressure

Engine kPa 61-104 (depends

on altitude and

barometric)

61-104 (depends

on altitude and

barometric)

General Description and

Operation

CMP Act.

Counter (Cam

Position Activity)

Engine Counts 0-255, always

increasing

0-255, always

increasing

DTC P0341 and P0342

Decel Fuel Mode Engine Active/

Inactive

Inactive Inactive General Description and

Operation, Deceleration

Mode

Desired EGR

Position

Engine Percent 0% 0% General Description and

Operation, EGR Pintle

Position Sensor

Desired Idle Engine RPM 750 — General Description and

Operation, Idle Air Control

(IAC) Valve

ECT (Engine

Coolant Temp)

Engine Degrees C,

Degrees F

80-100°C

(176-212°F)

80-100°C

(176-212°F)

General Description and

Operation, Engine Coolant

Temperature (ECT) Sensor

EGR Closed

Valve Pintle

Position

Engine Steps 20-40 20-40 General Description and

Operation, EGR Pintle

Position Sensor

EGR Duty Cycle Engine Percent 0% 0% General Description and

Operation, Linear EGR

Operation and Results of

Incorrect Operation

EGR Feedback Engine Volts 0.45-0.80 0.45-0.80 —

EGR Normalized Engine Percent 0% 0% —

Engine Load Engine Percent 2.0% - 5.5% 8.0% - 16.0% General Description and

Operation, Mass Air Flow

(MAF) Sensor

Time From Start Engine Sec Varies. Resets at

each engine start.

Varies. Resets at

each engine start. —

Engine Speed Engine RPM Within –50 to

+100 of “Desired

Idle”

Actual engine

speed

DTCs: P1508, P1509

Fuel Pump Engine On/Off On On Engine Fuel

HO2S Bank 1

Sen.1 (millivolts)

O2 Sensor

Data

Millivolts 50-950 changing

quickly

50-950, always

changing quickly

General Description and

Operation, Fuel control

HO2S

HO2S Bank 2

Sen.1 (millivolts)

O2 Sensor

Data

Millivolts 50-950 changing

quickly

50-950 changing

quickly

General Description and

Operation, Fuel Control

HO2S

HO2S Bank 1

Sen.1 (ready/not

ready)

O2 Sensor

Data

Ready

Yes/No

Ready

Yes

Ready

Yes

General Description and

Operation, Fuel Control

HO2S; DTC: P0135

HO2S Bank 2

Sen.1 (ready/not

ready)

O2 Sensor

Data

Ready

Yes/No

Ready

Yes

Ready

Yes

General Description and

Operation, Fuel Control

HO2S

HO2S Warm-Up

Time Bank 1

Sen.1

O2 Sensor

Data

Seconds 25-45 25-45 General Description and

Operation, Fuel Control

HO2S

HO2S Warm-Up

Time Bank 2

Sen.1

O2 Sensor

Data

Seconds 25-45 25-45 General Description and

Operation, Fuel Control

HO2S

IAT (Intake Air

Tem p)

Engine Degrees C,

Degrees F

0-100°C,

depends on

underhood

0-80°C, depends

on underhood

General Description and

Operation, Intake Air

Temperature (IAT) Sensor

Ignition Voltage Engine Volts 12.8-14.1 12.8-14.1 General Description and

Operation, Electronic

Ignition System

Inj. Pulse Bank 1 Engine Milliseconds 2.0-4.0 2.5-4.0 General Description, Fuel

Metering, Fuel Injector

Inj. Pulse Bank 2 Engine Milliseconds 2.0-4.0 2.5-4.0 General Description, Fuel

Metering, Fuel Injector

KS Noise

Channel (Knock

Sensor)

Engine Volts 0.10-0.40 0.50-1.75 General Description and

Operation, Knock Sensor

Purpose and Operation;

DTCs: P0352, P0327

Loop Status Engine Open/

Closed

Closed Closed General Description and

Operation, Fuel Metering

System; DTCs:

P0125-P0155

MAF (Mass Air

Flow)

Engine Grams per

second

2.85-6.65 9.5-16.5 General Description and

Operation, MAF; DTCs:

P101, P0102, P0103

MAP kPa

(Manifold

Absolute

Pressure)

Engine Kilopascals

——

General Description and

Operation, Manifold

Absolute Pressure (MAP)

Sensor; DTCs: P0106,

P0107, P0108

MIL Engine On/Off Off Off On-Board Diagnostic

System Check

Power

Enrichment

Engine Inactive/

Active

Inactive Inactive General Description and

Operation, Acceleration

Mode

Spark (Advance) Engine Degrees

Before Top

Dead Center

15-22 34-44 General Description and

Operation, Electronic

Ignition System

Tec h 2

Parameter

Data List Units

Displayed

Typical Data

Values (IDLE)

Typical Data

Values

(2500RPM)

Refer To

Start-Up ECT

(Engine Coolant

Tem p)

Engine Degrees C,

Degrees F

Depends on

engine coolant

temperature at

time of start-up

Depends on

engine coolant

temperature at

time of start-up

General Description and

Operation, Engine Coolant

Temperature (ECT) Sensor

Start-Up IAT

(Intake Air Temp)

Engine Degrees C,

Degrees F

Depends on

intake air

temperature at

time of start-up

Depends on

intake air

temperature at

time of start-up

General Description and

Operation, Intake Air

Temperature (IAT) Sensor

(Throttle

Position)

Engine Percent 0

—

General Description and

Operation, Throttle Position

(TP) Sensor; DTCs: P0121,

P0122,P0123

TP Sensor

(Throttle

Position)

Engine Volts 0.50-0.82 0.60-1.00 General Description and

Operation, Throttle Position

(TP) Sensor; DTCs: P0121,

P0122,P0123

Catalyst

Protection Mode

Engine No/Yes No No General Description, Fuel

Metering, catalytic

Converter Protection Mode

Vehicle Speed Engine MPH / km/h 0 0 4L30-E Automatic

Transmission Diagnosis

EVAP Purge

Solenoid

Engine Percent 65 99 General Description

VIM Solenoid Engine On/Off On On General Description

Security Wait

Time

Engine Active/

Inactive

Inactive Inactive —

Tec h 2

Parameter

Data List Units

Displayed

Typical Data

Values (IDLE)

Typical Data

Values

(2500RPM)

Refer To

No Malfunction Indicator Lamp (MIL)

D06RW00006

Circuit Description

The “Check Engine” lamp (MIL) should always be

illuminated and steady with the ignition “ON” and the

engine stopped. Ignition feed voltage is supplied to the

MIL bulb through the meter fuse. The powertrain

control module (PCM) turns the MIL “ON” by grounding

the MIL driver circuit.

Diagnostic Aids

An intermittent MIL may be cased by a poor connection,

rubbed-through wire insulation, or a wire broken inside

the insulation. Check for the following items:

•Inspect the PCM harness and connections for

improper mating, broken locks, improperly formed or

damaged terminals, poor terminal-to-wire connection,

and damaged harness.

•If the engine runs OK, check for a faulty light bulb, an

open in the MIL driver circuit, or an open in the

instrument cluster ignition feed.

•If the engine cranks but will not run, check for an

open PCM ignition or battery feed, or a poor PCM to

engine ground.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. A “No MIL” condition accompanied by a no-start

condition suggests a faulty PCM ignition feed or

battery feed circuit.

9. Using a test light connected to B+, probe each of the

PCM ground terminals to ensure that a good ground

is present. Refer to PCM Terminal End View for

terminal locations of the PCM ground circuits.

12. In this step, temporarily substitute a known good

relay for the PCM relay. The horn relay is nearby,

and it can be verified as “good” simply by honking

the horn. Replace the horn relay after completing

this step.

Important: 17. This vehicle is equipped with a PCM

which utilizes an electrically erasable programmable

read only memory (EEPROM). When the PCM is

replaced, the new PCM must be programmed. Refer to

Sections OC1 Service Programming System and 11A1

6VE1 Immobiliser.

No Malfunction Indicator Lamp (MIL)

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Attempt to start the engine.

Does the engine start? — Go to Step 3 Go to Step 6

3 Check the meter fuse for the instrument cluster

ignition feed circuit.

Is the fuse OK? — Go to Step 4 Go to Step 16

4 Ignition “ON,” probe the ignition feed circuit at the

cluster connector with a test light to ground.

Is the test light “ON?” — Go to Step 5 Go to Step 13

5 1. Ignition “OFF.”

2. Disconnect the PCM.

3. Jumper the MIL driver circuit at the PCM

connector to ground.

4. Ignition “ON.”

Is the MIL “ON?” — Go to Step 10 Go to Step 11

6 Check the PCM ignition feed and battery feed fuses

(15 A engine fuse and 15 A PCM fuse).

Are both fuses OK? — Go to Step 7 Go to Step 15

7 1. Ignition “OFF.”

2. Disconnect the PCM.

3. Ignition “ON.”

4. Probe the ignition feed circuit at the PCM harness

connector with a test light to ground.

Is the test light “ON?” — Go to Step 8 Go to Step 12

8 Probe the battery feed circuit at the PCM harness

connector with a test light to ground.

Is the test light “ON?” — Go to Step 9 Go to Step 14

9 Check for a faulty PCM ground connection.

Was a problem found? — Verify repair Go to Step 10

10 Check for damaged terminals at the PCM.

Was a problem found? — Verify repair Go to Step 17

11 Check for an open MIL driver circuit between the PCM

and the MIL.

Was a problem found? — Verify repair Go to Step 18

12 Substitute a known “good” relay for the PCM main

relay.

Was the malfunction fixed? — Verify repair Go to Step 13

13 Repair the open in the ignition feed circuit.

Is the action complete? — Verify repair —

14 Locate and repair the open PCM battery feed circuit.

Is the action complete? — Verify repair —

15 Locate and repair the short to ground in the PCM

ignition feed circuit or PCM battery feed circuit.

Is the action complete?—Verify repair—

16 Locate and repair the short to ground in the ignition

feed circuit to the instrument cluster, and replace the

fuse.

Is the action complete?—Verify repair—

17 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete?

Important: Is the action complete?—Verify repair—

18 Check the MIL driver circuit for a poor connection at

the instrument panel connector.

Was a problem found?

— Verify repair

Go to

Instrument

Panel in

Electrical

Diagnosis

Step Action Value(s) Yes No

Malfunction Indicator Lamp (MIL) “ON”Steady

D06RW00007

Circuit description

The malfunction indicator lamp (MIL) should always be

illuminated and steady with ignition “ON” and the engine

stopped. Ignition feed voltage is supplied directly to the

MIL indicator. The powertrain control module (PCM)

turns the MIL “ON” by grounding the MIL driver circuit.

The MIL should not remain “ON” with the engine

running and no DTC(s) set. A steady MIL with the

engine running and no DTC(s) suggests a short to

ground in the MIL driver circuit.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation, or a wire broken inside

the insulation. Check for the following items:

•Poor connection or damaged harness – Inspect the

PCM harness and connectors for improper mating,

broken locks, improperly formed or damaged

terminals, poor terminal-to-wire connection, and

damaged harness.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. If the MIL does not remain “ON” when the PCM is

disconnected, the MIL driver wiring is not faulty.

3. If the MIL driver circuit is OK, the instrument panel

cluster is faulty.

Important: 6. This vehicle is equipped with a PCM

which utilizes an electrically erasable programmable

read only memory (EEPROM). When the PCM is

replaced, the new PCM must be programmed.Refer to

Sections OC1 Service Programming System and 11A1

6VE1 Immobiliser.

Malfunction Indicator Lamp (MIL) “ON”Steady

StepActionValue(s)YesNo

1 Was the “On-Board diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 1.Ignition “OFF,” disconnect PCM.

2.Ignition “ON,” observe the MIL (Service Engine

Soon lamp).

Is the MIL “ON?”—Go to Step 3Go to Step 5

3 1.Ignition “OFF,” disconnect the instrument panel

cluster.

2.Check the MIL driver circuit between the PCM and

the instrument panel cluster for a short to ground.

3.If a problem is found, repair as necessary.

Was the MIL driver circuit shorted to ground?—

Go to OBD

System CheckGo to Step 4

4 Replace the instrument panel cluster.

Is the action complete?—

Go to OBD

System Check—

5 1.Ignition “OFF,” reconnect the PCM.

2.Using Tech 2, select “Output Miscellaneous Test”

and command the MIL “OFF.”

Did the MIL turn “OFF?”—

Go to OBD

System CheckGo to Step 6

6 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? —

Go to OBD

System Check —

Engine Cranks But Will Not Run

D06RX0 0004

Circuit Description

The electronic Ignition system uses a coil-at-plug

method of spark distribution. In this type of ignition

system, the powertrain control module (PCM) triggers

the correct driver inside the ignition coil, which then

triggers the correct ignition coil based on the 58X signal

received from the crankshaft position sensor (CKP).

The spark plug connected to the coil fires when the ICM

opens the ground circuit for the coil's primary circuit.

During crank, the PCM monitors the CKP 58X signal.

The CKP signal is used to determine which cylinder will

fire first. After the CKP 58X signal has been processed

by the PCM, it will command all six injectors to allow a

priming shot of fuel for all the cylinders. After the

priming, the injectors are left “OFF” during the next six

58X reference pulses from the CKP. This allows each

cylinder a chance to use the fuel from the priming shot.

During this waiting period, a camshaft position (CMP)

signal pulse will have been received by the PCM. The

CMP signal allows the PCM to operate the injectors

sequentially based on camshaft position. If the

camshaft position signal is not present at start-up, the

PCM will begin sequential fuel delivery with a 1-in-6

chance that fuel delivery is correct. The engine will run

without a CMP signal, but will set a DTC code.

Diagnostic Aids

An intermittent problem may be caused by a poor

connection, rubbed-through wire insulation or a wire

broken inside the insulation. Check for the following

items:

•Poor connection or damaged harness – Inspect the

PCM harness and connectors for improper mating,

broken locks, improperly formed or damaged

terminals, poor terminal-to-wire connection, and

damaged harness.

•Faulty engine coolant temperature sensor – Using

Tech 2, compare engine coolant temperature with

intake air temperature on a completely cool engine.

Engine coolant temperature should be within 10°C of

intake air temperature. If not, replace the ECT

sensor.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

5. An obvious cause of low fuel pressure would be an

empty fuel tank.

6. The engine will easily start and run if a few injectors

are disabled. It is not necessary to test all injectors

at this time since this step is only a test to verify that

all of the injectors have not been disabled by fuel

contamination.

7. A blinking test light verifies that the PCM is

monitoring the 58X crankshaft reference signal and

is capable of activating the injectors. If there is an

open or shorted driver circuit, DTCs 201-206 should

be set.

19. By using a spark tester, each ignition coil's ability to

produce 25,000 volts is verified.

25. If there is an open or shorted driver circuit, DTCs

201-206 should be set. All six injector driver circuits

can be checked at one time without removing the

intake manifold if a 5-8840-2636-0 test light is

available. This is the alternative procedure:

•With the ignition “OFF,” disconnect the gray

connector located at the rear of the air filter,

attached to a bracket on the purge canister.

•Connect test light 5-8840-2636-0 to the connector.

Do any of the light constantly illuminate or fail to

blink when the engine is cranked? If so, repair the

short or open circuit, or replace the PCM if

indicated.

This procedure only tests the driver circuit as far as the

test connection, so step 31 is added to test the circuit all

the way to the injector.

Engine Cranks But Will Not Run

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Check the 15 A (C9) ignition coil fuse, the 15 A (C8)

engine fuse, and the 30 A (F13) PCM fuse.

Was a fuse blown? — Go to Step 3 Go to Step 4

3 Check for a short to ground and replace the fuse.

Is the action complete? — Verify repair —

4 1. Ignition “OFF,” install a fuel pressure gauge at the

test fitting on the fuel supply line in the engine

compartment. (Use a shop cloth to absorb any

fuel leakage while making the connection.)

2. Ignition “ON,” observe the fuel pressure.

Is the fuel pressure within the specified values, and

does it hold steady?

285-376kPa

(43-55psi) Go to Step 6 Go to Step 5

5 Is any fuel pressure indicated?

—

Go to Fuel

System

Electrical Test

Go to Fuel

System

Diagnosis

6 Install an injector switch box to the injector test

connector, and attempt to operate the injector.

Did the fuel pressure drop when the injector is

operated? — Go to Step 7 Go to Step 12

7 Install an injector test light at the #2 cylinder injector

harness connector.

Does the light blink when the engine is cranked? — Go to Step 8 Go to Step 18

8 1. Ignition “ON.”

2. With the ignition coil connectors disconnected,

touch each coil connector's ignition feed terminal

with a grounded test light (the ignition feed wire is

black with orange tracer).

Did the test light illuminate? — Go to Step 10 Go to Step 9

9 Repair the open ignition feed circuit.

Is the action complete? — Verify repair —

10 While the coil connectors are disconnected, touch

each connector's secondary ground terminal with a

test light to B+. (The ground wires are black.)

Did the test light illuminate at each coil connector? — Go to Step 12 Go to Step 11

11 Repair the open secondary ground circuit.

Is the action complete? — Verify repair —

12 1. Test the fuel for contamination.

2. If a problem is found, clean the fuel system and

correct the contaminated fuel condition as

necessary. Replace the fuel filter and replace any

injectors that are not delivering fuel (see Injector

Balance Test).

Was a problem found? — Verify repair Go to Step 13

13 1. Remove any ignition coil and install a spark tester

at the spark plug end of the coil.

2. Observe the tester while the engine is cranking.

Was a crisp, blue spark observed? Only one or two

sparks followed by no result is considered the same

as “No Spark.” — Go to Step 15 Go to Step 14

14 Replace the ignition coil, and return to Step 13 to test

the remaining coils.

Is the action complete? — Verify repair —

15 Repeat Step 13 for each coil. Remove only one coil at

a time, and reinstall each coil on its spark plug after

testing, but do not refasten coils with screws at this

time.

After all coils have passed the spark test, does the

engine start? —

Refasten all

coils with their

screws Go to Step 16

16 1. Remove the spark plugs from all cylinders.

2. Visually inspect the spark plug electrodes.

3. Replace any spark plugs with loose or missing

electrodes or cracked insulators.

Did your inspection reveal any spark plugs exhibiting

excessive fouling? —

Correct the

fouling

condition Go to Step 17

Step Action Value(s) Yes No

17 Refer to Engine Mechanical Diagnosis to diagnose the

following conditions:

• Faulty or incorrect camshaft drive belts

• Leaking or sticky valves or rings

• Excessive valve deposits

• Loose or worn rocker arms

• Weak valve springs

• Incorrect valve timing

• Leaking head gasket

Is the action complete? — Verify repair Go to Step 19

18 Observe the “Engine Speed” data display on the scan

tool while cranking the engine.

Is the engine RPM indicated? (If the scan tool is

normally powered from the cigarette lighter socket,

and if the scan tool display goes blank while cranking

the engine, it will be necessary to power the scan tool

directly from the vehicle battery.) — Go to Step 19 Go to Step 28

19 1. Disconnect the 7-pin gray connector at the rear of

the air filter beneath the point where the air duct

attaches to the MAF sensor.

2. Ignition “ON.”

3. Using a test light connected to ground, probe the

ignition terminal at the PCM (female) side of the

7-pin connector.

Is the test light “ON?” — Go to Step 20 Go to Step 26

20 1. At the PCM (female) side of the connector,

connect a test light between the ignition + terminal

and one of the injector driver circuits at the same

connector.

2. Ignition “ON.”

3. Observe the test light, and repeat the test for each

injector driver circuit.

Did the test light stay on when checking any of the 6

injector driver circuits? — Go to Step 21 Go to Step 23

21 1. Ignition “OFF,” disconnect the PCM.

2. Ignition “ON,” observe the test light.

Is the test light “ON?” — Go to Step 22 Go to Step 27

22 Locate and repair the short to ground in the injector

driver circuit.

Is the action complete? — Verify repair —

23 1. Using the same test location as in step 20,

connect a test light between the ignition terminal

and one of the driver circuits.

2. Crank the engine and observe the test light.

3. Repeat for each injector driver circuit.

Did the light blink during the test for each circuit? — Go to Step 25 Go to Step 24

24 Check for an open injector driver circuit.

Was a problem found? — Verify repair Go to Step 27

Step Action Value(s) Yes No

25 1.At the injector (male) side of the gray connector,

connect an ohmmeter between the ignition pin

and one of the driver circuit pins.

2.Check for continuity in the circuit.

3.Repeat for each injector circuit. The readings

should be approximately equal to the specified

value for injector resistance.

Was a problem found?12.5 ohmsVerify repairGo to Step 8

26 Repair the ignition feed circuit.

Is the action complete?—Verify repair—

27 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

28 1. Raise the vehicle and disconnect the CKP sensor

harness.

2. Ignition “ON.”

3. With a test light to ground, probe the harness

ignition feed terminal.

Did the light illuminate? — Go to Step 30 Go to Step 29

29 Check the ignition feed wire between the sensor and

the PCM for a short to ground or open circuit.

Is the action complete? — Verify repair —

30 1. Ignition “ON.”

2. At the CKP harness connector, connect a test light

between the ignition and ground terminals.

Did the light illuminate? — Go to Step 32 Go to Step 31

31 Check the sensor ground circuit for an open or short

to voltage.

Is the action complete? — Verify repair —

32 Check the signal circuit between the sensor and the

PCM for a short to ground, short to voltage, or an

open.

Was a problem found? — Verify repair Go to Step 33

33 Replace the CKP sensor.

Is the action complete? — Verify repair Go to Step 27

Step Action Value(s) Yes No

Fuel System Electrical Test

D06RW101

Circuit Description

When the ignition switch is first turned “ON,” the

powertrain control module (PCM) energizes the fuel

pump relay which applies power to the in-tank fuel

pump. The fuel pump relay will remain “ON” as long as

the engine is running or cranking and the PCM is

receiving 58X crankshaft position pulses. If no 58X

crankshaft position pulses are present, the PCM

de-energizes the fuel pump relay within 2 seconds after

the ignition is turned “ON” or the engine is stopped.

The fuel pump delivers fuel to the fuel rail and injectors,

then to the fuel pressure regulator. The fuel pressure

regulator controls fuel pressure by allowing excess fuel

to be returned to the fuel tank. With the engine stopped

and ignition “ON,” the fuel pump can be turned “ON” by

using a command by Tech 2.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation, or a wire broken inside

the insulation. Check for the following items:

• Poor connection or damaged harness – Inspect the

PCM harness and connectors for improper mating,

broken locks, improperly formed or damaged

terminals, poor terminal-to-wire connection, and

damaged harness.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. If the fuel pump is operating but incorrect pressure is

noted, the fuel pump wiring is OK and the “Fuel

System Pressure Test” chart should be used for

diagnosis.

CAUTION: To reduce the risk of fire and personal

injury:

•It is necessary to relieve fuel system pressure

before connecting a fuel pressure gauge. Refer

to Fuel Pressure Relief Procedure, below.

•A small amount of fuel may be released when

disconnecting the fuel lines. Cover fuel line

fittings with a shop towel before disconnecting,

to catch any fuel that may leak out. Place the

towel in an approved container when the

disconnect is completed.

Fuel Pressure Relief Procedure

1.Remove the fuel cap.

2.Remove the fuel pump relay from the underhood

relay center.

3.Start the engine and allow it to stall.

4.Crank the engine for an additional 3 seconds.

Fuel Gauge Installation

1.Remove the shoulder fitting cap.

2.Install fuel gauge 5-8840-0378-0 to the fuel feed line

located in front of and above the right side valve

train cover .

3.Reinstall the fuel pump relay.

Fuel System Electrical Test

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Read the “Caution” above.

2. Relieve the fuel system pressure and install the

fuel pump pressure gauge to the test fitting.

3. Use Tech 2 to command the fuel pump “ON.”

Is there an immediate pressure build-up which

indicates the pump is running? — Go to Step 3 Go to Step 4

3 1. Verify that the pump is not running by removing

the fuel filler cap and listening.

2. Command the pump “ON” with Tech 2.

Did the pump turn “OFF” after 2 seconds? — Test completed Go to Step 12

4 1. Ignition “OFF.”

2. Remove the fuel pump relay.

3. Using a test light connected to ground, probe the

battery feed to the relay.

Did the light illuminate? — Go to Step 6 Go to Step 5

5 Repair short or open battery feed to fuel pump relay.

Is the action complete? — Verify repair —

6 1. Connect a test light between the two wires that

connect to the fuel pump relay pull-in coil.

2. Ignition “ON.”

Did the test light illuminate for 2 seconds and then turn

off? — Go to Step 12 Go to Step 7

7 1. With a test light connected to battery (–), probe

the fuel pump relay connector at the wire which

runs from the relay pull-in coil to the PCM.

2. Ignition “ON.”

Did the test light illuminate for 2 seconds and then turn

off? — Go to Step 8 Go to Step 9

8 Locate and repair open in the fuel pump relay ground

circuit.

Is the action complete? — Verify repair —

9 Check for short or open between the PCM and the

fuel pump relay.

Was a problem found? — Verify repair Go to Step 10

10 1.Check the fuel pump relay circuit for a poor

terminal connection at the PCM.

2.If a problem is found, replace terminal as

necessary.

Was a problem found?—Verify repairGo to Step 11

11 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

12 1. Reconnect the fuel pump relay.

2. Disconnect the fuel pump electrical connector at

the fuel tank.

3. Using a test light connected to ground, probe the

fuel pump feed wire (harness side).

4. Command the fuel pump “ON” with Tech 2.

Did the light illuminate for 2 seconds? — Go to Step 15 Go to Step 13

13 1. Honk the horn to verify that the horn relay is

functioning.

2. Substitute the horn relay for the fuel pump relay.

3. Leave the test light connected as in step 12.

4. Command the fuel pump “ON” with Tech 2.

Did the test light illuminate for 2 seconds when the

fuel pump was commanded “ON?” — Go to Step 17 Go to Step 14

14 1. Re-connect the horn relay in its proper location.

2. Check for a short circuit, blown fuse or open circuit

between the relay and the fuel tank.

Is the action complete? — Verify repair —

15 1. With the fuel pump electrical connector at the fuel

tank disconnected, connect a test light between

the feed wire and the ground wire (harness side).

2. Command the fuel pump “ON” with Tech 2.

Did the test light illuminate for 2 seconds? — Go to Step 18 Go to Step 16

16 Repair the open circuit in the fuel pump ground wire.

Is the action complete? — Verify repair —

17 1. Re-connect the horn relay in its proper location.

2. Replace the fuel pump relay.

Is the action complete? — Verify repair —

18 Replace the fuel pump.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Fuel System Diagnosis

140RW020

EndOFCallout

Circuit Description

When the ignition switch is turned “ON,” the powertrain

control module (PCM) will turn “ON” the in-tank fuel

pump. The in-tank fuel pump will remain “ON” as long

as the engine is cranking or running and the PCM is

receiving 58X crankshaft position pulses. If there are no

58X crankshaft position pulses, the PCM will turn the

in-tank fuel pump “OFF” 2 seconds after the ignition

switch is turned “ON” or 2 seconds after the engine

stops running.

The in-tank fuel pump is an electric pump within an

integral reservoir. The in-tank fuel pump supplies fuel

through an in-line fuel filter to the fuel rail assembly.

The fuel pump is designed to provide fuel at a pressure

above the pressure needed by the fuel injectors. A fuel

pressure regulator, attached to the fuel rail, keeps the

fuel available to the fuel injectors at a regulated

pressure. Unused fuel is returned to the fuel tank by a

separate fuel return line.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Connect the fuel pressure gauge to the fuel feed line

as shown in the fuel system illustration. Wrap a

shop towel around the fuel pressure connection in

order to absorb any fuel leakage that may occur

when installing the fuel pressure gauge. With the

ignition switch “ON” and the fuel pump running, the

fuel pressure indicated by the fuel pressure gauge

should be 333-376kPa (48-55psi). This pressure is

controlled by the amount of pressure the spring

inside the fuel pressure regulator can provide.

3. A fuel system that cannot maintain a constant fuel

Legend

(1) Fuel Filler Cap

(2) Fuel Tank

(3) Rollover Valve

(4) Fuel Pump and Sender Assembly

(5) Fuel Filter

(6) Fuel Rail Right

(7) Right Bank

(8) Fuel Rail Left

(9) Left Bank

(10) Fuel Pressure Control Valve

(11) Common Chamber

(12) Duty Solenoid Valve

(13) Throttle Valve

(14) Canister

(15) Evapo Shut Off Valve

pressure has a leak in one or more of the following

areas:

•The fuel pump check valve.

•The fuel pump flex line.

•The valve or valve seat within the fuel pressure

regulator.

•The fuel injector(s).

4. Fuel pressure that drops off during acceleration,

cruise, or hard cornering may case a lean condition.

A lean condition can cause a loss of power, surging,

or misfire. A lean condition can be diagnosed using

a Tech II Tech 2. If an extremely lean condition

occurs, the oxygen sensor(s) will stop toggling. The

oxygen sensor output voltage(s) will drop below 500

mV. Also, the fuel injector pulse width will increase.

Important: Make sure the fuel system is not operating

in the “Fuel Cut-Off Mode.”

When the engine is at idle, the manifold pressure is

low (high vacuum). This low pressure (high vacuum)

is applied to the fuel pressure regulator diaphragm.

The low pressure (high vacuum) will offset the

pressure being applied to the fuel pressure regulator

diaphragm by the spring inside the fuel pressure

regulator. When this happens, the result is lower

fuel pressure. The fuel pressure at idle will vary

slightly as the barometric pressure changes, but the

fuel pressure at idle should always be less than the

fuel pressure noted in step 2 with the engine “OFF.”

16. Check the spark plug associated with a particular

fuel injector for fouling or saturation in order to

determine if that particular fuel injector is leaking. If

checking the spark plug associated with a particular

fuel injector for fouling or saturation does not

determine that a particular fuel injector is leaking,

use the following procedure:

•Remove the fuel rail, but leave the fuel lines and

injectors connected to the fuel rail. Refer to Fuel

Rail Assembly in On-Vehicle Service.

•Lift the fuel rail just enough to leave the fuel

injector nozzles in the fuel injector ports.

CAUTION: In order to reduce the risk of fire and

personal injury that may result from fuel spraying

on the engine, verify that the fuel rail is positioned

over the fuel injector ports and verify that the fuel

injector retaining clips are intact.

•Pressurize the fuel system by connecting a 10

amp fused jumper between B+ and the fuel pump

relay connector.

•Visually and physically inspect the fuel injector

nozzles for leaks.

17. A rich condition may result from the fuel pressure

being above 376kPa (55psi). A rich condition may

cause a DTC P0132 or a DTC P0172 to set.

Driveability conditions associated with rich

conditions can include hard starting (followed by

black smoke) and a strong sulfur smell in the

exhaust.

20. This test determines if the high fuel pressure is due

to a restricted fuel return line or if the high fuel

pressure is due to a faulty fuel pressure regulator.

21. A lean condition may result from fuel pressure below

333kPa (48psi). A lean condition may cause a DTC

P0131 or a DTC P0171 to set. Driveability

conditions associated with lean conditions can

include hard starting (when the engine is cold ),

hesitation, poor driveability, lack of power, surging ,

and misfiring.

22. Restricting the fuel return line causes the fuel

pressure to rise above the regulated fuel pressure.

Command the fuel pump “ON” with Tech 2. The fuel

pressure should rise above 376kPa (55psi) as the

fuel return line becomes partially closed.

NOTE: Do not allow the fuel pressure to exceed

414kPa (60psi). Fuel pressure in excess of 414kPa

(60psi) may damage the fuel pressure regulator.

CAUTION: To reduce the risk of fire and personal

injury:

•It is necessary to relieve fuel system pressure

before connecting a fuel pressure gauge. Refer

to Fuel Pressure Relief Procedure, below.

• A small amount of fuel may be released when

disconnecting the fuel lines. Cover fuel line

fittings with a shop towel before disconnecting,

to catch any fuel that may leak out. Place the

towel in an approved container when the

disconnect is completed.

Fuel Pressure Relief Procedure

1. Remove the fuel cap.

2. Remove the fuel pump relay from the underhood

relay center.

3. Start the engine and allow it to stall.

4. Crank the engine for an additional 3 seconds.

Fuel Gauge Installation

1. Remove the shoulder fitting cap.

2. Install fuel gauge 5-8840-0378-0 to the fuel feed line

located in front of and above the right side valve

train cover.

3. Reinstall the fuel pump relay.

Fuel System Diagnosis

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Turn the ignition “OFF.”

2. Turn the air conditioning system “OFF.”

3. Relieve fuel system pressure and install the fuel

pressure gauge.

4. Turn the ignition “ON.”

NOTE: The fuel pump will run for approximately 2

seconds. Use Tech 2 to command the fuel pump“ON”.

5. Observe the fuel pressure indicated by the fuel

pressure gauge with the fuel pump running.

Is the fuel pressure within the specified limits?

290-376kPa

(42-55psi) Go to Step 3 Go to Step 17

3 NOTE: The fuel pressure will drop when the fuel

pump stops running, then it should stabilize and

remain constant.

Does the fuel pressure indicated by the fuel pressure

gauge remain constant? — Go to Step 4 Go to Step 12

4 1. When the vehicle is at normal operation

temperature, turn the ignition “ON” to build fuel

pressure and observe the measurement on the

gauge.

2. Start the engine and observe the fuel pressure

gauge.

Did the reading drop by the amount specified after the

engine was started?

21-105kPa

(3-15psi) Go to Step 5 Go to Step 9

5 Is fuel pressure dropping off during acceleration,

cruise, or hard cornering? — Go to Step 6

Check for

improper fuel

6 Visually and physically inspect the following items for

a restriction:

• The fuel filter.

• The fuel feed line.

Was a restriction found? — Verify repair Go to Step 7

7 Remove the fuel tank and visually and physically

inspect the following items:

• The fuel pump strainer for a restriction.

• The fuel line for a leak.

• Verify that the correct fuel pump is in the vehicle.

Was a problem found in any of these areas? — Verify repair Go to Step 8

8 Replace the fuel pump.

Is the action complete? — Verify repair —

9 1. Disconnect the vacuum hose from the fuel

pressure regulator.

2. With the engine idling, apply 12-14 inches of

vacuum to the fuel pressure regulator.

Does the fuel pressure indicated by the fuel pressure

gauge drop by the amount specified?

21-105kPa

(3-15psi) Go to Step 10 Go to Step 11

10 Locate and repair the loss of vacuum to the fuel

pressure regulator.

Is the action complete? — Verify repair —

11 Replace the fuel pressure regulator.

Is the action complete? — Verify repair —

12 1. Run the fuel pump with Tech 2.

2. After pressure has built up, turn off the pump and

clamp the supply hose shut with suitable locking

pliers.

Does the fuel pressure indicated by the fuel pressure

gauge remain constant? — Go to Step 13 Go to Step 15

13 Visually inspect the fuel supply line and repair any

leaks.

Was a problem found? — Verify repair Go to Step 14

14 Remove the fuel tank and inspect for leaky hose or

in-tank fuel line.

Was a problem found? — Verify repair Go to Step 8

15 1. If the pliers are still clamped to the fuel supply

hose, remove the locking pliers.

2. With suitable locking pliers, clamp the fuel return

line to prevent fuel from returning to the fuel tank.

3. Run the fuel pump with Tech 2.

4. After pressure has built up, remove power to the

pump.

Does the fuel pressure indicated by the fuel pressure

gauge remain constant? — Go to Step 11 Go to Step 16

16 Locate and replace any leaking fuel injector(s).

Is the action complete? — Verify repair —

17 Is the fuel pressure indicated by the fuel pressure

gauge above the specified limit?

376kPa

(55psi) Go to Step 18 Go to Step 21

18 1. Relieve the fuel pressure. Refer to the Fuel

Pressure Relief.

2. Disconnect the fuel return line from the fuel rail.

3. Attach a length of flexible hose to the fuel rail

return outlet passage.

4. Place the open end of the flexible hose into an

approved gasoline container.

5. Run the fuel pump with Tech 2.

6. Observe the fuel pressure indicated by the fuel

pressure gauge with the fuel pump running.

Is the fuel pressure within the specified limits?

290-376kPa

(42-55psi) Go to Step 19 Go to Step 20

19 Locate and correct the restriction in the fuel return

line.

Is the action complete? — Verify repair —

20 Visually and physically inspect the fuel rail outlet

passages for a restriction.

Was a restriction found? — Verify repair Go to Step 11

21 Is the fuel pressure indicated by the fuel pressure

gauge above the specified value? 0kPa (0psi) Go to Step 22 Go to Step 23

Step Action Value(s) Yes No

22 1.Command the fuel pump “ON” with Tech 2.

2.Using suitable pliers which will not damage the

fuel hose, gradually apply pressure with the pliers

to pinch the flexible fuel return hose closed.

CAUTION: Do not let the fuel pressure exceed the

second specified value.

Does the fuel pressure indicated by the fuel pressure

gauge rise above the first specified value?

376kPa

(55psi)

414kPa

(60psi) Go to Step 11 Go to Step 7

23 1. Command the fuel pump “ON” with Tech 2.

2. Remove the fuel filler cap and listen for the sound

of the fuel pump running.

3. Turn the pump off.

Was the fuel pump running? — Go to Step 7

Go to Fuel

System

Electrical Test

Chart

Step Action Value(s) Yes No

Idle Air Control (IAC) System Check

Circuit Description

The powertrain control module (PCM) controls engine

idle speed with the idle air control (IAC) valve. To

increase idle speed, the PCM retracts the IAC valve

pintle away from its seat, allowing more air to bypass

the throttle bore. To decrease idle speed, it extends the

IAC valve pintle towards its seat, reducing by pass air

flow. Tech 2 will read the PCM commands to the IAC

valve in counts. Higher counts indicate more air bypass

(higher idle). Lower counts indicate less air is allowed

to bypass (lower idle).

Diagnostic Aids

A slow, unstable, or fast idle may be caused by a

non-IAC system problem that cannot be overcome by

the IAC valve. Out of control range IAC Tech 2 counts

will be above 60 if idle is too low, and zero counts if idle

is too high. The following checks should be made to

repair a non-IAC system problem:

•Vacuum leak (high idle) – If idle is too high, stop the

engine. Fully extend (low) IAC with the Tech 2. Start

the engine. If idle speed is above 800 RPM, locate

and correct the vacuum leak, including the PCV

system. Check for binding of the throttle blade or

linkage.

•Lean heated oxygen sensor signal (high air/fuel ratio)

– The idle speed may be too high or too low. Engine

speed may vary up and down, and disconnecting the

IAC valve does not help. Diagnostic trouble codes

P0131, P0151, P0171, or P0174 may be set. Tech 2

oxygen (O2) voltage will be less than 100 mV (0.1 V).

Check for low regulated fuel pressure, water in fuel,

or a restricted injector.

•Rich heated oxygen sensor signal (low air/fuel ratio)

– The idle speed will be too low. Tech 2 IAC counts

will usually be above 80. The system is obviously

rich and may exhibit black smoke in the exhaust.

Tech 2 O2 voltage will be fixed at about 750 mV (0.75

V). Check for high fuel pressure, or a leaking or

sticking injector. A silicon-contaminated heated

oxygen sensor will show an O2 voltage slow to

respond on Tech 2.

•Throttle body – Remove the IAC valve and inspect

the bore for foreign material.

•IAC valve electrical connections – IAC valve

connections should be carefully checked for proper

contact.

•PCV valve – An incorrect or faulty PCV valve may

result in an incorrect idle speed. Refer to Diagnosis,

Rough Idle, Stalling. If intermittent poor driveability or

idle symptoms are resolved by disconnecting the

IAC, carefully recheck the connections and valve

terminal resistance, or replace the IAC.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

1. The Tech 2 is used to extend and retract the IAC

valve. Valve movement is verified by an engine

speed change. If no change in engine speed occurs,

the valve can be resettled when removed from the

throttle body.

2. This step checks the quality of the IAC movement in

step 1. Between 700 revolutions per minute (RPM)

and about 1500 RPM, the engine speed should

change smoothly with each flash of the tester light in

both extend and retract. If the IAC valve is retracted

beyond the control range (about 1500 RPM), it may

take many flashes to extend the IAC valve before

engine speed will begin to drop. This is normal on

certain engines. Fully extending the IAC may cause

engine stall. This may be normal.

Idle Air Control (IAC) System Check

Step Action Value(s) Yes No

1 1. Ignition “OFF.”

2. Connect the Tech 2.

3. Set the parking brake.

4. Block the wheels.

5. Turn the air conditioning “OFF.”

6. Idle the engine in Park (A/T) or Neutral (M/T).

7. Operate the IAC test.

8. The engine speed should decrease and increase

as the IAC is cycled.

Does the RPM change? — Go to Step 2 Go to Step 3

2 RPM should change smoothly.

Does the RPM change within the range specified?

700-1500

RPM — Go to Step 3

3 Check the IAC passages.

Are the IAC passages OK? — Go to Step 4 Go to Step 5

4 Clear any obstruction from the IAC passages.

Is the action complete? — Verify repair —

5 Replace the IAC. Refer to On-Vehicle Service, Idle

Air Control Valve.

Is the action complete? — Verify repair —

Knock Sensor (KS) System Check (Engine Knock, Poor Performance, or Poor

Economy)

D06RW035

Circuit Description

The knock sensor (KS) sends an AC voltage signal to

the powertrain control module (PCM). As the KS

detects engine knock, the signal to the PCM changes in

amplitude and frequency. The PCM retards timing if the

engine speed is over 900 RPM.

Diagnostic Aids

If the KS system checks OK, but detonation is the

complaint, refer to Diagnosis, Detonation/Spark Knock.

Test Description

The numbers below refer to the step numbers on the

Diagnostic Chart.

9. The change in signal speed depends on how hard

the tapping is done. Normally there is about 1.5 to

10 mV at PCM pin A2 with the engine off. Loud

tapping should be able to make the reading jump to

20-25 mV AC.

Knock Sensor (KS) System Check (Engine Knock, Poor Performance, or Poor

Economy)

StepActionValue(s)YesNo

1 Is DTC P0325 or P0327 set?

—

Go to DTC

P0325 or DTC

P0327Go to Step 2

2 Run the engine at 1500 RPM.

Is there an internal engine knock?—Go to Step 3Go to Step 4

3 Repair the mechanical problem.

Is the action complete?—Verify repair—

4 1.Install Tech 2.

2.Turn the ignition “ON.”

3.Cycle through the list until “Knock Retard” is

displayed.

Is knock retard at the specified value?0°Go to Step 6Go to Step 7

5 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Important: Is the action complete?—Verify repair—

6 1. Start the engine.

2. Monitor the knock retard display on Tech 2 while

changing the throttle setting to place different

loads on the engine.

Is knock retard at the specified value? (Turn the

ignition“OFF.”) 0°Go to Step 9 Go to Step 7

7 1. At the rear of the engine, behind the rear fuel

injector on the lift side, disconnect the 2-wire

knock sensor harness connector.

2. Attach the positive lead of DVM to B+.

3. On the main harness side of the connector, use

the negative lead of the DVM to probe the

connector pin that is connected to the black wire.

Dose the DVM indicate the specified value?

(Reconnect the knock sensor harness.) B+ Go to Step 9 Go to Step 8

8 Repair the open black wire ground for the shield which

prevents stray electromagnetic pulses from affecting

the knock signal.

Is the action complete? — Verify repair —

9 1. Reconnect the wire harness.

2. Set a DVM to AC voltage.

3. With the DVM, backprobe the PCM connector at

A2.

4. Tap the engine lift brackprobe with a socket

extension.

Did the DVM show an increase in AC voltage while

tapping on the lift bracket? — System OK Go to Step 10

10 Replace the knock sensor.

Is the action complete? — Verify repair —

Exhaust Gas Recirculation (EGR) System Check

D06RW106

Circuit Description

A properly operation exhaust gas recirculation (EGR)

system will directly affect the air/fuel requirements of the

engine. Since the exhaust gas introduced into the air/

fuel mixture is an inert gas (contains very little or no

oxygen), less fuel is required to maintain a correct air/

fuel ratio.

Introducing exhaust gas into the combustion chamber

lowers combustion temperatures and reduces the

formation of oxides of nitrogen (NOx) in the exhaust

gas. Lower combustion temperatures also prevent

detonation.

If the EGR pintle were to stay closed, the inert exhaust

gas would be replaced with air and the air/fuel mixture

would be leaner. The powertrain control module (PCM)

would compensate for the lean condition by adding fuel,

resulting in higher long term fuel trim values.

Diagnostic Aids

The EGR valve chart is a check of the EGR system. An

EGR pintle constantly in the closed position could cause

detonation and high emissions of NOx. It could also

result in high long term fuel trim values in the open

throttle cell, but not in the closed throttle cell. An EGR

pintle constantly in the open position would cause a

rough idle. Also, an EGR mounted incorrectly (rotated

180°) could cause rough idle. Check for the following

items:

•EGR passages – Check for restricted or blocked

EGR passages.

•Manifold absolute pressure sensor – A manifold

absolute pressure sensor may shift in calibration

enough to affect fuel delivery. Refer to Manifold

Absolute Pressure Output Check.

Exhaust Gas Recirculation (EGR) System Check

Step Action Value(s) Yes No

1 Check the EGR valve for looseness.

Is the EGR valve Loose? — Go to Step 2 Go to Step 3

2 Tighten the EGR valve.

Is the action complete? — Verify repair —

3 1. Place the transmission selector in Park or Neutral.

2. Start the engine and idle until warm.

3. Using Tech 2, command EGR “50% ON.”

Does the engine idle rough and lose RPMs? —

EGR system

working

properly. No

problem found. Go to Step 4

4 1. Engine “OFF.”

2. Ignition “ON.”

3. Using a test light to ground, check the EGR

harness between the EGR valve and the ignition

feed.

Does the test light illuminate? — Go to Step 6 Go to Step 5

5 Repair the EGR harness ignition feed.

Was the problem corrected? — Verify repair Go to Step 6

6 1. Remove the EGR valve.

2. Visually and physically inspect the EGR valve

pintle, valve passages and adapter for excessive

deposits, obstructions or any restrictions.

Does the EGR valve have excessive deposits,

obstructions or any restrictions? — Go to Step 7 Go to Step 8

7 Clean or replace EGR system components as

necessary.

Was the problem corrected? — Verify repair Go to Step 8

8 1. Ground the EGR valve metal case to battery (–).

2. Using Tech 2, command EGR “ON” and observe

the EGR valve pintle for movement.

Does the EGR valve pintle move according to

command? — Go to Step 9

Go to DTC

P1406 chart

9 1. Remove the EGR inlet and outlet pipes from the

intake and exhaust manifolds.

2. Visually and physically inspect manifold EGR

ports and EGR inlet and outlet pipes for blockage

or restriction caused by excessive deposits or

other damage.

Do the manifold EGR ports or inlet and outlet pipes

have excessive deposits, obstructions, or any

restrictions? — Go to Step 10

EGR system

working

properly. No

problem found.

10 Clean or replace EGR system components as

necessary.

Is the action complete? — Verify repair —

Manifold Absolute Pressure (MAP) Output Check

D06RW102

Circuit Description

The manifold absolute pressure (MAP) sensor

measures the changes in the intake MAP which result

from engine load (intake manifold vacuum) and engine

speed changes; and converts these into a voltage

output. The powertrain control module (PCM) sends a

5-volt reference voltage to the MAP sensor. As the

MAP changes, the output voltage of the sensor also

changes. By monitoring the the sensor output voltage,

the PCM knows the MAP. A lower pressure (low

voltage) output voltage will be about 1-2 volts at idle.

Higher pressure (high voltage) output voltage will be

about 4-4.8 volts at wide open throttle. The MAP sensor

is also used, under certain conditions, to measure

barometric pressure, allowing the PCM to make

adjustments for different altitudes. The PCM uses the

MAP sensor to diagnose proper operation of the EGR

system, in addition to other functions.

Test Description

Important: Be sure to used the same diagnostic test

equipment for all measurements.

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Applying 34 kPa (10 Hg) vacuum to the MAP sensor

should cause the voltage to be 1.5-2.1 volts less

than the voltage at step 1. Upon applying vacuum

to the sensor, the change in voltage should be

instantaneous. A slow voltage change indicates a

faulty sensor.

3. Check the vacuum hose to the sensor for leaking or

restriction, Be sure that no other vacuum devices

are connected to the MAP hose.

Important: Make sure the electrical connector remains

securely fastened.

4. Disconnect the sensor from the bracket. Twist the

sensor with your hand to check for an intermittent

connection. Output changes greater than 0.10 volt

indicate a bad sensor.

Manifold Absolute Pressure (MAP) Output Check

Step Action Value(s) Yes No

1 1. Turn the ignition “OFF”and leave it “OFF” for 15

seconds.

2. Ignition “ON.” Don't crank engine.

3. Tech 2 should indicate a manifold absolute

pressure (MAP) sensor voltage.

4. Compare this scan reading to scan reading of a

known good vehicle obtained using the exact

same procedure as in Steps 1-4.

Is the voltage reading the same +/–0.40 volt? — Go to Step 2 Go to Step 5

2 1. Disconnect the vacuum hose at the MAP sensor

and plug the hose.

2. Connect a hand vacuum pump to the MAP sensor.

3. Start the engine.

4. Apply 34 kPa (10 Hg) of vacuum and note the

voltage change.

Is the voltage change 1.5-2.1 volts less than Step 1? — Go to Step 3 Go to Step 4

3 No trouble found. Check the sensor cover for leakage

or restriction.

Does the hose supply vacuum to the MAP sensor

only? — Go to Step 5 Go to Step 4

4 Repair the material to block.

Is the action complete? — Verify repair —

5 Check the sensor connection.

Is the sensor connection good? — Go to Step 6 Go to Step 7

6 Replace the sensor. Refer to On-Vehicle Service,

MAP Sensor.

Is the action complete? — Verify repair —

7 Repair the poor connection.

Is the action complete? — Verify repair —

PCM Diagnostic Trouble Codes

The following table lists the diagnostic trouble codes

supported by this vehicle application. If any DTCs not

listed here are displayed by a Tech 2, the Tech 2 data

may be faulty; notify the Tech 2 manufacturer of any

DTCs displayed that are not included in the following

table.

A - Emission related P-code, check engine light on as

soon as a failure detected.

B - Emission related P-code, check engine light on if a

failure detected in two consecutive trips.

C - Non emission related P-code, check engine light

on if a failure detected in one trip.

D - Non emission related P-code, no check engine

light, but P-code will be set if a failure detected.

X - Do not check.

PCM Diagnostic Trouble Codes

Diagnostic Trouble Code (DTC) P0101 MAF System Performance

D06RW103

Circuit Description

The mass air flow (MAF) sensor measures the amount

of air which passes through it into the engine during a

given time. The powertrain control module (PCM) uses

the mass air flow information to monitor engine

operating conditions for fuel delivery calculations. A

large quantity of air entering the engine indicates an

acceleration or high load situation, while a small

quantity or air indicates deceleration or idle.

The MAF sensor produces a frequency signal which

can be monitored using a Tech 2. DTC P0101 will be

set if the signal from the MAF sensor does not match a

predicted value based on throttle position and engine

RPM.

Conditions for Setting the DTC

• The engine is running.

• No TP sensor or MAP sensor DTCs are set.

• The throttle is steady, TP angle doesn't change by

more than 1%.

• System voltage is between 11.5 volts and 16 volts.

• Calculated air flow is between 25 g/second and 40 g/

second.

• Above conditions present for at least 1 second.

• MAF signal frequency indicates an airflow

significantly higher or lower than a predicted value

based on throttle position and engine RPM for a total

of 12.5 seconds over a 25-second period of time.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• The PCM calculates an airflow value based on idle air

control valve position, throttle position, RPM and

barometric pressure.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0101 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

An intermittent may be caused by the following:

• Poor connections.

• Mis-routed harness.

• Rubbed through wire insulation.

• Broken wire inside the insulation.

Refer to Intermittents under service category

Symptoms.

Any un-metered air may cause this DTC to set. Check

for the following:

•The duct work at the MAF sensor for leaks.

•An engine vacuum leak.

•The PCV system for vacuum leaks.

•An incorrect PCV valve.

•The engine oil dip stick not fully seated.

•The engine oil fill cap loose or missing.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. The MAF system performance or “rationality”

diagnostic uses the MAP sensor signal along with

other input to calculate an expected airflow rate that

is then compared to the actual measured airflow

from the MAF sensor. The first few steps of this

table verify that the MAP sensor is working properly.

6. Using Freeze Frame and/or Failure Records data

may aid in locating an intermittent condition. If the

DTC cannot be duplicated, the information included

in the Freeze Frame and/or Failure Records data

can be useful in determining how many miles since

the DTC set. The Fail Counter and Pass Counter

can also be used to determine how many ignition

cycles the diagnostic reported a pass and/or a fail.

Operate the vehicle within the same Freeze Frame

conditions (RPM, load, vehicle speed , temperature,

etc.) that were noted. This will isolate when the DTC

failed.

For any test that requires back probing the PCM or

component harness connectors, use the Connector

Test Adapter Kit J 35616-A. Using this kit will

prevent any damage to the harness connector

terminals.

7. Any un-metered air may cause this DTC to set.

Check the PVC system for vacuum leaks. Also

inspect the dip stick for being pulled out. Check the

oil fill cap for being loose.

8. Verifies the signal circuit from the MAF sensor

electrical connector to the PCM.

9. Verifies whether a ground and B+ circuit is available.

10. Checks a signal circuit for an open.

11. Checks for a signal circuit shorted to B+.

DTC P0101 – MAF System Performance

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. Using a Tech 2, select “MAP” from the Engine 1

Data List.

Is the value displayed greater than the value shown? 85kPa Go to Step 3 Go toStep 13

3 1. Remove the MAP sensor from the intake manifold

but leave the electrical harness connected.

2. Connect a hand operated vacuum pump to the

MAP sensor.

3. Observe the MAP display while slowly applying

vacuum up to 20" Hg as indicated on the pump

gauge.

Each 1" of vacuum applied should result in a 3 to

4kPa drop in the MAP sensor value on the Tech 2 and

the value should change smoothly with each increase

in vacuum.

Did the MAP value change smoothly through the

entire range of the test without any erratic readings? — Go to Step 13 Go to Step 4

4 With 20" Hg vacuum applied to the MAP sensor, is the

MAF sensor reading the same or less than the value

shown? 34kPa Go to Step 5 Go to Step 13

5 Disconnect the vacuum source from the MAP sensor.

Does the MAP sensor reading return to its original

value? — Go to Step 6 Go to Step 13

6 1. Ignition “ON,” engine “OFF.”

2. Review the Freeze Frame and/or Failure Records

data for this DTC and note parameters.

3. Ignition “OFF” for 15 seconds.

4. Start the engine and operate the vehicle within the

conditions required for this diagnostic to run, and

as close to the conditions recorded in Freeze

Frame /Failure Records possible. (Special

operating conditions that need to be met before

the PCM will run this diagnostic (where applicable)

are listed in“Conditions for Setting the DTC”).

5. Using the Tech 2, select “DTC,” then enter the

DTC number which was set.

Does the Tech 2 indicate that this diagnostic failed this

ignition? — Go to Step 7

Refer to

Diagnostic Aids

7 1. Check for the following conditions:

• Objects blocking the MAF sensor inlet screen;

• Intake manifold vacuum leaks;

• Vacuum leaks at throttle body;

• Vacuum leaks EGR value flange and pipes.

• Crankcase ventilation valve faulty, missing, or

incorrectly installed.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go toStep 8

8 1. Ignition “OFF.”

2. Disconnect the MAF sensor connector.

3. Ignition “ON,” engine “OFF.”

4. Using DVM 5-8840-0285-0, measure voltage

between the MAF sensor signal circuit and

chassis ground.

Is the voltage near the specified value? 5 V Go to Step 9 Go toStep 10

9 Connect a test light (5-8840-0607-0) between the

MAF sensor ignition feed and ground circuits at the

MAF sensor harness connector.

Is the test light “ON?” — Go to Step 13 Go toStep 12

10 Is the voltage less than the specified value? 4.5 V Go to Step 13 Go toStep 11

11 1. Ignition “OFF,” disconnect the PCM.

2. Ignition “ON,” engine “OFF.”

3. Measure voltage between the MAF signal circuit

and ground.

Does the voltage measure near the specified value? 0 V Go to Step 13 Go toStep 12

12 Connect a test light (5-8840-0607-0) between the

MAF sensor ignition feed circuit and chassis ground.

Is the test light “ON?” — Go to Step 13 Go toStep 7

13 1. Check for a poor connection at the MAF sensor.

2. If a poor connection is found, replace faulty

terminal(s). Refer to Repair Procedures in

Electrical Diagnosis (8A Cell 5).

Was a poor connection found? — Verify repair Solved

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0102 MAF Sensor Circuit Low Frequency

T321122

Circuit Description

The mass air flow (MAF) sensor measures the amount

of air which passes through it into the engine during a

given time. The powertrain control module (PCM) uses

the mass air flow information to monitor engine

operating conditions for fuel delivery calculations. A

large quantity of air entering the engine indicates an

acceleration or high load situation, while a small

quantity of air indicates deceleration or idle.

The MAF sensor produces a frequency signal which

can be monitored using a Tech 2. The frequency will

vary within a range of around 2500Hz at idle to around

1900Hz at maximum engine load. DTC P0102 will be

set if the signal from the MAF sensor is below the

possible range of a normally operating MAF sensor.

Conditions for Setting the DTC

• The engine is running above 500 RPM for greater

than 10 seconds.

• System voltage is above 11.5 volts.

• MAF signal frequency is below 1000Hz for a total of

50-percent of the last 1000 samples monitored. A

sample is taken every cylinder event.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM calculates an air flow value based on idle

air control valve position, throttle position, RPM and

barometric pressure.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0102 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

• Misrouted harness – Inspect the MAF sensor harness

to ensure that it is not routed too close to high voltage

wires.

• Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the Tech 2 while moving connectors and wiring

harnesses related to the MAF sensor. A change in

the display will indicate the location of the fault.

•Plugged intake air duct or filter element – A

wide-open throttle acceleration from a stop should

cause the mass air flow displayed on a Tech 2 to

increase from about 3-6 g/second at idle to 100 g/

second or greater at the time of the 1-2 shift. If not,

check for a restriction.

If DTC P0102 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. This step verifies that the problem is present at idle.

4. A voltage reading of less than 4 or over 5 volts at the

MAF sensor signal circuit indicates a fault in the

wiring or a poor connection.

5. This verifies that ignition feed voltage and a good

ground are available at the MAF sensor.

DTC P0102 – MAF Sensor Circuit Low Frequency

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Start the engine.

2. With the engine idling, monitor “MAF Frequency”

display on the Tech 2.

Is the “MAF Frequency” below the specified value? 3g/Sec Go to Step 4 Go to Step 5

3 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC

P0102.

Does the Tech 2 indicate DTC P0102 failed this

ignition? — Go to Step 4

Refer to

Diagnostic Aids

4 1. Ignition “OFF.”

2. Disconnect the MAF sensor connector.

3. Ignition “ON,” engine “OFF.”

4. Using a DVM, measure voltage between the MAF

sensor signal circuit and battery ground.

Is the voltage near the specified value? 5 V Go to Step 5 Go to Step 8

5 Connect a test light between the MAF sensor ignition

feed and ground circuits at the MAF sensor harness

connector.

Is the test light “ON?” — Go to Step 13 Go to Step 6

6 Connect a test light between the MAF sensor ignition

feed circuit and battery ground.

Is the test light “ON?” — Go to Step 12 Go to Step 7

7 1. Check for a poor connection at the MAF sensor.

2. If a poor connection is found, replace the faulty

terminal(s).

Was a poor connection found? — Verify repair Go to Step 11

8 1. Ignition “OFF.”

2. Disconnect the MAF sensor.

3. Disconnect the PCM connector for the MAF signal

circuit.

4. Ignition “ON,” engine “OFF.”

5. With the DVM, measure the voltage between the

MAF signal terminal at the PCM and battery

ground.

Is the voltage under the specified value? 4 V Go to Step 9 Go to Step 10

9 1.Ignition “OFF.”

2.Disconnect the PCM white connector.

3.Ignition “ON.”

4.Check the MAF sensor signal circuit for a short to

5 volts.

Is the action complete?—Verify repair—

10 1.Ignition “OFF.”

2.Disconnect the PCM white connector.

3.Ignition “ON.”

4.Check the MAF sensor signal circuit between the

PCM and the MAF sensor for an open, short to

ground, or short to the MAF ground circuit.

Is the action complete?—Verify repairGo to Step 13

11 Locate and repair the open in the ground circuit to the

MAF sensor.

Is the action complete?—Verify repair—

12 Locate and repair the open in the ignition feed circuit

to the MAF sensor.

Is the action complete?—Verify repair—

13 Replace the MAF sensor.

Is the action complete?—Verify repairGo to Step 14

14 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0103 MAF Sensor Circuit High Frequency

T321122

Circuit Description

The mass air flow (MAF) sensor measures the amount

of air which passes through it into the engine during a

given time. The powertrain control module (PCM) uses

the mass air flow information to monitor engine

operating conditions for fuel delivery calculations. A

large quantity of air entering the engine indicates an

acceleration or high load situation, while a small

quantity of air indicates deceleration or idle.

The MAF sensor produces a frequency signal which

can be monitored using a Tech 2. The frequency will

vary within a range of around 2500Hz at idle to around

9000Hz at maximum engine load. DTC P0103 will be

set if the signal from the MAF sensor is above the

possible range of a normally operating MAF sensor.

Conditions for Setting the DTC

• The engine is running above 500 RPM for more than

10 seconds.

• System voltage is above 11.5 volts.

• MAF signal frequency is above 10,000Hz (10.0kHz)

for a total of 50 percent of the last 200 samples

monitored. A sample is taken every cylinder event.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM calculates an airflow value based on idle air

control valve position, throttle position, RPM and

barometric pressure.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for clearing the MIL/DTC

• DTC P0103 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

If DTC P0103 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. This step verifies that the problem is present at idle.

4. A frequency reading with the MAF sensor connector

disconnected indicates an electromagnetic

interfernce (EMI) related fault.

DTC – MAF Sensor Circuit High Frequency

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 1.Ignition “ON,” engine “OFF.”

2.Review and record Tech 2 Failure Records data.

3.Operate the vehicle within Failure Records

conditions as noted.

4.Using a Tech 2, monitor “DTC” info for DTC

P0103.

Does the Tech 2 indicate DTC P0103 failed this

ignition?—Go to Step 3

Refer to

Diagnostic Aids

3 1.Start the engine.

2.With the engine idling, monitor “MAF Frequency”

display on the Tech 2.

Is “MAF Frequency” above the specified value?219g/SecGo to Step 4 Go to Step 7

4 1.Ignition “OFF.”

2.Disconnect the MAF sensor connector.

3.Ignition “ON,” engine idling.

4.Using a Tech 2, monitor “MAF Frequency.”

Does the Tech 2 indicate a “MAF Frequency” at the

specified value?0.0g/SecGo to Step 5 Go to Step 6

5 Replace the MAF sensor.

Is the action complete?—Verify repairGo to Step 8

6 1.Check the MAF harness for incorrect routing near

high voltage components (solenoids, relays,

motors).

2.If incorrect routing is found, correct the harness

routing.

Was a problem found?—Verify repairGo to Step 7

7 1.With the engine idling, monitor “MAF Frequency”

display on the Tech 2.

2.Quickly snap open throttle to wide open throttle

while under a road load and record value.

Does the Tech 2 indicate “MAF Frequency” above the

specified value?219g/SecGo to Step 5 Go to Step 8

8 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0107 MAP Sensor Circuit Low Voltage

D06RW102

Circuit Description

The manifold absolute pressure (MAP) sensor responds

to changes in intake manifold pressure (vacuum). The

MAP sensor signal voltage to the powertrain control

module (PCM) varies from below 2 volts at idle (high

vacuum) to above 4 volts with the ignition “ON,” engine

not running or at wide-open throttle (low vacuum).

The MAP sensor is used to determine manifold

pressure changes while the exhaust gas recirculation

(EGR) flow test diagnostic is being run (refer to DTC

P0401), to determine engine vacuum level for some

other diagnostics and to determine barometric pressure

(BARO). The PCM monitors the MAP signals for

voltages outside the normal range of the MAP sensor. If

the PCM detects a MAP signal voltage that is

excessively low, DTC P0107 will be set.

Conditions for Setting the DTC

• No TP sensor DTCs present.

• Engine is running.

• Throttle angle is above 1% if engine speed is less

than 1000RPM.

• Throttle angle is above 2% if engine speed is above

1000RPM.

• The MAP sensor indicates manifold absolute

pressure at or below 11kPa for a total of

approximately 10 seconds over a 16-second period.

• Ignition voltage more than 11 volts.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will default to a BARO value of 79.3kPa.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0107 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Check for intermittent codes.

• The MAP sensor shares a 5 Volt reference with the

Rough Road Sensor. If these codes are also set, it

could indicate a problem with the 5 Volt reference

circuit .

• The MAP sensor shares a ground with the Rough

Road Sensor, the ECT sensor, and the Transmission

Fluid Temperature sensor.

•Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the MAP display on the Tech 2 while moving

connectors and wiring harnesses related to the

sensor. A change in the display will indicate the

location of the fault.

If DTC P0107 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

If it is determined that the DTC occurs intermittently,

performing the DTC P0107 Diagnostic Chart may

isolate the cause of the fault.

DTC P0107 – MAP Sensor Circuit Low Voltage

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. With the throttle closed, observe the MAP value

displayed on the Tech 2.

Is the MAP value near the specified value?

11kPa at sea

level Go to Step 4 Go to Step 3

3 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “Specific DTC” info for

DTC P0107.

Does the Tech 2 indicate DTC P0107 failed? — Go to Step 4

Refer to

Diagnostic Aids

4 1. Ignition “OFF.”

2. Disconnect the MAP sensor electrical connector.

3. Jumper the 5 volt reference “A” circuit and the

MAP signal together at the MAP sensor harness

connector.

4. Ignition “ON.”

5. Observe the MAP value displayed on the Tech 2.

Is the MAP value near the specified value? 5 V 104kPa Go to Step 10 Go to Step 5

5 1. Disconnect the jumper.

2. Connect a test light between B+ and the MAP

sensor signal circuit at the MAP sensor harness

connector.

3. Observe the MAP value displayed on the Tech 2.

Is the MAP value near the specified value. 5 V 104kPa Go to Step 6 Go to Step 8

6 1. Ignition “OFF.”

2. Disconnect the PCM and check the 5 volt

reference “A” circuit for an open or short to

ground.

3. If the 5 volt reference “A” circuit is open or shorted

to ground, repair it as necessary.

Was the 5 volt reference “A” circuit open or shorted to

ground? — Verify repair Go to Step 7

7 Check the 5 volt reference “A” circuit for a poor

connection at the PCM and replace the terminal if

necessary.

Did the terminal require replacement? — Verify repair Go to Step 11

8 1.Ignition “OFF.”

2.Disconnect the PCM, and check the MAP signal

circuit for an open, short to ground, or short to the

sensor ground circuit.

3.If the MAP sensor signal circuit is open or shorted

to ground, repair it as necessary.

Was the MAP signal circuit open or shorted to

ground?—Verify repairGo to Step 9

9 Check the MAP sensor signal circuit for a poor

connection at the PCM and the MAP sensor; replace

the terminal if necessary.

Did the terminal require replacement?—Verify repairGo to Step 11

10 Replace the MAP sensor.

Is the action complete?—Verify repair—

11 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0108 MAP Sensor Circuit High Voltage

D06RW102

Circuit Description

The manifold absolute pressure (MAP) sensor responds

to changes in intake manifold pressure (vacuum). The

MAP sensor signal voltage to the powertrain control

module (PCM) varies from below 2 volts at idle (high

vacuum) to above 4 volts with the key “ON,” engine not

running or at wide-open throttle (low vacuum).

The MAP sensor is used to determine manifold

pressure changes while the linear EGR flow test

diagnostic is being run (refer to DTC P0401), to

determine engine vacuum level for some other

diagnostics and to determine barometric pressure

(BARO). The PCM monitors the MAP signals for

voltages outside the normal range of the MAP sensor. If

the PCM detects a MAP signal voltage that is

excessively high, DTC P0108 will be set.

Conditions for Setting the DTC

• No TP sensor DTCs present.

• Engine is running for more than 10 seconds.

• Throttle position is below 3% if engine speed is below

1000 RPM.

• Throttle position is below 10% if engine speed is

above 1000 RPM.

• The MAP sensor indicates an intermittent manifold

absolute pressure above 80kPa for a total of

approximately 10 seconds over a 16-second period.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will default to a BARO value of 79.3kPa.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0108 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

• Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the MAP display on the Tech 2 while moving

connectors and wiring harnesses related to the

sensor. A change in the display will indicate the

location of the fault.

If DTC P0108 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

If it is determined that the DTC occurs intermittently,

performing the DTC P1108 Diagnostic Chart may

isolate the cause of the fault.

DTC P0108 – MAP Sensor Circuit High Voltage

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. If the engine idle is rough, unstable or incorrect,

repair the idle problem before using this chart.

Refer to Symptoms section.

2. With the engine idling, note the MAP value on the

Tech 2.

Is the MAP reading above the specified value? 90kPa Go to Step 4 Go to Step 3

3 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “Specific DTC” info for

DTC P0108.

Does the Tech 2 indicate DTC P0108 failed this

ignition? — Go to Step 4

Refer to

Diagnostic Aids

4 1. Ignition “OFF.”

2. Disconnected the MAP sensor electrical

connector.

3. Ignition “ON.”

4. Note the MAP sensor voltage displayed on the

Tech 2.

Is the MAP sensor voltage at the specified value? 0.0 V 11kPa Go to Step 5 Go to Step 6

5 Probe the sensor ground circuit with a test light to B+.

Is the test light “ON?” — Go to Step 7 Go to Step 9

6 1. Check the MAP signal circuit for a short to voltage

or a short to the 5 volt reference “A” circuit.

2. If the MAP sensor signal circuit is shorted, repair

circuit as necessary.

Was the MAP sensor signal circuit shorted? — Verify repair Go to Step 11

7 1. Check for a poor sensor ground terminal

connection at the MAP sensor electrical

connector.

2. If a problem if found, replace the faulty terminal.

Did the terminal require replacement? — Verify repair Go to Step 8

8 Check for a plugged or leaking vacuum supply to the

MAP sensor.

Is the vacuum supply plugged or leaking? — Verify repair Go to Step 12

9 1. Check for a poor sensor ground terminal

connection at the PCM.

2. If a problem is found, replace the faulty terminal.

Did the terminal require replacement? — Verify repair Go to Step 10

10 1. Check the continuity of the MAP sensor ground

circuit.

2. If the MAP sensor ground circuit measures over 5

ohms, repair open or poor connection.

Was a condition found and corrected? — Verify repair Go to Step 11

11 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify Repair —

12 Replace the MAP sensor.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0112 IAT Sensor Circuit Low Voltage

D06RW026

Circuit Description

The intake air temperature (IAT) sensor is a thermistor

which measures the temperature of the air entering the

engine. The powertrain control module (PCM) applies 5

volts through a pull-up resistor to the IAT sensor. When

the intake air is cold, the sensor resistance is high and

the PCM will monitor a high signal voltage on the IAT

signal circuit. If the intake air is warm, the sensor

resistance is lower, causing the PCM to monitor a lower

voltage. DTC P0112 will set when the PCM detects an

excessively low signal voltage on the intake air

temperature sensor signal circuit.

Conditions for Setting the DTC

• The engine has been running for over 2 minutes.

• Vehicle speed is greater than 30 mph (48 km/h) .

• IAT signal voltage indicates and intake air

temperature greater than 148°C (298°F) (about 5

volts) for a total of 12.5 seconds over a 25-second

period of time.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0112 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Poor connection at PCM – Inspect harness

connectors for backed-bout terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

• Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the IAT display on the Tech 2 while moving

connectors and wiring harnesses related to the IAT

sensor. A change in the IAT display will indicate the

location of the fault.

If DTC P0112 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart:

2. Verifies that the fault is present.

3. If DTC P0112 can be repeated only by duplicating

the Failure Records condition, refer to the

Temperature vs. Resistance Value table. The table

may be used to test the IAT sensor at various

temperatures to evaluate the possibility of a “shifted”

sensor that may be stored above or below a certain

temperature. If this is the case, replace the IAT

sensor. If the IAT sensor appears to be OK, the fault

is intermittent; refer to Diagnostic Aids.

Intake Air Temperature Sensor

°C°FOHMS

Temperature vs. Resistance Values (approximate)

100 212 177

80 176 332

60 140 667

45 113 1188

35 95 1802

25 77 2796

15 59 4450

5 41 7280

–5 23 12300

–15 5 21450

–30 –22 52700

–40 –40 100700

DTC P0112–IAT Sensor Circuit Low Voltage

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 1.Ignition “ON,” engine “OFF.”

2.Using a Tech 2, monitor the intake air temperature

(IAT).

Is the intake air temperature greater than the specified

value?

148°C

(283°F)Go to Step 4 Go to Step 3

3 1.Ignition “ON,” engine “OFF.” Review and record

Tech 2 Failure Records data.

2.Operate the vehicle within Failure Records

conditions as noted.

3.Using a Tech 2, monitor the “Specific DTC” info for

DTC P0112.

Does the Tech 2 indicate DTC P0112 failed this

ignition?—

Refer to Test

Description

Refer to

Diagnostic Aids

4 1.Ignition “OFF.”

2.Disconnect the IAT sensor electrical connector.

3.Ignition “ON.”

4.Observe the intake air temperature on the Tech 2.

Is the intake air temperature below the specified

value?

–38°C (–

36°F)Go to Step 6 Go to Step 5

5 1.Ignition “OFF.”

2.Disconnect the PCM electrical connectors.

3.Check the IAT sensor signal circuit for a short to

ground.

Is the IAT sensor signal circuit shorted to ground?—Verify repairGo to Step 7

6 Replace the IAT sensor.

Is the action complete?—Verify repair—

7 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0113 IAT Sensor Circuit High Voltage

D06RW026

Circuit Description

The intake air temperature (IAT) sensor is a thermistor

which measures the temperature of the air entering the

engine. The powertrain control module (PCM) applies 5

volts through a pull-up resistor to the IAT sensor. When

the intake air is cold, the sensor resistance is high and

the PCM will monitor a high signal voltage on the IAT

signal circuit. If the intake air is warm, the sensor

resistance is lower causing the PCM to monitor a lower

voltage. DTC P0113 will set when the PCM detects an

excessively high signal voltage on the intake air

temperature sensor signal circuit.

Conditions for Setting the DTC

• The engine has been running for over 4 minutes.

• Vehicle speed is less than 20 mph (32 km/h).

• ECT signal temperature is above 60°C (140°F).

• Mass air flow is less then 20 g/second.

• IAT signal voltage indicates an intake air temperature

less than –39°C (–38°F) for total of 12.5 seconds

over a 25-second period.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0113 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• The IAT sensor shares a ground with the EGR

position sensor and the TP sensor. Check the

ground if these DTC's are set.

• Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

• Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the IAT display on the Tech 2 while moving

connectors and wiring harnesses related to the IAT

sensor. A change in the IAT display will indicate the

location of the fault.

If DTC P0113 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart:

2. Verifies that the fault is present.

3. If DTC P0113 can be repeated only by duplicating

the Failure Records conditions, refer to the

“Temperature vs. Resistance Values” table. The

table may be used to test the IAT sensor at various

temperatures to evaluate the possibility of a “shifted”

sensor that may be open above or below a certain

temperature. If this is the case, replace the IAT

sensor. If the IAT sensor appears to be OK, the fault

is intermittent; refer to Diagnostic Aids.

Intake Air Temperature Sensor

DTC P0113 –IAT Sensor Circuit High Voltage

°C°FOHMS

Temperature vs. Resistance Values (approximate)

100212177

80176332

60140667

451131188

35951802

25772796

15594450

5417280

–52312300

–15521450

–30–2252700

–40–40100700

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Ignition “ON,” engine “OFF.” Observe the “Intake Air

Temp” display on the Tech 2.

Is the “Intake Air Temp” below the specified value?

–38°C (–

36°F) Go to Step 4 Go to Step 3

3 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data

parameters.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “Specific DTC” info for

DTC P0113.

Does the Tech 2 indicate DTC P0113 failed? —

Refer to Test

Description

Refer to

Diagnostic Aids

4 1. Ignition “OFF.”

2. Disconnect the IAT sensor electrical connector.

3. Jumper the IAT signal circuit and the sensor

ground circuit together at the IAT sensor harness

connector.

4. Ignition “ON.”

5. Observe the “Intake Air Temp” display on the Tech

Is the “Intake Air Temp” at the specified value?

140°C

(284°F) Go to Step 6 Go to Step 5

5 1. Jumper the IAT signal circuit at the IAT sensor

harness connector to chassis ground.

2. Observe the “Intake Air Temp” display on the Tech

Is the “Intake Air Temp” at the specified value?

140°C

(284°F) Go to Step 7 Go to Step 8

6 Check for poor connections at the IAT sensor and

replace terminals if necessary.

Did any terminals require replacement? — Verify repair Go to Step 10

7 1.Ignition “OFF.”

2.Disconnect the PCM, and check the IAT sensor

ground circuit for an open.

3.If the IAT sensor ground circuit is open, repair it as

necessary.

Was the IAT sensor ground circuit open?—Verify repairGo to Step 9

8 1.Ignition “OFF.”

2.Disconnect the PCM, and check the IAT signal

circuit for an open.

3.If the IAT sensor signal circuit is open, repair it as

necessary.

Was the IAT signal circuit open?—Verify repairGo to Step 9

9 Check for a poor sensor ground or IAT signal circuit

terminal connection at the PCM and replace

terminal(s) if necessary.

Did any of the terminals need to be replaced?—Verify repairGo to Step 11

10 Replace the IAT sensor.

Is the action complete?—Verify repair—

11 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0117 ECT Sensor Circuit Low Voltage

060RY00304

Circuit Description

The engine coolant temperature (ETC) sensor is a

thermistor mounted on a coolant crossover pipe at the

rear of the engine. The powertrain control module

(PCM) applies a voltage (about 5 volts) through a

pull-up resistor to the ECT signal circuit. When the

engine coolant is cold, the sensor (thermistor)

resistance is high, therefore the PCM will measure a

high signal voltage. As the engine coolant warms, the

sensor resistance becomes lower, and the ECT signal

voltage measured at the PCM drops. With a fully

warmed-up engine, the ECT signal voltage should

measure about 1.5 to 2.0 volts.

Conditions for Setting the DTC

• Engine running time is longer than one minute.

• The ECT sensor signal indicates an engine coolant

temperature greater than 150°C (302°F) (about 0.10

V) for a total of 50 seconds over a 100–second

period.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will substitute the ECT reading with a

default engine coolant temperature value. The

default value is based on start-up intake air

temperature and running time.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0117 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

• Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the ECT display on the Tech 2 while moving

connectors and wiring harnesses related to the ECT

sensor. A change in the ECT display will indicate the

location of the fault.

If DTC P0117 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Verifies that the fault is present.

3. If DTC P0117 can be repeated only by duplicating

the Failure Records conditions, refer to the

“Temperature vs. Resistance Values” table. The

table may be used to test the ECT sensor at various

temperatures to evaluate the possibility of a “shifted”

sensor that may be shorted above or below a certain

temperature. If this is the case, replace the ECT

sensor. If the ECT sensor appears to be OK, the

fault is intermittent; refer to Diagnostic Aids.

Engine Coolant Temperature Sensor

°C°FOHMS

Temperature vs. Resistance Values (approximate)

100 212 177

80 176 332

60 140 667

45 113 1188

35 95 1802

25 77 2796

15 59 4450

5 41 7280

–5 23 12300

–15 5 21450

–30 –22 52700

–40 –40 100700

DTC P0117 – ECT Sensor Low Voltage

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 1.Ignition “ON,” engine “OFF.”

2.Observe the “Eng Cool Temp” display on the Tech

Is the “Eng Cool Temp” below the specified value?

139°C

(282°F)Go to Step 4 Go to Step 3

3 1.Ignition “ON,” engine “OFF.”

2.Review and record Tech 2 Failure Records data.

3.Operate the vehicle within Failure Records

conditions as noted.

4.Using a Tech 2, monitor “Specific DTC” info for

DTC P0117.

Does the Tech 2 indicate DTC P0117 failed this

ignition?—Go to Step 4

Refer to

Diagnostic Aids

4 1.Disconnect the ECT sensor electrical connector.

2.Observe the “Eng Cool Temp” display on the Tech

Is the “Eng Cool Temp” at the specified value?

–39°C (–

38°F)Go to Step 6 Go to Step 5

5 1.Ignition “OFF.”

2.Disconnect the PCM and check the ECT signal

circuit for a short to ground or a short to the sensor

ground circuit.

3.If the ECT signal circuit is shorted. repair it as

necessary.

Was the ECT signal circuit shorted to ground?—Verify repairGo to Step 7

6 Replace the ECT sensor.

Is the action complete?—Verify repair—

7 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0118 ECT Sensor Circuit High Voltage

060RY00304

Circuit Description

The engine coolant temperature (ETC) sensor is a

thermistor mounted in on a coolant crossover pipe at

the rear of the engine. The powertrain control module

(PCM) applies a voltage (about 5 volts) through a

pull-up resistor to the ECT signal circuit. When the

engine coolant is cold, the sensor (thermistor)

resistance is high, therefore the PCM will measure a

high signal voltage. As the engine coolant warms, the

sensor resistance becomes less, and the ECT signal

voltage measured at the PCM drops. With a fully

warmed-up engine, the ECT signal voltage should

measure about 1.5 to 2.0 volts.

Conditions for Setting the DTC

• Engine running time is longer than 1.5 minutes.

• The ECT sensor signal indicates an engine coolant

temperature of –39°C (–38°F) or less (about 5 volts)

for a total of 50 seconds over a 100-second period.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will substitute the ECT reading with a

default engine coolant temperature value. The

default value is based on start-up intake air

temperature and running time.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0118 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

The ECT shares a ground with the Transmission Fluid

Temperature sensor, the Rough Road sensor, and the

MAP sensor.

Check the ground if these DTCs are also set.

• Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

• Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the ECT display on the Tech 2 while moving

connectors and wiring harnesses related to the ECT

sensor. A change in the ECT display will indicate the

location of the fault.

If DTC P0118 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

If it is determined that the DTC occurs intermittently,

performing the DTC P1115 Diagnostic Chart may isolate

the cause of the fault.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Verifies that the fault is present.

3. If DTC P0118 can be repeated only by duplicating

the Failure Records conditions, refer to the

“Temperature vs. Resistance Value” table. The table

may be used to test the ECT sensor at various

temperatures to evaluate the possibility of a “shifted”

sensor that may be shorted above or below a certain

temperature. If this is the case, replace the ECT

sensor. If the ECT sensor appears to be OK, the

fault is intermittent; refer to Diagnostic Aids.

Engine Coolant Temperature Sensor

DTC P0118 – ECT Sensor Circuit High Voltage

°C°FOHMS

Temperature vs. Resistance Values (approximate)

100212177

80176332

60140667

451131188

35951802

25772796

15594450

5417280

–52312300

–15521450

–30–2252700

–40–40100700

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. Observe the “Eng Cool Temp” display on the Tech

Is the “Eng Cool Temp” below the specified value?

–39°C (–

38°F) Go to Step 4 Go to Step 3

3 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor the “Specific DTC” info for

DTC P0118.

Does the Tech 2 indicate DTC P0118 failed? —

Refer to Test

Description

Refer to

Diagnostic Aids

4 1. Disconnect the ECT sensor electrical connector.

2. Jumper the ECT signal circuit and the sensor

ground circuit together at the ECT sensor harness

connector.

3. Observe the “Eng Cool Temp” display on the Tech

Is the “Eng Cool Temp” at the specified value?

140°C

(284°F) Go to Step 6 Go to Step 5

5 1. Jumper the ECT signal circuit at the ECT sensor

harness connector to chassis ground.

2. Observe the “Eng Cool Temp” display on the Tech

Is the “Eng Cool Temp” at the specified value?

140°C

(284°F) Go to Step 7 Go to Step 8

6 Check for poor connections at the ECT sensor and

replace terminals if necessary.

Did any terminals require replacement? — Verify repair Go to Step 10

7 1.Ignition “OFF.”

2.Disconnect the PCM, and check the ECT sensor

ground circuit for an open.

3.If the ECT sensor ground circuit is open, repair it

as necessary.

Was the ECT sensor ground circuit open?—Verify repairGo to Step 9

8 1.Ignition “OFF.”

2.Disconnect the PCM, and check the ECT signal

circuit for an open.

3.If the ECT sensor signal circuit is open, repair it as

necessary.

Was the ECT signal circuit open?—Verify repairGo to Step 9

9 Check for a poor sensor ground or ECT signal circuit

terminal connection at the PCM and replace

terminal(s) if necessary.

Did any of the terminals need to be replaced?—Verify repairGo to Step 11

10 Replace the ECT sensor.

Is the action complete?—Verify repair—

11 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0121 TP System Performance

D06RW028

Circuit Description

The throttle position (TP) sensor circuit provides a

voltage signal that changes relative to throttle blade

angle. The signal voltage will vary from about 0.6 volts

at closed throttle to about 4.5 volts at wide open throttle

(WOT).

The TP signal is used by the powertrain control module

(PCM) for fuel control and many of the PCM-controlled

outputs. The PCM monitors throttle position and

compares actual throttle position from the TP sensor to

a predicted TP value calculated from engine speed. If

the PCM detects an out-of-range condition, DTC P0121

will set.

Conditions for Setting the DTC

• The engine is running.

• No MAP DTCs, or P0121, P0122, P0123 are set.

• MAP reading is below 55kPa.

• Throttle is steady, throttle angle is changing less than

1%.

• Predicted throttle angle is not close to actual throttle

angle.

• Above conditions are present for a total of 12.5

seconds over a 25-second period of time.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

• The PCM will use a default throttle position based on

mass air flow and RPM.

Conditions for Clearing the MIL/DTC

• DTC P0121 can be cleared by using the Tech 2

“Clear info ” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Skewed MAP signal or faulty Map sensor – An

incorrect MAP signal may cause the PCM to

incorrectly calculate the predicted TP sensor value

during high engine load situations. Check for an

unusually low MAP reading. This condition can

cause DTC P0121 to be set.

• Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks improperly formed or damaged

terminals, and poor terminal-to-wire connection.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the ECT display on the Tech 2 while moving

connectors and wiring harnesses related to the

sensor. A change in the display will indicate the

location of the fault.

If DTC P0121 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

DTC P0121 –TP System Performance

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine not running.

2. Observe the MAP reading on the Tech 2.

Is the MAP reading less than the specified value? 65kPa Go to Step 3 Go to Step 6

3 1. Disconnected the MAP sensor.

2. Connect a test light between the 5 volt reference

“A” circuit and the MAP signal circuit at the MAP

sensor harness connector.

3. Observe the MAP reading on the Tech 2.

Is the MAP reading less than the specified value? 65kPa Go to Step 5 Go to Step 4

4 1. Check the MAP signal circuit between the PCM

and the MAP sensor for an open, short to ground,

or short to the MAP ground circuit.

2. If the MAP signal circuit is open or shorted, repair

it as necessary.

Was the MAP signal circuit open or shorted? — Verify repair Go to Step 12

5 Replace the MAP sensor.

Is the action complete? — Verify repair —

6 Observe the TP angle reading on the Tech 2 while

slowly opening the throttle.

Does the TP angle increase steadily and evenly from

the closed throttle value to the wide open throttle

value?

Closed

throttle = 0%

Wide open

throttle =

100%

Refer to

Diagnostic Aids Go to Step 7

7 1. Disconnect the TP sensor.

2. Observe the TP sensor reading on the Tech 2.

Is the TP sensor reading near the specified value? 0 V Go to Step 8 Go to Step 9

8 1. Connect a test light between the 5 volt reference

“A” circuit and the TP sensor signal circuit at the

TP sensor harness connector.

2. Observe the TP sensor reading on the Tech 2.

Is the TP sensor reading at the specified value? 5 V Go to Step 11 Go to Step 10

9 Check the following items:

1. TP signal circuit for a short to voltage.

2. TP sensor ground circuit for high resistance

between the PCM and the TP sensor.

3. TP sensor ground circuit for a poor connection.

4. If a problem is found, repair wiring harness as

necessary.

Was a problem found? — Verify repair Go to Step 12

10 Check the following items:

1.TP signal circuit or 5 volt reference “A” circuit for a

poor connection.

2.TP signal circuit or 5 volt reference “A” circuit for

high resistance between the PCM and the TP

sensor.

3.If a problem is found, repair wiring harness as

necessary.

Was a problem found?—Verify repairGo to Step 12

11 Replace the TP sensor.

Is the action complete?—Verify repair—

12 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0122 TP Sensor Circuit Low Voltage

D06RW028

Circuit Description

The throttle position (TP) sensor circuit provides a

voltage signal that changes relative to throttle blade

angle. The signal voltage will vary from below 0.6 volts

at closed throttle to about 4.5 volts at wide open throttle

(WOT).

The TP signal is used by the powertrain control module

(PCM) for fuel control and many of the PCM–controlled

outputs.

Conditions for Setting the DTC

• The ignition is “ON.”

• TP sensor signal voltage is less than 0.22 volt for a

total of 0.78 second over a 1.5-second period.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

• The PCM will use a default throttle position based on

mass air flow and RPM.

Conditions for Clearing the MIL/DTC

• DTC P0122 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Check intermittent codes.

• The TP sensor shares a 5 Volt reference with the

EGR position sensor. Check the 5 Volt reference if

these DTCs are also set.

• The TP sensor shares a ground with the IAT sensor,

the EGR position sensor.

• Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

• Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the throttle position display on the Tech 2 while

moving connectors and wiring harnesses related to

the TP sensor. A change in the display will indicate

the location of the fault.

If DTC P0122 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

DTC P0122 –TP Sensor Circuit Low Voltage

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. With the throttle closed, observe the “TP Sensor”

display on the Tech 2.

Is the “TP Sensor” below the specified value? 0.22 V Go to Step 4 Go to Step 3

3 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor the “DTC” info for DTC

P0122.

Does the Tech 2 indicate DTC P0122 failed? — Go to Step 4

Refer to

Diagnostic Aids

4 1. Ignition “OFF.”

2. Disconnect the TP sensor electrical connector.

3. Jumper the 5 volt reference “A” circuit and the TP

signal together at the TP sensor harness

connector.

4. Ignition “ON.”

Observe the “TP Sensor” display on the Tech 2.

Is the “TP Sensor” at the specified value? 5 V Go to Step 10 Go to Step 5

5 1. Disconnect jumper.

2. Connect a test light between B+ and the TP

sensor signal circuit at the TP sensor harness

connector.

Observe the “TP Sensor” display on the Tech 2.

Is the “TP Sensor” at the specified value? 5 V Go to Step 6 Go to Step 8

6 1. Ignition “OFF.”

2. Disconnect the PCM and check the 5 volt

reference “A” circuit for an open or short to

ground.

3. If the 5 volt reference “A” circuit is open or shorted

to ground, repair it as necessary.

Was the 5 volt reference “A” circuit open or shorted to

ground? — Verify repair Go to Step 7

7 Check the 5 volt reference “A” circuit for a poor

connection at the PCM and replace the terminal if

necessary.

Did the terminal require replacement? — Verify repair Go to Step 12

8 1. Ignition “OFF.”

2. Disconnect the PCM, and check the TP signal

circuit for an open, short to ground, or short to the

sensor ground circuit.

3. If the TP sensor signal circuit is open or shorted to

ground, repair it as necessary.

Was the TP signal circuit open or shorted to ground? — Verify repair Go to Step 9

9 Check the TP sensor signal circuit for a poor

connection at the PCM and replace the terminal if

necessary.

Did the terminal require replacement? — Verify repair Go to Step 12

10 Check the TP sensor signal circuit for a poor

connection at the TP sensor and replace the terminal

if necessary.

Did the terminal require replacement?—Verify repairGo to Step 11

11 Replace the TP sensor.

Is the action complete?—Verify repair—

12 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0123 TP Sensor Circuit High Voltage

D06RW028

Circuit Description

The throttle position (TP) sensor circuit provides a

voltage signal that changes relative to throttle blade

angle. The signal voltage will vary from about 0.6 volts

at closed throttle to about 4.5 volts at wide open throttle

(WOT).

The TP signal is one of the most important inputs used

by the powertrain control module (PCM) for fuel control

and many of the PCM-controlled outputs.

Conditions for Setting the DTC

• The ignition is “ON.”

• TP sensor signal voltage is greater than 4.88 volts for

a total of 0.78 second over a 1.5-second period.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

• The PCM will use a default throttle position based on

mass air flow and RPM.

Conditions for Clearing the MIL/DTC

• DTC P0123 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Check intermittent codes.

• The TP sensor shares a 5 Volt reference with the

EGR position sensor. Check the 5 Volt reference if

these DTCs are also set.

• The TP sensor shares a ground with the IAT sensor

and the EGR position sensor. Check the ground if

these other DTCs are also set.

• Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

• Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the TP sensor display on the Tech 2 while moving

connectors and wiring harnesses related to the TP

sensor. A change in the display will indicate the

location of the fault.

• Faulty TP sensor – With the ignition key “ON,” engine

“OFF,” observe the TP sensor display on the Tech 2

while slowly depressing the accelerator to wide open

throttle. If a voltage over 4.88 volts is seen at any

point in normal accelerator travel, replace the TP

sensor.

If DTC P0123 cannot be duplicated, the information

included in the Failure Records data can be useful in

determining vehicle mileage since the DTC was last set.

Test Description

Number (s) below refer to the step number(s) on the

Diagnostic Chart.

7. Components that share the TP sensor 5 volt

reference “A” circuit include the following device:

•EGR valve

Disconnect the component while observing the TP

sensor display on the Tech 2. If the reading changes

drastically when this component is disconnected,

replace the component that affected the reading.

DTC P0123 – TP Sensor Circuit High Voltage

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. With the throttle closed, observe the “TP Sensor”

display on the Tech 2.

Is the “TP Sensor” above the specified value? 4.88 V Go to Step 4 Go to Step 3

3 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “Specific DTC” info for

DTC P0123.

Does the Tech 2 indicate DTC P0123 failed. — Go to Step 4

Refer to

Diagnostic Aids

4 1. Disconnect the TP sensor electrical connector.

2. Observe the “TP Sensor” display on the Tech 2.

Is the “TP Sensor” near the specified value? 0 V Go to Step 5 Go to Step 6

5 Probe the sensor ground circuit at the TP sensor

harness connector with a test light connected to B+.

Is the test light “ON?” — Go to Step 7 Go to Step 10

6 1. Ignition “OFF,” disconnect the PCM.

2. Ignition “ON,” engine “OFF.”

3. Check for a short to voltage on the TP sensor

signal circuit.

4. If the TP sensor signal circuit is shorted, repair it

as necessary.

Was the TP sensor signal circuit shorted? — Verify repair Go to Step 12

7 1. Ignition “ON.”

2. Monitor the “TP Sensor” Tech 2 display while

disconnecting each of the components that share

the 5 volt reference “A” circuit (one at a time).

3. If the “TP Sensor” Tech 2 display changes,

replace the component that caused the display to

change when disconnected.

Does disconnecting any of these components cause

the “TP Sensor” display to change? — Verify repair Go to Step 8

8 1.Ignition “OFF,” disconnect the PCM.

2.Ignition “ON,” engine “OFF.”

3.Check for a short to B+ on the 5 volt reference “A”

circuit.

4.If the 5 volt reference “A” circuit is shorted, repair it

as necessary.

Was the 5 volt reference “A” circuit shorted?—Verify repairGo to Step 9

9 Check for poor electrical connections at the TP sensor

and replace terminals if necessary.

Did any terminals require replacement?—Verify repairGo to Step 11

10 1.Ignition “OFF.”

2.Disconnect the PCM, and check for an open

sensor ground circuit to the TP sensor.

3.If a problem is found, repair it as necessary.

Was the sensor ground circuit to the TP sensor open?—Verify repairGo to Step 12

11 Replace the TP sensor.

Is the action complete?—Verify repair—

12 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0131 HO2S Circuit Low Voltage Bank 1 Sensor 1

060RW236

Circuit Description

The powertrain control module (PCM) supplies a bias

voltage of about 450 mV between the heated oxygen

sensor (HO2S) signal high and signal low circuits.

When measured with a 10 megaohm digital voltmeter,

this may display as low as 350 mV. The oxygen sensor

varies the voltage within a range of about 1000 mV

when the exhaust is rich, down through about 10 mV

when exhaust is lean. The PCM constantly monitors

the HO2S signal during “closed loop” operation and

compensates for a rich or lean condition by decreasing

or increasing injector pulse width as necessary. If the

Bank 1 HO2S 1 voltage remains excessively low for an

extended period of time, DTC P0131 will be set.

Conditions for Setting the DTC

•No related DTCs.

•Vehicle is operating in “closed loop.”

•Engine coolant temperature is above 60°C (140°F).

•“Closed loop” commanded air/fuel ratio is between

14.5 and 14.8.

•Throttle angle is between 3% and 19%.

•Bank 1 HO2S 1 signal voltage remains below 22 mV

during normal “closed loop” operation for a total of 77

seconds over a 90-second period of time.

Action Taken When the DTC Sets

•The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

•The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

•“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

•DTC P0131 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Heated oxygen sensor wiring – The sensor pigtail

may be routed incorrectly and contacting the exhaust

system.

•Poor PCM to engine block grounds.

•Fuel pressure – The system will go lean if pressure is

too low. The PCM can compensate for some

decrease. However, If fuel pressure is too low, a

DTC P0131 may be set. Refer to Fuel System

Diagnosis.

• Lean injector(s) – Perform “Injector Balance Test.”

•Vacuum leaks – Check for disconnected or damaged

vacuum hoses and for vacuum leaks at the intake

manifold, throttle body, EGR system, and PCV

system.

•Exhaust leaks – An exhaust leak may cause outside

air to be pulled into the exhaust gas stream past the

HO2S, causing the system to appear lean. Check for

exhaust leaks that may cause a false lean condition

to be indicated.

•MAF sensor – The system can go lean if the MAF

sensor signal indicates an engine airfiow

measurement that is not correct. Disconnect the

MAF sensor to see if the lean condition is corrected.

If so, replace the MAF sensor.

•Fuel contamination – Water, even in small amounts,

can be delivered to the fuel injectors. The water can

cause a lean exhaust to be indicated. Excessive

alcohol in the fuel can also cause this condition.

Refer to Fuel System Diagnosis for the procedure to

check for fuel contamination.

•If none of the above conditions are present, replace

the affected HO2S.

Test Description

Number(s) below refer to step numbers on the

diagnostic chart.

3. DTC P0131 failing during operation may indicate a

condition described in the “Diagnostic Aids” above.

If the DTC P0131 test passes while the Failure

Records conditions are being duplicated, an

intermittent condition is indicated.

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.

DTC P0131 –HO2S Circuit Low Voltage Bank 1 Sensor 1

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Install the Tech 2.

2. Run the engine at operating temperature.

3. Operate the vehicle within the parameters

specified under “Conditions for Setting the DTC”

criteria included in Diagnostic Support.

4. Using a Tech 2, monitor Bank 1 HO2S 1 voltage.

Does the Bank 1 HO2S 1 voltage remain below the

specified value? 22 mV Go to Step 4 Go to Step 3

3 1. Ignition “ON,” engine “OFF,” review and record

Tech 2 Failure Records data and note parameters.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “Specific DTC” info for

DTC P0131 until the DTC P0131 test runs.

Note test result.

Does Tech 2 indicate DTC P0131 failed this ignition? — Go to Step 4

Refer to

Diagnostic Aids

4 1. Turn the ignition “OFF.”

2. Disconnect the PCM.

3. Check the Bank 1 HO2S 1 high and low circuits for

a short to ground or a short to the heater ground

circuit.

Are the Bank 1 HO2S 1 signal circuits shorted to

ground? — Go to Step 5 Go to Step 6

5 Repair the Bank 1 HO2S 1 signal circuit.

Is the action complete? — Verify repair —

6 1. Turn the ignition “OFF,” HO2S 1 and PCM

disconnected.

2. Check for continuity between the high and low

signal circuits.

Was there continuity between the high and low

circuits? — Go to Step 7 Go to Step 8

7 Repair the short between the high and low circuits.

Is the action complete?—Verify repair—

8 1.Ignition “OFF.”

2.Reconnect the PCM, leave the sensor

disconnected.

3.Ignition “ON.”

Does the Tech 2 indicate Bank 1 HO2S 1 voltage

between the specified values?425-475 mV

Refer to

Diagnostic Aids Go to Step 9

9 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0132 HO2S Circuit High Voltage Bank 1 Sensor 1

060RW236

Circuit Description

The powertrain control module (PCM) supplies a bias

voltage of about 450 mV between the heated oxygen

sensor (HO2S) signal and low circuits. When measured

with a 10 megaohm digital voltmeter, this may display

as low as 320 mV. The oxygen sensor varies the

voltage within a range of about 1000 mV when exhaust

is rich, down through about 10 mV when exhaust is

lean. The PCM constantly monitors the HO2S signal

during “closed loop” operation and compensates for a

rich or lean condition by decreasing or increasing

injector pulse width as necessary. If the Bank 1 HO2S 1

voltage remains excessively high for an extended

period of time, DTC P0132 will be set.

Conditions for Setting the DTC

•No related DTCs.

•Engine coolant temperature is above 60°C (140°F)

•“Closed loop” commanded air/fuel ratio is between

14.5 and 14.8.

•Throttle angle is between 3% and 19%.

•Bank 1 HO2S 1 signal voltage remains above 952

mV during normal “closed loop” operation for a total

of 77 seconds over a 90-second period.

•Bank 1 HO2S 1 signal voltage remains above 500

mV during “deceleration fuel cutoff mode” operation

for 3 seconds.

Action Taken When the DTC Sets

•The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

•The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

•“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

•DTC P0132 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check the following items:

•Fuel pressure – The system will go rich if pressure is

too high. The PCM can compensate for some

increase. However, if fuel pressure is too high, a

DTC P0132 may be set. Refer to Fuel System

Diagnosis.

•Perform “Injector Balance Test” – Refer to Fuel

System Diagnosis.

•MAF sensor –The system can go rich if MAF sensor

signal indicates an engine airflow measurement that

is not correct. Disconnect the MAF sensor to see it

the rich condition is corrected. If so, replace the MAF

sensor.

•Check for a leak in the fuel pressure regulator

diaphragm by checking the vacuum line to the

regulator for the presence of fuel. There should be

no fuel in the vacuum line.

•An intermittent TP sensor output will cause the

system to go rich due to a false indication of the

engine accelerating.

•Shorted Heated Oxygen Sensor (HO2S) –If the

HO2S is internally shorted, the HO2S voltage

displayed on the Tech 2 will be over 1 volt. Try

disconnecting the affected HO2S with the key “ON,”

engine “OFF.” If the displayed HO2S voltage

changes from over 1000 mV to around 450 mV,

replace the HO2S. Silicon contamination of the

HO2S can also cause a high HO2S voltage to be

indicated. This condition is indicated by a powdery

white deposit on the portion of the HO2S exposed to

the exhaust stream. If contamination is noticed,

replace the affected HO2S.

•Open HO2S Signal Circuit or Faulty HO2S–A poor

connection or open in the HO2S signal circuit can

cause the DTC to set during deceleration fuel mode.

An HO2S which is faulty and not allowing a full

voltage swing between the rich and lean thresholds

can also cause this condition. Operate the vehicle by

monitoring the HO2S voltage with a Tech 2. If the

HO2S voltage is limited within a range between 300

mV to 600 mV, check the HO2S signal circuit wiring

and associated terminal conditions.

•If none of the above conditions are present, replace

the affected HO2S.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. DTC P0132 failing during “deceleration fuel cutoff

mode” operation may indicate a condition described

in the “Diagnostic Aids” above. If the DTC P0132

test passes while the Failure Records conditions are

being duplicated, an intermittent condition is

indicated.

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.

DTC P0132 – HO2S Circuit High Voltage Bank 1 Sensor 1

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Install the Tech 2.

2. Run the engine at operating temperature.

3. Operate the vehicle within parameters specified

under “Conditions for Setting the DTC” included in

Diagnostic Support.

4. Using a Tech 2, monitor Bank 1 HO2S 1 voltage.

Does the Bank 1 HO2S 1 voltage remain above the

specified value?

952 mV (500

mV in

deceleration

fuel cutoff

mode) Go to Step 4 Go to Step 3

3 1. Ignition “ON,” review and record Tech 2 Failure

Records data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “Specific DTC” info for

DTC P0132 until the DTC P0132 test runs.

4. Note the test result.

Does the Tech 2 indicate DTC P0132 failed this

ignition? — Go to Step 4

Refer to

Diagnostic Aids

4 1. Ignition “OFF.”

2. Disconnect Bank 1 HO2S 1.

3. Ignition “ON.”

4. At HO2S Bank 1 Sensor 1 connector (PCM side)

use a DVM to measure voltages at the high and

low signal terminals.

Are the voltages in the specified range? 3-4 V Go to Step 5 Go to Step 6

5 Repair short to voltage in signal circuit.

Is the action complete?—Verify repair—

6 1.Ignition “ON,” engine“OFF.”

2.At Bank 1 HO2S 1 connector (PCM side) jumper

both the HO2S high and low signal circuits (PCM

side) to ground.

3.Using a Tech 2, monitor Bank 1 HO2S 1 voltage.

Is Bank 1 HO2S 1 voltage below the specified value?10 mVGo to Step 7 Go to Step 8

7 1.Disconnect the jumpers to ground from Bank 1

HO2S 1 PCM-side connector.

2.With the HO2S 1 connector disconnected, monitor

Bank 1 HO2S 1 voltage.

Is Bank 1 HO2S 1 voltage between the specified

values?425-475 mV

Refer to

Diagnostic Aids Go to Step 8

8 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0134 HO2S Circuit Insufficient Activity Bank 1 Sensor 1

060RW237

Circuit Description

• The powertrain control module (PCM) supplies a bias

voltage of about 450mV between the heated oxygen

sensor (HO2S) high and low circuits. When

measured with a 10 megaohm digital voltmeter, this

may display as low as 320mV. The oxygen sensor

varies the voltage within a range of about 1000mV

when the exhaust is rich, down through about 10mV

when exhaust is lean. The PCM constantly monitors

the HO2S signal during “closed loop” operation and

compensates for a rich or lean condition by

decreasing or increasing injector pulse width as

necessary. If the Bank 1 HO2S 1 voltage remains at

or near the 450mV bias for an extended period of

time, DTC P0134 will be set, indicating an open

sensor signal or sensor low circuit.

• Heated oxygen sensors are used to minimize the

amount of time required for “closed loop” fuel control

operation and to allow accurate catalyst monitoring.

The oxygen sensor heater greatly decreases the

amount of time required for fuel control sensors Bank

1 HO2S 1 and Bank 2 HO2S 1 to become active.

• Oxygen sensor heaters are required by post-catalyst

monitor sensors to maintain a sufficiently high

temperature for accurate exhaust oxygen content

readings further from the engine.

Conditions for Setting the DTC

• No related DTCs.

• Battery voltage is above 10 volts.

• Engine run time is longer than 40 seconds.

• Oxygen sensor heater has been determined to be

functioning properly.

• Bank 1 HO2S 1 signal voltage remains between

400mV and 500mV for a total of 77 seconds over a

90-second period of time.

Action Take When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

• “Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

• DTC P0134 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection or damaged harness – Inspect the

harness connectors for backed-out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, poor terminal-to-wire connection,

and damaged harness.

•Faulty HO2S heater or heater circuit – With the

ignition “ON,” engine “OFF,” after a cool down period,

the HO2S 1 voltage displayed on Tech 2 is normally

455-460mV. A reading over 1000mV indicates a

signal line shorted to voltage. A reading under 5mV

indicates a signal line shorted to ground or signal

lines shorted together. Disconnect the HO2S and

connect a test light between the HO2S ignition feed

and heater ground circuits. If the test light does not

light for 2 seconds when the ignition is turned on,

repair the open ignition feed or sensor ground circuit

as necessary. If the test light lights and the HO2S

signal and low circuits are OK, replace the HO2S.

•Intermittent test – With the Ignition “ON,” monitor the

HO2S signal voltage while moving the wiring harness

and related connectors. If the fault is induced, the

HO2S signal voltage will change. This may help

isolate the location of the malfunction.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. If the DTC P0134 test passes while the Failure

Records conditions are being duplicated, an

intermittent conditions is indicated.

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.

DTC P0134 –HO2S Circuit Insufficient Activity Bank 1 Sensor 1

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Install Tech 2.

2. Run the engine at operating temperature.

3. Operate the engine above 1200 RPM for two

minutes.

Does Tech 2 indicate Bank 1 HO2S 1 voltage varying

outside the specified values? 400-500mV Go to Step 3 Go to Step 4

3 1. Ignition “ON,” engine “OFF,” review and record

Tech 2 Failure Records data and note parameters.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using Tech 2, monitor “Specific DTC” info for DTC

P0134 until the DTC P0134 test runs.

4. Note the test result.

Does Tech 2 indicate DTC P0134 failed this ignition? — Go to Step 4

Refer to

Diagnostic Aids

4 Check for a damaged harness.

Was a problem found? — Verify repair Go to Step 5

5 Check for poor Bank 1 HO2S 1 high and low circuit

terminal connections at the Bank 1 HO2S 1 harness

connector and replace terminal(s) if necessary.

Did any terminals require replacement? — Verify repair Go to Step 6

6 Check for poor Bank 1 HO2S 1 high and low circuit

terminal connections at the PCM and replace

terminals if necessary.

Did any terminals require replacement? — Verify repair Go to Step 7

7 1. Ignition “OFF.”

2. With the PCM disconnected, check continuity of

the Bank 1 HO2S 1 high circuit.

3. If the Bank 1 HO2S 1 high circuit measures over

5.0 ohms, repair open or poor connection as

necessary.

Was a Bank 1 HO2S 1 high circuit problem found and

corrected? — Verify repair Go to Step 8

8 1.Ignition “OFF.”

2.With the PCM disconnected, check continuity of

the Bank 1 HO2S 1 low circuit.

3.If the Bank 1 HO2S 1 low circuit measures over 5

ohms, repair open or poor connection as

necessary.

Was a Bank 1 HO2S 1 low circuit problem found and

corrected?—Verify repairGo to Step 9

9 1.Ignition “ON,” engine “OFF.”

2.Disconnect Bank 1 HO2S 1 and jumper the HO2S

high and low circuits (PCM side) to ground.

3.Using Tech 2, monitor Bank 1 HO2S 1 voltage.

Is Bank 1 HO2S 1 voltage in the specified range?0-10mVGo to Step 10 Go to Step 11

10 Replace Bank 1 HO2S 1.

Is the action complete?—Verify repair—

11 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0151 HO2S Circuit Low Voltage Bank 2 Sensor 1

060RW190

Circuit Description

The powertrain control module (PCM) supplies a bias

voltage of about 450mV between the heated oxygen

sensor (HO2S) signal high and signal low circuits.

When measured with a 10 megaohm digital voltmeter,

this may display as low as 320mV. The oxygen sensor

varies the voltage within a range of about 1000mV

when the exhaust is rich, down through about 10mV

when exhaust is lean. The PCM constantly monitors

the HO2S signal during “closed loop” operation and

compensates for a rich or lean condition by decreasing

or increasing injector pulse width as necessary. If the

Bank 2 HO2S 1 voltage remains excessively low for an

extended period of time, DTC P0151 will be set.

Conditions for Setting the DTC

•No related DTCs.

•The engine is operating in “closed loop.”

•Engine coolant temperature is above 60°C (140°F).

•“Closed loop” commanded air/fuel ratio is between

14.5 and 14.8.

•Throttle angle is between 3% and 19%.

•Bank 2 HO2S 1 signal voltage remains below 22mV

during normal “closed loop” operation for a total of 77

seconds over a 90-second period of time.

Action Taken When the DTC Sets

•The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

•The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

•“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

•DTC P0151 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

•Heated oxygen sensor wiring – The sensor pigtail

may be mispositioned and contacting the exhaust

system.

•Poor PCM to engine block grounds.

•Fuel pressure – The system will go lean if pressure is

too low. The PCM can compensate for some

decrease. However, if fuel pressure is too low, a DTC

P0151 may be set. Refer to Fuel System Diagnosis.

• Lean injector(s) – Perform “Injector Balance Test.”

• Vacuum leaks – Check for disconnected or damaged

vacuum hoses and for vacuum leaks at the intake

manifold, throttle body, EGR system, and PCV

system.

•Exhaust leaks – An exhaust leak may cause outside

air to be pulled into the exhaust gas stream past the

HO2S, causing the system to appear lean. Check for

exhaust leaks that may cause a false lean condition

to be indicated.

•MAF sensor –The system can go lean if the MAF

sensor signal indicates an engine airflow

measurement that is not correct. Disconnect the MAF

sensor to see if the lean condition is corrected. If so,

replace the MAF sensor.

•Fuel contamination – Water, even in small amounts,

can be delivered to the fuel injectors. The water can

cause a lean exhaust to be indicated. Excessive

alcohol in the fuel can also cause this condition.

Refer to Fuel System Diagnosis for the procedure to

check for fuel contamination.

•If none of the above conditions are present, replace

the affected HO2S.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. DTC P0151 failing during operation may indicate a

condition described in the “Diagnostic Aids” above.

If the DTC P0151 test passes while the Failure

Records conditions are being duplicated, an

intermittent condition is indicate.

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.

DTC P0151 – HO2S Circuit Low Voltage Bank 2 Sensor 1

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Install Tech 2.

2. Run the engine at operating temperature.

3. Operate the vehicle within the parameters

specified under “Conditions for Setting the DTC”

criteria included in Diagnostic Support.

4. Using Tech 2, monitor Bank 2 HO2S 1 voltage.

Does the Bank 2 HO2S 1 voltage remain below the

specified value? 22mV Go to Step 4 Go to Step 3

3 1. Ignition “ON,” engine “OFF,” review and record

Tech 2 Failure Records data and note parameters.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using Tech 2, monitor “Specific DTC” info for DTC

P0151 until the DTC P0151 test runs.

4. Note test result.

Does Tech 2 indicate DTC P0151 failed this ignition? — Go to Step 4

Refer to

Diagnostic Aids

4 1. Turn ignition “OFF.”

2. Disconnect the PCM.

3. Check the Bank 2 HO2S 1 high and low signal

circuits for a short to ground or a short to the

heater ground circuit.

Were Bank 2 HO2S 1 signal circuits shorted? — Go to Step 5 Go to Step 6

5 Repair the Bank 2 HO2S 1 signal circuit.

Is the action complete? — Verify repair —

6 1. Ignition “OFF.”

2. Leave the PCM and HO2S 1 disconnected.

3. Check for continuity between the high and low

signal circuits.

Was there continuity between the high and low

circuits? — Go to Step 7 Go to Step 8

7 Repair the short between the high and low circuits.

Is the action complete? — Verify repair —

8 1.Ignition “OFF.”

2.Reconnect the PCM, leave HO2S 2 disconnected.

3.Ignition “ON.”

Does Tech 2 indicate Bank 2 HO2S 1 voltage near the

specified value?425-475mV

Refer to

Diagnostic Aids Go to Step 9

9 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0152 HO2S Circuit HIGH Voltage Bank 2 Sensor 1

060RW190

Circuit Description

The powertrain control module (PCM) supplies a bias

voltage of about 450mV between the heated oxygen

sensor (HO2S) signal high and signal low circuits.

When measured with a 10 megaohm digital voltmeter,

this may display as low as 320mV. The oxygen sensor

varies the voltage within a range of about 1000mV

when the exhaust is rich, down through about 10mV

when exhaust is lean. The PCM constantly monitors

the HO2S signal during “closed loop” operation and

compensates for a rich or lean condition by decreasing

or increasing the injector pulse width as necessary. If

the Bank 2 HO2S 1 voltage remains excessively high

for an extended period of time, DTC P0152 will be set.

Conditions for Setting the DTC

•No related DTCs.

•The engine is operating in “closed loop.”

•The engine coolant temperature is above 60°C

(140°F).

•“Closed loop” commanded air/fuel ratio between 14.5

and 14.8.

•Throttle angle between 3% and 19%.

•Bank 2 HO2S 1 signal voltage remains above 952mV

during normal “closed loop” operation for a total of 77

seconds over a 90-second period.

•Bank 2 HO2S 1 signal voltage remains above 500mV

during deceleration fuel cutoff mode operation for up

to 3 seconds.

Action Taken When the DTC Sets

•The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

•The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

•“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

•DTC P0152 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

•Fuel pressure – The system will go rich if pressure is

too high. The PCM can compensate for some

increase. However, if fuel pressure is too high, a

DTC P0152 may be set. Refer to Fuel System

Diagnosis.

•Rich injector(s) – Perform “Injector Balance Test.”

•Leaking injector – Refer to Fuel System Diagnosis.

•Evaporative emissions (EVAP) system – Check the

canister for fuel saturation. If the canister is full of

fuel, check EVAP control system components and

hoses. Refer to Evaporative Emission (EVAP)

Control System.

•MAF sensor – The system can go rich if the MAF

sensor signal indicates an engine airflow

measurement that is not correct. Disconnect the MAF

sensor to see if rich condition is corrected. If so,

replace MAF sensor.

•Check for leaking fuel pressure regulator diaphragm

by checking vacuum line to regulator for the presence

of fuel. There should be no fuel in the vacuum line.

•TP sensor – An intermittent TP sensor output will

cause the system to go rich, due to a false indication

of the engine accelerating.

•Shorted Heated Oxygen Sensor (HO2S)– If the

HO2S is internally shorted, the HO2S voltage

displayed on Tech 2 will be over 1 volt. Try

disconnecting the affected HO2S with the key “ON,”

engine “OFF.” If the displayed HO2S voltage

changes from over 1000mV to around 450mV,

replace the HO2S. Silicon contamination of the

HO2S can cause a high HO2S voltage to be

indicated. This condition is indicated by powdery

white deposit on the portion of the HO2S exposed to

the exhaust stream. If contamination is noticed,

replace the affected HO2S.

•Open HO2S Signal Circuit of Faulty HO2S– A poor

connection or open in the HO2S signal circuit can

cause the DTC to set during deceleration fuel mode.

An HO2S which is faulty and not allowing a full

voltage switch between the rich and lean thresholds

can also cause the condition. Operate the vehicle

while monitoring the HO2S voltage with Tech 2. If the

HO2S is limited within a range between 300mV to

600mV, check the HO2S signal circuit wiring and

associated terminal connections.

•If none of the above conditions are present, replace

the affected HO2S.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. DTC P0152 failing during deceleration fuel cutoff

mode operation may indicate a condition described

in the “Diagnostic Aids” above. If the DTC P0152

test passes while the Failure Records conditions are

being duplicated, an intermittent condition is

indicated.

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.

DTC P0152 – HO2S Circuit High Voltage Bank 2 Sensor 1

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Install Tech 2.

2. Engine is at operating temperature.

3. Operate the vehicle within the parameters

specified under “Conditions for Setting the DTC”

criteria included in Diagnostic Support.

4. Using Tech 2, monitor Bank 2 HO2S 1 voltage.

Does the Bank 2 HO2S 1 voltage remain above the

specified value?

952mV

(500mV in

deceleration

fuel cut-off

mode) Go to Step 4 Go to Step 3

3 1. Ignition “ON.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using Tech 2, monitor “Specific DTC” info for DTC

P0152 until the DTC P0152 test runs.

5. Note the test result.

Does Tech 2 indicate DTC P0152 failed this ignition? — Go to Step 4

Refer to

Diagnostic Aids

4 1.Ignition “OFF.”

2.Disconnect Bank 2 HO2S 1.

3.Ignition “ON.”

4.At HO2S Bank 2 Sensor 1 connector (PCM side)

use a DVM to measure voltages at the high and

low signal terminals.

Are the voltages in the specified range?3-4 VGo to Step 5 Go to Step 6

5 Repair short to voltage in signal circuit.

Is the action complete?—Verify repair—

6 1.Ignition “ON,” engine“OFF.”

2.At Bank 2 HO2S 1 connector (PCM side) jumper

both the HO2S high and low signal circuits (PCM

side) to ground.

3.Using Tech 2, monitor Bank 2 HO2S 1 voltage.

Is Bank 2 HO2S 1 voltage below the specified value?10mVGo to Step 7 Go to Step 8

7 1.Disconnect the jumpers to ground from Bank 2

HO2S 1 PCM-side connector.

2.With the HO2S 1 connector disconnected,

monitor Bank 2 HO2S 1 voltage.

Is the Bank 2 HO2S 1 voltage between the specified

values?425-475mV

Refer to

Diagnostic Aids Go to Step 8

8 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0171 Fuel Trim System Lean Bank 1

D06RW030

Circuit Description

To provide the best possible combination of driveability,

fuel economy, and emission control, a “closed loop” air/

fuel metering system is used. While in “closed loop,”

the powertrain control module (PCM) monitors the Bank

1 HO2S 1 and Bank 2 HO2S 1 signals and adjusts fuel

delivery based upon the HO2S signal voltages. A

change made to fuel delivery will be indicated by the

long and short term fuel trim values which can be

monitored with a Tech 2. Ideal fuel trim values are

around 0%; if the HO2S signals are indicating a lean

condition the PCM will add fuel, resulting in fuel trim

values above 0%. If a rich condition is detected, the

fuel trim values will be below 0%, indicating that the

PCM is reducing the amount of fuel delivered. If an

excessively lean condition is detected on Bank 1, the

PCM will set DTC P0171.

The PCM's maximum authority to control long term fuel

trim allows a range between –15% (automatic

transmission) or –12% (manual transmission) and

+20%. The PCM monitors fuel trim under various

engine speed/load fuel trim cells before determining the

status of the fuel trim diagnostic.

Conditions for Setting the DTC

• No Tech 2 test is being run.

• None of the following: EGR DTCs, HO2S DTCs,

(response, transition, open, low volts, no activity),

MAF DTCs, TP sensor DTCs, MAP DTCs, IAT DTCs,

canister purge DTCs, EVAP DTCs, injector circuit

DTCs, or misfire DTCs.

• Engine coolant temperature is between 25°C (77°F)

and 100°C (212°F).

• Intake air temperature is between –40°C (–40°F) and

120°C (248°F).

•Manifold absolute pressure is between 24 kPa and

99 kPa.

•Throttle angle is steady below 95%.

•Vehicle speed is below 136 km/h (85 mph).

•Engine speed is between 400 and 6,000 RPM.

•Barometric pressure is greater than 72.5 kPa.

•Mass air flow is between 2 g/second and 200 g/

second.

•Ignition voltage is above 9.5 volts.

•Fuel system is in “closed loop.”

Action Taken When the DTC Sets

•The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

•The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0171 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the Bank 1 HO2S 1 display on the Tech 2 while

moving connectors and wiring harnesses related to

the engine harness. A change in the display will

indicate the location of the fault.

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.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. DTCs other than P0171 and P0174 may indicate a

condition present which may cause a lean condition.

If this is the case, repairing the condition which

caused the other DTC will most likely correct the

DTC P0171/P0174.

4. If the DTC P0171 test passes while the Failure

Records conditions are being duplicated, the lean

condition is intermittent. Refer to Diagnostic Aids or

Symptoms for additional information on diagnosing

intermittent problems.

DTC P0171 – Fuel Trim System Lean Bank 1

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Are any DTCs set other than P0171 and P0174?

—

Go to the

applicable DTC

charts and

repair the other

DTCs before

proceeding with

this chart Go to Step 3

3 1. Start the engine and operate the vehicle in “closed

loop.”

2. Observe the “BANK 1 L.T. FUEL TRIM” display

on the Tech 2.

Is the displayed value greater than the specified

value?

L.T. Fuel

Trim: +20% Go to Step 5 Go to Step 4

4 1. Review and record the Tech 2 Failure Records

data.

2. Clear the DTC P0171/P0174 and operate the

vehicle to duplicate the Failure Records

conditions.

3. Monitor the Tech 2 “Specific DTC” info for DTC

P0171 while operating the vehicle to duplicate the

Failure Records conditions.

4. Continue operating the vehicle until the DTC

P0171 test runs and note the test result.

Does the Tech 2 indicate DTC P0171 failed this

ignition? — Go to Step 5

The lean

condition is not

present. If a

driveability

symptom still

exists, refer to

Symptoms

section.

5 Was DTC P0174 also set? — Go to Step 6 Go to Step 15

6 Visually and physically inspect the vacuum hoses for

disconnects, splits, kinks, improper routing and

improper connections and repair any problem found.

Did your inspection reveal a problem requiring repair? — Verify repair Go to Step 7

7 Visually and physically inspect the crankcase

ventilation valve for proper installation and repair any

problem found (refer to Crankcase Ventilation

System).

Did your inspection reveal a problem requiring repair? — Verify repair Go to Step 8

8 1. Inspect the MAF sensor inlet screen for damage

or for the presence of foreign objects which may

partially block the air flow sample through the MAF

sensor.

2. Correct any problem that is found as necessary.

Did your inspection of the MAF sensor reveal a

condition requiring repair? — Verify repair Go to Step 9

9 Start the engine and note the idle quality.

Is a high or unsteady idle being experienced? — Go to Step 10 Go to Step11

10 1. Visually and physically inspect the throttle body,

intake manifold, EGR valve and the EGR feed

pipe for vacuum leaks.

2. Repair any vacuum leaks as necessary.

Did your inspection reveal a vacuum leak? — Verify repair Go to Step 11

11 Check the fuel for excessive water, alcohol, or other

contaminants (see Diagnosis in Engine Fuel for the

procedure) and correct the contaminated fuel

condition if present (see Engine Fuel).

Was the fuel contaminated? — Verify repair Go to Step 12

12 1. Visually and physically inspect the PCM injector

grounds, power grounds and sensor grounds to

ensure that they are clean, tight, and in their

proper locations.

2. If a faulty ground condition is present, correct it as

necessary.

Did your inspection reveal a condition requiring

repair? — Verify repair Go to Step 13

Step Action Value(s) Yes No

13 1. Disconnect the MAF sensor electrical connector.

2. Operate the vehicle in “closed loop” while

monitoring the “BANK 1 S.T. FUEL TRIM”

displayed on the Tech 2.

Does “BANK 1 S.T. FUEL TRIM” value decrease to

near the specified value? 0% Go to Step 19 Go to Step 14

14 Perform the procedure in the “Fuel System Pressure

Test” and repair fuel system problem if necessary.

Did Fuel System Pressure Test isolate a condition

requiring repair? — Verify repair Go to Step 15

15 1. Visually and physically inspect the intake

manifold, injector O-rings, EGR adapter, EGR

valve and the EGR feed pipes for vacuum leaks.

2. Repair any problem that is found.

Did your inspection reveal a problem? — Verify repair Go to Step 16

16 Visually and physically inspect the Bank 1 exhaust

manifold for leaks and loose or missing hardware and

correct any problem found.

Did your inspection reveal a problem? — Verify repair Go to Step 17

17 Perform the “Injector Balance Test,” and correct any

problem found (refer to Fuel Metering System).

Did Injector Balance Test isolate a problem? — Verify repair Go to Step 18

18 1. Visually and physically inspect the Bank 1 HO2S 1

to ensure that it is installed securely and that the

Bank 1 HO2S 1 pigtail and wiring harness are not

contacting the exhaust or otherwise damaged.

2. If a problem is found, correct it as necessary.

Did your inspection reveal a problem? — Verify repair

Refer to

Diagnostic Aids

19 Replace the MAF sensor.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0172 Fuel Trim System Rich Bank 1

D06RW030

Circuit Description

To provide the best possible combination of driveability,

fuel economy, and emission control, a “closed loop” air/

fuel metering system is used. While in “closed loop,”

the powertrain control module (PCM) monitors the Bank

1 heated oxygen sensors (HO2S) 1 and Bank 2 HO2S 1

signals and adjusts fuel delivery based upon the HO2S

signal voltages. A change made to fuel delivery will be

indicated by the long and short term fuel trim values

which can be monitored with a Tech 2. Ideal fuel trim

values are around 0%; if the HO2S signals are

indicating a lean condition the PCM will add fuel,

resulting in fuel trim values above 0%. If a rich condition

is detected, the fuel trim values will be below 0%,

indicating that the PCM is reducing the amount of fuel

delivered. If an excessively rich condition is detected on

Bank 1, the PCM will set DTC P0172.

The PCM's maximum authority to control long term fuel

trim allows a range between –15% (automatic

transmission) or –12 (manual transmission) and +20%.

The PCM's maximum authority to control short term fuel

trim allows a range between –11% and +20%. The

PCM monitors fuel trim under various engine speed/

load fuel trim cells before determining the status of the

fuel trim diagnostic.

Conditions for Setting the DTC

• No Tech 2 test is being run.

• None of the following was set: EGR DTCs, HO2S

DTCs, (response, transition, open, low volts, no

activity), MAF DTCs, TPS DTCs, MAP DTCs, IAT

DTCs, canister purge DTCs, EVAP DTCs, injector

circuit DTCs, or misfire DTCs.

• Engine coolant temperature is between 25°C (77°F)

and 100°C (212°F).

• Intake air temperature is between –40°C (–40°F) and

120°C (248°F).

•Manifold absolute pressure is between 24 kPa and

99 kPa.

•Throttle angle is steady below 95%.

•Vehicle speed is below 136 km/h (85 mph).

•Engine speed is between 400 and 6,000 RPM.

•Barometric pressure is greater than 72.5 kPa.

•Mass air flow is between 2 g/second and 200 g/

second.

•Ignition voltage is above 9.5 volts.

•Fuel system is in “closed loop.”

Action Taken When the DTC Sets

•The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

•The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0172 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the Bank 1 HO2S 1 display on the Tech 2 while

moving connectors and wiring harnesses related to

the engine harness. A change in the display will

indicate the location of the fault.

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.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. DTCs other than P0172 and P0175 may indicate a

condition present which may cause a lean condition.

If this is the case, repairing the condition which

caused the other DTC will most likely correct the

DTC P0172/P0175.

4. If the DTC P0172 test passes while the Failure

Records conditions are being duplicated, the rich

condition is intermittent. Refer to Diagnostic Aids or

Symptoms for additional information on diagnosing

intermittent problems.

DTC P0172 – Fuel Trim System Rich Bank 1

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Are any DTCs set other than P0172 and P0175?

—

Go to the

applicable DTC

charts and

repair the other

DTCs before

proceeding with

this chart Go to Step 3

3 1. Start the engine and operate the vehicle in “closed

loop.”

2. Observe “B1 Long Term Fuel Trim” display on the

Tech 2.

Is the displayed value more negative than the

specified value?

L.T. Fuel

Trim: –15%

(auto. trans.)

OR –12%

(man. trans.) Go to Step 5 Go to Step 4

4 1. Review and record the Tech 2 Failure Records

data.

2. Clear the DTC P0172/P0175 and operate the

vehicle to duplicate the Failure Records

conditions.

3. Monitor the Tech 2 “DTC” info for DTC P0172

while operating the vehicle to duplicate the Failure

Records conditions.

4. Continue operating the vehicle until the DTC

P0172 test runs and note test result.

Does the Tech 2 indicate DTC P0172 failed this

ignition? — Go to Step 5

The rich

condition is not

present. If a

driveability

symptom still

exists, refer to

Symptoms.

5 Is DTC P0175 also set? — Go to Step 6 Go to Step 15

6 Visually and physically inspect the air filter element

and replace it if necessary.

Did the air filter require replacement? — Verify repair Go to Step 7

7 Visually and physically inspect the air intake duct for

collapse or restriction and repair if necessary.

Did your inspection reveal a condition requiring

repair? — Verify repair Go to Step 8

8 Inspect the MAF sensor inlet screen for damage or for

the presence of foreign objects which may partially

block air flow through the screen and correct any

problem found.

Did your inspection of the MAF sensor reveal a

condition requiring repair or replacement? — Verify repair Go to Step 9

9 Start the engine and note the idle quality.

Is a low or unsteady idle being experienced? — Go to Step 10 Go to Step 11

10 1. Ignition “OFF.”

2. Physically inspect the throttle body bore, throttle

plate, and IAC passages for coking and foreign

objects.

3. If a problem was found, repair as necessary.

Did your inspection reveal a condition requiring

repair? — Verify repair Go to Step 11

11 1.Disconnect the vacuum hose from the fuel

pressure regulator and inspect the hose for the

presence of fuel.

2.If fuel is present in the vacuum hose, replace the

fuel pressure regulator (refer to Fuel Metering

System).

Did the fuel pressure regulator require replacement?—Verify repairGo to Step 12

12 Ignition “ON,” engine “OFF,” monitor the TP Angle

display on the Tech 2 while slowly depressing the

accelerator pedal.

Does the TP Angle display increase steadily and

evenly from minimum value at closed throttle to

maximum value at wide-open throttle?

Minimum 0%

Maximum

100%Go to Step 13 Go to Step 18

13 1.Disconnect the MAF sensor electrical connector.

2.Operate the vehicle in “closed loop” while

monitoring the “BANK 1 L.T. FUEL TRIM” and

“BANK 1 S. T. FUEL TRIM” display on the Tech 2.

Did both values change to near the specified value?0%Go to Step 19 Go to Step 14

14 1.Perform “Fuel System Pressure Test.”

2.If Fuel System Pressure Test isolates a problem,

repair as necessary (refer to Engine Fuel or Fuel

Metering System).

Did the Fuel System Pressure Test isolate a problem

requiring repair?—Verify repairGo to Step 16

15 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

16 1. Perform the “Injector Balance Test.”

2. If Injector Balance Test isolates a problem, repair

as necessary (refer to Fuel Metering System).

Did the Injector Balance Test isolate a problem

requiring repair? — Verify repair Go to Step 17

17 1. Remove and visually/physically inspect the Bank

1 HO2S 1 for silicon contamination. This will be

indicated by a powdery white deposit on the

portion of the HO2S that is exposed to the

exhaust stream.

2. If contamination is evident on the Bank 1 HO2S 1,

replace the contaminated sensors.

Did the sensor require replacement? — Verify repair

Refer to

Diagnostic Aids

18 1. Check the TP sensor mounting screws and tighten

or replace them as necessary if they are loose or

missing.

2. If the screws are OK, replace the TP sensor.

Is the action complete? — Verify repair —

19 Replace the MAF sensor.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0174 Fuel Trim System Lean Bank 2

D06RW031

Circuit Description

To provide the best possible combination of driveability,

fuel economy, and emission control, a “closed loop” air/

fuel metering system is used. While in “closed loop,”

the powertrain control module (PCM) monitors the Bank

1 HO2S 1 and Bank 2 HO2S 1 signals and adjusts fuel

delivery based upon the HO2S signal voltages. A

change made to fuel delivery will be indicated by the

long and short term fuel trim values which can be

monitored with a Tech 2. Ideal fuel trim values are

around 0%; if the HO2S signals are indicating a lean

condition the PCM will add fuel, resulting in fuel trim

values above 0%. If a rich condition is detected, the fuel

trim values will be below 0%, indicating that the PCM is

reducing the amount of fuel delivered. If an excessively

lean condition is detected on Bank 2, the PCM will set

DTC P0174.

The PCM's maximum authority to control long term fuel

trim allows a range between –15%(automatic

transmission) or –12%(manual transmission) and

+20%. The PCM monitors fuel trim under various

engine speed/load fuel trim cells before determining the

status of the fuel trim diagnostic.

Conditions for Setting the DTC

• No Tech 2 test is being run.

• None of the following DTCs are set: idle system,

EGR, HO2S, (response, transition, open, low volts,

no activity), MAF, TP sensor, MAP, IAT, canister

purge, EVAP, injector circuit, or misfire.

• Engine coolant temperature is between 25°C (77°F)

and 100°C (212°F).

• Intake air temperature is between –40°C (–40°F) and

120°C (248°F).

•Manifold absolute pressure is between 24 kPa and

99 kPa.

•Throttle angle is steady below 95%.

•Vehicle speed is below 136 km/h (85 mph).

•Engine speed is between 400 and 6,000 RPM.

•Barometric pressure is greater than 72.5 kPa.

•Mass air flow is between 2 g/second and 200 g/

second.

•Ignition voltage is above 9.5 volts.

•Fuel system is in “closed loop.”

Action Taken When the DTC Sets

•The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the failure is detected.

•The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0174 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the Bank 2 HO2S 1 display on the Tech 2 while

moving connectors and wiring harnesses related to

the engine harness. A change in the display will

indicate the location of the fault.

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.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. DTCs other than P0171 and P0174 may indicate a

condition present which may cause a lean condition.

If this is the case, repairing the condition which

caused the other DTC will most likely correct the

DTC P0171/P0174.

4. If the DTC P0174 test passes while the Failure

Records conditions are being duplicated, the lean

condition is intermittent. Refer to Diagnostic Aids or

Symptoms for additional information on diagnosing

intermittent problems.

DTC P0174 – Fuel Trim System Lean Bank 2

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Are any DTCs set other than P0174 and P0171?

—

Go to the

applicable DTC

charts and

repair the other

DTCs before

proceeding with

this chart. Go to Step 3

3 1. Start the engine and operate the vehicle in “closed

loop.”

2. Observe the “BANK 2 L.T. FUEL TRIM” display on

the Tech 2.

Is the displayed values greater than the specified

values?

L.T. Fuel

Trim: +20% Go to Step 5 Go to Step 4

4 1. Review and record Tech 2 Failure Records data.

2. Clear the DTC P0171/P0174 and operate the

vehicle to duplicate the Failure Records

conditions.

3. Monitor the Tech 2 “DTC” info for DTC P0174

while operating the vehicle to duplicate the Failure

Records conditions.

4. Continue operating the vehicle until the DTC

P0174 test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0174 failed this

ignition? — Go to Step 5

The lean

condition is not

present. If a

driveability

symptom still

exists, refer to

Symptoms

section.

5 Was DTC P0171 also set? — Go to Step 6 Go to Step 15

6 Visually and physically inspect the vacuum hoses for

disconnects, splits, kinks, improper routing and

improper connections and repair any problem found.

Did your inspection reveal a problem requiring repair? — Verify repair Go to Step 7

7 Visually and physically inspect the crankcase

ventilation valve for proper installation and repair any

problem found (refer to Crankcase Ventilation

System).

Did your inspection reveal a problem requiring repair? — Verify repair Go to Step 8

8 1. Inspect the MAF sensor inlet screen for damage

or for the presence of foreign objects which may

partially block the air flow sample through the MAF

sensor.

2. Correct any problem that is found as necessary.

Did your inspection of the MAF sensor reveal a

condition requiring repair? — Verify repair Go to Step 9

9 Start the engine and note the idle quality.

Is a high or unsteady idle being experienced? — Go to Step 10 Go to Step 11

10 1. Visually and physically inspect the throttle body,

intake manifold, EGR valve and the EGR feed

pipe for vacuum leaks.

2. Repair any vacuum leaks as necessary.

Did your inspection reveal a vacuum leak? — Verify repair Go to Step 11

11 Check the fuel for excessive water, alcohol, or other

contaminants (see Diagnosis in Engine Fuel for

procedure) and correct the contaminated fuel

condition is present (see Engine Fuel).

Was the fuel contaminated? — Verify repair Go to Step 12

12 1. Visually and physically inspect the PCM injector

grounds, power grounds and sensor grounds to

ensure that they are clean, tight, and in their

proper locations.

2. If a faulty ground condition is present, correct it as

necessary.

Did your inspection reveal a condition requiring

repair? — Verify repair Go to Step 13

13 1. Disconnect the MAF sensor electrical connector.

2. Operate the vehicle in “closed loop” while

monitoring the “BANK 1 S.T. FUEL TRIM”

displayed on the Tech 2.

Does the “BANK 1 S.T. FUEL TRIM” value decrease

to near the specified value? 0% Go to Step 19 Go to Step 14

14 Perform the procedure in the "Fuel System Pressure

Test" and repair fuel system problem if necessary.

Did the Fuel System Pressure Test isolate a condition

requiring repair? — Verify repair Go to Step 15

15 1. Visually and physically inspect the intake

manifold, injector O-rings, EGR adapter, EGR

valve and the EGR feed pipes for vacuum leaks.

2. Repair any problem that is found.

Did your inspection reveal a problem? — Verify repair Go to Step 16

16 Visually and physically inspect the Bank 2 exhaust

manifold for leaks and loose or missing hardware and

correct any problem found.

Did your inspection reveal a problem? — Verify repair Go to Step 17

17 Perform the “Injector Balance Test,” and correct any

problem found (refer to Fuel Metering System).

Did the Injector Balance Test isolate a problem? — Verify repair Go to Step 18

18 1. Visually and physically inspect the Bank 2 HO2S 1

to ensure that it is installed securely and that the

Bank 2 HO2S 1 pigtail and wiring harness are not

contacting the exhaust or otherwise damaged.

2. If a problem is found, correct it as necessary.

Did your inspection reveal a problem? — Verify repair

Refer to

Diagnostic Aids

19 Replace the MAF sensor.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0175 Fuel Trim System Rich Bank 2

D06RW031

Circuit Description

To provide the best possible combination of driveability,

fuel economy, and emission control, a “closed loop” air/

fuel metering system is used. While in “closed loop,”

the powertrain control module (PCM) monitors the Bank

1 HO2S 1 and Bank 2 HO2S 1 signals and adjusts fuel

delivery based upon the HO2S signal voltages. A

change made to fuel delivery will be indicated by the

long and short term fuel trim values which can be

monitored with a Tech 2. Ideal fuel trim values are

around 0%; if the HO2S signals are indicating a lean

condition the PCM will add fuel, resulting in fuel trim

values above 0%. If a rich condition is detected, the fuel

trim values will be below 0%, indicating that the PCM is

reducing the amount of fuel delivered. If an excessively

rich condition is detected on Bank 2, the PCM will set

DTC P0175.

The PCM's maximum authority to control long term fuel

trim allows a range between –15%(automatic

transmission) or –12%(manual transmission) and

+20%. The PCM's maximum authority to control short

term fuel trim allows a range between –11% and +20%.

The PCM monitors fuel trim under various engine

speed/load fuel trim cells before determining the status

of the fuel trim diagnostic.

Conditions for Setting the DTC

• No Tech 2 test is being run.

• None of the following DTCs are set: idle system,

EGR, HO2S, (response, transition, open, low volts,

no activity), MAF, TPS, MAP, IAT, canister purge,

EVAP, injector circuit, or misfire.

• Engine coolant temperature is between 25°C (77°F)

and 100°C (212°F).

• Intake air temperature is between –40°C (–40°F) and

120°C (248°F).

•Manifold absolute pressure is between 24 kPa and

99 kPa.

•Throttle angle is steady below 95%.

•Vehicle speed is below 136 km/h (85 mph).

•Engine speed is between 400 and 6,000 RPM.

•Barometric pressure is greater than 72.5 kPa.

•Mass air flow is between 2 g/second and 200 g/

second.

•Ignition voltage is above 9.5 volts.

•Fuel system is in “closed loop.”

Action Taken When the DTC Sets

•The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the failure is detected.

•The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0175 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM – Inspect harness

connectors for backed -out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the Bank 2 HO2S 1 display on the Tech 2 while

moving connectors and wiring harnesses related to

the engine harness. A change in the display will

indicate the location of the fault.

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.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. DTCs other than P0172 and P0175 may indicate a

condition present which may cause a lean condition.

If this is the case, repairing the condition which

caused the other DTC will most likely correct the

DTC P0172/P0175.

4. If the DTC P0175 test passes while the Failure

Records conditions are being duplicated, the rich

condition is intermittent. Refer to Diagnostic Aids or

Symptoms for additional information on diagnosing

intermittent problems.

DTC P0175 – Fuel Trim System Rich Bank 2

StepActionValue(s)YesNo

1 Was the "On-Board Diagnostic (OBD) System Check"

performed? — Go to Step 2

Go to OBD

System Check

2 Are any DTCs set other than P0172 and P0175?

—

Go to the

applicable DTC

charts and

repair the other

DTCs before

proceeding with

this chart. Go to Step 3

3 1. Start the engine and operate the vehicle in “closed

loop.”

2. Observe the “BANK 2 L.T. FUEL TRIM” display on

the Tech 2.

Is the displayed value more negative than the

specified value?

L.T. Fuel

Trim: –15%

(auto. trans.)

OR –12%

(man. trans.) Go to Step 5 Go to Step 4

4 1. Review and record the Tech 2 Failure Records

data.

2. Clear the DTC P0172/P0175 and operate the

vehicle to duplicate the Failure Records

conditions.

3. Monitor the Tech 2 “DTC” info for DTC P0175

while operating the vehicle to duplicate the Failure

Records conditions.

4. Continue operating the vehicle until the DTC

P0175 test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0175 failed this

ignition? — Go to Step 5

The rich

condition is not

present. If a

driveability

symptom still

exists, refer to

Symptoms.

5 Was DTC P0172 also set? — Go to Step 6 Go to Step 15

6 Visually and physically inspect the air filter element

and replace it if necessary.

Did the air filter require replacement? — Verify repair Go to Step 7

7 Visually and physically inspect the air intake duct for

collapse or restriction and repair if necessary.

Did your inspection reveal a problem requiring repair? — Verify repair Go to Step 8

8 Inspect the MAF sensor inlet screen for damage or for

the presence of foreign objects which may partially

block air flow through the screen and correct any

problem found.

Did your inspection of the MAF sensor reveal a

condition requiring repair or replacement? — Verify repair Go to Step 9

9 Start the engine and note the idle quality.

Is a low or unsteady idle being experienced? — Go to Step 10 Go to Step 11

10 1. Turn the ignition off and physically inspect the

throttle body bore, throttle plate, and IAC

passages for coking and foreign objects.

2. If a problem was found, repair as necessary.

Did your inspection reveal a condition requiring

repair? — Verify repair Go to Step 11

11 1.Disconnect the vacuum hose from the fuel

pressure regulator and inspect the hose for the

presence of fuel.

2.If fuel is present in the vacuum hose, replace the

fuel pressure regulator (refer to Fuel Metering

System).

Did the fuel pressure regulator require replacement?—Verify repairGo to Step 12

12 1.Ignition “ON,” engine “OFF.”

2.Monitor the TP Angle display on the Tech 2 while

slowly depressing the accelerator pedal.

Does the TP Angle display increase steadily and

evenly from minimum value at closed throttle to

maximum value at wide-open throttle?

Minimum 0%

Maximum

100%Go to Step 13 Go to Step 18

13 1.Disconnect the MAF sensor electrical connector.

2.Operate the vehicle in “closed loop” while

monitoring the “BANK 1 L.T. FUEL TRIM” and

“BANK 1 S.T. FUEL TRIM” display on the Tech 2.

Did both values change to near the specified value?0%Go to Step 19 Go to Step 14

14 1.Perform the “Fuel System Pressure Test.”

2.If Fuel System Pressure Test isolates a problem,

repair as necessary (refer to Engine Fuel or Fuel

Metering System).

Did the Fuel System Pressure Test isolate a condition

requiring repair?—Verify repairGo to Step 16

15 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

16 1. Perform the “Injector Balance Test.”

2. If the Injector Balance Test isolates a problem,

repair as necessary (refer to Fuel Metering

System).

Did the Injector Balance Test isolate a problem

requiring repair? — Verify repair Go to Step 17

17 1. Remove and visually/physically inspect the Bank

2 HO2S 1 for silicon contamination. This will be

indicated by a powdery white deposit on the

portion of the HO2S that is exposed to the exhaust

stream.

2. If contamination is evident on the Bank 2 HO2S 1,

replace the contaminated sensor.

Did the sensor require replacement? — Verify repair

Refer to

Diagnostic Aids

18 1. Check the TP sensor mounting screws and tighten

or replace them as necessary if they are loose or

missing.

2. If the screws are OK, replace the TP sensor.

Is the action complete? — Verify repair —

19 Replace the MAF sensor.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0201 Injector 1 Control Circuit

D06RW034

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector. When

a driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to

detect a fault. If the voltage is not what the PCM

expects to monitor on the circuit, a DTC is set. This

DTC is also set if an injector driver is shorted to voltage

or if there is an open circuit.

Conditions for Setting the DTC

• The battery voltage is more than 9 volts.

• The engine is turning, determined by 58X crankshaft

position input signal.

• The injector voltage does not equal the ignition

voltage when the injector is commanded “OFF” or the

injector voltage does not equal 0 volts when the

injector is commanded “ON.”

• The above conditions are met for 15 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0201 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to

voltage will cause a DTC P0201 to set. It will also cause

a misfire due to an inoperative injector. A misfire DTC

will also be set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is

faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0201 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. On the Trooper, the special

7-way gray connector is located at the front of the

charcoal canister. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for cylinder

1 is “ON” steady before cranking the engine as well

as while cranking the engine, then the injector driver

circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. The Fuel Injector

Coil Test Procedure will check if the injectors are

faulty.

R321054

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded at

all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9. The reading should be about 12-14W.

10. Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0201 – Injector 1 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Will the engine start?

—Go to Step 3

Go to Engine

Cranks But Will

Not Run chart

3 1. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0201 reset? — Go to Step 5 Go to Step 4

4 1. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0201 reset? — Go to Step 5

Go to

Diagnostic Aids

5 1. Engine “OFF.”

2. Disconnect the injector connector.

3. Install an injector test light 5-8840-2636-0 on the

injector test connector.

4. Crank the engine and note the light.

Does the injector test light blink? —

Go to Fuel

Injector Coil

Test Procedure Go to Step 6

6 Note whether the injector test light for cylinder 1 was

“OFF” or “ON” steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to Step 7 Go to Step 9

7 1.Disconnect the PCM connector for the affected

injectors.

2.With a test light connected to B+, probe the

affected injector driver circuit.

Does the test light illuminate?—Go to Step 8 Go to Step 15

8 Repair short to ground in the injector driver circuit.

Is the action complete?—

Go to OBD

System Check —

9 1.Disconnect the injector test connector.

2.At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 1 (green with

white tracer).

Does the ohmmeter indicate continuity?—Go to Step 11 Go to Step 10

10 Repair the open injector harness wire or open injector.

Is the action complete?—Verify repair—

11 At the PCM side of the injector test connector, check

the green/white wire for a short to voltage.

Was there a short to voltage?—Go to Step 12 Go to Step 13

12 Repair the short to voltage.

Is the action complete?—Verify repair—

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit?—Go to Step 14 Go to Step 15

14 Repair the open circuit.

Is the action complete?—Verify repair—

15 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0202 Injector 2 Control Circuit

D06RW034

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector. When

a driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to

detect a fault. If the voltage is not what the PCM

expects to monitor on the circuit, a DTC is set. This

DTC is also set if an injector driver is shorted to voltage

or if there is an open circuit.

Conditions for Setting the DTC

• The battery voltage is more than 9 volts.

• The engine is turning, determined by 58X crankshaft

position input signal.

• The injector voltage does not equal the ignition

voltage when the injector is commanded “OFF” or the

injector voltage does not equal 0 volts when the

injector is commanded “ON.”

• The above conditions are met for 15 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0202 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to

voltage will cause a DTC P0202 to set. It will also cause

a misfire due to an inoperative injector. A misfire DTC

will also be set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is

faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0202 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. On the Trooper, the special

7-way gray connector is located at the front of the

charcoal canister. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for cylinder

2 is “ON” steady before cranking the engine as well

as while cranking the engine, then the injector driver

circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. The Fuel Injector

Coil Test Procedure will check if the injectors are

faulty.

R321055

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded at

all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9. The reading should be about 12-14W.

10. Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0202 – Injector 2 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Will the engine start?

—Go to Step 3

Go to Engine

Cranks But Will

Not Run chart

3 1. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0202 reset? — Go to Step 5 Go to Step 4

4 1. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0202 reset? — Go to Step 5

Go to

Diagnostic Aids

5 1. Engine “OFF.”

2. Disconnect the injector test connector.

3. Install an injector test light 5-8840-2636-0 on

injector connector.

4. Crank the engine and note the light.

Does the cylinder 2 test light blink? —

Go to Fuel

Injector Coil

Test Procedure Go to Step 6

6 Note whether the injector test light for cylinder 2 was

“OFF” or “ON” steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to Step 7 Go to Step 9

7 1.Disconnect the PCM connector for the affected

injectors.

2.With a test light connected to B+, probe the

affected injector driver circuit.

Does the test light illuminate?—Go to Step 8 Go to Step 15

8 Repair short to ground in the injector driver circuit.

Is the action complete?—

Go to OBD

System Check —

9 1.Disconnect the injector test connector.

2.At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 2 (green with

orange tracer).

Does the ohmmeter indicate continuity?—Go to Step 11 Go to Step 10

10 Repair the open injector harness wire or open injector.

Is the action complete?—Verify repair—

11 At the PCM side of the injector test connector, check

the green/orange wire for a short to voltage.

Was there a short to voltage?—Go to Step 12 Go to Step 13

12 Repair the short to voltage.

Is the action complete?—Verify repair—

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit?—Go to Step 14 Go to Step 15

14 Repair the open circuit.

Is the action complete?—Verify repair—

15 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0203 Injector 3 Control Circuit

D06RW034

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector. When

the driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to

detect a fault. If the voltage is not what the PCM

expects to monitor on the circuit, a DTC is set. This

DTC is also set if an injector driver is shorted to voltage

or if there is an open circuit.

Conditions for Setting the DTC

• The battery voltage is more than 9 volts.

• The engine is turning, determined by the 58X

crankshaft position input signal.

• The injector voltage does not equal the ignition

voltage when the injector is commanded “OFF” or the

injector voltage does not equal 0 volts when the

injector is commanded “ON.”

• The above conditions are met for 15 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0203 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to

voltage will cause a DTC P0203 to set. It will also cause

a misfire due to an inoperative injector. A misfire DTC

will also be set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is

faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0203 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. On the Trooper, the special

7-way gray connector is located at the front of the

charcoal canister. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for cylinder

3 is “ON” steady before cranking the engine as well

as while cranking the engine, then the injector driver

circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. The Fuel Injector

Coil Test Procedure will check if the injectors are

faulty.

R321056

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded at

all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9. The reading should be about 12-14W.

10. Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0203 – Injector 3 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Will the engine start?

—Go to Step 3

Go to Engine

Cranks But Will

Not Run chart

3 1. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0203 reset? — Go to Step 5 Go to Step 4

4 1. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0203 reset? — Go to Step 5

Go to

Diagnostic Aids

5 1. Engine “OFF.”

2. Disconnect the injector test connector .

3. Install an injector test light 5-8840-2636-0 on

injector connector.

4. Crank the engine and note the light.

Does the cylinder 3 test light blink? —

Go to Fuel

Injector Coil

Test Procedure Go to Step 6

6 Note whether the injector test light for cylinder 3 was

“OFF” or “ON” steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to Step 7 Go to Step 9

7 1.Disconnect the PCM connector for the affected

injectors.

2.With a test light connected to B+, probe the

affected injector driver circuit.

Does the test light illuminate?—Go to Step 8 Go to Step 15

8 Repair short to ground in the injector driver circuit.

Is the action complete?—

Go to OBD

System Check —

9 1.Disconnect the injector test connector.

2.At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 3 (green).

Does the ohmmeter indicate continuity?—Go to Step 11 Go to Step 10

10 Repair the open injector harness wire or open injector.

Is the action complete?—Verify repair—

11 At the PCM side of the injector test connector, check

the green wire for a short to voltage.

Was there a short to voltage?—Go to Step 12 Go to Step 13

12 Repair the short to voltage.

Is the action complete?—Verify repair—

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit?—Go to Step 14 Go to Step 15

14 Repair the open circuit.

Is the action complete?—Verify repair—

15 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0204 Injector 4 Control Circuit

D06RW034

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector. When

the driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to

detect a fault. If the voltage is not what the PCM

expects to monitor on the circuit, a DTC is set. This

DTC is also set if an injector driver is shorted to voltage

or if there is an open circuit.

Conditions for Setting the DTC

• The battery voltage is more than 9 volts.

• The engine is turning, determined by the 58X

crankshaft position input signal.

• The injector voltage does not equal the ignition

voltage when the injector is commanded “OFF” or the

injector voltage does not equal 0 volts when the

injector is commanded “ON.”

• The above conditions are met for 15 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0204 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to

voltage will cause a DTC P0204 to set. It will also cause

a misfire due to an inoperative injector. A misfire DTC

will also be set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is

faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0204 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. On the Trooper, the special

7-way gray connector is located at the front of the

charcoal canister. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for

cylinder 4 is “ON” steady before cranking the engine

as well as while cranking the engine, then the

injector driver circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. The Fuel Injector

Coil Test Procedure will check if the injectors are

faulty.

R321057

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded at

all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9. The reading should be about 12-14W.

10. Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0204 – Injector 4 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Will the engine start?

—Go to Step 3

Go to Engine

Cranks But Will

Not Run chart

3 1. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0204 reset? — Go to Step 5 Go to Step 4

4 1. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0204 reset? — Go to Step 5

Go to

Diagnostic Aids

5 1. Engine “OFF.”

2. Disconnect the injector test connector.

3. Install an injector test light 5-8840-2636-0 on

injector connector.

4. Crank the engine and note the light.

Does the cylinder 4 test light blink? —

Go to Fuel

Injector Coil

Test Procedure Go to Step 6

6 Note whether the injector test light for cylinder 4 was

“OFF” or “ON” steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to Step 7 Go to Step 9

7 1.Disconnect the PCM connector for the affected

injectors.

2.With a test light connected to B+, probe the

affected injector driver circuit.

Does the test light illuminate?—Go to Step 8 Go to Step 15

8 Repair short to ground in the injector driver circuit.

Is the action complete?—

Go to OBD

System Check —

9 1.Disconnect the injector test connector.

2.At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 4 (green/red).

Does the ohmmeter indicate continuity?—Go to Step 11 Go to Step 10

10 Repair the open injector harness wire or open injector.

Is the action complete?—Verify repair—

11 At the PCM side of the injector test connector, check

the green/red wire for a short to voltage.

Was there a short to voltage?—Go to Step 12 Go to Step 13

12 Repair the short to voltage.

Is the action complete?—Verify repair—

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit?—Go to Step 14 Go to Step 15

14 Repair the open circuit.

Is the action complete?—Verify repair—

15 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0205 Injector 5 Control Circuit

D06RW034

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector. When

the driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. If the voltage is not what the PCM expects to

monitor on the circuit, a DTC is set. This DTC is also

set if an injector driver is shorted to voltage or if there is

an open circuit.

Conditions for Setting the DTC

• The battery voltage is more than 9 volts.

• The engine is turning, determined by the 58X

crankshaft position input signal.

• The injector voltage does not equal the ignition

voltage when the injector is commanded “OFF” or the

injector voltage does not equal 0 volts when the

injector is commanded “ON.”

• The above conditions are met for 15 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0205 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to

voltage will cause a DTC P0205 to set. It will also cause

a misfire due to an inoperative injector. A misfire DTC

will also be set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is

faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0205 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. On the Trooper, the special

7-way gray connector is located at the front of the

charcoal canister. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for

cylinder 5 is “ON” steady before cranking the engine

as well as while cranking the engine, then the

injector driver circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. The Fuel Injector

Coil Test Procedure will check if the injectors are

faulty.

R321058

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded at

all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9. The reading should be about 12-14W.

10. Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0205 – Injector 5 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Will the engine start?

—Go to Step 3

Go to Engine

Cranks But Will

Not Run chart

3 1. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0205 reset? — Go to Step 5 Go to Step 4

4 1. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0205 reset? — Go to Step 5

Go to

Diagnostic Aids

5 1. Engine “OFF.”

2. Disconnect the injector test connector.

3. Install an injector test light 5-8840-2636-0 on

injector connector.

4. Crank the engine and note the light.

Does the cylinder 5 test light blink? —

Go to Fuel

Injector Coil

Test Procedure Go to Step 6

6 Note whether the injector test light for cylinder 5 was

“OFF” or “ON” steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to Step 7 Go to Step 9

7 1.Disconnect the PCM connector for the affected

injectors.

2.With a test light connected to B+, probe the

affected injector driver circuit.

Does the test light illuminate?—Go to Step 8 Go to Step 15

8 Repair short to ground in the injector driver circuit.

Is the action complete?—

Go to OBD

System Check —

9 1.Disconnect the injector test connector.

2.At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 5 (green with

black tracer).

Does the ohmmeter indicate continuity?—Go to Step 11 Go to Step 10

10 Repair the open injector harness wire or open injector.

Is the action complete?—Verify repair—

11 At the PCM side of the injector test connector, check

the green/black wire for a short to voltage.

Was there a short to voltage?—Go to Step 12 Go to Step 13

12 Repair the short to voltage.

Is the action complete?—Verify repair—

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit?—Go to Step 14 Go to Step 15

14 Repair the open circuit.

Is the action complete?—Verify repair—

15 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0206 Injector 6 Control Circuit

D06RW034

Circuit Description

The powertrain control module (PCM) has six individual

injector driver circuits. Each controls an injector. When

the driver circuit is grounded by the PCM, the injector is

activated. The PCM monitors the current in each driver

circuit. The voltage on each driver is monitored to

detect a fault. If the voltage is not what the PCM

expects to monitor on the circuit, a DTC is set. This

DTC is also set if an injector driver is shorted to voltage

or if there is an open circuit.

Conditions for Setting the DTC

• The battery voltage is more than 9 volts.

• The engine is turning, determined by 58X crankshaft

position input signal.

• The injector voltage does not equal the ignition

voltage when the injector is commanded “OFF” or the

injector voltage does not equal 0 volts when the

injector is commanded “ON.”

• The above conditions are met for 15 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0206 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

An injector driver circuit that is open or shorted to

voltage will cause a DTC P0206 to set. It will also cause

a misfire due to an inoperative injector. A misfire DTC

will also be set indicating which cylinder is inoperative.

Long term and short term fuel trims that are excessively

high or low are a good indication that an injector is

faulty.

Use Fuel Injector Coil Test Procedure to check for faulty

injectors.

Test Description

The number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. This step determines if DTC P0206 is the result of a

hard failure or an intermittent condition.

5. A special injector test connector is provided so that

the injectors can be electrically tested without

removal of the manifold. On the Trooper, the special

7-way gray connector is located at the front of the

charcoal canister. The test connector can be

identified by the blue connector lock which is

tethered to the wiring harness. If the light for

cylinder 6 is “ON” steady before cranking the engine

as well as while cranking the engine, then the

injector driver circuit is shorted to ground.

If the test light blinks while cranking, the PCM and

the wiring to the injectors are OK. The Fuel Injector

Coil Test Procedure will check if the injectors are

faulty.

R321059

7. Because the test light was “ON” steady, voltage to

the injector is OK, but the driver circuit is grounded at

all times. This step determines if the circuit is

shorted to ground or the PCM is faulty.

9. The reading should be about 12-14W.

10. Locating the open in the harness or in the injector

will require removal of the manifold to provide

access.

DTC P0206 – Injector 6 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Will the engine start?

—Go to Step 3

Go to Engine

Cranks But Will

Not Run chart

3 1. Install the Tech 2. Clear the DTC.

2. Idle the engine for one minute.

Does DTC P0206 reset? — Go to Step 5 Go to Step 4

4 1. Review the Freeze Frame data with the ignition

“ON” and the engine “OFF” and note the

parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0206 reset? — Go to Step 5

Go to

Diagnostic Aids

5 1. Engine “OFF.”

2. Disconnect the injector test connector.

3. Install an injector test light 5-8840-2636-0 on

injector connector.

4. Crank the engine and note the light.

Does the cylinder 6 test light blink? —

Go to Fuel

Injector Coil

Test Procedure Go to Step 6

6 Note whether the injector test light for cylinder 6 was

“OFF” or “ON” steady in step 5.

Was the test light “ON” steady while cranking the

engine? — Go to Step 7 Go to Step 9

7 1.Disconnect the PCM connector for the affected

injectors.

2.With a test light connected to B+, probe the

affected injector driver circuit.

Does the test light illuminate?—Go to Step 8 Go to Step 15

8 Repair short to ground in the injector driver circuit.

Is the action complete?—

Go to OBD

System Check —

9 1.Disconnect the injector test connector.

2.At the injector side of the harness, connect an

ohmmeter between the positive wire (red with blue

tracer) and the wire for cylinder 6 (green with

yellow tracer).

Does the ohmmeter indicate continuity?—Go to Step 11 Go to Step 10

10 Repair the open injector harness wire or open injector

Is the action complete?—Verify repair—

11 At the PCM side of the injector test connector, check

the green/yellow wire for a short to voltage.

Was there a short to voltage?—Go to Step 12 Go to Step 13

12 Repair the short to voltage.

Is the action complete?—Verify repair—

13 Check for an open circuit between the injector test

connector and the PCM.

Was there an open circuit?—Go to Step 14 Go to Step 15

14 Repair the open circuit.

Is the action complete?—Verify repair—

15 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0325 KS Module Circuit

D06RW035

Circuit Description

The knock sensor is used to detect engine detonation,

allowing the powertrain control module (PCM) to retard

ignition control (IC) spark timing based on the knock

sensor (KS) signal being received. The knock sensor

produces an AC signal so that under a no knock

condition the signal on the KS circuit measures about

0.007 V AC. The KS signal's amplitude and frequency

depend upon the amount of knock being experienced.

The PCM contains a non-replaceable knock filter

module called a signal-to-noise enhancement filter

(SNEF) module. This filter module in the PCM

determines whether knock is occurring by comparing

the signal level on the KS circuit with the voltage level

on the noise channel. The noise channel allows the

PCM to reject any false knock signal by knowing the

amount of normal engine mechanical noise present.

Normal engine noise varies depending on engine speed

and load. When the PCM determines that an

abnormally low noise channel voltage level is being

experienced, a DTC P0325 will set.

Conditions for Setting the DTC

• Engine has been running for at least 30 seconds.

• The PCM determines that its internal signal from its

knock filter module indicates a continuous knocking

condition for more than 10 seconds.

Action Taken When the DTC Sets

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

• The PCM will use a “substitute” default spark retard

value of 6 degrees to minimize knock during

conditions when knock is likely to occur.

Conditions for Clearing the MIL/DTC

• DTC P0325 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

• Poor connection at PCM – Inspect the knock sensor

and PCM connectors for backed-out terminals,

broken locks, and improperly formed or damaged

terminals.

• Misrouted harness – Inspect the knock sensor

harness to ensure that it is not routed too close to

high voltage wires such as spark plug leads.

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.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Ensures that the fault is present.

DTC P0325 – KS Module Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 Important: If an engine knock can be heard, repair

the engine mechanical problem before proceeding

with this diagnostic.

1.Operate the vehicle within parameters specified

under criteria included in “Conditions for Setting

the DTC.”

2.Using Tech 2, monitor “Specific DTC” info for DTC

P0325 until the DTC P0325 test runs.

3.Note the test result.

Does Tech 2 indicate DTC P0325 failed this ignition?—Go to Step 4 Go to Step 3

3 1.Ignition “ON,” engine “OFF.”

2.Review and record Tech 2 Failure Records data

for DTC P0325.

3.Operate the vehicle within Failure Records

conditions.

4.Using Tech 2, monitor “Specific DTC” info for DTC

P0325 until the DTC P0325 test runs.

Does Tech 2 indicate DTC P0325 test failed this

ignition?—Go to Step 4

Refer to

Diagnostic Aids

4 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0327 KS Sensor Circuit

D06RW035

Circuit Description

The powertrain control module (PCM) uses the knock

sensor to detect engine detonation, allowing the PCM to

retard ignition control (IC) spark timing based on the

knock sensor (KS) signal being received. The knock

sensor produces an AC signal so that under a no knock

condition the signal on the KS circuit measures about

0.007 V AC. The signal amplitude and frequency are

dependent upon the amount of knock being

experienced.

The PCM monitors the KS signal and can diagnose the

KS sensor and circuitry.

Conditions for Setting the DTC

• Engine running for at least 10 seconds.

• The TP sensor is greater than 5%.

• The ECT sensor is greater than 60°C (140°F).

• Engine speed is between 2000 and 4000 RPM.

• The knock sensor signal voltage is less than 0.20

volts, or greater than 4.8 volts.

• All conditions are present for more than 15 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

• The PCM will use a calculated spark retard value to

minimize knock during conditions when knock is likely

to occur. The calculated value will vary based on

engine speed and load.

Conditions for Clearing the MIL/DTC

• DTC P0327 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

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.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Ensures that the fault is present.

4. The knock sensor is attached to a short jumper

harness, so it can be tested without removing the

intake manifold. A 2-wire connector for the knock

sensor is accessible behind the left rear fuel injector.

DTC P0327 – KS Sensor Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 Important: If an engine knock can be heard, repair

the engine mechanical problem before proceeding

with this diagnostic.

1. Operate the engine within the conditions specified

in diagnostic support “Conditions for Setting the

DTC.”

2. Using Tech 2, monitor “Specific DTC” info for DTC

P0327 until the DTC P0327 test runs.

3. Note the test result.

Does Tech 2 indicate DTC P0327 failed this ignition? — Go to Step 4 Go to Step 3

3 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions.

4. Using Tech 2, monitor “Specific DTC” info for DTC

P0327 until the DTC P0327 test runs.

5. Note the test result.

Does Tech 2 indicate DTC P0327 failed this ignition? — Go to Step 4

Refer to

Diagnostic Aids

4 1. Check for a damaged terminal at the knock sensor

connector.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 5

5 Using a test light to battery +, check the black/blue

wire (PCM side) to verify that the shield connection is

good.

Did the test light illuminate? — Go to Step 7 Go to Step 6

6 Repair the open shield ground.

Is the action complete? — Verify repair —

7 1. Ignition “OFF,” disconnect the PCM.

2. Check the KS signal circuit for a poor terminal

connection at the PCM.

3. If a problem is found, replace the faulty terminal.

Was a problem found? — Verify repair Go to Step 8

8 1. Ignition “OFF,” PCM disconnected.

2. Check the KS signal circuit between the PCM and

the knock sensor connector for an open, a short to

voltage, or a short to ground.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

9 1. Ignition “OFF,” PCM disconnected.

2. Knock sensor connected.

3. Measure the resistance of the knock sensor by

connecting the DVM between the PCM connector

and the engine block.

Is the resistance of each knock sensor near the

specified value? 100K ohms Go to Step 10 Go to Step 11

10 1.Ignition “OFF,” PCM disconnected.

2.Connect the DVM to monitor AC voltage between

the PCM connector and engine ground.

3.Tap on the engine lift bracket with a socket

extension while observing the signal indicated on

the DVM.

Is any signal indicated on the DVM while tapping on

the engine lift bracket?—Go to Step 12 Go to Step 11

11 Replace the knock sensor.

Is the action complete?—Verify repair—

12 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0336 58X Reference Signal Circuit

D06RW032

Circuit Description

The 58X reference signal is produced by the crankshaft

position (CKP) sensor. During one crankshaft

revolution, 58 crankshaft pulses will be produced. The

powertrain control module (PCM) uses the 58X

reference signal to calculate engine RPM and

crankshaft position. The PCM constantly monitors the

number of pulses on the 58X reference circuit and

compares them to the number of camshaft position

(CMP) signal pulses being received. If the PCM

receives an incorrect number of pulses on the 58X

reference circuit, DTC P0336 will set.

Conditions for Setting the DTC

• Engine is running.

• Extra or missing pulse is detected between

consecutive 58X reference pulses.

• Above condition is detected in 10 of 100 crankshaft

rotations.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0336 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation or a wire broken inside

the insulation. Check for:

•Poor connection - Inspect the PCM harness and

connectors for improper mating, broken locks,

improperly formed or damaged terminals, and poor

terminal-to-wire connection.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK,

disconnect the PCM, turn the ignition on and observe

a voltmeter connected to the 58X reference circuit at

the PCM harness connector while moving connectors

and wiring harnesses related to the ICM. A change

in voltage will indicate the location of the fault.

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.

DTC P0336 – 58X Reference Signal Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 Attempt to start the engine.

Does the engine start?

—Go to Step 3

Go to “Engine

Cranks But Will

Not Run” chart

3 1.Review and record Failure Records information.

2.Clear DTC P0336.

3.Start the engine and idle for 1 minute.

4.Observe DTCs.

Is DTC P0336 set?—Go to Step 4

Refer to

Diagnostic Aids

4 1.Disconnect the PCM and CKP sensor.

2.Check for an open or a short to ground in the 58X

reference circuit between the CKP sensor

connector and the PCM harness connector.

3.If a problem is found, repair as necessary.

Was a problem found?—Verify repairGo to Step 5

5 1.Reconnect the PCM and CKP sensor.

2.Connect a DVM to measure voltage on the 58X

reference circuit at the PCM connector.

3.Observe the voltage while cranking the engine.

Is the voltage near the specified value?2.5 VGo to Step 8 Go to Step 6

6 Check the connections at the CKP sensor and replace

the terminals if necessary.

Did any terminals require replacement?—Verify repairGo to Step 7

7 Replace the CKP sensor. Use caution to avoid any

hot oil that may drip out.

Is the action complete?—Verify repair—

8 Check connections at the PCM and replace the

terminals if necessary.

Did any terminals require replacement?—Verify repairGo to Step 9

9 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0337 CKP Sensor Circuit Low Frequency

D06RW032

Circuit Description

The 58X reference signal is produced by the crankshaft

position (CKP) sensor. During one crankshaft

revolution, 58 crankshaft reference pulses will be

produced. The powertrain control module (PCM) uses

the 58X reference signal to calculate engine RPM and

crankshaft position. The PCM constantly monitors the

number of pulses on the 58X reference circuit and

compares them to the number of camshaft position

(CMP) signal pulses being received. If the PCM does

not receive pulses on the 58X reference circuit, DTC

P0337 will set.

Conditions for Setting the DTC

• No camshaft position (CMP) sensor DTCs are set.

• Engine cranking.

• Crankshaft position (CKP) sensor signal is not

present between two cam pulses.

• CKP reference pulse is not detected within 8 CMP

pulses.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0337 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation or a wire broken inside

the insulation. Check for:

•Poor connection – Inspect the PCM harness and

connectors for improper mating, broken locks,

improperly formed or damaged terminals, and poor

terminal-to-wire connection.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK,

disconnect the PCM, turn the ignition on and observe

a voltmeter connected to the 58X reference circuit at

the PCM harness connector while moving connectors

and wiring harnesses related to the ICM. A change in

voltage will indicate the location of the fault.

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.

DTC P0337 – CKP Sensor Circuit Low Frequency

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Attempt to start the engine.

Does the engine start? — Go to Step 3 Go to Chart 3

3 1. Review and record Failure Records information.

2. Clear DTC P0337.

3. Start the engine and idle for 1 minute.

4. Observe DTCs.

Is DTC P0337 set? — Go to Step 4

Refer to

Diagnostic Aid

4 1. Disconnect the CKP sensor.

2. Ignition “ON.”

3. Using a DVM, verify that 5 V reference and ground

are being supplied at the sensor connector (PCM

side).

Are 4-6 volts and ground available at the sensor? — Go to Step 7 Go to Step 5

5 1. Ignition “ON.”

2. With a DVM, backprobe the PCM connector 5 V

reference and ground connections.

Are 5 V reference and ground available at the PCM? — Go to Step 6 Go to Step 11

6 Check 5 V reference or ground between the CKP

sensor and PCM and repair the open circuit, short to

ground or short to voltage.

Is the action complete? Verify repair —

7 1. Ignition “OFF.”

2. Disconnect the PCM and CKP sensor.

3. Check for an open or a short to ground in the 58X

reference circuit between the CKP sensor

connector and the PCM harness connector.

4. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 8

8 1. Reconnect the PCM and CKP sensor.

2. Connect a DVM to measure voltage on the 58X

reference circuit at the PCM connector.

3. Observe the voltage while cranking the engine.

Is the voltage near the specified value? — Go to Step 11 Go to Step 9

9 Check the connections at the CKP sensor and replace

the terminals if necessary.

Did any terminals require replacement? 2.5 V Verify repair Go to Step 10

10 Replace the CKP sensor. Use caution and avoid hot

oil that may drip out.

Is the action complete? — Verify repair —

11 Check the connections at the PCM and replace the

terminals if necessary.

Did any terminals require replacement?—Verify repair Go to Step 12

12 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0341 CMP Sensor Circuit Performance

D06RW032

Circuit Description

The CMP signal is produced by the camshaft position

(CMP) sensor pulses when the engine is running and

crankshaft position (CKP) sync pulses are also being

received. The powertrain control module (PCM) uses

the CMP signal pulses to initiate sequential fuel

injection. The PCM constantly monitors the number of

pulses on the CMP signal circuit and compares the

number of CMP pulses to the number of 58X reference

pulses received. If the PCM receives an incorrect

number of pulses on the CMP reference circuit, DTC

P0341 will set and the PCM will initiate injector

sequence without the CMP signal with a one in six

chance that injector sequence is correct. The engine

will continue to start and run normally, although the

misfire diagnostic will be affected if a misfiring condition

occurs.

Conditions for Setting the DTC

• The engine is running (1X CMP reference pulses are

being received).

• The CMP sensor signal is not detected at the correct

interval every 6 cylinders.

• Above condition fails for 100 occurrences within 200

test samples.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• The PCM will initiate the injector sequence without

the CMP signal with a one in six chance that the

injector sequence is correct.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0341 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation or a wire broken inside

the insulation. Check for:

• Poor connection – Inspect the PCM harness and

connectors for improper mating, broken locks,

improperly formed or damaged terminals, and poor

terminal-to-wire connection.

• Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK,

disconnect the PCM, turn the ignition on and observe

a voltmeter connected to the CMP signal circuit at the

PCM harness connector while moving connectors

and wiring harnesses related to the ICM and the CMP

sensor. A change in voltage will indicate the location

of the fault.

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.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Ensures that the fault is present.

12. Determines whether the fault is being caused by a

missing camshaft magnet or a faulty sensor. The

voltage measured in this step should read around 4

volts, toggling to near 0 volts when the CMP sensor

interfaces with the camshaft magnet.

DTC P0341 – CMP Sensor Circuit Performance

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using Tech 2, monitor “Specific DTC” info for DTC

P0341 until the DTC P0341 test runs.

5. Note the test result.

Does Tech 2 indicate DTC P0341 failed this ignition? — Go to Step 3

Refer to

Diagnostic Aids

3 1. Disconnect the CMP sensor.

2. Measure the voltage between the sensor feed

circuit and the sensor ground circuit at the CMP

sensor harness connector.

Does the voltage measure near the specified value? 4-6 V Go to Step 4 Go to Step 5

4 Measure the voltage between the CMP sensor signal

circuit and the sensor ground circuit at the CMP

sensor harness connector.

Does the voltage measure near the specified value? 4-6 V Go to Step 11 Go to Step 8

5 If the voltage measured in step 3 was less than 4-6

volts, proceed directly to step 6 without completing

this step.

If the voltage in step 3 was greater than 4-6 V, repair

the short to voltage in the CMP feed circuit.

Is the action complete? — Verify repair —

6 1. Check for poor connections at the camshaft

position sensor.

2. If a problem is found, repair it as necessary.

Was a problem found? — Verify repair Go to Step 7

7 1. Ignition “OFF,” disconnect the PCM and the CMP

sensor.

2. Check the following circuits for an open between

the ignition coil and the CMP sensor:

• The sensor feed circuit.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

8 1. Ignition “OFF,” disconnect the PCM (leave the

CMP sensor disconnected).

2. Ignition “ON,” check the following circuits:

• The CMP sensor signal circuit for an open or a

short to voltage.

• The CMP sensor input signal circuit for a short

to ground.

3. If a problem is found, repair it as necessary.

Was a problem found? — Verify repair Go to Step 9

9 Check for a short or open in the sensor ground circuit.

Was a problem found? — Verify repair Go to Step 10

10 1. Check for poor connections at the PCM.

2. If a problem is found, repair it as necessary.

Was a problem found? — Verify repair Go to Step 11

11 Backprobe the PCM connector with a DVM to monitor

voltage on the camshaft position input signal circuit

while cranking the engine with the sensor connected.

(Use rubber band, tape, or an assistant to keep the

DVM lead in contact with the sensor terminal during

this test.)

Does the voltage toggle between the specified

values?4-0 VGo to Step 15 Go to Step 12

12 1.Remove the CMP sensor from the engine front

cover (leave the sensor wiring connected).

2.Place a magnet on the CMP sensor.

(If you use a magnet that is too small to cover the face

of the sensor, test on every part of the sensor face

because only a small area will respond to this test.)

Does the DVM display a voltage near the specified

value?0 VGo to Step 13 Go to Step 14

13 Replace the faulty or missing camshaft position

sensor magnet.

Is the action complete?—Verify repair—

14 Replace the camshaft position sensor.

Is the action complete?—Verify repair—

15 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0342 CMP Sensor Circuit Low

D06RW032

Circuit Description

The CMP signal produced by the camshaft position

(CMP) sensor pulses when the engine is running and

crankshaft position (CKP) sync pulses are also being

received. The hall type CMP sensor and the CKP

sensor share 5 V and ground connections at the

powertrain control module (PCM). The third wire at the

sensor is a signal circuit to the PCM. The PCM uses

the CMP signal pulses to initiate sequential fuel

injection. The PCM constantly monitors the number of

pulses on the CMP signal circuit and compares the

number of CMP pulses to the number of 58X reference

pulses received. If the PCM does not receive pulses on

the CMP reference circuit, DTC P0342 will set and the

PCM will initiate injector sequence without the CMP

signal with a one in six chance that injector sequence is

correct. The engine will continue to start and run

normally, although the misfire diagnostic will be affected

if a misfiring condition occurs.

Conditions for Setting the DTC

• The engine is running.

• The CMP sensor signal is not received by the PCM

once every 6 cylinders.

• The above condition occurs for 10 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• The PCM will initiate injector sequence without the

CMP signal with a one in six chance that the injector

sequence is correct.

•The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0342 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation or a wire broken inside

the insulation. Check for:

•Poor connection – Inspect the PCM harness and

connectors for improper mating, broken locks,

improperly formed or damaged terminals, and poor

terminal to wire connection.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK,

disconnect the PCM, turn the ignition on and observe

a voltmeter connected to the CMP signal circuit at the

PCM harness connector while moving connectors

and wiring harnesses related to the ICM and the CMP

sensor. A change in voltage will indicate the location

of the fault.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. Ensures that the fault is present.

14. Determines whether the fault is being caused by a

missing camshaft magnet or a faulty PCM. The

voltage measured in this step should read around 4

volts, toggling to near 0 volts when the CMP sensor

interfaces with the camshaft magnet.

DTC P0342 – CMP Sensor Circuit Low

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using Tech 2, monitor “Specific DTC” information

for DTC P0342 until the DTC P0342 test runs.

5. Note test result.

Does Tech 2 indicate DTC P0342 failed this ignition? — Go to Step 3

Refer to

Diagnostic Aids

3 1. Ignition “ON.”

2. Disconnect the CMP sensor.

3. Measure the voltage between the sensor feed

circuit and the sensor ground circuit at the CMP

sensor harness connector.

Does the voltage measure near the specified value? 4-6 V Go to Step 7 Go to Step 4

4 1. Ignition “OFF,” disconnect the PCM and the CMP

sensor.

2. Check for poor connections at the camshaft

position sensor.

3. If a problem is found, repair it as necessary.

Was a problem found? — Verify repair Go to Step 5

5 1. Check for poor connections at the PCM.

2. If a problem is found, repair it as necessary.

Was a problem found? — Verify repair Go to Step 6

6 1. Check the following circuits between the PCM and

the CMP sensor:

• The sensor feed circuit. Open or short to

ground?

• The sensor ground circuit. Open or short to

voltage?

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair —

7 1. Ignition “ON,” engine “OFF.”

2. Measure the voltage between the CMP sensor

signal circuit and the sensor ground circuit at the

CMP sensor harness connector.

Does the voltage measure near the specified value? 4-6 V Go to Step 8 Go to Step 9

8 1. Turn the ignition “OFF.”

2. Disconnect the PCM and connect a DVM to

monitor voltage on the camshaft position signal

circuit at the PCM connector.

3. Ignition “ON.”

4. Monitor the voltage display on the DVM while

repeatedly touching the CMP sensor signal circuit

at the CMP sensor connector with a test light to

ground.

Does the DVM voltage display switch between 0 and

approximately 5 volts when the test light is touched to

the CMP sensor signal circuit? — Go to Step 12 Go to Step 9

9 1. Ignition “OFF.”

2. Leave the PCM disconnected.

3. Ignition “ON.”

4. Probe the camshaft position signal circuit at the

PCM connector with a test light to B+.

5. If the test light is “ON,” locate and repair the short

to ground in the camshaft position input signal

circuit.

Was either circuit shorted to ground? — Verify repair Go to Step 10

10 1. Ignition “OFF.”

2. Leave the PCM disconnected.

3. Ignition “ON.”

4. Probe the camshaft position signal circuit with a

test light to ground.

5. If the test light is “ON,” locate and repair the short

to voltage in the camshaft position input signal

circuit.

Was the test light“ON”? — Verify repair Go to Step 11

11 1. Ignition “OFF,” disconnect the PCM (leave the

CMP sensor disconnected).

2. Ignition “ON,” check the following circuit:

• The CMP sensor signal circuit for an open.

3. If a problem is found, repair it as necessary.

Was a problem found? — Verify repair —

12 1. Ignition “ON.”

2. Remove the CMP sensor from the engine front

cover (leave the sensor wiring connected).

3. Place a magnet on the CMP sensor. If you use a

magnet that is too small to cover the face of the

sensor, test on every part of the sensor face

because only a small area will respond to this test.

Does the DVM display a voltage near the specified

value? 0 V Go to Step 14 Go to Step 13

13 Replace the camshaft position sensor.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

14 1. Reinstall the CMP sensor to the engine front

cover.

2. Observe the DVM connected to monitor voltage

on the camshaft position signal circuit while

cranking the engine.

Does the voltage toggle between the specified

values? 4-0 V Go to Step 15 Go to Step 16

15 Replace the PCM.

NOTE: The replacement PCM must be programmed.

Refer to Sections OC1 Service Programming System

and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

16 Replace faulty or missing camshaft magnet.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0351 Ignition 1 Control Circuit

D06RW072

Circuit Description

The powertrain control module's (PCM) control circuit 1

provides a zero-volt or a 5-volt output signal to the

ignition coil. The normal voltage on the circuit is zero

volts. When the ignition coil receives the 5-volt signal

from the PCM, it provides a ground path for the B+

supply to the primary side of the number 1 ignition coil.

When the PCM shuts off the 5 volts to the ignition coil,

the ignition coil turns “OFF.” This causes the ignition

coil primary magnetic field to collapse, producing a

voltage in the secondary coil which fires the spark plug.

The circuit between the PCM and ignition coil is

monitored for an open circuit, short to voltage, and short

to ground. When the PCM detects a problem on ignition

control circuit 1, it will set a DTC P0351.

Conditions for Setting the DTC

• The ignition is “ON.”

• The engine is turning, determined by the 58X

crankshaft position input signal.

• The output voltage is not equal to 5 volts when output

is “ON.”

• The output voltage is not equal to 0 volts when output

is “OFF.”

• Twenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0351 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

Tech 2 display related to DTC P0351 while moving

the connector and wiring related to the ignition

system. A change in the display will indicate the

location of the fault.

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.

DTC P0351 – Ignition 1 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use Tech 2 to monitor the “Specific DTC”

information for DTC P0351 until the DTC P0351

test runs.

5. Note the test result.

Does Tech 2 indicate DTC P0351 failed this ignition

cycle? — Go to Step 3

Go to

Diagnostic Aids

3 Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to Step 4

4 Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to Step 5

5 1. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 1 at the

PCM with a DVM.

Is the voltage near the specified value? 25-55 mV Go to Step 6 Go to Step 9

6 1. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM

for the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to Step 7 Go to Step 13

7 1. Ignition “OFF.”

2. Disconnect the 3-pin and 5-pin connectors at the

ignition coil.

3. Check ignition control circuit 1 voltage at the

ignition coil connector while cranking the engine.

Does the voltage measure between the specified

values? 200-1200 mV Go to Step 8 Go to Step 11

8 Replace the ignition coil.

Is the action complete? — Verify repair —

9 1. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 1 for short to ground.

Was a problem found? — Verify repair Go to Step 10

10 Check ignition control circuit 1 for short to voltage.

Was a problem found? — Verify repair Go to Step 13

11 Check for an open ignition control circuit 1.

Was the ignition control circuit open?—Go to Step 12 Go to Step 13

12 Repair the open ignition control circuit.

Is the action complete?—Verify repair—

13 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0352 Ignition 2 Control Circuit

D06RW072

Circuit Description

The powertrain control module's (PCM) control circuit 2

provides a zero-volt or a 5-volt output signal to the

ignition coil. The normal voltage on the circuit is zero

volts. When the ignition coil receives the 5-volt signal

from the PCM, it provides a ground path for the B+

supply to the primary side of the number 2 ignition coil.

When the PCM shuts off the 5 volts to the ignition coil,

the ignition coil turns “OFF.” This causes the ignition

coil primary magnetic field to collapse, producing a

voltage in the secondary coil which fires the spark plug.

The circuit between the PCM and ignition coil is

monitored for an open circuit, short to voltage, and short

to ground. When the PCM detects a problem on ignition

control circuit 2, it will set a DTC P0352.

Conditions for Setting the DTC

• The ignition is “ON.”

• The engine is turning, determined by the 58 X

crankshaft position input signal.

• The output voltage is not equal to 5 volts when output

is “ON.”

• The output voltage is not equal to 0 volts when output

is “OFF.”

• Twenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0352 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the Tech 2 display related to DTC P0352 while

moving the connector and wiring related to the

ignition system. A change in the display will indicate

the location of the fault.

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.

DTC P0352 – Ignition 2 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “Specific DTC”

information for DTC P0352 until the DTC P0352

test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0352 failed this

ignition cycle? — Go to Step 3

Go to

Diagnostic Aids

3 Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to Step 4

4 Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to Step 5

5 1. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 2 at the

PCM with a DVM .

Is the voltage near the specified value? 25-55 mV Go to Step 6 Go to Step 9

6 1. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM

for the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to Step 7 Go to Step 13

7 1. Ignition “OFF.”

2. Disconnect the 3-pin and 5-pin connectors at the

ignition coil.

3. Check ignition control circuit 2 voltage at the

ignition coil connector while cranking the engine

connector.

Does the voltage measure between the specified

values? 200-1200 mV Go to Step 8 Go to Step 11

8 Replace the ignition coil.

Is the action complete? — Verify repair —

9 1. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 2 for short to ground.

Was a problem found? — Verify repair Go to Step 10

10 Check ignition control circuit 2 for short to voltage.

Was a problem found?—Verify repairGo to Step 13

11 Check for an open ignition control circuit 1.

Was the ignition control circuit open?—Go to Step 12 Go to Step 13

12 Repair the open ignition control circuit.

Is the action complete?—Verify repair—

13 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0353 Ignition 3 Control Circuit

D06RW072

Circuit Description

The powertrain control module's (PCM) control circuit 3

provides a zero-volt or a 5-volt output signal to the

ignition coil. The normal voltage on the circuit is zero

volts. When the ignition coil receives the 5-volt signal

from the PCM, it provides a ground path for the B+

supply to the primary side of the number 3 ignition coil.

When the PCM shuts off the 5 volts to the ignition coil,

the ignition coil turns “OFF.” This causes the ignition

coil primary magnetic field to collapse, producing a

voltage in the secondary coil which fires the spark plug.

The circuit between the PCM and ignition coil is

monitored for an open circuit, short to voltage, and short

to ground. When the PCM detects a problem on ignition

control circuit 3, it will set a DTC P0353.

Conditions for Setting the DTC

• The ignition is “ON.”

• The engine is turning, determined by the 58X

crankshaft position input signal.

• The output voltage is not equal to 5 volts when output

is “ON.”

• The output voltage is not equal to 0 volts when output

is “OFF.”

• Twenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0353 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the Tech 2 display related to DTC P0353 while

moving the connector and wiring related to the

ignition system. A change in the display will indicate

the location of the fault.

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.

DTC P0353 – Ignition 3 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “Specific DTC”

information for DTC P0353 until the DTC P0353

test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0353 failed this

ignition cycle? — Go to Step 3

Go to

Diagnostic Aids

3 Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to Step 4

4 Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to Step 5

5 1. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 3 at the

PCM with a DVM positive lead with the negative

lead to ground.

Is the voltage near the specified value? 25-55 mV Go to Step 6 Go to Step 9

6 1. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM

for the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to Step 7 Go to Step 13

7 1. Ignition “OFF.”

2. Disconnect the 3-pin and 5-pin connectors at the

ignition coil.

3. Check ignition control circuit 3 voltage at the

ignition coil connector while cranking the engine.

Does the voltage measure between the specified

values? 200-1200mV Go to Step 8 Go to Step 11

8 Replace the ignition coil.

Is the action complete? — Verify repair —

9 1. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 3 for short to ground.

Was a problem found? — Verify repair Go to Step 10

10 Check ignition control circuit 3 for short to voltage.

Was a problem found?—Verify repairGo to Step 13

11 Check for an open ignition control circuit 1.

Was the ignition control circuit open?—Go to Step 12 Go to Step 13

12 Repair the open ignition control circuit.

Is the action complete?—Verify repair—

13 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0354 Ignition 4 Control Circuit

D06RW072

Circuit Description

The powertrain control module's (PCM) control circuit 4

provides a zero-volt or a 5-volt output signal to the

ignition coil. The normal voltage on the circuit is zero

volts. When the ignition coil receives the 5-volt signal

from the PCM, it provides a ground path for the B+

supply to the primary side of the number 4 ignition coil.

When the PCM shuts off the 5 volts to the ignition coil,

the ignition coil turns “OFF.” This causes the ignition

coil primary magnetic field to collapse, producing a

voltage in the secondary coil which fires the spark plug.

The circuit between the PCM and ignition coil is

monitored for an open circuit, short to voltage, and short

to ground. When the PCM detects a problem on ignition

control circuit 4, it will set a DTC P0354.

Conditions for Setting the DTC

• The ignition is “ON.”

• The engine is turning, determined by the 58X

crankshaft position input signal.

• The output voltage is not equal to 5 volts when output

is “ON.”

• The output voltage is not equal to 0 volts when output

is “OFF.”

• Twenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0354 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the Tech 2 display related to DTC P0354 while

moving the connector and wiring related to the

ignition system. A change in the display will indicate

the location of the fault.

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.

DTC P0354 – Ignition 4 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “Specific DTC”

information for DTC P0354 until the DTC P0354

test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0354 failed this

ignition cycle? — Go to Step 3

Go to

Diagnostic Aids

3 Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to Step 4

4 Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to Step 5

5 1. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 4 at the

PCM with a DVM positive lead with the negative

lead to ground.

Is the voltage near the specified value? 25-55 mV Go to Step 6 Go to Step 9

6 1. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM

for the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to Step 7 Go to Step 13

7 1. Ignition “OFF.”

2. Disconnect the 3-pin and 5-pin connectors at the

ignition coil.

3. Check ignition control circuit 4 voltage at the

ignition coil connector while cranking the engine.

Does the voltage measure between the specified

values? 200-1200 mV Go to Step 8 Go to Step 11

8 Replace the ignition coil.

Is the action complete? — Verify repair —

9 1. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 4 for short to ground.

Was a problem found? — Verify repair Go to Step 10

10 Check ignition control circuit 4 for short to voltage.

Was a problem found?—Verify repairGo to Step 13

11 Check for an open ignition control circuit 1.

Was the ignition control circuit open?—Go to Step 12 Go to Step 13

12 Repair the open in ignition control circuit.

Is the action complete?—Verify repair—

13 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0355 Ignition 5 Control Circuit

D06RW072

Circuit Description

The powertrain control module's (PCM) control circuit 5

provides a zero-volt or a 5-volt output signal to the

ignition coil. The normal voltage on the circuit is zero

volts. When the ignition coil receives the 5-volt signal

from the PCM, it provides a ground path for the B+

supply to the primary side of the number 5 ignition coil.

When the PCM shuts off the 5 volts to the ignition coil,

the ignition coil turns “OFF.” This causes the ignition

coil primary magnetic field to collapse, producing a

voltage in the secondary coil which fires the spark plug.

The circuit between the PCM and ignition coil is

monitored for an open circuit, short to voltage, and short

to ground. When the PCM detects a problem on ignition

control circuit 5, it will set a DTC P0355.

Conditions for Setting the DTC

• The ignition is “ON.”

• The engine is turning, determined by the 58X

crankshaft position input signal.

• The output voltage is not equal to 5 volts when output

is “ON.”

• The output voltage is not equal to 0 volts when output

is “OFF.”

• Twenty test failures occur within 40 samples of

continuous spark events.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0355 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the Tech 2 display related to DTC P0355 while

moving the connector and wiring related to the

ignition system. A change in the display will indicate

the location of the fault.

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.

DTC P0355 – Ignition 5 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “Specific DTC”

information for DTC P0355 until the DTC P0355

test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0355 failed this

ignition cycle? — Go to Step 3

Go to

Diagnostic Aids

3 Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to Step 4

4 Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to Step 5

5 1. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 5 at the

PCM with a DVM positive lead with the negative

lead to ground.

Is the voltage near the specified value? 25-55 mV Go to Step 6 Go to Step 9

6 1. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM

for the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to Step 7 Go to Step 13

7 1. Ignition “OFF.”

2. Disconnect the 3-pin and 5-pin connectors at the

ignition coil.

3. Check ignition control circuit 5 voltage at the

ignition coil connector while cranking the engine.

Does the voltage measure between the specified

values? 200-1200 mV Go to Step 8 Go to Step 11

8 Replace the ignition coil.

Is the action complete? — Verify repair —

9 1. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 5 for short to ground.

Was a problem found? — Verify repair Go to Step 10

10 Check ignition control circuit 5 for short to voltage.

Was a problem found?—Verify repairGo to Step 13

11 Check for an open ignition control circuit 1.

Was the ignition control circuit open?—Go to Step 12 Go to Step 13

12 Repair the open ignition control circuit.

Is the action complete?—Verify repair—

13 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0356 Ignition 6 Control Circuit

D06RW072

Circuit Description

The powertrain control module's (PCM) control circuit 6

provides a zero-volt or a 5-volt output signal to the

ignition coil. The normal voltage on the circuit is zero

volts. When the ignition coil receives the 5-volt signal

from the PCM, it provides a ground path for the B+

supply to the primary side of the number 6 ignition coil.

When the PCM shuts off the 5 volts to the ignition coil,

the ignition coil turns “OFF.” This causes the ignition

coil primary magnetic field to collapse, producing a

voltage in the secondary coil which fires the spark plug.

The circuit between the PCM and ignition coil is

monitored for an open circuit, short to voltage, and short

to ground. When the PCM detects a problem on ignition

control circuit 6, it will set a DTC P0356.

Conditions for Setting the DTC

• The ignition is “ON.”

• The engine is turning, determined by the 58X

crankshaft position input signal.

• The output voltage is not equal to 5 volts when output

is “ON.”

• The output voltage is not equal to 0 volts when output

is “OFF.”

• Twenty test failures occur within 40 samples of

continuous circuit monitoring.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P0356 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM – Inspect the harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connections.

•Damaged harness – Inspect the wiring harness for

damage. If the harness appears to be OK, observe

the Tech 2 display related to DTC P0356 while

moving the connector and wiring related to the

ignition system. A change in the display will indicate

the location of the fault.

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.

DTC P0356 – Ignition 6 Control Circuit

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine “OFF.”

2. Review and record Tech 2 Failure Records data.

3. Operate the vehicle within Failure Record

conditions as noted.

4. Use a Tech 2 to monitor the “Specific DTC”

information for DTC P0356 until the DTC P0356

test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0356 failed this

ignition cycle? — Go to Step 3

Go to

Diagnostic Aids

3 Check for faulty connection at ignition coil.

Was a problem found? — Verify repair Go to Step 4

4 Check for faulty connection at PCM connector.

Was a problem found? — Verify repair Go to Step 5

5 1. Ignition “ON,” engine “OFF.”

2. Back probe the ignition control circuit 6 at the

PCM with a DVM positive lead with the negative

lead to ground.

Is the voltage near the specified value? 25-55 mV Go to Step 6 Go to Step 9

6 1. Ignition “ON,” engine running.

2. Back probe the ignition control circuit at the PCM

for the cylinder being tested.

Is the voltage in the specified range, rapidly toggling

back and forth to a reading 20-50 mV higher? 100-180 mV Go to Step 7 Go to Step 13

7 1. Ignition “OFF.”

2. Disconnect the 3-pin and 5-pin connectors at the

ignition coil.

3. Check ignition control circuit 6 voltage at the

ignition coil connector while cranking the engine.

Does the voltage measure between the specified

values? 200-1200 mV Go to Step 8 Go to Step 11

8 Replace the ignition coil.

Is the action complete? — Verify repair —

9 1. Ignition “OFF.”

2. Disconnect the PCM and the ignition coil.

3. Check ignition control circuit 6 for short to ground.

Was a problem found? — Verify repair Go to Step 10

10 Check ignition control circuit 6 for short to voltage.

Was a problem found?—Verify repairGo to Step 13

11 Check for an open ignition control circuit 1.

Was the ignition control circuit open?—Go to Step 12 Go to Step 13

12 Repair the open ignition control circuit.

Is the action complete?—Verify repair—

13 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0402 EGR Pintle Crank Error

D06RW106

Circuit Description

The powertrain control module (PCM) monitors the

EGR valve pintle position input to ensure that the valve

responds properly to commands from the PCM, and to

detect a fault if pintle position is stuck open. If the PCM

detects a pintle position signal indicates more than

21.5% and more than for 625 msec during cranking, the

PCM will set DTC P0402.

Conditions for Setting the DTC

• Ignition voltage is between 11 and 16 volts.

• Intake Air temp is more than 3°C

• At Engine revolution less than 600 RPM, EGR pintle

position indicates more than 21.5% and more than for

625 msecs.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0402 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

• Foreign material on EGR valve between pintle and

seat may cause EGR stuck open. Inspect foreign

material in EGR valve.

• Excessive carbon deposit may cause unsmooth

operation of EGR valve shaft. Inspect carbon deposit

and clean up inside of carbon deposit.

• Poor connection or damaged harness–inspect the

wiring harness for damage If the harness appears to

be OK, observe the EGR actual position display on

Tech 2 while moving connectors and wiring

harnesses related to EGR valve. A change in the

display will indicate the location of the fault.

NOTE: If the EGR valve shows signs of excessive heat,

check the exhaust system for blockage (possibly a

plugged catalytic converter) using the“Restricted

Exhaust System Check”.

DTC P0402 – EGR Pintle Crank Open Error

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition“ON”, engine“OFF”, review and record

Tech 2 Failure Records data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using Tech 2, monitor “Specific DTC” info for DTC

P0402 until the DTC P0402 test runs. Note the

result.

Does Tech 2 indicates DTC P0402 failed this ignition? — Go to Step 3

Refer to

Diagnostic Aids

3 1. Disconnect the EGR valve harness connector.

2. Inspect the EGR valve and connectors for

damaged pin or terminals.

Were there any damaged pins or terminals? — Go to Step 4 Go to Step 5

4 Repair the damaged pin or terminal.

Is the action complete? — Verify repair —

5 1. Remove EGR valve from Engine.

2. Inspect EGR valve whether there is any foreign

material between seat and pintle.

Was any foreign material in EGR valve? — Go to Step 6 Go to Step 7

6 1. Remove EGR valve foreign material from EGR

valve and clean up inside.

2. Visually inspect damage of pintle and seat, which

leakage may occur.

Was there any severe damage which affects function? — Go to Step 7

Verify repair

Go to Step 8

7 1. Reconnect.

2. Ignition“OFF”.

3. Install Tech 2.

4. Run the engine at idle.

5. On Tech-II, select special function for EGR.

6. Use the “UP” arrow to increase the EGR from 0%

to 40%.

Did EGR work properly? — — Go to Step 8

8 Replace the EGR valve.

Does DTC P0402 still fail “DTC” test on Tech 2? — Go to Step 9 Verify repair

9 Replace the EGR valve.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0404 EGR Open Stuck

D06RW106

Circuit Description

The powertrain control module (PCM) monitors the

EGR valve pintle position input to ensure that the valve

responds properly to commands from the PCM, and to

detect a fault if pintle position is different from

commanded position. If the PCM detects a pintle

position signal indicates more than 15 points different

between current and commanded and more than 15

seconds, the PCM will set DTC P0404.

Conditions for Setting the DTC

• Ignition voltage is between 11 and 16 volts.

• Intake Air temp is more than 3°C.

• Desire EGR position is more than 0.

• The difference between desired EGR and current

EGR is less than 3%.

• Difference EGR pintle position between current and

commanded position becomes more than 15% and

last more than 15 seconds, and this condition meets

three times in a trip. Then it trigger, the PCM lights

on.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) as soon as failure detected after

consecutive 2nd trip in which the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0404 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

• Excessive carbon deposit on EGR valve shaft may

cause EGR stuck open or unsmooth operation.

Those carbon deposit may occur by unusual port

operation. Clean up carbon may make smooth

function of EGR valve.

• Poor connection or damaged harness – Inspect the

wiring harness for damage. If the harness appears to

be OK, observe the EGR actual position display on

Tech 2 while moving connectors and wiring

harnesses related to EGR valve. A change in the

display will indicate the location of the fault.

DTC P0404 – E GR Open Stuck

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 1.Ignition “ON,” engine“OFF”, review and record

Tech 2 Failure Records Data.

2.Operate the vehicle within Failure Records

conditions as noted.

3.Using Tech 2, monitor “Specific DTC” info for DTC

P0404 until the DTC P0404 test runs. Note the

result.

Does Tech 2 indicates DTC P0404 failed this ignition?—Go to Step 3

Refer to

Diagnostic Aids

3 1.Disconnect the EGR valve harness connector.

2.Inspect the EGR valve and connectors for

damaged pin or terminals.

Were there any damaged pins or terminals?—Go to Step 4 Go to Step 5

4 Repair the damaged pin or terminal.

—Verify repair

Is the action

complete?

5 1.Remove EGR valve from Engine.

2.Inspect EGR valve whether there is any

excessive carbon deposit on EGR shaft.

Was excessive carbon deposit 0n EGR valve shaft?—Go to Step 6 Go to Step 7

6 1.Clean up EGR valve shaft and inside of EGR

valve.

2.Visually inspect damage of pintle and seat

whether there is bent, leakage may occur.

Was there any severe damage which affects function?—Go to Step 8

Verify repair

Go to Step 7

7 1.Reconnect.

2.Ignition“OFF”.

3.Install Tech 2.

4.Run the engine at idle.

5.On Tech 2, select F3:Misc. Test; F2:EGR.

6.Use the “UP” arrow to increase the EGR from 0%

to 40%.

Did EGR work properly?——Go to Step 8

8 Replace the EGR valve.

Does DTC P0404 still fail “DTC” test on Tech 2?—Go to Step 9 Verify repair

9 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0405 EGR Low Voltage

D06RW106

Circuit Description

The powertrain control module (PCM) monitors the

EGR valve pintle position input to ensure that the valve

responds properly to command from the PCM. If

current pintle position voltage indicates less than 0.1 V

and last more than 10 seconds, then the PCM will set

DTC P0405.

Conditions for Setting the DTC

• Ignition voltage is between 11 and 16 volts.

• EGR pintle position output voltage is less than 0.1

volt and last more than 10 sec. Action taken when

the DTC sets.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) as soon as failure detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0405 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

• Poor connection or damaged harness – Inspect the

wiring harness for damage. If the harness appears to

be OK, observe the EGR actual position display on

Tech 2 while moving connectors and wiring

harnesses related to EGR valve. A change in the

display will indicate the location of the fault.

DTC P0405 – EGR Low Volt

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine“OFF”, review and record

Tech 2 Failure Records Data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using Tech 2, monitor “DTC” info for DTC P0405

until the DTC P0405 test runs. Note the result.

Does Tech 2 indicates DTC P0405 failed this ignition? — Go to Step 3

Refer to

Diagnostic Aids

3 1. Disconnect the EGR valve harness connector.

2. Inspect the EGR valve and connectors for

damaged pin or terminals.

Were there any damaged pins or terminals? — Go to Step 4 Go to Step 5

4 Repair the damaged pin or terminal.

Is the action complete? — Verify repair —

5 1. Disconnect the EGR harness connector.

2. Ignition“ON”.

3. At the EGR valve, use a DVM to check the voltage

at the 5 volt reference wire (RED) and ground (B).

Did the DVM indicate the specified value? 4–6 V Go to Step 6 Go to Step 7

6 1. Disconnect the EGR harness connector.

2. Measure resistance between terminal B and D.

Was resistance in range? 5–5.5 KWGo to Step 10 Go to Step 17

7 1. Ignition“ON”.

2. At the PCM connector, backprobe with a DVM at

the 5 volt reference for the EGR valve.

Did the DVM indicate the specified value? 4–6 V Go to Step 8 Go to Step 9

8 Repair the open 5 volt reference circuit.

Is the action complete? — Verify repair —

9 Repair the damaged sensor ground wire.

Is the action complete? — Verify repair —

10 1. Disconnect the EGR harness

2. Use an ohmmeter to measure between the pintle

position pin and the sensor ground pin on the

EGR valve.

NOTE: J-35616 Connector Test Adapter Kit may be

useful for gaining access to the recessed pins on the

valve.

Was the ohmmeter reading approximately equal to the

specified value? 1 to 1.25 KWGo to Step 11 Go to Step 17

11 1. Ignition“ON”.

2. Backprobe with a DVM to measure voltage at

EGR valve pintle position pin and sensor ground

pin.

Was voltage in range?

Less than

0.1V Go to Step 17 Go to Step 12

12 1. Ignition“ON”.

2. Backprobe with a DVM to measure voltage at

PCM sensor ground pin and pintle position pin.

Was voltage in range?

Less than

0.1V Go to Step 13 Go to Step 18

13 1.Ignition“OFF”.

2.Disconnect the EGR harness.

3.Check short circuit between EGR pintle position

circuit and EGR ground circuit.

Was any short circuit?—Go to Step 14 Go to Step 18

14 Locate and repair the short to ground in the pintle

position circuit

Is the action complete?—Verify repair—

15 1.Ignition“OFF”.

2.Disconnect the PCM.

3.Ignition“ON”.

4.Measure the voltage between the EGR pintle

position circuit and ground.

Is the measured voltage near the specified value?

Less than

0.1VGo to Step 17 Go to Step 16

16 Check for a short circuit between other wires and the

pintle position circuit

Was any short circuit?—

Repair short

circuit

Verify repairGo to Step 17

17 Replace the EGR valve.

Does DTC P1404 still fail “specific DTC test on Tech

2?—Go to Step 18 Verify repair

18 Examine the PCM pin and terminal connection.

Was there a damaged terminal?—Go to Step 4 Go to Step 19

19 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0406 EGR High Voltage

D06RW106

Circuit Description

The powertrain control module (PCM) monitors the

EGR valve pintle position input to ensure that the valve

responds properly to command from the PCM. If

current pintle position voltage indicates more than 4.8 V

and last more than 10 seconds, then the PCM will set

DTC P0406.

Conditions for Setting the DTC

• Ignition voltage is between 11 and 16 volts.

• EGR pintle position output voltage is more than 4.8

volt and last more than 10 sec.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) as soon as failure detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0404 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

Check for the following conditions:

• Poor connection or damaged harness – Inspect the

wiring harness for damage. If the harness appears to

be OK, observe the EGR actual position display on

Tech 2 while moving connectors and wiring

harnesses related to EGR valve. A change in the

display will indicate the location of the fault.

DTC P0406 – EGR High Voltage

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,” engine“OFF”, review and record

Tech 2 Failure Records Data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using Tech 2, monitor “DTC” info for DTC P0406

until the DTC P0406 test runs. Note the result.

Does Tech 2 indicates DTC P0406 failed this ignition? — Go to Step 3

Refer to

Diagnostic Aids

3 1. Disconnect the EGR valve harness connector.

2. Inspect the EGR valve and connectors for

damaged pin or terminals.

Were there any damaged pins or terminals? — Go to Step 4 Go to Step 5

4 Repair the damaged pin or terminal.

Is the action complete? — Verify repair

Is the action

complete?

5 1. Disconnect the EGR harness connector.

2. Ignition“ON”.

3. At the EGR valve, use a DVM to check the voltage

at the 5 volt reference wire (RED).

Did the DVM indicate the specified value? 4–6V Go to Step 8 Go to Step 6

6 1. Ignition“ON”.

2. At the PCM connector, backprobe with a DVM at

the 5 volt reference for the EGR valve.

Did the DVM indicate the specified value? 4–6 V Go to Step 7 Go to Step 16

7 Repair the open 5 volt reference circuit

Is the action complete? — Verify repair —

8 1. Ignition “OFF”

2. Disconnect the EGR harness.

3. Use a DVM to check for an resistance between D

(5 V reference) and B (Sensor Ground) at EGR

sensor terminals.

NOTE: J-35616 Connector Test Adapter Kit may be

useful for gaining access to the recessed pins on the

valve.

Was there measured resistance in range? 5 to 5 KWGo to Step 9 Go to Step 15

9 1. Ignition“OFF”.

2. Disconnect the EGR harness.

3. Use a DVM to check for an resistance between B

and C at EGR sensor terminal.

Was there open circuit? — Go to Step 15 Go to Step 10

10 1. Ignition“OFF”.

2. Disconnect the EGR harness at PCM connector.

3. Use a DVM to check for shorted wire between A1

and B7.

Was there shorted wire? — Go to Step 14 Go to Step 11

11 1. Ignition“ON”.

2. Use a DVM to backprobe at terminal C of EGR

valve for voltage.

Was measured voltage more than 4.8V?

more than

4.8V Go to Step 12 Go to Step 12

12 1.Ignition“ON”.

2.Stay the EGR harness connected.

3.Check voltage by backproving at PCM B7

terminal.

Was voltage more than 4.8V?4.8VGo to Step 16 Go to Step 13

13 1.Locate short circuit at EGR harness between RED

to RED or GREEN, RED to YEL.

2.Replace EGR harness.

Is the action complete?—Verify repair—

14 Replace EGR harness.

Is the action complete?—Verify repair—

15 Replace the EGR valve.

Does DTC P1404 still fail “specific DTC test on Tech

2?—Go to Step 16 Verify repair

16 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0502 VSS Circuit Low Input

D06RW019

Circuit Description

The vehicle speed sensor has a magnet rotated by the

transmission output shaft. Attached to the sensor is a

hall effect circuit the interacts with the magnetic field

treated by the rotating magnet. A 12-volt operating

supply for the speed sensor hall circuit is supplied from

the meter fuse. The VSS pulses to ground the 9-volt

signal sent from the powertrain control module (PCM)

on the reference circuit. The PCM interprets vehicle

speed by the number of pulses to ground per second on

the reference circuit.

Conditions for Setting the DTC

• Engine is running.

• Engine coolant temperature is above 60°C (140°F).

• Engine speed is between 1800 RPM and 2500 RPM.

• Throttle angle is between 10% and 40%.

• Engine load is greater than 50 kPa.

• MAP sensor indicates greater than 50 kPa manifold

pressure.

• PCM detects no VSS signal for 12.5 seconds over a

period of 25 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first time the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P0502 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

10. To avoid backprobing the VSS and possibly

damaging a seal or terminal, the VSS output can be

tested at the point where the transmission harness

connects to the engine harness. Power and ground

are applied by jumpers to the VSS through the

connectors which are located just in front of the air

cleaner assembly. The VSS signal is monitored with

a DVM as the rear driveshaft turns. The wheels can

be turned to rotate the driveshaft, or in

2-wheels-drive vehicles the driveshaft can be turned

directly.

12. The speedometer-to-PCM VSS signal wire is

spliced to a wire leading to the cruise control

module. If a short to ground or voltage is indicated

between the PCM and speedometer, it could be on

the cruise control circuit if the vehicle is equipped

with cruise control.

DTC P0502 – VSS Circuit Low Input

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Does the speedometer work? — Go to Step 10 Go to Step 3

3 1. Disconnect the VSS connector.

2. Ignition “ON.”

3. Using a test light to battery +, probe the connector

ground wire.

Did the light illuminate? — Go to Step 5 Go to Step 4

4 Repair the sensor ground.

Is the action complete? — Verify repair —

5 1. Ignition “ON,” sensor disconnected.

2. Using a DVM, measure at the VSS connector

between ground and voltage supply.

Was the measurement near the specified value?

Battery

voltage Go to Step 7 Go to Step 6

6 Repair the open or short to ground which may have

blown the meter fuse.

Is the action complete? — Verify repair —

7 1. Ignition “ON,” VSS disconnected.

2. Using a DVM, measure at the VSS connector

between ground and the wire from the

speedometer.

Was the measurement near the specified value? 7.5-8 V Go to Step 9 Go to Step 8

8 Check for an open or short circuit between the

speedometer and the VSS.

Was an open or short circuit located? — Verify repair Go to Step 9

9 Replace the speedometer.

Is the action complete? — Verify repair —

10 1.Ignition “OFF.”

2.Disconnect the MAF sensor and remove the air

cleaner assembly and filter element to gain

access to the 16-way black connector located

immediately to the rear of the left front headlamp.

The connector attaches the VSS wires from the

transmission harness to the left-side engine

harness.

3.Disconnect the black 16-way connector.

4.Select a terminal adapter from kit J 35616 that can

be used with a jumper to supply B+ to the blue

wire with a yellow tracer (transmission side of the

connector).

5.Use another terminal adapter to attach a voltmeter

to the light-green wire with a while tracer (next to

the wire in the previous step.)

6.Disconnect the blue connector next to the black

16-way connector, and locate the black/red tracer

wire at one corner of the blue connector. The

black/red wire is the VSS ground. Use a terminal

adapter to attach a jumper to ground to the black/

red VSS ground wire at the transmission side of

the blue connector.

7.Raise the rear wheels off the ground with

transmission in neutral.

Does the DVM toggle back and forth between 0.6 V

and 10 V as the wheels (and driveshaft) are rotated?—Go to Step 11 Go to Step 12

11 Replace the VSS.

Is the action complete?—Verify repair—

12 Check for an open or short between the PCM and the

speedometer.

Was a problem found?—Verify repairGo to Step 13

13 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P0562 System Voltage Low

D06RW020

Circuit Description

The powertrain control module (PCM) monitors the

system voltage on the ignition feed terminal to the PCM.

A system voltage DTC will set whenever the voltage is

below a calibrated value.

Conditions for Setting the DTC

• Ignition “ON.”

• System voltage is below 11.5 volts for 15 minutes.

Action Taken When the DTC Sets

• The PCM will not illuminate the malfunction indicator

lamp (MIL).

• The PCM will store as Failure Records conditions

which were present when the DTC was set. This

information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

• A history DTC P0562 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

• DTC P0562 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

If the DTC sets when an accessory is operated, check

for a poor connection or excessive current draw.

DTC P0562 – System Voltage Low

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 Using a Tech 2, measure the battery voltage at the

battery.

Is the battery voltage greater than the specified value?11.5 VGo to Step 3

Charge battery,

then go to Step

3 1.Using a Tech 2.

2.Select “Ignition Volts” on the Tech 2.

3.Start the engine and raise the engine speed to the

specified value.

4.Load the electrical system by turning on the

headlights, high blower, etc.

Is the ignition voltage approximately equal to the

specified value?

2000 RPM

12.8-14.1 VGo to Step 4

Go to Starting/

Charging

4 1.Ignition “OFF.”

2.Disconnect the PCM connector at the PCM.

3.Using a DVM, measure the battery voltage at the

PCM connector A-4.

Is it approximately equal to battery voltage?—

Check for

excessive

current draw

with ignition

“OFF,” engine

“OFF.”Go to Step 5

5 1.Check for faulty connections at the PCM harness

terminals.

2.Repair as necessary.

Was a repair necessary?—Verify repairGo to Step 6

6 Check for an open battery feed circuit to the PCM.

Is the action complete?—Verify repairGo to Step 7

7 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0563 System Voltage High

Circuit Description

The powertrain control module (PCM) monitors the

system voltage on the ignition feed terminals to the

PCM. A system voltage DTC will set whenever the

voltage is above a calibrated value.

Conditions for Setting the DTC

•Ignition “ON.”

•System voltage is above 16 volts for 15 minutes.

Action Taken When the DTC Sets

•The PCM will not illuminate the malfunction indicator

lamp (MIL).

•The PCM will store as Failure Records only

conditions which were present when the DTC was

set. This information will not be stored as Freeze

Frame data.

Conditions for Clearing the MIL/DTC

•A history DTC P0563 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

•DTC P0563 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

If the DTC sets when an accessory is operated, check

for a poor connection or excessive current draw.

DTC P0563 – System Voltage High

StepActionValue(s)YesNo

1 Was the “ON-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 Using a Tech 2, measure the battery voltage at the

battery.

Is the battery voltage less than the specified value?11.5 VGo to Step 3 Go to Step 4

3 1.Charge the battery and clean the battery

terminals.

2.Clean the battery ground cable connection if

corrosion is indicated.

Is the battery voltage less than the specified value?11.5 VReplace batteryGo to Step 4

4 1.Turn “OFF” all the accessories.

2.Install a Tech 2.

3.Select the ignition voltage parameter on the Tech

4.Start the engine and raise the engine RPM to the

specified value.

Is the voltage more than 2.5 volts greater than the

measurement taken in step 2 or 3?2000 RPM

Go to Starting/

ChargingGo to Step 5

5 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to UBS 98 model year

Immobiliser Workshop Manual.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P0601 PCM Memory

Circuit Description

The powertrain control module (PCM) used in this

vehicle utilizes an electrically erasable programmable

read-only memory (EEPROM). The EEPROM contains

program information and the calibrations required for

engine, transmission, and powertrain diagnostics

operation.

Unlike the PROM used in past applications, the

EEPROM is not replaceable.

Conditions for Setting the DTC

•The PCM detects an internal program fault (check

sum error).

Action Taken When the DTC Sets

•The PCM will not illuminate the malfunction indicator

lamp (MIL).

•The PCM will store conditions which were present

when the DTC was set in the Failure Records data

only.

Conditions for Clearing the MIL/DTC

•DTC P0601 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

•DTC P0601 indicates that the contents of the

EEPROM have changed since the PCM was

programmed. The only possible repair is PCM

replacement.

DTC P0601 – PCM Memory

StepActionValue(s)YesNo

1 —

Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1154 HO2S Circuit Transition Time Ratio Bank 2 Sensor 1

060RW190

Circuit Description

The powertrain control module (PCM) monitors the

heated oxygen sensor (HO2S) activity for 90 seconds

after “closed loop” and stoichiometric operation have

been enabled. During the monitor period the PCM

counts the number of times that the HO2S responds

from rich-to-lean and from lean-to-rich and adds the

amount of time it took to complete all transitions. With

this information, an average time for all transitions can

be determined. The PCM then divides the rich-to-lean

average by the lean-to-rich average to obtain a ratio. If

the HO2S transition time ratio is not within this range,

DTC P1154 will be set, indicating that the oxygen

sensor is not responding as expected to changes in

exhaust oxygen content.

Conditions for Setting the DTC

• No related DTCs.

• Engine coolant temperature (ETC) is above 50°C

(122°F) for automatic transmission; 75°C (167°F) for

manual transmission.

• The engine is operating in “closed loop.”

• The engine has been running at least one minute.

• Canister purge duty cycle is greater than 2%.

• Engine speed is between 1500 RPM and 3000 RPM.

• Mass air flow is between 9 g/second and 42 g/

second.

• Above conditions are present for a 3-second

monitoring period.

• 90 seconds after “closed loop” and stoichiometric

operation have been enabled, Bank 2 HO2S 1

transition ratio between lean to rich and rich to lean is

less than 0.44 or greater than 3.8.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• "Open loop" fuel control will be in effect.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P1154 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

A multifunction in the HO2S heater ignition feed or

ground circuit may cause a DTC P1154 to set. Check

HO2S heater circuitry for intermittent faults or poor

connections. If connections and wiring are OK and DTC

P1154 continues to set, replace the Bank 2 HO2S 1.

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.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

3. A condition that affects other heated oxygen sensors

indicates probable contamination. To avoid

damaging replacement sensors, correct the

condition which caused the contamination before

replacing the affected sensors.

5. This step checks for conditions which may cause the

heated oxygen sensor to appear faulty. Correct any

of the described conditions if present.

8. To avoid damaging replacement sensors, correct the

condition which caused the contamination before

replacing the affected sensors.

DTC P1154 – HO2S Transition Time Ratio Bank 2 Sensor 1

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 Important: If any other DTCs are set (except P1133

and/or P1134), refer to those DTCs before proceeding

with this diagnostic chart.

1. Idle the engine at operating temperature.

2. Operate the vehicle within parameters specified

under “Conditions for Setting the DTC” criteria

included in Diagnostic Support.

3. Using a Tech 2, monitor “Specific DTC” info for

DTC P1154 until the DTC P1154 test runs.

Note the test result.

Does Tech 2 indicate DTC failed this ignition? — Go to Step 3

Refer to

Diagnostic Aids

3 Did Tech 2 also indicate P1133, and/or P1134 test

failed? — Go to Step 17 Go to Step 4

4 Check for leaks at the pipe joints.

Are the joints leaking? — Go to Step 5 Go to Step 6

5 Tighten the U-bolt nuts at the leaking joints.

Is your action complete? — Go to Step 2 —

6 Check for gaskets that are damaged or improperly

installed.

Are there damaged or misaligned gaskets? — Go to Step 7 Go to Step 8

7 1. Replace the damaged gaskets.

2. Align the connections.

3. Tighten the connections.

Is your action complete? — Go to Step 2 —

8 Check for loose exhaust flange connections.

Are the flange connections loose? — Go to Step 9 Go to Step 10

9 Tighten the stud nuts or bolts to specifications.

Is your action complete? — Go to Step 2 —

10 Check for burned or corroded exhaust pipes.

Are the exhaust pipes burned or corroded? — Go to Step 11 Go to Step 12

11 Replace the exhaust pipes, as required.

Is your action complete? — Go to Step 2 —

12 Check for leaks at the exhaust manifold.

Are there leaks at the exhaust manifold? — Go to Step 13 Go to Step 14

13 Tighten the bolts to specifications or replace the

manifold if necessary.

Is your action complete? — Go to Step 2 —

14 Visually/physically inspect the following items:

•Ensure that the Bank 2 HO2S 1 is securely

installed.

•Check for corrosion on terminals.

•Check terminal tension (at Bank 2 HO2S 1 and at

the PCM).

•Check for damaged wiring.

Was a problem found in any of the above areas?—Go to Step 18 Go to Step 15

15 1.Disconnect Bank 1 HO2S 1.

2.Ignition “ON.”

3.Using a DVM at the PCM side of the HO2S 1

connector, measure the voltage between the high

signal circuit and ground.

Also measure the voltage between the low signal

circuit and ground.

Are both voltages in the specified range?3-4VGo to Step 16 Go to Step 19

16 1.With Bank 1 HO2S 1 disconnected, jumper the

high and low (PCM side) signal circuits to ground.

2.Ignition “ON.”

3.Using Tech 2, monitor the Bank 2 HO2S 1 voltage.

Does the scan too indicate less than 10 mV and

immediately return to about 450 mV when the jumper

is removed?—Go to Step 21 Go to Step 22

17 Replace affected heated oxygen sensors.

NOTE: Before replacing sensors, the cause of the

contamination must be determined and corrected.

•Fuel contamination.

•Use of improper RTV sealant.

•Engine oil/coolant consumption.

Is the action complete?—Verify repair—

18 Repair condition as necessary.

Is the action complete?—Verify repair—

19 Check for faulty PCM connections or terminal

damage.

Is the action complete?—Verify repairGo to Step 20

20 Repair open, short or grounded signal circuit.

Is the action complete?—Verify repair—

21 Replace Bank 2 HO2S 1.

Is the action complete?—Verify repair—

22 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P1171 Fuel System Lean During Acceleration

060RW193-1

Circuit Description

The powertrain control module (PCM) internal circuitry

can identify if the vehicle fuel system is capable of

supplying adequate amounts of fuel during heavy

acceleration (power enrichment). The PCM monitors

the voltage of the oxygen sensor during power

enrichment. When a power enrichment mode of

operation is requested during “closed loop” operation

(by heavy acceleration), the PCM will provide more fuel

to the engine. Under these conditions the PCM should

detect a “rich” condition (high oxygen sensor voltage).

If this “rich” exhaust is not detected at this time, a DTC

P1171 will set. A plugged fuel filter, restricted fuel line,

restricted in-tank filter or defective fuel pump can

prevent adequate amounts of fuel from being supplied

during power enrichment mode.

Conditions for Setting the DTC

• No related DTCs.

• Engine is operating in “closed loop power

enrichment” mode for 3 seconds.

• Engine coolant temperature is above 60°C (140°F).

• While in “power enrichment” mode the oxygen sensor

voltage remains below 400 mV for 3 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) the first the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

•DTC P1171 can be cleared by using Tech 2 “Clear

Info” function or by disconnecting the PCM battery

feed.

Diagnostic Aids

•A restricted fuel filter or fuel line, restricted in-tank

filter, or a defective fuel pomp may supply adequate

amounts of fuel at idle, but may not be able to supply

enough fuel during heavy acceleration.

•Water or alcohol in the fuel may cause low HO2S

voltage during acceleration.

•Check for faulty or plugged fuel injector(s).

•Check for low fuel.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

4. When the engine is idling or at steady cruise, the

HO2S voltage should vary from between

approximately 100 mV to 900 mV. It is possible to

measure a satisfactory fuel pressure at idle even

though the pressure may drop at high flow

requirements. It may be necessary to watch fuel

pressure at high engine load.

5. Wrap a shop towel around the fuel pressure

connector to absorb any small amount of fuel

leakage that may occur when installing gauge.

Ignition “ON,” pump pressure should be 280-320

kPa.

DTC P1171 – Fuel System Lean During Acceleration

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 Are any component-related DTCs set?

—

Go to

component

DTC charts Go to Step 3

3 1. Check the vehicle's fuel tank for an adequate

amount of fuel.

2. Add fuel to the vehicle's fuel tank if the tank is

almost empty.

Was fuel added to the vehicle's fuel tank? — Go to Step 4 Go to Step 5

4 1. Place the transmission in park.

2. Using Tech 2, observe HO2S 1 voltage while

running warm engine 75°C-95°C (167°F-203°F) at

1200 RPM.

3. HO2S 1 voltage should vary within the specified

range.

4. Quickly open the throttle halfway for a few

seconds.

Did the voltage suddenly rise toward the high end of

the specified range? 100-900mV Go to Chart A-7 Go to Step 5

5 1. Disconnect the fuel pump relay and crank the

engine to relieve the fuel pressure.

2. Install the fuel pressure gauge.

3. Start the engine and idle at normal operating

temperature.

4. Disconnect the vacuum line going to the fuel

pressure regulator.

With the engine running, is the fuel pressure within the

specified range?

280-325 kPa

(41-46 psi)

Go to OBD

System Check Go to Step 6

6 Check for restricted fuel lines or restricted in-line filter.

Was a problem found? — Verify repair Go to Step 7

7 1. Ignition “OFF.”

2. Remove the fuel pump relay and replace it with a

fused jumper which will connect the relay's battery

terminal to the terminal leading to the fuel pump

fuse.

3. While the fuel pump is operating, use pliers to

slowly close the return line (do not exceed the first

specified value).

Using the pliers to restrict the return line, can the fuel

pressure be manipulated to exceed the second

specified value?

414kPa

(60psi)

325kPa

(46psi)

Go to

Diagnostic Aids Go to Step 8

8 Check for:

• Faulty fuel pump

• Restricted fuel pump strainer (sock)

• Incorrect fuel pump

• Incorrect fuel being used

• Hot fuel

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P1380 ABS Rough Road ABS System Fault

Circuit Description

The powertrain control module (PCM) monitors ABS

fault signal. When PCM receives fault signal, PCM will

set DTC P1380.

Conditions for Setting the DTC

•Vehicle speed is more than 5 mph.

•Load is less than 99%.

•Engine revolution is less than 6250 rpm.

•PCM receives ABS fault signals from ABS unit.

•Ignition on.

•Misfire DTCs exist.

•100 test failures within 120 test samples.

Action Taken When the DTC Sets

•The PCM will store DTC 1380 only, no MIL turn on.

Conditions for Clearing the MIL/DTC

•A history DTC P1380 will clear after 40 consecutive

warm-up cycles have occurred without a fault.

•DTC 1380 can be cleared by using Tech-2 or

disconnecting the PCM battery feed.

Diagnostic Aids

Check for the following conditions:

•PCM and ABS communication line short circuit to

other line may cause faulty signal. Inspect

communication line.

•Follow ABS ECU diagnosis procedure, refer to ABS

procedure page.

DTC P1380 – ABS Rough Road ABS System Fault

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 1.Ignition “ON,” engine“OFF”, review and record

Tech 2 Failure Records Data.

2.Operate the vehicle within Failure Records

conditions as noted.

3.Using a Tech 2, monitor “Specific DTC” info for

DTC P1380 and Misfire DTCs until the DTC

P1380 and Misfire DTCs test runs. Note the result.

Does the Tech 2 indicates DTC P1380 and Misfire

DTCs failed this ignition?—

Refer to

ABS

diagnosis

After inspect

ABS, unit

repeat Step

Still problem

exists, go to

Step 3

Clear DTC by

Tech 2

3 Check short circuit among communication line of

PCM/ABS and others.

Was short circuit?—

Repair

wiring

Verify repairGo to Step 4

4 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1404 EGR Closed Stuck

D06RW106

Circuit Description

The powertrain control module (PCM) monitors the

EGR valve pintle position input to ensure that the valve

responds properly to commands from the PCM, and to

detect a fault if current pintle zero position is different

from the learned zero position. If the PCM detects a

pintle position signal indicates more than 30 % different

between current zero position and the learned zero

position and more than 5 seconds, and this condition

meet 3 times during trip, then the PCM will set DTC

P1404.

Conditions for Setting the DTC

• Ignition voltage is between 11 and 16 volts.

• Intake Air temp is more than 3°C.

• Desire EGR position is 0.

• Difference EGR pintle position between current and

the learned zero is more than 30 % last more than 5

seconds, and meet three time to the above condition

during a trip. Then it trigger the PCM lights on.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after consecutive 2nd trip in which the

fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P1404 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Excessive carbon deposit on EGR valve shaft or/and

foreign material may cause no return to EGR valve

fully seated. Those carbon deposit may occur by

unusual port operation. Remove foreign material or/

and excessive carbon deposit on EGR valve shaft

may make return to EGR valve fully seated.

• Poor connection or damaged harness – Inspect the

wiring harness for damage. Same as P1406

description

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.

DTC P1404 – EGR Closed Stuck

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 1.Ignition “ON,” engine“OFF”, review and record

Tech 2 Failure Records Data.

2.Operate the vehicle within Failure Records

conditions as noted.

3.Using a Tech 2, monitor “DTC inf. for DTC P1404

until the DTC P1404 test runs. Note the result.

Does the Tech 2 indicates DTC P1404 failed this

ignition? —Go to Step 3

Refer to

Diagnostic Aids

3 1.Disconnect the EGR valve harness connector.

2.Inspect the EGR valve and connectors for

damaged pin or terminals.

Were there any damaged pins or terminals?—Go to Step 4 Go to Step 5

4 Repair the damaged pin or terminal.

Is the action complete?—Verify repair—

5 1.Remove EGR valve from Engine.

2.Inspect EGR valve whether there is any

excessive carbon deposit on EGR shaft.

3.Inspect any foreign material inside of EGR valve.

Was excessive carbon deposit on EGR valve shaft or/

and foreign material in EGR valve ?—Go to Step 6 Go to Step 7

6 1.Clean up EGR valve shaft and inside of EGR

valve.

2.Remove foreign material from EGR valve.

3.Visually inspect damage of pintle and seat

whether there is bent, leakage may occur.

Was there any severe damage which affects function?3–6 ohmsGo to Step 8

Verify repair

Go to Step 7

7 1.Reconnect.

2.Ignition“OFF”.

3.Install the Tech 2.

4.Run the engine at idle.

5.On the Tech 2, select F3:Misc. Test F5:EGR.

6.Use the “UP” arrow to increase the EGR from 0%

to 40%.

Did EGR work properly?——Go to Step 8

8 1.Reset the learned zero EGR valve position.

2.Repeat step 7.

Did EGR work properly?—Verify repairGo to Step 9

9 Replace the EGR valve.

Replace the EGR valve. Does DTC P1404 still fail

“specific DTC” test on the Tech 2?—Go to Step 10 Verify repair

10 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1508 IAC System Low RPM

T321115

Circuit Description

The powertrain control module (PCM) controls engine

idle speed by adjusting the position of the idle air control

(IAC) motor pintle. The IAC is a bi-directional stepper

motor driven by two coils. The PCM applies current to

the IAC coils in steps (counts) to extend the IAC pintle

into a passage in the throttle body to decrease air flow.

The PCM reverses the current to retract the pintle,

increasing air flow. This method allows highly accurate

control of idle speed and quick response to changes in

engine load. If the PCM detects a condition where too

low of an idle speed is present and the PCM is unable to

adjust idle speed by increasing the IAC counts, DTC

P1508 will set, indicating a problem with the idle control

system.

Conditions for Setting the DTC

• No Tech 2 test is being run.

• None of these DTCs are set: TP sensor, VSS, ECT,

EGR, fuel system, MAF, MAP, IAT, canister purge,

injector control or ignition control.

• Barometric pressure is above 75 kPa.

• Engine coolant temperature (ECT) is above 50°C

(120°F).

• Engine speed is more than 100-200 RPM lower than

desired idle, based upon coolant temperature.

• The engine has been running for at least 125

seconds.

• Vehicle speed is less than 1 mph.

• Canister purge duty cycle is above 10%.

• Ignition voltage is between 9.5 volts and 16.7 volts.

• The throttle is closed.

• Engine speed is lower than desired idle.

• All of the above conditions are met for 10 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P1508 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

•Poor connection at PCM or IAC motor – Inspect

harness connectors for backed-out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, and poor terminal-to-wire

connection.

•Damaged harness – Inspect the wiring for damage.

•Restricted air intake system – Check for a possible

collapsed air intake duct, restricted air filter element,

or foreign objects blocking the air intake system.

•Throttle body – Check for objects blocking the IAC

passage or throttle bore, excessive deposits in the

IAC passage and on the IAC pintle, and excessive

deposits in the throttle bore and on the throttle plate.

•Large vacuum leak – Check for a condition that

causes a large vacuum leak, such as an incorrectly

installed or faulty PCV valve or a disconnected brake

booster hose.

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.

DTC P1508 – IAC System Low RPM

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Start the engine.

2. Turn all accessories “OFF”(A/C, rear defroster,

etc).

3. Using a Tech 2, command RPM up to 1500, down

to 500, and the up to 1500 while monitoring the

“Engine Speed” on the Tech 2.

NOTE: This Tech 2 command may cause the engine

to “cut out” when RPM goes above 1500. If this

occurs, the “cutting out” will stop when the Tech 2

command for the test is discontinued, or if the Tech 2

command is changed to less than 1500 RPM.

Does the “Engine Speed” remain within the specified

value of the “Desired Idle” for each RPM command? ± 50 RPM

No trouble

found. Go to

Diagnostic Aids Go to Step 3

3 1. Disconnect the IAC.

2. Install IAC Node Light 5-8840-2312-0 or

equivalent.

3. With the engine running, command RPM up to

1500, down to 500, and then up to 1500 while

observing the node light.

NOTE: This Tech 2 command may cause the engine

to “cut out” when RPM goes above 1500. If this

occurs, the “cutting out” will stop when the Tech 2

command for the test is discontinued, or if the Tech 2

command is changed to less than 1500 RPM.

Does each node light cycle red and green

(never“OFF”)? — Go to Step 5 Go to Step 4

4 1. Check the following circuits for an open, short to

voltage, short ground, or poor connections at the

PCM:

• IAC “A” Low.

• IAC “A” High.

• IAC “B” Low.

• IAC “B” High.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 8

5 Visually/physically inspect for following conditions:

•Restricted air intake system. Check for a possible

collapsed air intake duct, restricted air filter

element, or foreign objects blocking the air intake

system.

•Throttle body. Check for objects blocking the IAC

passage or throttle bore, excessive deposits in the

IAC passage and on the IAC pintle, and excessive

deposits in the throttle bore and on the throttle

plate.

Do any of the above require a repair?—

Refer to

appropriate

section for

on-vehicle

serviceGo to Step 6

6 1.Check for a poor connection at the IAC harness

connector.

2.If a problem is found, replace faulty terminals as

necessary.

Was a problem found?—Verify repairGo to Step 7

7 Replace the IAC valve.

Is the action complete?—Verify repair—

8 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P1509 IAC System High RPM

T321115

Circuit Description

The powertrain control module (PCM) controls engine

idle speed by adjusting the position of the idle air control

(IAC) motor pintle. The IAC is a bi-directional stepper

motor driven by two coils. The PCM applies current to

the IAC coils in steps (counts) to extend the IAC pintle

into a passage in the throttle body to decrease air flow.

The PCM reverses the current to retract the pintle,

increasing air flow. This method allows highly accurate

control of idle speed and quick response to changes in

engine load. If the PCM detect a condition where too

high of an idle speed is present and the PCM is unable

to adjust idle speed by increasing the IAC counts, DTC

P1509 will set, indicating a problem with the idle control

system.

Conditions for Setting the DTC

• No Tech 2 test is being run.

• None of these DTCs are set: TP sensor, VSS, ECT,

EGR, fuel system, MAF, MAP, IAT, canister purge,

injector control or ignition control.

• Barometric pressure is above 75 kPa.

• Engine coolant temperature is above 50°C (120°F).

• Engine speed is more than 100-200 RPM lower than

desired idle, based upon coolant temperature.

• The engine has been running for at least 125

seconds.

• Vehicle speed is less than 1 mph.

• Canister purge duty cycle is above 10%.

• Ignition voltage is between 9.5 volts and 16.7 volts.

• Engine speed is lower than desired idle.

• All of the above conditions are met for 5 seconds.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator

lamp (MIL) after the second consecutive trip in which

the fault is detected.

• The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

Conditions for Clearing the MIL/DTC

• DTC P1509 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Poor connection at PCM or IAC motor – Inspect

harness connectors for backed-out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, and poor terminal-to-wire

connection.

•Damaged harness – Inspect the wiring for damage.

•Vacuum leak – Check for a condition that causes a

vacuum leak, such as disconnected or damaged

hoses, leaks at the EGR valve and the EGR pipe to

the intake manifold, leaks at the throttle body, faulty

or incorrectly installed PCV valve, leaks at the intake

manifold, etc.

•Throttle body – Check for sticking throttle plate. Also

inspect the IAC passage for deposits or objects which

keep the IAC pintle from fully extending.

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.

DTC P1509 – IAC System High RPM

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Start the engine.

2. Turn all accessories “OFF” (A/C, rear defroster,

etc.).

3. Using a Tech 2, command RPM up to 1500, down

to 500, and then up to 1500 while monitoring

“Engine Speed” on the Tech 2.

NOTE: This Tech 2 command may cause the engine

to “cut out” when RPM goes above 1500. If this

occurs, the “cutting out” will stop when the Tech 2

command for the test is discontinued, or if the Tech 2

command is changed to less than 1500 RPM.

Does the “Engine Speed” remain within the specified

value of “Desired Idle” for each RPM command? ± 50 RPM

No trouble

found. Go to

Diagnostic Aids Go to Step 3

3 1. Disconnect the IAC.

2. Install IAC Node Light 5-8840-2312-0 or

equivalent.

3. With the engine running, command RPM up to

1500, down to 500, and then up to 1500 while

observing the node light.

NOTE: This Tech 2 command may cause the engine

to “cut out” when RPM goes above 1500. If this

occurs, the “cutting out” will stop when the Tech 2

command for the test is discontinued, or if the Tech 2

command is changed to less than 1500 RPM.

Does each node light cycle red and green

(never“OFF”)? — Go to Step 5 Go to Step 4

4 1. Check the following circuits for an open, short to

voltage, short ground, or poor connections at the

PCM:

• IAC “A” Low

• IAC “A” High

• IAC “B” Low

• IAC “B” High

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 8

5 Visually/physically inspect for following conditions:

•Vacuum leaks.

•Throttle plate or throttle shaft for binding.

•Accelerator and cruise control cables for being

misadjusted or for binding.

•Faulty, missing, or incorrectly installed PCV valve.

Do any of the above require a repair?—

Refer to

appropriate

section for

on-vehicle

serviceGo to Step 6

6 1.Check for a poor connection at the IAC harness

connector.

2.If a problem is found, replace faulty terminals as

necessary.

Was a problem found?—Verify repairGo to Step 7

7 Replace the IAC valve.

Is the action complete?—Verify repair—

8 Replace the PCM.

Important: The replacement PCM must be

programmed, Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P1618 Serial Peripheral Interface (SPI) PCM Interprocessor

Communication Error

Circuit Description

The serial peripheral interface (SPI) communication is

used internally by the PCM to send messages between

the engine processor and the automatic transmission

processor. Included in each message sent between the

two-processors is a checksum of the message. Both

the engine processor and automatic transmission

processor will compare this check sum value with the

calculated value. If the checksums don't match, the

processor will view the new data as being corrupted and

ignore the values. The processor will then use the

previous message. The receiving processor will then

send a message to the sending processor informing it

that it's last message was corrupted.

Conditions for Setting the DTC

•Battery voltage is above 9.0 V for 2 seconds.

•The PCM detects an internal program fault (check

sum of data communications error).

•Check sum fault present for 3 out 6 seconds.

•No TCM resets for 2 seconds.

Action Taken When the DTC Sets

•The PCM will flash the “Check Trans” lamp the first

time the fault is detected.

•The PCM will store conditions which were present

when the DTC was set as Freeze Frame and in the

Failure Records data.

•The automatic transmission will operate in the “safety

mode” to protect the mechanical parts of the

transmission. Shift quality and/or gear changes may

not be normal.

Conditions for Clearing the MIL/DTC

•DTC P1618 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

DTC P1618 – Serial Peripheral Interface (SPI) PCM Interprocessor

Communication Error

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed?—Go to Step 2

Go to OBD

System Check

2 Is the EEPROM calibration the latest version

available?—Go to Step 4 Go to Step 3

3 Reprogram the PCM with the latest available

calibrations.

Does DTC 1618 re-appear when the OBD System

Check is repeated?—Go to Step 4

Repair

completed

4 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Diagnostic Trouble Code (DTC) P1625 PCM Unexpected Reset

Circuit Description

The powertrain control module (PCM) monitors

unexpected PCM reset. This will not turn on MIL light

on, only records code DTC P1625.

Conditions for Setting the DTC

• Clock or COP reset.

Action Taken When the DTC Sets

• The PCM will not illuminate the malfunction indicator

lamp (MIL).

• The PCM will store conditions which were present

when the DTC was set as Failure Records only. This

information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

• DTC P1625 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• P1625 alone stored does not need diagnosis. Clear

DTC code.

Diagnostic Trouble Code (DTC) P1626 - No Response From Immobiliser

4JX1 ICU Circuit.CDR

Circuit Description

The PCM decides whether that is an abnomality in the

Immobiliser control system. DTC P1626 or are recorded

by the PCM when there is no response from

Immobiliser.

Condition for Setting the DTC

•No signal from Immobiliser Control Unit to PCM

Action Taken When the DTC sets

•Rapid flashing of the MIL (“CHECK ENGINE” lamp).

•The Engine does not start.

Condition for Clearing the MIL/DTC

•Clear DTC information with TECH 2. Refer to Section

0C TECH 2 Diagnosis

Diagnostic Aids

Check for the following conditions:

• Poor connection at ECM and ImmobiliserInspect

harness connectors for backed out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, and poor terminal to wire

connection.

• Damaged harness-Inspect the wiring harness for

damage, If the harness appears to be OK, disconnect

the PCM and Immobiliser, turn the ignition “ON" and

observe a voltmeter connected to the suspect driver

circuit at the ECM and Immobiliser harness connector

while moving connectors and wiring harnesses

relates to the MIL. A change in voltage will indicate

the location of the fault.

Immobiliser

Relay

Powertrain

Control

Module

Immobiliser

Control

Unit

Battery +ve

(Fuse C16)

Switched 12V

(Fuse C8)

Ground

Vehicle Speed

Signal

“Check Engine”

Lamp

DLC

DIAGNOSTIC

CONNECTION

DLC PIN 7

Antenna

Coil

0.5 YELLOW

0.5 RED/WHITE

0.5 LIGHT GREEN/WHITE

0.85 RED/YELLOW

0.5 PURPLE

0.5 WHITE/BLACK

0.5 GREEN/YELLOW

0.5 BLUE

0.5 BLACK

0.5 ORANGE/BLACK

2A-13

Ignition

Switch

DTC P1626-No Response From Immobiliser

StepActionValue(s)YesNo

1Was the “On-Board Diagnostic (OBD) system Check"

performed? — Go to Step 2

Go to OBD

system check

2Using the Tech2 system selection menu, select ‘Body

- Immobiliser - DTC’ function.

Does the Tech2 display B**** appear?

—

Refer to

Section 11

“Engine

Immobiliser

System" Go to Step 3

3Using the Tech2 system selection menu, select

‘Powertrain - DTC’ function.

Does the Tech2 display a DTC P1626 as

“PRESENT”?

— Go to Step 4

Refer to

Diagnostic Aids

if DTC P1626 is

displayed as

“NOT

PRESENT”

4Check the PCM and ICU harness and connectors for:

1.Backed out terminals, improper mating, broken

locks, improperly formed or damaged terminals,

and poor terminal to wire connection.

2.Damaged harness - Inspect the wiring harness for

damage.

If a problem found, repair as necessary.

Was a problem found? — Verify repairGo to Step 5

5With a DMM, check for an open circuit or a short to

voltage circuit between PCM pin D7 and ICU pin 6

(white/black wire).

If a problem found, repair as necessary.

Was a problem found? — Verify repair Go to Step 6

6Replace the ECM.

Important: The replacement PCM must be

programmed. Refer to Section 0C-1 - Service

Programming System.

Important: Refer to Section 11 - Engine Immobiliser

System for the Immobiliser Programming procedure.

Important: Ensure the latest software program is

downloaded to the ECM.

Is the action complete?

— Verify repair —

Diagnostic Trouble Code (DTC) P1631 - Received Response Was Not Correct

060RA00003

Circuit Description

The PCM decides whether that is an abnomality in the

Immobiliser control system. A DTC P1631 is recorded

by the ECM when received response was not correct.

Condition for Setting the DTC

•Received response was not correct.

Action Taken When the DTC Sets

•Rapid flashing of the MIL (“CHECK ENGINE” lamp).

•The Engine does not start.

Condition for Clearing the MIL/DTC

•Clear DTC information with TECH 2. Refer to Section

0C TECH 2 Diagnosis

Diagnostic Aids

Check for the following conditions:

• Poor connection at PCM and Immobiliser - Inspect

harness connectors for backed out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, and poor terminal to wire

connection.

• Damaged harness - Inspect the wiring harness for

damage, If the harness appears to be OK, disconnect

the PCM and Immobiliser, turn the ignition “ON" and

observe a voltmeter connected to the suspect driver

circuit at the PCM and Immobiliser harness connector

while moving connectors and wiring harnesses

relates to the MIL. A change in voltage will indicate

the location of the fault.

Immobiliser

Relay

Powertrain

Control

Module

Immobiliser

Control

Unit

Battery +ve

(Fuse C16)

Switched 12V

(Fuse C8)

Ground

Vehicle Speed

Signal

“Check Engine”

Lamp

DLC

DIAGNOSTIC

CONNECTION

DLC PIN 7

Antenna

Coil

0.5 YELLOW

0.5 RED/WHITE

0.5 LIGHT GREEN/WHITE

0.85 RED/YELLOW

0.5 PURPLE

0.5 WHITE/BLACK

0.5 GREEN/YELLOW

0.5 BLUE

0.5 BLACK

0.5 ORANGE/BLACK

2 A-13

Ignition

Switch

DTC P1631 - Received Response Was Not Correct

StepActionValue(s)YesNo

1Was the “On-Board Diagnostic (OBD) system Check"

performed? — Go to Step 2

Go to OBD

system check

2Using the Tech2 system selection menu, select ‘Body

- Immobiliser - DTC’ function.

Does the Tech2 display B**** appear?

—

Refer to

Section 11

“Engine

Immobiliser

System" Go to Step 3

3Using the Tech2 system selection menu, select

‘Powertrain - DTC’ function.

Does the Tech2 display a DTC P1631 as

“PRESENT”?

— Go to Step 4

Refer to

Diagnostic Aids

if DTC P1631 is

displayed as

“NOT

PRESENT”

4Check the ECM and ICU harness and connectors for:

1.Backed out terminals, improper mating, broken

locks, improperly formed or damaged terminals,

and poor terminal to wire connection.

2.Damaged harness - Inspect the wiring harness for

damage.

If a problem found, repair as necessary.

Was a problem found?

Verify repairGo to Step 5

5Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Section 0C-1 - Service

Programming System.

Important: Refer to Section 11 - Engine Immobiliser

System for the Immobiliser Programming procedure.

Important: Ensure the latest software program is

downloaded to the PCM.

Is the action complete?

— Verify repair —

Diagnostic Trouble Code (DTC) P1640 Driver-1-Input High Voltage

Circuit Description

Output driver modules (ODMs) are used by the

powertrain control module (PCM) to turn “ON” many of

the current-driven devices that are needed to control

various engine and transmission functions. Each ODM

is capable of controlling up to 7 separate outputs by

applying ground to the device which the PCM is

commanding “ON.”

Unlike the Quad Driver Modules (QDMs) used in prior

model years, ODMs have the capability of diagnosing

each output circuit individually. DTC P1640 set

indicates an improper voltage level has been detected

on an ODM output.

Since A/C is an option, No A/C will cause the air

conditioning clutch relay output to always fault. If a fault

is seen on the air conditioning clutch relay output, it will

not be logged as a fault until the A/C request input

interrupts a high voltage, indicating that A/C has been

installed.

Conditions for Setting the DTC

• Ignition “ON.”

• Engine running.

• No DTC 1618.

• Ignition voltage is above 13.2 volts for 4 seconds.

• Output voltage does not equal ignition voltage when

output is “OFF” or output voltage is not less than 1

volt when output is “ON.”

• Above conditions occur for at least 1 second.

Action Taken When the DTC Sets

• The PCM will not illuminate the malfunction indicator

lamp (MIL).

• The PCM will store conditions which were present

when the DTC was set as Failure Records only. This

information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

• DTC P1640 can be cleared by using the Tech 2

“Clear Info” function or by disconnecting the PCM

battery feed.

Diagnostic Aids

Check for the following conditions:

• Poor connection at PCM – Inspect harness

connectors for backed-out terminals, improper

mating, broken locks, improperly formed or damaged

terminals, and poor terminal-to-wire connection.

• Damaged harness – Inspect the wiring harness for

damage, If the harness appears to be OK,

disconnect the PCM, turn the ignition “ON” and

observe a voltmeter connected to the suspect driver

circuit at the PCM harness connector while moving

connectors and wiring harnesses relates to the MIL.

A change in voltage will indicate the location of the

fault.

• Poor connection at component – Examine for

damaged connectors, unplugged connector, or

damaged terminals at the following locations:

Instrument cluster harness, canister purge solenoid,

A/C clutch relay. An open ignition feed circuit at any

of these components will cause DTC P1640 to be set.

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.

The following PCM pins are controlled by output driver

modules (ODMs):

• A13 – “Check Engine Lamp”

• A14 – "Check Trans"

• B14 – A/C Clutch

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

6. The Tech 2 Driver Module Status indicates the PCM

pin that is affected.

11. The Tech 2 may indicate “short circuit” even when

the problem is an open circuit. The cause of an

open circuit may be in the component itself-lamp,

purge, solenoid, or A/C compressor relay.

13. A short to ground on the ignition side of the

component will blow the fuse. Since the fuse was

checked in Step 4, a short to ground would be

between the affected component and the PCM.

DTC P1640 – Driver-1-Input High Voltage

StepActionValue(s)YesNo

1 Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Ignition “ON,”engine “OFF.”

2. Install the Tech 2.

3. Review and record Tech 2 Failure Records data.

4. Operate the vehicle within Failure Records

conditions as noted.

5. Use the Tech 2 to indicate DTC P1640.

Does the Tech 2 indicate DTC P1640? — Go to Step 3 —

3 Check the fuse for the driver circuit that was shown as

faulty.

Was the fuse blown? — Go to Step 4 Go to Step 5

4 1. Check for a short to ground between the fuse and

the affected component.

2. Replace the fuse after making any necessary

repairs.

Is the action complete? — Verify repair —

5 Disconnect the PCM connector for the affected driver

circuit.

Is there any damage to the PCM pin or connector? — Go to Step 6 Go to Step 7

6 Repair the damaged pin or terminal.

Is the action complete? — Verify repair —

7 Were either of the lamp circuits for “Check Engine” or

“Check Trans.” indicated as faulty by the Tech 2? — Go to Step 8 Go to Step 14

8 1. Leave the PCM connector for the lamp driver

circuit disconnected.

2. Ignition “ON.”

3. Using a DVM, check the voltage at the PCM

connector for the affected lamp driver circuit.

Was the voltage equal to the specified value? B+ Go to Step 16 Go to Step 9

9 1. Ignition “ON.”

2. Check for battery voltage at the fuse for the

affected lamp circuit.

Was battery voltage available at the fuse? — Go to Step 11 Go to Step 10

10 Repair the open circuit between the ignition switch

and the fuse.

Is the action complete? — Verify repair —

11 1. Ignition “OFF.”

2. Disconnect the PCM connector for the affected

driver terminal.

3. Connect an ohmmeter between a good ground

and the PCM connector for the affected driver.

Did the ohmmeter indicate continuity? — Go to Step 12 Go to Step 13

12 Repair the short to ground between the affected

component and its PCM driver terminal.

Is the action complete? — Verify repair —

13 Repair the open circuit between the fuse and the PCM

driver terminal for the affected circuit.

Is the action complete? — Verify repair —

14 1.Connect the PCM.

2.Start the engine and let it idle.

3.Backprobe the affected terminal at the PCM with a

DVM.

Was the voltage equal to the specified value?+BGo to Step 16Go to Step 15

15 1.Run the engine at idle.

2.Check for battery voltage at the fuse for the

affected circuit.

Was battery voltage available at the fuse?—Go to Step 11Go to Step 10

16 Replace the PCM.

Important: The replacement PCM must be

programmed. Refer to Sections OC1 Service

Programming System and 11A1 6VE1 Immobiliser.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Diagnostic Trouble Code (DTC) P1648 - Received Incorrect Security Code

060RA00003

Circuit Description

The PCM decides whether that is an abnomality in the

Immobiliser control system. A DTC P1648 is recorded

by the PCM when it receives an incorrect security code.

Condition for Setting the DTC

•Received security code is incorrect.

Action Taken When the DTC Sets

•Rapid flashing of the MIL (“CHECK ENGINE” lamp).

•The Engine does not start.

Condition for Clearing the MIL/DTC

•Clear DTC information with TECH 2. Refer to Section

0C TECH 2 Diagnosis

Diagnostic Aids

Check for the following conditions:

• Poor connection at PCM and Immobiliser - Inspect

harness connectors for backed out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, and poor terminal to wire

connection.

• Damaged harness - Inspect the wiring harness for

damage, If the harness appears to be OK, disconnect

the PCM and Immobiliser, turn the ignition “ON" and

observe a voltmeter connected to the suspect driver

circuit at the PCM and Immobiliser harness connector

while moving connectors and wiring harnesses

relates to the MIL. A change in voltage will indicate

the location of the fault.

Immobiliser

Relay

Powertrain

Control

Module

Immobiliser

Control

Unit

Battery +ve

(Fuse C16)

Switched 12V

(Fuse C8)

Ground

Vehicle Speed

Signal

“Check Engine”

Lamp

DLC

DIAGNOSTIC

CONNECTION

DLC PIN 7

Antenna

Coil

0.5 YELLOW

0.5 RED/WHITE

0.5 LIGHT GREEN/WHITE

0.85 RED/YELLOW

0.5 PURPLE

0.5 WHITE/BLACK

0.5 GREEN/YELLOW

0.5 BLUE

0.5 BLACK

0.5 ORANGE/BLACK

2 A-13

Ignition

Switch

DTC P1648 - Received Incorrect Security Code

StepActionValue(s)YesNo

1Was the “On-Board Diagnostic (OBD) system Check"

performed? — Go to Step 2

Go to OBD

system check

2 Using the Tech2 system selection menu, select ‘Body

- Immobiliser - DTC’ function.

Does the Tech2 display B**** appear?

—

Refer to

Section 11

“Engine

Immobiliser

System" Go to Step 3

3 Using the Tech2 system selection menu, select

‘Powertrain - DTC’ function.

Does the Tech2 display a DTC P1648 as

“PRESENT”?

— Go to Step 4

Refer to

Diagnostic Aids

if DTC P1648 is

displayed as

“NOT

PRESENT”

4 Check the PCM and ICU harness and connectors for:

1. Backed out terminals, improper mating, broken

locks, improperly formed or damaged terminals,

and poor terminal to wire connection.

2. Damaged harness - Inspect the wiring harness for

damage.

If a problem found, repair as necessary.

Was a problem found? Verify repair Go to Step 5

5 Recheck the security code.

Is the action complete? — Verify repair —

Diagnostic Trouble code (DTC) P1649 - Security Code & Security Key Not Programmed

060RA00003

Circuit Description

The PCM decides whether that is an abnomality in the

Immobiliser control system. DTC P1649 are recorded

by the PCM when security code & secret key not

programmed.

Condition for Setting the DTC

•Security code & secret key not programmed.

Action Taken When the DTC Sets

•Rapid flashing of the MIL (“CHECK ENGINE” lamp).

•The Engine does not start.

In case replacement ECM/ECM, Action

Taken When the DTC Sets

•Rapid flashing of the MIL (“CHECK ENGINE” lamp).

•The Engine does not start.

Condition for Clearing the MIL/DTC

•Clear DTC information with TECH 2. Refer to Section

0C TECH 2 Diagnosis

Diagnostic Aids

Check for the following conditions:

• Poor connection at PCM and ImmobiliserInspect

harness connectors for backed out terminals,

improper mating, broken locks, improperly formed or

damaged terminals, and poor terminal to wire

connection.

• Damaged harness-Inspect the wiring harness for

damage, If the harness appears to be OK, disconnect

the PCM and Immobiliser, turn the ignition “ON" and

observe a voltmeter connected to the suspect driver

circuit at the PCM and Immobiliser harness connector

while moving connectors and wiring harnesses

relates to the MIL.

A change in voltage will indicate the location of the

fault.

Immobiliser

Relay

Powertrain

Control

Module

Immobiliser

Control

Unit

Battery +ve

(Fuse C16)

Switched 12V

(Fuse C8)

Ground

Vehicle Speed

Signal

“Check Engine”

Lamp

DLC

DIAGNOSTIC

CONNECTION

DLC PIN 7

Antenna

Coil

0.5 YELLOW

0.5 RED/WHITE

0.5 LIGHT GREEN/WHITE

0.85 RED/YELLOW

0.5 PURPLE

0.5 WHITE/BLACK

0.5 GREEN/YELLOW

0.5 BLUE

0.5 BLACK

0.5 ORANGE/BLACK

2 A-13

Ignition

Switch

DTC P1649 - Security Code & Secret Key Not Programmed

StepActionValue(s)YesNo

1Was the “On-Board Diagnostic (OBD) system Check"

performed? — Go to Step 2

Go to OBD

system check

2Using the Tech2 system selection menu, select Body

function.

Does the Tech2 display a DTC B****?

—

Refer to

Section11

“Engine

Immobiliser

System" Go to Step 3

3Using the Tech2 system selection menu, select

‘Powertrain - DTC’ function.

Does the Tech2 display a DTC P1649 as

“PRESENT”?

— Go to Step 4

Refer to

Diagnostic Aids

if DTC P1649 is

displayed as

“NOT

PRESENT”

4Replace the PCM.

Important: The replacement ECM must be

programmed. Refer to Section 0C-1 - Service

Programming System.

Important: Refer to Section 11 - Engine Immobiliser

System for the Immobiliser Programming procedure.

Important: Ensure the latest software program is

downloaded to the ECM.

Is the action complete?

— Go to Step 5 —

5 Does the Tech2 display a DTC P1649? — Go to Step 3 Verify repair

Symptom Diagnosis

Preliminary Checks

Before using this section, perform the “On-Board

Diagnostic (OBD) System Check” and verify all of the

following items:

•The Powertrain Control Module (PCM) and

malfunction indicator lamp (MIL) (Service Engine

Soon lamp) are operating correctly.

•There are no DTC(s) stored.

•Tech 2 data is within normal operating range. Refer

to Typical Scan Data Values.

•Verify the customer complaint and locate the correct

symptom in the table of contents. Perform the

procedure included in the symptom chart.

Visual/Physical Check

Several of the symptom procedures call for a careful

visual/physical check. This can lead to correcting a

problem without further checks and can save valuable

time.

This check should include the following items:

•PCM grounds for cleanliness, tightness and proper

location.

•Vacuum hoses for splits, kinks, and proper

connections, as shown on the “Vehicle Emission

Control Information” label. Check thoroughly for any

type of leak or restriction.

•Air intake ducts for collapsed or damaged areas.

•Air leaks at throttle body mounting area, mass air flow

(MAF) sensor and intake manifold sealing surfaces.

•Ignition wires for cracking, hardness, and carbon

tracking.

•Wiring for proper connections, pinches and cuts.

Intermittents

Important: An intermittent problem may or may not

turn on the malfunction indicator lamp (MIL) or store a

DTC. DO NOT use the Diagnostic Trouble Code (DTC)

charts for intermittent problems. The fault must be

present to locate the problem.

Most intermittent problems are caused by faulty

electrical connections or wiring. Perform a careful

visual/physical check for the following conditions:

•Poor mating of the connector halves or a terminal not

fully seated in the connector (backed out).

•Improperly formed or damaged terminal.

•All connector terminals in the problem circuit should

be carefully checked for proper contact tension.

•Poor terminal-to-wire connection. This requires

removing the terminal from the connector body to

check.

Road test the vehicle with a J 39200 Digital Multimeter

connected to a suspected circuit. An abnormal voltage

when the malfunction occurs is a good indication that

there is a fault in the circuit being monitored.

Use Tech 2 to help detect intermittent conditions. Tech

2s have several features that can be used to locate an

intermittent condition. Use the following feature to find

intermittent faults:

•Using Tech 2's “Freeze Frame” buffer or “Failure

Records” buffer can aid in locating an intermittent

condition. Review and record the information in the

freeze frame or failure record associated with the

intermittent DTC being diagnosed. The vehicle can

be driven within the conditions that were present

when the DTC originally set.

To check for loss of diagnostic code memory,

disconnect the MAP sensor and idle the engine until the

MIL (Service Engine Soon lamp) comes on. DTC

P0107 should be stored and kept in memory when the

ignition is turned “OFF.” If not, the PCM is faulty. When

this test is completed, make sure that you clear the DTC

P0107 from memory.

Intermittent MIL illumination with no stored DTC may be

caused by the following:

•Ignition coil shorted to ground and arcing at ignition

wires or plugs.

•MIL wire to PCM shorted to ground.

•Poor PCM grounds. Refer to the PCM wiring

diagrams.

Check for improper installation of electrical options such

as lights, cellular phones, etc. Route ignition coil wiring

away from the ignition coils. Check all wires from the

PCM to the ignition coil for poor connections.

Check for an open diode across the A/C compressor

clutch and check for other open diodes (refer to wiring

diagrams in Electrical Diagnosis).

If problem has not been found, refer to PCM Connector

Symptom tables.

Hard Start Symptom

StepActionValue(s)YesNo

1 DEFINITION: Engine cranks, but does not start for a

long time. Does eventually run, or may start but

immediately stalls.

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3

3 Was a visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 Check engine coolant temperature (ECT) sensor for

shift in value. After 8 hours with the hood up and the

engine not running, connect Tech 2. With the ignition

“ON” and the engine not running, compare engine

coolant temperature to intake air temperature.

Are ECT and IAT within the specified value of each

other? ± 5°C (± 9°F) Go to Step 8 Go to Step 5

5 1. Using Tech 2, display the engine coolant

temperature and note the value.

2. Check the resistance of the engine coolant

temperature sensor.

3. Refer to Engine Coolant Temperature Sensor

Temperature vs. Resistance chart on DTC P0118

Diagnostic Support for resistance specifications.

Is the resistance value near the resistance for the

temperature noted? — Go to Step 7 Go to Step 6

6 Replace the ECT sensor.

Is the action complete? — Verify repair —

7 Locate and repair high resistance or poor connection

in the ECT signal circuit or the ECT sensor ground.

Is the action complete? — Verify repair —

8 1. Check for a faulty, plugged, or incorrectly installed

PCV valve.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

9 1. Check for water- or alcohol-contaminated fuel.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 10

10 1. Perform the procedure in Fuel System Pressure

Test.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 11

11 1. Check for proper ignition voltage output with spark

tester 5-8840-0383-0. Refer to Electric Ignition

System for procedure.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 12

12 1. Remove spark plugs. Check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits.

1. If spark plugs are fuel or oil fouled, the cause of

the fouling must be determined before replacing

the spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 13

13 1. Check for a loose ignition coil ground.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 14

14 1. Remove the ignition coils and check the ignition

coils for cracks or carbon tracking.

2. If a problem is found, replace affected coil(s) as

necessary.

Was a problem found? — Verify repair Go to Step 15

15 1. Check IAC operation. Perform the procedure in

the DTC P0506, Step 6 diagnostic table.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 16

16 1. Check for the following engine mechanical

problems (refer to Engine Mechanical):

• Low compression

• Leaking cylinder head gaskets

• Worn or incorrect camshaft

• Camshaft drive belt slipped or stripped

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 17

17 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

• Visual/physical inspection

• Tech 2 data

• Freeze Frame data/Failure Records buffer

• All electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Te ch n ic al

Assistance

Step Action Value(s) Yes No

Surges and/or Chuggles Symptom

StepActionValue(s)YesNo

1 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.

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3

3 Was a visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 Be sure that the driver understands transmission

torque converter clutch and A/C compressor operation

as explained in the owner's manual.

Inform the customer how the TCC and the A/C clutch

operate.

Is the customer experiencing a normal condition? — System OK Go to Step 5

5 1. Check the the fuel control heated oxygen sensors

(HO2S, B1S1 and B2S1). The fuel control heated

oxygen sensors (HO2S) should respond quickly to

different throttle positions. If they don't, check

them for silicon or other contaminants from fuel or

use of improper RTV sealant. The sensors may

have a white powdery coating.

Silicon contamination causes a high but false

HO2S signal voltage (rich exhaust indication).

The PCM will then reduce the amount of fuel

delivered to the engine, causing a severe

driveability problem. For more information, refer

to Powertrain Control Module (PCM) and Sensors.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 6

6 1. Check the fuel pressure. Refer to Fuel System

Pressure Test.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 7

7 Monitor the long term fuel trim on Tech 2.

Is the long term fuel trim significantly in the negative

range (rich condition)? — Go to Step 8 Go to Step 9

8 1. Check items that can cause the engine to run rich.

Refer to Diagnostic Aids in DTC P0172 Diagnostic

Support.

2. If a problem is found, repair as necessary.

Was a problem found? — Go to Step 10 Verify repair

9 1. Check items that can cause the engine to run

lean. Refer to Diagnostic Aids in DTC P0171.

2. If a problem is found, repair as necessary.

Was a problem found? — Go to Step 10 Verify repair

10 1. Check for proper ignition voltage output with spark

tester J 26792 (ST-125).

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 11

11 1. Check for a loose ignition coil ground.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 12

12 1. Check the ignition coils for cracks or carbon

tracking.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 13

13 1. Remove the spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits.

1. If spark plugs are fuel or oil fouled, the cause of

the fouling must be determined before replacing

the spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 14

14 1. Check the injector connections.

2. If any of the injector connectors are connected to

an incorrect cylinder, correct as necessary.

Was a problem found? — Verify repair Go to Step 15

15 1. Check PCM grounds for the cleanliness, tightness

and proper locations.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 16

16 1. Check MAF sensor connections.

2. If a problem is found, replace the faulty terminals

as necessary. Refer to Electrical Diagnosis for

wiring repair procedures.

Was a problem found? — Verify repair Go to Step 17

17 1. Visually/physically check vacuum hoses for splits,

kinks, and proper connections and routing as

shown on the “Vehicle Emission Control

Information” label.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 18

18 1. Check the exhaust system for possible restriction:

• Inspect the exhaust system for damaged or

collapsed pipes.

• Inspect the muffler for heat distress or possible

internal failure.

• Check for a possible plugged three-way

catalytic converter by checking the exhaust

system back pressure. Refer to Restricted

Exhaust System Check.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 19

Step Action Value(s) Yes No

19 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

• Visual/physical inspection

• Tech 2 data

• Freeze Frame data/Failure Records buffer

• All electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Te ch n ic al

Assistance

Step Action Value(s) Yes No

Lack of Power, Sluggish or Spongy Symptom

StepActionValue(s)YesNo

1 DEFINITION:

Engine delivers less than expected power. Little or no

increase in speed when accelerator pedal is pushed

down part-way.

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3

3 Was a visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 1. Remove and check the air filter element for dirt or

restrictions. Refer to Air Intake System in

ON-Vehicle Service.

2. Replace the air filter element if necessary.

Was a repair required? — Verify repair Go to Step 5

5 1. Check for low fuel pressure. Refer to Fuel System

Pressure Test.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 6

6 1. Check for water- or alcohol-contaminated fuel.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 7

7 1. Using Tech 2, monitor the knock sensor (KS)

system for excessive spark retard activity. Refer

to Knock Sensor (KS) System.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 8

8 1. Check for proper ignition voltage output with spark

tester J 26792 (ST-125).

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

9 1. Remove the spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits.

2. If spark plugs are gas or oil fouled, the cause of

the fouling must be determined before replacing

the spark plugs.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 10

10 1. Check the ignition coils for cracks or carbon

tracking.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 11

11 1. Check the PCM grounds for the cleanliness,

tightness and proper locations. Refer to the PCM

wiring diagrams in Electrical Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 12

12 1. Check the exhaust system for possible restriction:

• Inspect the exhaust system for damaged or

collapsed pipes.

• Inspect the muffler for heat distress or possible

internal failure.

• Check for a possible plugged three-way

catalytic converter by checking the exhaust

system back pressure. Refer to Restricted

Exhaust System Check.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 13

13 1. Check the torque converter clutch (TCC) for

proper operation. Refer to 4L30-E Transmission

Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 14

14 1. Check for an engine mechanical problem. Check

for low compression, incorrect or worn camshaft,

loose timing belt, etc. Refer to Engine

Mechanical.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 15

15 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

• Visual/physical inspection

• Tech 2 data

• Freeze Frame data/Failure Records buffer

• All electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Te ch n ic al

Assistance

Step Action Value(s) Yes No

Detonation/Spark Knock Symptom

StepActionValue(s)YesNo

1 DEFINITION:

A mild to severe ping, usually worse under

acceleration. The engine makes sharp metallic

knocks that change with throttle opening.

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3

3 Was a visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 If Tech 2 readings are normal (refer to Typical Scan

Values) and there are no engine mechanical faults, fill

the fuel tank with a known quality gasoline that has a

minimum octane rating of 87 and re-evaluate the

vehicle performance.

Is detonation present? — Go to Step 5 Verify repair

5 1. Check the transmission range switch circuit. Use

Tech 2 and be sure Tech 2 indicates that the

vehicle is in drive with the gear selector in drive or

overdrive.

2. If a problem is found, diagnose and repair the

transmission range switch as necessary (refer to

4L30-E Automatic Transmission Diagnosis).

Was a problem found? — Verify repair Go to Step 6

6 1. Check TCC operation. Refer to 4L30-E

Transmission Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 7

7 1. Check for obvious overheating problems:

• Low engine coolant.

• Restricted air flow to radiator, or restricted water

flow through radiator.

• Correct coolant solution should be a 50/50 mix

of approved HN2217 Coolant and water. Refer

to Engine Cooling.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 8

8 1. Check fuel pressure. Refer to Chart Fuel System

Pressure Test.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

9 1. Check items that can cause an engine to run lean

(long term fuel trim significantly in the positive

range). For a lean condition, refer to Diagnostic

Aids in DTC P0171 Diagnostic Support.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 10

Rough, Unstable, or Incorrect Idle, Stalling Symptom

10 1.Spark plugs for proper heat range. Refer to

General Information.

2.If incorrect spark plugs are installed, replace spark

plugs as necessary.

Did any spark plugs require replacement?—Verify repairGo to Step 11

11 1.Remove excessive carbon buildup with a top

engine cleaner. Refer to instructions on the top

engine cleaner can.

2.Re-evaluate vehicle performance.

Is detonation still present?—Go to Step 12 Verify repair

12 1.Check for an engine mechanical problem.

Perform a cylinder compression check. Refer to

Engine Mechanical.

2.If a problem is found, repair as necessary.

Was a problem found?—Verify repairGo to Step 13

13 1.Review all diagnostic procedures within this table.

2.If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

•Visual/physical inspection

•Tech 2 data

•Freeze Frame data/Failure Records buffer

•All electrical connections within a suspected

circuit and/or system.

3.If a problem is found, repair as necessary.

Was a problem found?—Verify repair

Contact

Technical

Assistance

StepActionValue(s)YesNo

1 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.

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Go to Step 13 Go to Step 3

3 Was a visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 1. Check the PCM grounds for cleanliness, tightness

and proper routing. Refer to the PCM wiring

diagrams in Electrical Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 5

5 Observe the long term fuel trim on Tech 2.

Is the long term fuel trim significantly in the negative

range (rich condition)? — Go to Step 6 Go to Step 7

Step Action Value(s) Yes No

6 1. Check items that can cause the engine to run rich.

Refer to Diagnostic Aids in DTC P0172 Diagnostic

Support.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

7 Is the long term fuel trim significantly in the positive

range (lean condition)? — Go to Step 8 Go to Step 9

8 1. Check items that can cause the engine to run

lean. Refer to Diagnostic Aids in DTC P0171

Diagnostic Support.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

9 1. Check for incorrect idle speed. Ensure that the

following conditions are present:

• The engine is fully warm.

• The accessories are “OFF.”

2. Using Tech 2, monitor the IAC position.

Is the IAC position within the specified values?

Between 10

and 50 counts Go to Step 11 Go to Step 10

10 1. Visually/physically inspect for the following

conditions:

• Restricted air intake system. Check for a

possible collapsed air intake duct, restricted air

filter element, or foreign objects blocking the air

intake system.

• Throttle body. Check for objects blocking the

IAC passage or throttle bore, excessive

deposits in the IAC passage and on the IAC

pintle, and excessive deposits in the throttle

bore and on the throttle plate.

• Large vacuum leak. Check for a condition that

causes a large vacuum leak, such as an

incorrectly installed or faulty crankcase

ventilation valve or a disconnected brake

booster hose.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 8

11 Check the injector connections. If any of the injectors

are connected to an incorrect cylinder, correct as

necessary.

Was a problem found? — Verify repair Go to Step 12

12 1. Perform the “Injector Coil/Balance Test” in Fuel

Metering System.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 13

13 1. Check for fuel in the pressure regulator vacuum

hose.

2. If fuel is present, replace the fuel pressure

regulator assembly. Refer to Fuel Metering

System.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 14

Step Action Value(s) Yes No

14 1. Check for proper ignition voltage output with spark

tester J 26792 (ST-125).

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 15

15 1. Remove spark plugs. Check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits.

2. If spark plugs are fuel or oil fouled, the cause of

the fouling must be determined before replacing

the spark plugs.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 16

16 1. Check for a loose ignition coil ground.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 17

17 1. Check ignition coils for cracks or carbon tracking.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 18

18 Using Tech 2, monitor the throttle position (TP) angle

with the engine idling.

Is the TP angle at the specified value and steady?

0% Go to Step 19

Refer to DTC

P0123 for

further

diagnosis

19 1. Check the positive crankcase ventilation (PCV)

valve for proper operation. Refer to Crankcase

Ventilation System.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 20

20 1. Check the transmission range switch circuit. Use

Tech 2 and be sure Tech 2 indicates that the

vehicle is in drive with the gear selector in drive or

overdrive.

2. If a problem is found, diagnose and repair the

transmission range switch as necessary (refer to

4L30-E Automatic Transmission Diagnosis).

Was a problem found? — Verify repair Go to Step 21

21 1. Check for the following engine mechanical items.

Refer to Engine Mechanical for diagnosis

procedures:

• EGR valve mounted backward. Compare with

a known-good vehicle.

• Low compression

• Sticking or leaking valves

• Worn camshaft lobe(s)

• Camshaft drive belt slipped or stripped

• Incorrect valve timing

• Worn rocker arms

• Broken valve springs

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 22

Step Action Value(s) Yes No

22 1. Check for faulty motor mounts. Refer to Engine

Mechanical for inspection of mounts.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 23

23 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

• Visual/physical inspection

• Tech 2 data

• Freeze Frame data/Failure Records buffer

• All electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Te ch n ic al

Assistance

Step Action Value(s) Yes No

Poor Fuel Economy Symptom

StepActionValue(s)YesNo

1 DEFINITION:

Fuel economy, as measured by an actual road test, is

noticeably lower than expected. Also, economy is

noticeably lower than it was on this vehicle at one

time, as previously shown by an actual road test.

(Non-standard tires will cause odometer readings to

be incorrect, and that may cause fuel economy to

appear poor when it is actually normal.)

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3

3 Was a visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 Check owner's driving habits.

• Is the A/C “ON” continually (demist mode“ON”)?

• Are tyres at the correct pressure?

• Are excessively heavy loads being carried?

• Is acceleration too much, too often?

Was a problem found? — Go to Step 5 Go to Step 6

5 Review the items in Step 4 with the customer and

advise as necessary.

Is the action complete? — System OK —

6 1. Visually/physically check: Vacuum hoses for

splits, kinks, and improper connections and

routing as shown on the “Vehicle Emission Control

Information” label.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 7

7 1. Remove and check the air filter element for dirt or

for restrictions. Refer to Air Intake System.

2. Replace the air filter element if necessary.

Was a repair required? — Verify repair Go to Step 8

8 1. Remove spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits. Refer to Spark Plug

Replacement.

NOTE: If spark plugs are fuel or oil fouled, the cause

of the fouling must be determined before replacing the

spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

9 1. Check for low engine coolant level. Refer to

Engine Cooling.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 10

10 1. Check for an incorrect or faulty engine thermostat.

Refer to Engine Cooling.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 11

11 1. Check for low engine compression. Refer to

Engine Mechanical.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 12

12 1. Check the TCC operation. Refer to 4L30-E

Transmission Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 13

13 1. Check the exhaust system for possible restriction:

• Inspect the exhaust system for damaged or

collapsed pipes.

• Inspect the muffler for heat distress or possible

internal failure.

• Check for a possible plugged three-way

catalytic converter by checking the exhaust

system back pressure. Refer to Restricted

Exhaust System Check.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 14

14 Check for proper calibration of the speedometer.

Does the speed indicated on the speedometer closely

match the vehicle speed displayed on Tech 2? — Go to Step 16 Go to Step 15

15 Diagnose and repair an inaccurate speedometer

condition as necessary. Refer to Vehicle Speed

Sensor in Electrical Diagnosis.

Was a problem found? — Verify repair —

16 1. Check the air intake system and the crankcase for

air leaks. Refer to Air Intake System and

Crankcase Ventilation System.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 17

17 1. Review all diagnostic procedures within this table.

2. When all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

• Visual/physical inspection

• Tech 2 data

• Freeze Frame data/Failure Records buffer

• All connections within a suspected circuit and/

or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 18

18 Perform the procedure in Fuel System Pressure Test.

Was the fuel pressure normal?

—

Contact

Technical

Assistance Verify repair

Step Action Value(s) Yes No

Excessive Exhaust Emissions or Odors Symptom

StepActionValue(s)YesNo

1 DEFINITION:

Vehicle fails an emission test. Vehicle has excessive

“rotten egg” smell. (Excessive odors do not

necessarily indicate excessive emissions.)

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Go to Step 12 Go to Step 3

3 Was a thorough visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 1. Check for vacuum leaks. Check vacuum lines,

intake manifold, throttle body, etc.

2. If a problem is found, repair as necessary.

Were any vacuum leaks located? — Go to Step 12 Go to Step 5

5 1. Check the fuel cap for proper installation.

2. Secure the fuel cap if necessary.

Was the fuel cap installed properly? — Go to Step 6 Go to Step 12

6 1. Check the fuel pressure. Perform the procedure

in Fuel System Pressure Test.

2. If a problem is found, repair as necessary.

Was a problem found? — Go to Step 12 Go to Step 7

7 1. Check for a faulty, plugged, or incorrectly installed

crankcase ventilation valve; also check the

crankcase ventilation system for plugging.

2. If a problem is found, repair as necessary.

Was a problem found? — Go to Step 12 Go to Step 8

8 1. Check the injector connections.

2. If any of the injectors are connected to an

incorrect cylinder, correct as necessary.

Was a problem found? — Go to Step 12 Go to Step 9

9 1. Perform the “Injector Coil/Balance Test” in Fuel

Metering System.

2. If a problem is found, repair as necessary.

Was a problem found? — Go to Step 12 Go to Step 10

10 1. Refer to Engine Cooling for cooling system

diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found? — Go to Step 12 Go to Step 11

11 1. Remove excessive carbon buildup with a top

engine cleaner. Refer to the instructions on the

top engine cleaner can.

2. Perform the exhaust emission test.

Does the vehicle pass the test? — System OK Go to Step 13

12 Perform the exhaust emission test.

Does the vehicle pass the test? — System OK Go to Step 13

13 Does the exhaust emission test indicate excessive CO

and HC levels or is long term fuel trim significantly in

the negative range (rich condition)? — Go to Step 14 Go to Step 15

14 1. Check items that can cause the engine to run rich.

Refer to Diagnostic Aids in DTC P0172 Diagnostic

Support. Make any necessary repairs.

2. Perform the exhaust emission test.

Does the vehicle pass the test? — System OK Go to Step 16

15 1. Check items that can cause the engine to run

lean. Refer to Diagnostic Aids in DTC P0171

Diagnostic Support. Make any necessary repairs.

2. Perform the exhaust emission test.

Does the vehicle pass the test? — System OK Go to Step 16

16 1. Check the EGR system.

2. If a problem is found, repair as necessary.

Was a problem found? — Go to Step 12 Go to Step 17

17 1. Check for an engine mechanical problem.

Perform a cylinder compression check (refer to

Engine Mechanical).

2. If a problem is found, repair as necessary.

Was a problem found? — Go to Step 12 Go to Step 18

18 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

• Visual/physical inspection

• Tech 2 data

• Freeze Frame data/Failure Records butter

• All electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Te ch n ic al

Assistance

Step Action Value(s) Yes No

Dieseling, Run-On Symptom

StepActionValue(s)YesNo

1 DEFINITION:

Engine continues to run after key is turned “OFF,” but

runs very rough. If engine runs smooth, check ignition

switch and adjustment.

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3

3 Was a visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 1. Check for a short between B+ and any of the

ignition feed circuits.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 5

5 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

• Visual/physical inspection

• Tech 2 data

• Freeze Frame data/Failure Records butter

• All electrical connections within a suspected

circuit and/or system

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Te ch n ic al

Assistance

Backfire Symptom

StepActionValue(s)YesNo

1 DEFINITION:

Fuel ignites in the intake manifold, or in the exhaust

system, making a loud popping noise.

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3

3 Was a visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 1. Check for proper ignition voltage coil output with

spark tester J 26792 (ST-125).

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 5

5 1. Remove spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits.

NOTE: If spark plugs are fuel or oil fouled, the cause

of the fouling must be determined before replacing the

spark plugs. Refer to DTC P0172 to determine the

cause of a rich condition or Engine Mechanical for an

oil fouling condition.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 6

6 1. Visually/physically inspect the ignition coils for

cracks.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 7

7 1. Check for an intermittent ignition system

malfunction:

• Intermittent CKP 58X signal.

• Intermittent ignition feed circuit or sensor

ground circuit to the crankshaft position sensor.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 8

8 1. Check the fuel pressure. Refer to Fuel System

Pressure Test.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

9 1. Check for the following engine mechanical

conditions.

Refer to Engine Mechanical for diagnosis

procedures:

• Low compression

• Sticking or leaking valves

• Worn camshaft lobe(s)

• Camshaft drive belt slipped or stripped

• Incorrect valve timing

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 10

10 1. Check the intake and exhaust manifold(s) for

casting flash. Refer to Engine Mechanical.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 11

11 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

• Visual/physical inspection

• Tech 2 data

• Freeze Frame data/Failure Records butter

• All electrical connections within a suspected

circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Te ch n ic al

Assistance

Step Action Value(s) Yes No

Cuts Out, Misses Symptom

StepActionValue(s)YesNo

1 DEFINITION:

Steady pulsation or jerking that follows engine speed;

usually more pronounced as engine load increases.

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Go to Step 13 Go to Step 3

3 Was a visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 1. Check the PCM grounds for clearness, tightness

and proper routing. Refer to the PCM wiring

diagrams in Electrical Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 5

5 Observe the long term fuel trim on Tech 2.

Is the long term fuel trim significantly in the negative

range (rich condition)? — Go to Step 6 Go to Step 7

6 1. Check items that can cause the engine to run rich.

Refer to Diagnostic Aids in DTC P0172 Diagnostic

Support.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

7 Is the long term fuel trim significantly in the positive

range (lean condition)? — Go to Step 8 Go to Step 9

8 1. Check items that can cause the engine to run

lean. Refer to Diagnostic Aids in DTC P0171

Diagnostic Support.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 9

9 1. Check for incorrect idle speed. Ensure that the

following conditions are present:

• The engine is fully warm.

• The accessories are “off.”

2. Using Tech 2, monitor the IAC position.

Is the IAC position within the specified values?

Between 5

and 50 counts Go to Step 11 Go to Step 10

10 1. Visually/physically inspect for the following

conditions:

• Restricted air intake system. Check for a

possible collapsed air intake duct, restricted air

filter element, or foreign objects blocking the air

intake system.

• Throttle body. Check for objects blocking the

IAC passage or throttle bore, excessive

deposits in the IAC passage and on the IAC

pintle, and excessive deposits in the throttle

bore and on the throttle plate.

• Large vacuum leak. Check for a condition that

causes a large vacuum leak, such as an

incorrectly installed or faulty PCV valve or brake

booster hose disconnected .

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 8

11 Check the injector connections. If any of the injectors

are connected to an incorrect cylinder, correct as

necessary.

Was a problem found? — Verify repair Go to Step 12

12 1. Perform the “Injector Coil/Balance Test” in Fuel

Metering System.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 13

13 1. Check for fuel in the pressure regulator vacuum

hose.

2. If fuel is present, replace the fuel pressure

regulator assembly. Refer to Fuel Metering

System.

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 14

14 1. Check for proper ignition voltage output with spark

tester J 26792 (ST-125). Refer to Electronic

Ignition System for the procedure.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 15

15 1. Remove spark plugs. Check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits.

NOTE: If spark plugs are gas or oil fouled, the cause

of the fouling must be determined before replacing the

spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 16

16 1. Check for a loose ignition coil ground.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 17

17 1. Check ignition coils for cracks or carbon tracking.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 18

Step Action Value(s) Yes No

18 Using Tech 2, monitor the TP angle with the engine

idling.

Is the TP angle at the specified value and steady?

0% Go to Step 19

Refer to DTC

P0123 for

further

diagnosis

19 1. Check the PCV valve for proper operation. Refer

to Crankcase Ventilation System.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 20

20 1. Check the transmission range switch circuit. Use

Tech 2 and be sure Tech 2 indicates that the

vehicle is in drive with the gear selector in drive or

overdrive.

2. If a problem is found, diagnose and repair the

transmission range switch as necessary (refer to

4L30-E Automatic Transmission Diagnosis).

Was a problem found? — Verify repair Go to Step 21

21 1. Check the following engine mechanical items.

Refer to Engine Mechanical for diagnosis

procedures:

• Low compression

• Sticking or leaking valves

• Worn camshaft lobe(s)

• Camshaft drive belt slipped or stripped

• Incorrect valve timing

• Worn rocker arms

• Broken valve springs

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 22

22 1. Check for faulty motor mounts. Refer to Engine

Mechanical for inspection of mounts.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 23

23 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

• Visual/physical inspection

• Tech 2 data

• Freeze Frame data/Failure Records butter

• All electrical connections within a suspected

circuit and/or system

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Te ch n ic al

Assistance

Step Action Value(s) Yes No

Hesitation, Sag, Stumble Symptom

StepActionValue(s)YesNo

1 DEFINITION:

Momentary lack of response as the accelerator is

pushed down. Can occur at any vehicle speed.

Usually most pronounced when first trying to make the

vehicle move, as from a stop sign. May cause the

engine to stall if severe enough.

Was the “On-Board Diagnostic (OBD) System Check”

performed? — Go to Step 2

Go to OBD

System Check

2 1. Perform a bulletin search.

2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom? — Verify repair Go to Step 3

3 Was a visual/physical check performed?

—Go to Step 4

Go to Visual/

Physical Check

4 1. Check the fuel control heated oxygen sensors

(HO2S, B1S1 and B2S1). The fuel control heated

oxygen sensors (HO2S) should respond quickly to

different throttle positions. If they don't, check

them for silicon or other contaminants from fuel or

use of improper RTV sealant. The sensors may

have a white powdery coating.

Silicon contamination causes a high but false

HO2S signal voltage (rich exhaust indication).

The PCM will then reduce the amount of fuel

delivered to the engine, causing a severe

driveability problem. For more information, refer

to Powertrain Control Module (PCM) and Sensors.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 5

5 1. Check the fuel pressure. Refer to Fuel System

Pressure Test.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 6

6 Observe the TP angle display on Tech 2 while slowly

increasing throttle pedal.

Does the TP angle display steadily increase from 0%

at closed throttle to 100% at WOT? — Go to Step 7 Go to Step 18

7 Monitor the long term fuel trim on Tech 2.

Is the long term fuel trim significantly in the negative

range (rich condition)? — Go to Step 8 Go to Step 9

8 1. Check items that can cause the engine to run rich.

Refer to Diagnostic Aids in DTC P0172 Diagnostic

Support.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 10

9 1. Check items that can cause the engine to run

lean. Refer to Diagnostic Aids in DTC P0171

Diagnostic Support.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 10

10 1. Check for proper ignition voltage output with spark

tester J 26792 (ST-125).

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 11

11 1. Check for a loose ignition coil ground.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 12

12 1. Check the ignition coils for cracks or carbon

tracking.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 13

13 1. Remove spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or

heavy deposits.

NOTE: If spark plugs are gas or oil fouled, the cause

of the fouling must be determined before replacing the

spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 14

14 1. Check the PCM grounds for clearness, tightness

and proper routing. Refer to the PCM wiring

diagrams in Electrical Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 15

15 1. Check the MAF sensor connections.

2. If a problem is found, replace the faulty terminals

as necessary. Refer to Electrical Diagnosis for

wiring repair procedures.

Was a problem found? — Verify repair Go to Step 16

16 1. Visually/physically check vacuum hoses for splits,

kinks, and proper connections and routing as

shown on the “Vehicle Emission Control

Information” label.

2. If a problem is found, repair as necessary.

Was a problem found? — Verify repair Go to Step 17

17 1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the

following:

• Visual/physical inspection

• Tech 2 data

• Freeze Frame data/Failure Records butter

• All electrical connections within a suspected

circuit and/or system

3. If a problem is found, repair as necessary.

Was a problem found? — Verify repair

Contact

Te ch n ic al

Assistance

18 Replace the TP sensor.

Is the action complete? — Verify repair —

Step Action Value(s) Yes No

Default Matrix Table

Service Procedure Default Strategy

A referral strategy has been established to assist the

technician with additional information when the cause of

the failure cannot be determined. If no problem is found

after performing diagnostics, then refer to the default

matrix table for further diagnostic information.

Default Matrix Ta ble

Strategy Based Diagnostic Charts Initial Diagnosis Default Section(s)

On-Board Diagnostic (OBD) System

Check

Vehicle does not enter diagnostics. Chassis Electrical

On-Board Diagnostic (OBD) System

Check

Vehicle enters diagnostics and

communicates with Tech 2. MIL is

“ON” in diagnostics. Engine does not

start and run.

Ignition System Check

On-Board Diagnostic (OBD) System

Check

Engine starts and runs, no PCM codes

set. Customer complains of vibration.

—

On-Board Diagnostic (OBD) System

Check

Engine starts and runs, no PCM codes

set. Customer complains of harsh or

soft shift, poor performance, delayed or

no engagement into drive or reverse,

transmission fluid leak, transmission

noise or vibration, or improper TCC

operation.

Automatic Transmission

PCM Power and Ground Check On-Board Diagnostic (OBD) System

Check.

Chassis Electrical

PCM Power and Ground Check On-Board Diagnostic (OBD) System

Check. PCM power and ground circuits

OK. Data link voltage incorrect.

Chassis Electrical

On-Board Diagnostic (OBD) System

Check

Engine starts and runs, no PCM codes

set. Customer complains of harsh or

soft shift, poor performance, delayed or

no engagement into drive or reverse,

transmission fluid leak, transmission

noise or vibration, or improper TCC

operation.

Automatic Transmission

Symptoms Initial Diagnosis Default Section(s)

Intermittents 1. On-board Diagnostic (OBD) system

check.

2. Careful visual/physical inspections.

Chassis Electrical

Hard Starts 1. OBD system check.

2. Sensors (ECT, MAP, MAF, TP) ;

MAP output chart.

3. Fuel system electrical test, fuel

system diagnosis.

4. Ignition system.

5. IAC system check.

Engine Mechanical, Ignition

System Check, Exhaust System

Diagnosis

Surges and/or Chuggles 1. OBD system check.

2. Heated oxygen sensors.

3. Fuel system diagnosis.

4. Ignition system.

Calibration ID “Broadcast Code”/

Service Bulletins, Ignition System

Check, Generator Output,

Exhaust System Diagnosis,

4L30-E System Test

Lack of Power, Sluggish or Spongy 1. OBD system check.

2. Fuel system diagnosis.

3. Ignition system.

4. Knock sensor.

5. EGR operation.

6. EGR system check.

Refer to Exhaust System in

Engine Exhaust, TCC Operation,

Calibration ID/Service Bulletins

Detonation/Spark Knock 1. OBD system check.

2. Transmission range switch.

3. EGR operation.

4. EGR system check.

5. TCC operation.

6. Fuel system diagnosis.

7. Ignition system.

8. Knock sensor.

TCC operation, Cooling System,

Ignition System Check,

Calibration ID/Service Bulletins

Hesitation, Sag, Stumble 1. OBD system check.

2. TP.

3. MAP output check.

4. Fuel system diagnosis.

5. Fuel injector and fuel injector

balance test.

6. Ignition system.

EGR Operation, EGR System

Check, Generator Output Voltage

(refer to Chassis Electrical),

Calibration ID/Service Bulletins,

Ignition System Check

Cuts Out, Misses 1. OBD system check.

2. Cylinder balance test.

Ignition System Check

Rough, Unstable, or Incorrect Idle,

Stalling

1. OBD system check.

2. Fuel injector and fuel injector

balance test.

3. Ignition system.

4. IAC operation.

5. EGR operation.

MAP Output Check, Throttle

Linkage, IAC System Check, EGR

System Check, A/C Clutch

Control Circuit Diagnosis,

Crankcase Ventilation System,

Calibration ID/Service Bulletins,

Generator Output Voltage (refer to

Chassis Electrical), Exhaust

Diagnosis

Poor Fuel Economy 1. OBD system check.

2. Careful visual/physical inspection.

3. Ignition system.

4. Cooling system.

TCC Operation, Exhaust System

(refer to Engine Exhaust)

Engine Cranks But Will Not Run 1. OBD system check. Fuel System Electrical Diagnosis,

Fuel System Diagnosis, Fuel

Injector and Fuel Injector Balance

Test.

Excessive Exhaust Emissions or

Odors

1. OBD system check.

2. Emission test.

3. Cooling system.

4. Fuel system diagnosis.

5. Fuel injector and fuel injector

balance test.

6. Crankcase ventilation system.

7. Ignition system.

8. MAP output check.

EGR System Check, Exhaust

Diagnosis, Calibration ID/Service

Bulletins

Symptoms Initial Diagnosis Default Section(s)

Dieseling, Run-On 1. OBD system check.

2. Careful visual/physical inspection.

3. Fuel system diagnosis.

—

Backfire 1. OBD system check.

2. Ignition system.

3. Fuel system diagnosis.

4. Fuel injector and fuel injector

balance test.

5. EGR operation, EGR system

check.

Exhaust System Diagnosis, Intake

Casting Flash, Ignition System

Check

Catalyst Monitor 1. OBD system check.

2. Careful visual/physical inspection.

3. Heated oxygen sensors.

Exhaust System

Fuel Trim 1. OBD system check.

2. Careful visual/physical inspection.

3. Fuel system diagnosis.

4. Heated oxygen sensors, MAF

sensors.

Exhaust System Intake Air

System

Evaporative Emissions 1. OBD system check.

2. Careful visual/physical inspection.

3. Fuel system diagnosis.

—

Heated Oxygen Sensors 1. OBD system check.

2. Careful visual/physical inspection.

Exhaust System

Symptoms Initial Diagnosis Default Section(s)

Camshaft Position (CMP) Sensor

Removal Procedure

1.Disconnect the negative battery cable.

2.Remove the engine cover.

3.Remove the common chamber assembly.

Refer to Common Chamber in Engine Mechanical.

014RW120

4.Disconnect the electrical connector to the CMP

sensor.

014RV053

5.Remove the CMP retaining bolt from the side of left

cylinder head.

6.Remove the CMP sensor from the cylinder head.

Inspection Procedure

1.Inspect the sensor O-ring for cracks or leaks.

2.Replace the O-ring if it is worn or damaged.

3.Lubricate the new O-ring with engine oil.

4.Install the lubricated O-ring.

Installation Procedure

1.Install the CMP sensor in the cylinder head.

2.Install the CMP sensor retaining bolt.

Tighten

•Tighten the retaining screw to 9 N·m (78 lb in.).

3.Connect the electrical connector to the CMP sensor.

014RV053

4.Install the common chamber assembly.

Refer to Common Chamber in Engine Mechanical.

014RW106

5. Install the engine cover.

6. Connect the negative battery cable.

Crankshaft Position (CKP) Sensor

Removal Procedure

1.Disconnect the negative battery cable.

2.Disconnect the electrical connector to the CKP

sensor.

3.Remove one bolt and the CKP sensor from the right

side of the engine block, just behind the mount.

NOTE: Use caution to avoid any hot oil that might drip

out.

TS22909

Inspection Procedure

1.Inspect the sensor O-ring for cracks or leaks.

2.Replace the O-ring if it is worn or damaged.

3.Lubricate the new O-ring with engine oil.

4.Install the lubricated O-ring.

Installation Procedure

1.Install the CKP sensor in the engine block.

2.Install the CKP sensor mounting bolt.

Tighten

•Tighten the mounting bolt to 9 N·m (78 lb in.).

TS22909

3.Connect the electrical connector to the CKP sensor.

4.Connect the negative battery cable.

Engine Coolant Temperature (ECT) Sensor

Removal Procedure

NOTE: Care must be taken when handling the engine

coolant temperature (ECT) sensor. Damage to the ECT

sensor will affect proper operation of the fuel injection

system.

1.Disconnect the negative battery cable.

2.Drain the radiator coolant. Refer to Draining and

Refilling Cooling System in Engine Cooling.

3. Disconnect the electrical connector.

014RW127

4.Remove the ECT sensor from the coolant

crossover.

014RW086

Installation Procedure

1.Apply sealer or the equivalent to the threads of the

ECT sensor.

2.Install the ECT sensor in the coolant crossover.

Tighten

•Tighten the ECT sensor to 30 N·m (22 lb ft.).

014RW086

3.Connect the electrical connector.

014RW085

4.Fill the radiator with coolant. Refer to Draining and

Refilling Cooling System in Engine Cooling.

5. Connect the negative battery cable.

Heated Oxygen Sensor (HO2S)

Removal Procedure

1. Disconnect the negative battery cable.

2. Locate the oxygen sensors.

• Bank 1 sensor 1 is mounted on the right-hand

front exhaust pipe.

TS22912

•Bank 2 sensor 1 is mounted on the exhaust pipe

ahead of the catalytic converter.

TS22914

3.Disconnect the pigtail from the wiring harness.

TS23739

Important: The pigtail is permanently attached to the

sensor. Be careful not to pull the wires out.

NOTE: Do not use a torch to remove an HO2S unless

the sensor is being replaced. Using a torch could

damage the sensor.

4. Remove the sensor from the exhaust pipe.

• Because of the expansion and contraction of the

metal in the exhaust system over time, this may

be difficult if the engine temperature is below

48°C (120°F).

TS23739

Inspection Procedure

All two sensors are identical. Inspect each in the same

way.

1. Inspect the pigtail and the electrical connector for

grease, dirt, corrosion, and bare wires or worn

insulation.

2. Inspect the louvered end of the sensor for grease,

dirt, or other contaminations.

TS23739

Installation Procedure

Important:

• A special anti-seize compound, P/N 5613695, is used

on the HO2S threads. This compound consists of

glass beads suspended in a liquid graphite solution.

The graphite burns away with engine heat, but the

glass beads will remain, making the sensor easier to

remove.

• New or service sensors will already have the

compound applied to the threads. If a sensor is

removed and is to be reinstalled for any reason, the

threads must have anti-seize compound applied.

1. Apply anti-seize compound or the equivalent to the

threads of the oxygen sensor, if necessary.

2. Install the oxygen sensor on the exhaust pipe in its

original position.

Tighten

• Tighten the oxygen sensor to 55 N·m (40 lb in.).

TS23739

3. Connect the pigtail to the wiring harness.

4. Connect the negative battery cable.

Intake Air Temperature (IAT) Sensor

Removal Procedure

1. Disconnect the negative battery cable.

2. Remove the engine cover

3. The IAT sensor is located in the intake air duct,

behind the throttle body.

4. Disconnect the electrical connector from the IAT

sensor.

TS23741

5. Remove the IAT sensor from the intake air duct by

using a rocking motion while pulling the sensor.

Installation Procedure

1. Install the IAT sensor into the grommet in the intake

air duct.

2. Correct the IAT electrical connector.

TS23741

3. Install the engine cover.

4. Connect the negative battery cable.

Knock Sensor (KS)

Removal Procedure

1.Disconnect the negative battery cable.

2.Drain the cooling system. Refer to Draining and

Filling the Cooling System in Engine Cooling.

3.Remove the engine cover.

4.Remove the common chamber assembly.

Refer to Common Chamber in Engine Mechanical.

014RW106

5.Disconnect the electrical connector from the knock

sensor.

014RW103

6.Unscrew the knock sensor from the engine block.

Installation Procedure

NOTE: Do not apply thread sealant to the sensor

threads. The sensor is coated at the factory and

applying additional sealant will affect the sensor's ability

to detect detonation.

1.Screw the knock sensor into the engine block.

Tighten

•Tighten the knock sensor to 20 N·m (177 lb in.).

014RW103

2.Connect the electrical connector to the knock

sensor.

3.Install the common chamber assembly.

Refer to Common Chamber in Engine Mechanical.

014RW106

4.Install the engine cover.

5.Fill the cooling system.

Refer to Draining and Filling the Cooling System in

Engine Cooling.

6. Connect the negative battery cable.

Mass Air Flow (MAF) Sensor

Removal Procedure

1. Disconnect the negative battery cable.

2. Disconnect the electrical connector from the MAF

sensor.

TS23740

3. Loosen the clamps which secure the intake air duct

and the air cleaner to the MAF sensor.

4. Remove the intake air duct from the MAF sensor.

5. Remove the MAF sensor from the air cleaner.

TS23781

Installation Procedure

1. Install the MAF sensor on the air cleaner with the

clamp.

2. Install the intake air duct and the clamp on the MAF

sensor.

TS23781

3. Tighten the clamps to secure the MAF sensor to the

intake air duct and the air cleaner.

4. Connect the MAF electrical connector.

5. Connect the negative battery cable.

Manifold Absolute Pressure (MAP) Sensor

Removal Procedure

1. Disconnect the negative battery cable.

2. Disconnect the electrical connector from the MAP

sensor.

055RW005

3. Remove the bolt securing the MAP sensor to the

mounting bracket on the common chamber.

4.Remove the MAP sensor from the mounting

bracket.

055RW002

Installation Procedure

1.Install the MAP sensor in the mounting bracket.

055RW002

2.Install the mounting bracket retaining bolt on the

common chamber.

3.Connect the MAP electrical connector.

055RW005

4.Connect the negative battery cable.

Malfunction Indicator Lamp (MIL)

Removal and Installation Procedure

Refer to Warning light bulb, indicator light valve,

illumination light bulb, A/T indicator light bulb in Meter

and Gauge.

Powertrain Control Module (PCM)

Service Precaution

NOTE: To prevent possible electrostatic discharge

damage to the PCM, do not touch the connector pins or

soldered components on the circuit board.

Electrostatic Discharge (ESD) Damage

Electronic components used in the control systems are

often designed to carry very low voltage. Electronic

components are susceptible to damage caused by

electrostatic discharge. Less than 100 volts of static

electricity can cause damage to some electronic

components. By comparison, it takes as much as 4,000

volts for a person to even feel the zap of a static

discharge.

There are several ways for a person to become

statically charged. The most common methods of

charging are by friction and by induction. An example of

charging by friction is a person sliding across a car seat.

Charging by induction occurs when a person with well

insulated shoes stands near a highly charged object

and momentarily touches ground. Charges of the same

polarity are drained off leaving the person highly

charged with the opposite polarity. Static charges can

cause damage, therefore, it is important to use care

when handling and testing electronic components.

NOTE: To prevent possible Electrostatic Discharge

damage, follow these guidelines:

•Do not touch the control module connector pins or

soldered components on the control module circuit

board.

•Do not open the replacement part package until the

part is ready to be installed.

•Before removing the part from the package, ground

the package to a known good ground on the vehicle.

•If the part has been handled while sliding across the

seat, or while sitting down from a standing position, or

while walking a distance, touch a known good ground

before installing the part.

NOTE: To prevent internal PCM damage, the ignition

must be in the “OFF” position in order to disconnect or

reconnect power to the PCM (for example: battery

cable, PCM pigtail, PCM fuse, jumper cables, etc.).

Important: When replacing the production PCM with a

service PCM, it is important to transfer the broadcast

code and production PCM number to the service PCM

label. This will allow positive identification of PCM parts

throughout the service life of the vehicle. Do not record

this information on the metal PCM cover.

Important: The ignition should always be in the “OFF”

position in order to install or remove the PCM

connectors.

Service of the PCM should normally consist of either

replacement of the PCM or EEPROM programming. If

the diagnostic procedures call for the PCM to be

replaced, the PCM should be checked first to ensure it

is the correct part. If it is, remove the faulty PCM and

install the new service PCM.

The service PCM EEPROM will not be programmed.

DTC P0601 indicates the check sum error.

Removal Procedure

1. Disconnect the negative battery cable.

2. Block the wheels.

3. Remove the front console assembly.

1. Remove the four screws.

TS23755

2. Remove the transfer shift lever knob by

unscrewing the knob.

3. Move the transmission gear selector out of the

park position.

4. Lift up sharply on the back edge of the

assembly.

5. Disconnect the seat heater switch connectors (if

equipped).

6. Disconnect the POWER and WINTER switch

connectors.

7. Lift out the front console assembly.

TS23756

4. Disconnect the red, white, and blue electrical

connectors at the PCM.

5. Remove the two screws in the front of the PCM.

6. Remove the one screw at the left rear of the PCM.

7. Pull the PCM straight out from the dashboard.

TS23757

Installation Procedure

1. Insert the PCM into the dashboard.

• Line up the holes in front for the mounting

screws.

2. Install the PCM with two screws in the front and one

screw at the left rear.

3. Plug the red, white, and blue connectors into the

appropriate sockets.

TS23757

EEPROM

General Description

The Electronically Erasable Programmable Read Only

Memory (EEPROM) is a permanent memory that is

physically soldered within the PCM. The EEPROM

contains program and calibration information that the

PCM needs to control powertrain operation.

EEPROM Programming

1. Step-up – Ensure that the following conditions have

been met:

• The battery is fully charged.

• The ignition is “ON.”

• The Vehicle Interface Module cable connection at

the DLC is secure.

2. Program the PCM using the latest software

matching the vehicle. Refer to up-to-date Techline

equipment user's instructions.

3. If the PCM fails to program, Refer to UBS 98 model

year Immobiliser Workshop Manual.

Functional Check

1. Perform the On-Board Diagnostic System Check.

2. Start the engine and run for one minute.

3. Scan for DTCs using the Tech 2.

Power Steering Pressure (PSP) Switch

General Description

The Power Steering Pressure (PSP) switch closes when

the hydraulic pressure reaches 3920 ± 690 kPa (570 ±

100 psi). This causes the PCM to actuate the idle air

control valve in order to prevent the additional load from

slowing down the engine. The switch opens when the

hydraulic pressure drops to 2970 ± 560 kPa (430 ± 80

psi).

Removal Procedure

1. Disconnect the PSP switch pigtail from the wiring

harness.

• The pigtail is permanently attached to the switch.

Do not attempt to remove the wires from the

sensor.

• Have a container ready to catch the power

steering fluid that leaks out of the line when the

switch is removed.

2.Remove the PSP switch from the power steering

line.

•Plug the line to prevent excessive loss of fluid

and possible contamination of the power steering

system.

TS23760

Installation Procedure

1.Install the PSP switch in the power steering line.

TS23760

2.Connect the PSP switch pigtail to the wiring

harness.

3.Check the power steering fluid level. Refer to

Power Steering.

4.Start the engine. Watch the PSP switch for signs of

fluid leakage.

Throttle Position (TP) Sensor

Removal Procedure

1.Disconnect the negative battery cable.

2.Disconnect the TPS electrical connector.

3.Remove the bolts and the TP sensor from the

throttle body.

TS23747

NOTE: Do not clean the TP sensor by soaking it in

solvent. The sensor will be damaged as a result.

Function Check

Use a Tech 2 to check the TP sensor output voltage at

closed throttle.

•The voltage should be under 0.85 volt.

•If the reading is greater than 0.85 volt, check the

throttle shaft to see if it is binding. Check that the

throttle cable is properly adjusted, also. Refer to

Throttle Cable Adjustment.

• If the throttle shaft is not binding and the throttle cable

is properly adjusted, install a new TP sensor.

Installation Procedure

1.Install the TP sensor on the throttle body with the

bolts.

TS23747

2.Connect the TP electrical connector.

3.Install the negative battery cable.

Vehicle Speed Sensor (VSS)

Removal Procedure

CAUTION: The VSS is located on the right side of

the transfer case just ahead of the rear propeller

shaft and very close to the exhaust pipes. Be sure

that the exhaust pipes are cool enough to touch

before trying to remove the VSS. If the pipes are

hot, you could be burned.

1.Disconnect the negative battery cable.

2.Disconnect the VSS electrical connector.

TS23748

3.Remove the bolt and the clamp securing the VSS in

place.

Important: Have a container ready to catch any fluid

that leaks out when the VSS is removed from the

transfer case.

TS23780

4. Remove the VSS from the transfer case by wiggling

it slightly and pulling it straight out.

Inspection Procedure

1. Inspect the electrical connector for signs of

corrosion or warping. Replace the VSS if the

electrical connector is corroded or warped.

2. Inspect the VSS driven gear for chips, breaks, or

worn condition. Replace the VSS if the driven gear

is chipped, broken or worn.

3. Inspect the O-ring for wear, nicks, tears, or

looseness. Replace the O-ring if necessary.

Installation Procedure

1. Install the VSS in the transfer case with the notch for

the connector facing the rear.

2. Secure the VSS in place with the clamp and the

bolt.

Tighten

• Tighten the bolt to 16 N·m (12 lb ft.).

TS23780

3. Connect the VSS electrical connector.

TS23748

4. Check the transfer case oil level. Add fluid if

necessary.

5. Connect the negative battery cable.

Air Cleaner/Air Filter

Removal Procedure

1. Loosen the clamp between the air cleaner lid and

the mass air flow sensor.

2. Release the four latches securing the lid to the air

cleaner housing.

3. Remove the air cleaner lid.

TS23973

4. Remove the air filter element.

TS23794

5. Remove the retaining bolts and the air cleaner

housing from the vehicle.

130RT002

Installation Procedure

1. Install the air cleaner housing in the vehicle with the

retaining bolts.

130RT002

2. Install the air filter element in the air cleaner

housing.

TS23794

3. Install the air cleaner lid on the MAF sensor and the

air cleaner housing.

TS23973

4. Tighten the clamp and secure the four latches

between the lid and the air cleaner housing.

Idle Air Control (IAC) Valve

Removal Procedure

1. Disconnect the negative battery cable.

2. Disconnect the IAC electrical connector.

3. Remove the bolts and the IAC valve from the throttle

body.

NOTE: Do not clean the IAC valve by soaking it in

solvent. The valve will be damaged as a result.

TS23745

Cleaning, Inspection, and Measurement

Procedure

•Clean the IAC valve O-ring sealing surface, pintle

valve seat and air passage.

–Use carburetor cleaner and a parts cleaning brush

to remove carbon deposits. Do not use a cleaner

that contains methyl ethyl ketone. This is an

extremely strong solvent and not necessary for this

type of deposit.

–Shiny spots on the pintle are normal and do not

indicate misalignment or a bent pintle shaft.

–If the air passage has heavy deposits, remove the

throttle body for complete cleaning.

TS23746

•Inspect the IAC valve O-ring for cuts, cracks, or

distortion. Replace the O-ring if damaged.

•In order to install a new IAC valve, measure the

distance between the tip of the pintle and the

mounting flange. If that measurement is 28 mm (1.1

in.) or less, the valve needs no adjustment. If the

measurement is greater than 28 mm (1.1 in.), apply

finger pressure and retract the valve. The force

required to retract the pintle on a new valve will not

damage the valve, shaft, or pintle.

NOTE: Do not push or pull on the IAC valve pintle on

IAC valves that have been in service. The force

required to move the pintle may damage it.

Important: Use an identical replacement part in order

to replace a valve. IAC valve pintle shape and diameter

are designed for the specific application.

TS23746

Installation Procedure

1.Install the IAC valve on the throttle body with the

bolts.

Tighten

•Tighten the bolts to 1 N·m (9 lb in.).

TS23745

2.Connect the IAC valve electrical connector.

3.Install the negative battery cable.

Common Chamber

Removal and Installation Procedure

Refer to Common Chamber in Engine Mechanical.

Accelerator Cable Assembly

Removal Procedure

1. Remove the engine cover.

2. Loosen the adjusting nut on the cable bracket

mounting on the common chamber.

101RW005

3. Remove the accelerator control cable (on the

throttle valve end).

101RW006

4. Remove the accelerator control cable (on the

accelerator pedal end).

TS23982

5. Remove the grommet.

6. Remove the accelerator control cable.

TS23983

Inspection Procedure

Check the following items, and replace the control cable

if any abnormality is found:

• The control cable should move smoothly.

• The control cable should not be bent or kinked.

• The control cable should be free of damage and

corrosion.

Installation Procedure

1.Install the accelerator control cable.

TS23983

2.Install the grommet.

3.Install the accelerator control cable (on the

accelerator pedal end).

TS23982

4.Install the accelerator control cable (on the throttle

valve end).

101RW006

5.Install the adjusting nut.

101RW007

6.Adjust the accelerator cable at the throttle body.

Refer to Accelerator Cable Adjustment .

7. Install the engine cover.

Adjustment Procedure

1.Loosen the adjusting nut and lock nut.

2.Pull outer cable closing fully the throttle valve.

3.Tighten adjusting nut and lock nut temporarily.

035RW004

4.Loosen adjusting nut by three turns and tighten lock

nut. Then, manually operating the throttle valve,

make sure that the valve lever returns up to the

stopper screw.

Important: The valve lever must return up to the

stopper screw. If the valve lever does not reach the

stopper screw, repeat the procedure again from step 1.

5. It does not reach the stopper screw, repeat from

step 1.

TS23782

Accelerator Pedal Replacement

Removal Procedure

1. Disconnect the cruise control cable from the

accelerator pedal assembly.

TS24053

2. Disconnect the accelerator pedal control cable from

the accelerator pedal assembly.

TS24054

3. Disconnect the wiring harness from the kick-down

switch.

TS24038

4. Remove the two screws from the accelerator pedal

assembly.

TS24055

5. Remove the accelerator pedal assembly from the

bulkhead.

Installation Procedure

1. Install the accelerator pedal assembly on the

bulkhead.

2. Install the two screws to the accelerator pedal

assembly.

TS24055

3. Connect the wiring harness to the kick-down switch.

TS24038

4. Connect the accelerator pedal control cable to the

accelerator pedal assembly.

TS24054

5. Connect the cruise control cable to the accelerator

pedal assembly.

TS24053

Pedal Stroke Adjustment Procedure

1. Loosen the jam nut and rotate the kick-down switch

counterclockwise.

TS24039

2. Fully depress the pedal and hold it by hand. Rotate

the switch clockwise until the switch clicks.

3. Rotate the switch 1/2 turn further and lock it in this

position by tightening the jam nut.

TS24040

4. Step on the accelerator pedal and make sure there

is a clicking sound at the full-stroke position.

Fuel Filter Cap

General Description

The fuel filler cap includes a vacuum valve and a

pressure valve.

If high vacuum or high pressure occurs in the fuel tank,

each valve works to adjust the pressure in order to

prevent damage to the tank at the EGR valve.

TS23767

Inspection Procedure

NOTE: Replace the fuel filler cap with the same type of

filler cap that was originally installed on the vehicle.

• Check the seal ring in the filler cap for any

abnormality and for seal condition.

• Replace the filler cap if any abnormality is found.

Fuel Filter

Removal Procedure

1. Disconnect the negative battery cable.

2. Remove the fuel filler cap.

041RW005

3. Disconnect the fuel line from the fuel filter on the

engine side.

4. Disconnect the fuel line from the fuel filter on the

fuel tank side.

041RW006

5. Remove the bolt on the fuel filter holder.

041RW007

6. Remove the fuel filter.

041RW008

Inspection Procedure

1. Replace the fuel filter when the following occur:

• Fuel leaks from the fuel filter body.

• The fuel filter body is damaged.

• The fuel filter is clogged with dirt or sediment.

2. If the drain hole is clogged, clean the drain.

041RW009

Installation Procedure

1. Install the fuel filter in the correct direction.

041RW008

2. Install the bolt on the fuel filter holder.

041RW007

3. Connect the fuel line on the engine side.

4. Connect the fuel line on the fuel tank side.

041RW006

5. Install the fuel filler cap.

041RW005

6. Connect the negative battery cable.

Fuel Gauge Unit

Removal Procedure

1. Disconnect the negative battery cable.

2. Loosen the fuel filler cap.

3. Drain the fuel from the tank.

Tighten

• Tighten the drain plug to 20 N·m (14 lb ft.).

TS22907

4. Disconnect the wiring connector from the fuel gauge

unit.

TS23771

5. Remove the fuel gauge unit retaining screws.

6. Remove the fuel gauge unit.

• Cover or plug the fuel tank to prevent dust, dirt, or

debris from entering the tank.

TS22911

Installation Procedure

1.Install the fuel gauge unit.

2.Install the fuel gauge unit retaining screws.

TS22911

3.Connect the wiring connector to the fuel gauge unit.

TS23771

4.Fill the fuel tank with fuel.

•Tighten the fuel filler cap.

•Check for leaks at the fuel gauge unit gasket.

5.Connect the negative battery cable.

Fuel Injectors

Removal Procedure

NOTE: If the fuel injectors are leaking, the engine oil

may be contaminated with fuel. Check the oil for signs

of contamination and change the oil and the filter if

necessary.

NOTE: Use care in removing the fuel injectors in order

to prevent damage to the fuel injector electrical

connector pins or the fuel injector nozzles. The fuel

injector is an electrical component and should not be

immersed in any type of cleaner as this may damage

the fuel injector.

Important: Fuel injectors are serviced as a complete

assembly only.

1.Disconnect the negative battery cable.

2.Remove the upper intake manifold. Refer to

Common Chamber in Engine Mechanical..

3.Remove the fuel rail. Refer to Fuel Rail.

014RW164

4. Remove the injector retainer clip.

055RW009

5. Remove the fuel injector assembly.

6. Remove the O-ring from the fuel injector.

7. Remove the O-ring backup from the fuel injector .

Inspection Procedure

1.Inspect the O-rings for cracks or leaks.

2.Replace worn or damaged O-rings.

3.Lubricate the new O-rings with engine oil before

installation.

Installation Procedure

1.Install the O-ring backup on the fuel injector.

2.Install the new O-ring on the fuel injector.

3.Install the fuel injector on the fuel rail.

055RW009

4.Use new fuel injector retainer clips to retain the fuel

injector to the fuel rail.

5.Coat the end of the fuel injector with engine oil.

6.Install the fuel rail. Refer to Fuel Rail.

014RW164

7.Install the upper intake manifold. Refer to Common

Chamber in Engine Mechanical.

8.Install the engine cover.

9.Connect the negative battery cable.

Fuel Pressure Regulator

Removal Procedure

CAUTION: To reduce the risk of fire and personal

injury, it is necessary to relieve the fuel system

pressure before servicing the fuel system

components.

CAUTION: After relieving the system pressure, a

small amount of fuel may be released when

servicing fuel lines or connections. Reduce the

chance of personal injury by covering the fuel line

fittings with a shop towel before disconnecting the

fittings. The towels will absorb any fuel that may

leak out. When the disconnect is completed, place

the towel in an approved container.

NOTE: Compressed air must never be used to test or

clean a fuel pressure regulator, as damage to the fuel

pressure regulator may result.

NOTE: To prevent damage to the fuel pressure

regulator, do not immerse the pressure regulator in

solvent.

1.Depressurize the fuel system. Refer to Fuel

Pressure Relief Procedure.

2.Disconnect the negative battery cable.

3.Remove the fuel pump relay. Refer to Fuel Pump

Relay.

4. Remove the pressure regulator hose from the fuel

pressure regulator.

014RW110

5. Remove the two bolts from the protector that

secures the common chamber.

014RW109

6. Remove the fuel pressure regulator attaching screw.

F06RW043

7. Remove the fuel pressure regulator from the fuel

rail.

Disassembly Procedure

1. Remove the O-ring from the fuel pressure regulator.

2. Loosen the swivel nut.

3. Remove the fuel return line from the fuel pressure

regulator.

4. Remove the O-ring from the fuel return line.

• The O-ring may be left inside the fuel pressure

regulator instead of on the fuel return line.

F06RW043

Assembly Procedure

1. Install a new O-ring on the fuel return line.

2. Install the fuel return line on the fuel pressure

regulator.

NOTE: Do not over-tighten the swivel nut on the fuel

pressure regulator. The fuel pressure regulator can be

damaged and fuel may leak if the swivel nut is

over-tightened.

3. Tighten the swivel nut.

4. Install a new O-ring on the fuel pressure regulator.

Installation Procedure

1.Install the fuel pressure regulator attaching screw.

Tighten

•Tighten the fuel pressure regulator attaching screw

to 3 N·m (26 lb in.).

F06RW043

2.Install the fuel pressure regulator on the fuel rail.

3.Install the two bolts to the protector that secures the

common chamber.

014RW109

4.Install the pressure regulator hose to the fuel

pressure regulator.

014RW110

5.Install the fuel pump relay. Refer to Fuel Pump

Relay.

6. Connect the negative battery cable.

7. Crank the engine until it starts. Cranking the engine

may take longer than usual due to trapped air in the

fuel lines.

Fuel Metering System

Fuel Pressure Relief Procedure

CAUTION: To reduce the risk of fire and personal

injury, it is necessary to relieve the fuel system

pressure before servicing the fuel system

components.

CAUTION: After relieving the system pressure, a

small amount of fuel may be released when

servicing fuel lines or connections. Reduce the

chance of personal injury by covering the fuel line

fittings with a shop towel before you disconnect the

fittings. The towels will absorb any fuel that may

leak out. When the disconnect is completed, place

the towel in an approved container.

1.Remove the fuel cap.

2.Remove the fuel pump relay from the underhood

relay box. Refer to Fuel Pump Relay.

TS23976R

3.Start the engine and allow it to stall.

4.Crank the engine for 30 seconds.

5.Disconnect the negative battery cable.

Fuel Pump Assembly

Removal Procedure

1.Disconnect the negative battery cable.

2.Drain all the fuel from the tank.

3.Install and tighten the drain plug.

Tighten

•Tighten the drain plug to 20 N·m (14 lb ft.).

4.Remove the fuel tank. Refer to Fuel Tank.

5.Remove the retaining screws from the fuel tank.

6.Remove the fuel pump assembly from the fuel tank.

•Cover the fuel pump opening in order to prevent

dust, dirt, or debris from entering the fuel tank.

TS23795

Inspection Procedure

1.Inspect the fuel pump gasket for tears, cracks,

stretching, or rotting. If any of these conditions are

found, replace the fuel pump gasket.

2.Inspect the in-tank fuel filter for tears or evidence of

dirt, debris, or water in the fuel. If any of these

conditions are found, replace the in-tank fuel filter.

Installation Procedure

1.Install the fuel pump assembly.

2.Install the fuel pump assembly retaining screws.

3.Install the fuel tank assembly. Refer to Fuel Tank.

4. Fill the tank with fuel.

5. Tighten the fuel filler cap.

6. Connect the negative battery cable.

TS23795

Fuel Pump Relay

Removal Procedure

1. Remove the fuse and relay box cover from under

the hood.

2. Consult the diagram on the cover to determine

which is the correct relay.

3. Insert a small screwdriver into the catch slot on the

forward side of the fuel pump relay.

• The screwdriver blade will release the catch

inside.

T321092

4. Pull the relay straight up and out of the fuse and

relay box.

TS23976R

Installation Procedure

1. Insert the relay into the correct place in the fuse and

relay box with the catch slot facing forward.

2. Press down until the catch engages.

• An audible “click” will be heard.

T321092

3. Install the fuse and relay box cover.

Fuel Rail Assembly

Removal Procedure

NOTE:

• Do not attempt to remove the fuel inlet fitting on the

fuel rail. It is staked in place. Removing the fuel inlet

fitting will result in damage to the fuel rail or the

internal O-ring seal.

• Use care when removing the fuel rail assembly in

order to prevent damage to the injector electrical

connector terminals and the injector spray tips.

•Fittings should be capped and holes plugged during

servicing to prevent dirt and other contaminants from

entering open lines and passages.

Important: An eight-digit identification number is

stamped on the side of the fuel rail. Refer to this

number when you service the fuel rail or when a

replacement part is required.

TS24022

Before removal, the fuel rail assembly may be cleaned

with a spray type engine cleaner. Follow the spray

package instructions. Do not immerse the fuel rails in

liquid cleaning solvent.

1.Depressurize the fuel system. Refer to Fuel

Pressure Relief Procedure in this Section.

2.Disconnect the negative battery cable.

3.Remove the engine cover.

4.Disconnect the accelerator pedal cable from throttle

body and cable bracket.

5.Disconnect the connectors from manifold absolute

pressure sensor, solenoid valve, electric vacuum

sensing valve.

6.Disconnect the vacuum hose on canister VSV and

positive crankcase ventilation hose.

7.Remove the common chamber. Refer to the

common chamber in Engine Mechanical.

1.Lift up carefully on the fuel injectors. Do not

separate the fuel injectors from the fuel rail.

2.If an injector becomes separated from the fuel

rail, the infector O-ring seals and the retainer

clip must be replaced.

3.Drain residual fuel into an approved container.

014RW164

8.If removal of the fuel pressure regulator is

necessary, refer to Fuel Pressure Regulator.

9.If removal of the fuel injectors is necessary, refer to

Fuel Injectors.

Installation Procedure

1.If the fuel injectors were removed, install them.

Refer to Fuel Injectors.

2.If the fuel pressure regulator was removed, install it.

Refer to Fuel Pressure Regulator.

3.Install the common chamber. Refer to common

chamber in engine Mechanical.

014RW164

4. Connect the vacuum hose on Canister VSV and

positive crankcase ventilation hose.

5. Connect the connectors to manifold absolute

pressure sensor, solenoid valve, electric vacuum

sensing valve.

6. Connect the accelerator pedal cable to throttle body

and cable bracket.

7. Install the engine cover.

8. Connect the negative battery cable.

9. Crank the engine until it starts. Cranking the engine

may take longer than usual due to trapped air in the

fuel rail and in the injectors.

Fuel Tank

Removal Procedure

1. Disconnect the negative battery cable.

2. Loosen the fuel filler cap.

3. Drain the fuel from the tank into an approved

container.

4. Install and tighten the drain plug.

Tighten

• Tighten the drain plug to 20 N·m (14 lb ft.).

5. Disconnect the fuel filler hose at the fuel tank.

6. Disconnect the air breather hose at the fuel tank.

TS23796

7. Remove the undercover retaining bolts.

8. Remove the undercover.

TS23797

9. Disconnect the wiring connector to the fuel pump.

10. Disconnect the wiring connector to the fuel gauge

unit.

11. Remove the fuel gauge unit connector from the

bracket.

12. Disconnect the EVAP vapor hose.

13. Disconnect the fuel supply hose.

14. Disconnect the fuel return hose.

• Plug the hoses to prevent dust from entering the

hoses.

TS23769

15. Remove the fuel tank retaining bolts on both sides.

16. Remove the fuel tank.

TS23770

Installation Procedure

1. Install the fuel tank.

• Place the flanges on the left and right side of the

tank on the bracket.

2. Install the fuel tank retaining bolts.

Tighten

• Tighten the fuel tank retaining bolts to 36 N·m (27

lb ft.).

TS23770

3. Connect the fuel return hose.

4. Connect the fuel supply hose.

5. Connect the EVAP vapor hose.

6. Connect the wiring connector for the fuel gauge unit.

7. Connect the fuel gauge wiring connector to the

bracket.

8. Connect the wiring connector for the fuel pump.

TS23769

9. Install the undercover.

10. Secure the undercover with the retaining bolts.

TS23797

11. Connect the fuel filler fuse at the tank.

12.Connect the air breather hose at the tank.

TS23796

13.Fill the fuel tank with fuel.

14.Tighten the fuel filler cap.

15.Connect the negative battery cable.

Throttle Body (TB)

Removal Procedure

1.Disconnect the negative battery cable.

2.Drain the cooling system. Refer to Cooling System.

3.Remove the accelerator cable assembly. Refer to

Accelerator Cable in Engine Speed Control

System..

4.Disconnect the electrical connectors:

•Throttle position (TP) sensor.

•Idle air control (IAC) solenoid.

•Intake air temperature (IAT) sensor. Refer to

Intake Air Temperature Sensor.

035RW023

5.Disconnect the vacuum hose below the air horn.

6.Remove the intake air duct clamp.

7.Disconnect the intake air duct.

8.Disconnect the coolant lines from the throttle body.

9.Remove the bolts from the common chamber.

10.Remove the throttle body from the common

chamber.

11.Remove the gasket from the upper intake manifold.

035RW024

12.Remove the IAC. Refer to Idle Air Control (IAC)

Solenoid.

13.Remove the TP sensor. Refer to Throttle Position

(TP) Sensor.

Inspection Procedure

NOTE: Do not use solvent of any type when you clean

the gasket surfaces on the intake manifold and the

throttle body assembly. The gasket surfaces and the

throttle body assembly may be damaged as a result.

•If the throttle body gasket needs to be replaced,

remove any gasket material that may be stuck to the

mating surfaces of the manifold.

•Do not leave any scratches in the aluminum casting.

Installation Procedure

1.Install the TP sensor. Refer to Throttle Position (TP)

Sensor.

2.Install the IAC. Refer to Idle Air Control (IAC)

Solenoid.

3. Install the gasket on the common chamber.

4. Install the throttle body on the common chamber.

5.Secure the gasket and the throttle body with the four

bolts.

•The vacuum lines must be properly routed under

the throttle body before tightening the mounting

bolts.

Tighten

•Tighten the throttle body mounting bolts to 24 N·m

(17 lb ft.).

035RW024

6.Install the coolant lines.

7.Connect all the vacuum lines.

8.Install the intake air duct.

9.Tighten the intake air duct clamp.

10.Connect all the electrical connectors:

•Throttle position (TP) sensor.

•Idle air control (IAC) solenoid.

•Intake air temperature (IAT) sensor. Refer to

Intake Air Temperature Sensor.

035RW023

11.Install the accelerator cable assembly. Refer to

Accelerator Cable in Engine Speed Control

System..

12.Fill the cooling system. Refer to Cooling System.

13. Install the negative battery cable.

Electronic Ignition System

Removal Procedure

1. Disconnect the negative battery cable.

2. Disconnect the electrical connector at the ignition

coil.

3. Remove the two screws that secure the ignition coil

to the rocker cover.

014RW108

4. Remove the ignition coil and the spark plug boot

from the spark plug.

• Twist the ignition coil while pulling it straight up.

014RW091

5.Use the spark plug socket in order to remove the

spark plug from the engine.

Spark Plug Gap Check

•Check the gap of all spark plugs before installation.

•Use a round wire feeler gauge to ensure an accurate

check.

•Plugs installed with the wrong gap can cause poor

engine performance and excessive emissions.

Installation Procedure

NOTE: The plug must thread smoothly into the cylinder

head and be fully seated. Use a thread chaser if

necessary to clean the threads in the cylinder head.

Cross-threading or failure to fully seat the spark plug

can cause plug overheating, exhaust blow-by gas, or

thread damage. Do not overtighten the spark plugs.

Over tightening can cause aluminum threads to strip.

1.Install the spark plug in the engine. Use the

appropriate spark plug socket.

Tighten

•Tighten the spark plug to 18 N·m (13 lb ft.).

2.Install the ignition coil and spark plug boot over the

spark plug.

014RW108

3.Secure the ignition coil to the rocker cover with two

screws.

014RW091

4.Connect the electrical connector at the ignition coil.

5.Connect the negative battery cable.

Catalytic Converter

Removal and Installation Procedure

Refer to Engine Exhaust in Engine.

Air Conditioning Relay

Removal Procedure

1. Remove the fuse and relay box cover from under

the hood.

2. Consult the diagram on the cover to determine

which is the correct relay.

3.Insert a small screwdriver into the catch slot on the

forward side of the fuel pump relay.

•The screwdriver blade will release the catch

inside.

T321092

4.Pull the relay straight up and out of the fuse and

relay box.

TS23986

Installation Procedure

1.Insert the relay into the correct place in the fuse and

relay box with the catch slot facing forward.

2.Press down until the catch engages.

•An audible “click” will be heard.

3.Install the fuse and relay box cover.

TS23986

EVAP Canister Hoses

Service Information

To view the routing of the EVAP canister hoses, refer to

Vehicle Emission Control Information in Diagnosis.

Use 6148M or equivalent when you replace the EVAP

canister hoses.

EVAP Canister

Removal Procedure

1. Disconnect the negative battery cable.

2. Disconnect the three hoses from the EVAP canister.

014RW145

3. Remove the retaining two bolts on the mounting

bracket and slide the canister out of mounting

bracket.

014RW146

Inspection Procedure

1. Inspect the hoses for cracks and leaks.

2. Inspect the canister for a damaged case.

Installation Procedure

1. Slide the canister into mounting bracket and install

the mounting bracket two bolts.

014RW146

2. Connect the three hoses to the EVAP canister.

014RW145

3. Disconnect the negative battery cable.

EVAP Canister Purge Solenoid

Removal Procedure

1. Disconnect the electrical connector from the EVAP

canister purge solenoid.

2. Disconnect the vacuum hoses from the EVAP

canister purge solenoid.

014RW136

3. Remove the EVAP canister purge solenoid retaining

bolt from the upper intake manifold.

4.Remove the EVAP canister purge solenoid.

014RW137

Installation Procedure

1.Install the EVAP canister purge solenoid on the

upper intake manifold.

2.Install the EVAP canister purge solenoid retaining

bolt.

3.Connect the vacuum hoses to the EVAP canister

purge solenoid.

014RW137

4.Connect the electrical connector to the EVAP

canister purge solenoid.

014RW138

Fuel Tank Vent Valve

Removal and Installation Procedure

Refer to Fuel Pump

Linear Exhaust Gas Recirculation (EGR)

Valve

Removal Procedure

1. Disconnect the negative battery cable.

2. Disconnect the electrical connector at the EGR

valve.

014RW139

3. Remove the bolt and the nut from the upper intake

manifold.

014RW098

4. Remove the EGR valve from the upper intake

manifold.

5. Remove the gasket from the upper intake manifold.

Installation Procedure

1. Install the gasket on the upper intake manifold.

2. Install the EGR valve on the upper intake manifold.

3. Secure the EGR valve and the gasket with the bolt

and the nut.

NOTE: It is possible to install the EGR valve rotated

180° from the correct position. Make sure that the base

of the valve is placed so that it aligns with the mounting

flange.

014RW098

4. Connect the electrical connector at the EGR valve.

014RW139

5. Connect the negative battery cable.

Positive Crankcase Ventilation (PCV) Valve

Removal Procedure

1. Remove the vacuum hose at the PCV valve.

• Slide the clamp back to release the hose.

2. Pull the PCV valve from the rubber grommet in the

right valve cover.

014RW097

Inspection Procedure

1. Shake the valve and listen for the rattle of the

needle inside the valve.

2.If the valve does not rattle, replace the valve.

Installation Procedure

1.Push the PCV valve into the rubber grommet in the

left valve cover.

2.Install the vacuum hose on the PCV valve and

secure the vacuum hose with the clamp.

014RW097

Wiring and Connectors

Wiring Harness Service

The control module harness electrically connects the

control module to the various solenoids, switches and

sensors in the vehicle engine compartment and

passenger compartment.

Replace wire harnesses with the proper part number

replacement.

Because of the low amperage and voltage levels utilized

in powertrain control systems, it is essential that all

wiring in environmentally exposed areas be repaired

with crimp and seal splice sleeves.

The following wire harness repair information is

intended as a general guideline only. Refer to Chassis

Electrical for all wire harness repair procedures.

Connectors and Terminals

Use care when probing a connector and when replacing

terminals. It is possible to short between opposite

terminals. Damage to components could result.

Always use jumper wires between connectors for circuit

checking. NEVER probe through Weather-Pack seals.

Use an appropriate connector test adapter kit which

contains an assortment of flexible connectors used to

probe terminals during diagnosis. Use an appropriate

fuse remover and test tool for removing a fuse and to

adapt the fuse holder to a meter for diagnosis.

Open circuits are often difficult to locate by sight

because oxidation or terminal misalignment are hidden

by the connectors. Merely wiggling a connector on a

sensor, or in the wiring harness, may temporarily correct

the open circuit. Intermittent problems may also be

caused by oxidized or loose connections.

Be certain of the type of connector/terminal before

making any connector or terminal repair. Weather-Pack

and Com-Pack III terminals look similar, but are

serviced differently.

PCM Connectors and Terminals

Removal Procedure

1. Remove the connector terminal retainer.

2. Push the wire connected to the affected terminal

through the connector face so that the terminal is

exposed.

3. Service the terminal as necessary.

Installation Procedure

1. Bend the tab on the connector to allow the terminal

to be pulled into position within the connector.

2. Pull carefully on the wire to install the connector

terminal retainer.

Wire Harness Repair: Twisted Shielded

Cable

Removal Procedure

1. Remove the outer jacket.

2. Unwrap the aluminum/mylar tape. Do not remove

the mylar.

047

3. Untwist the conductors.

4. Strip the insulation as necessary.

048

Installation Procedure

1. Splice the wires using splice clips and rosin core

solder.

2. Wrap each splice to insulate.

3. Wrap the splice with mylar and with the drain

(uninsulated) wire.

049

4. Tape over the whole bundle to secure.

050

Twisted Leads

Removal Procedure

1. Locate the damaged wire.

2. Remove the insulation as required.

051

Installation Procedure

1. Use splice clips and rosin core solder in order to

splice the two wires together.

052

2. Cover the splice with tape in order to insulate it from

the other wires.

053

3. Twist the wires as they were before starting this

procedure.

054

4. Tape the wires with electrical tape. Hold in place.

055

Weather-Pack Connector

Tools Required

J 28742-A Weather-Pack II Terminal Remover

Removal Procedure

A Weather-Pack connector can be identified by a rubber

seal at the rear of the connector. This engine room

connector protects against moisture and dirt, which

could from oxidation and deposits on the terminals.

This protection is important, because of the low voltage

and the low amperage found in the electronic systems.

1. Open the secondary lock hinge on the connector.

070

2. Use tool J 28742-A or the equivalent to remove the

pin and the sleeve terminals. Push on J 28742-A to

release.

NOTE: Do the use an ordinary pick or the terminal may

be bent or deformed. Unlike standard blade terminals,

these terminals cannot be straightened after they have

been improperly bent.

071

3. Cut the wire immediately behind the cable seal.

072

Installation Procedure

Make certain the connectors are properly seated and all

of the sealing rings are in place when you reconnect the

leads. The secondary lock hinge provides a backup

locking feature for the connector. The secondary lock

hinge is used for added reliability. This flap should

retain the terminals even if the small terminal lock tangs

are not positioned properly.

Do not replace the Weather-Pack connections with

standard connections. Read the instructions provided

with the Weather-Pack connector and terminal

packages.

1. Replace the terminal.

2. Slip the new seal onto the wire.

3. Strip 5 mm (0.2") of insulation from the wire.

4. Crimp the terminal over the wire and the seal.

073

5. Push the terminal and the connector to engage the

locking tangs.

070

6. Close the secondary locking hinge.

Com-Pack III

General Information

The Com-Pack III terminal looks similar to some

Weather-Pack terminals. This terminal is not sealed

and is used where resistance to the environment is not

required. Use the standard method when repairing a

terminal. Do not use the Weather-Pack terminal tool J

28742-A or equivalent. These will damage the

terminals.

Metri-Pack

Tools Required

J 35689 Terminal Remover

Removal Procedure

Some connectors use terminals called Metri-Pack

Series 150. These may be used at the engine coolant

temperature (ECT) sensor.

1. Slide the seal (1) back on the wire.

2. Insert the J 35689 tool or equivalent (3) in order to

release the terminal locking tang (2).

060

3. Push the wire and the terminal out through the

connector. If you reuse the terminal, reshape the

locking tang.

Installation Procedure

Metri-Pack terminals are also referred to as

“pull-to-seat” terminals.

1. In order to install a terminal on a wire, the wire must

be inserted through the seal (2) and through the

connector (3).

2. The terminal (1) is then crimped onto the wire.

061

3. Then the terminal is pulled back into the connector

to seat it in place.

General Description (PCM and Sensors)

58X Reference PCM Input

The powertrain control module (PCM) uses this signal

from the crankshaft position (CKP) sensor to calculate

engine RPM and crankshaft position at all engine

speeds. The PCM also uses the pulses on this circuit to

initiate injector pulses. If the PCM receives no pulses

on this circuit, DTC P0337 will set. The engine will not

start and run without using the 58X reference signal.

A/C Request Signal

This signal tells the PCM when the A/C mode is

selected at the A/C control head. The PCM uses this to

adjust the idle speed before turning “ON” the A/C clutch.

The A/C compressor will be inoperative if this signal is

not available to the PCM.

Refer to A/C Clutch Circuit Diagnosis for A/C wiring

diagrams and diagnosis for the A/C electrical system.

Crankshaft Position (CKP) Sensor

The crankshaft position (CKP) sensor provides a signal

used by the powertrain control module (PCM) to

calculate the ignition sequence. The CKP sensor

initiates the 58X reference pulses which the PCM uses

to calculate RPM and crankshaft position.

Refer to Electronic Ignition System for additional

information.

0013

Camshaft Position (CMP) Sensor and

Signal

The camshaft position (CMP) sensor sends a CMP

signal to the PCM. The PCM uses this signal as a “sync

pulse” to trigger the injectors in the proper sequence.

The PCM uses the CMP signal to indicate the position

of the #1 piston during its power stroke. This allows the

PCM to calculate true sequential fuel injection (SFI)

mode of operation. If the PCM detects an incorrect

CMP signal while the engine is running, DTC P0341 will

set. If the CMP signal is lost while the engine is

running, t he fuel injection system will shift to a

calculated sequential fuel injection mode based on the

last fuel injection pulse, and the engine will continue to

run. As long as the fault is present, the engine can be

restarted. It will run in the calculated sequential mode

with a 1-in-6 chance of the injector sequence being

correct.

Refer to DTC P0341 for further information

0014

Engine Coolant Temperature (ECT) Sensor

The engine coolant temperature (ECT) sensor is a

thermistor (a resistor which changes value based on

temperature) mounted in the engine coolant stream.

Low coolant temperature produces a high resistance of

100,000 ohms at –40°C (–40°F). High temperature

causes a low resistance of 70 ohms at 130°C (266°F).

The PCM supplies a 5-volt signal to the ECT sensor

through resistors in the PCM and measures the

voltage. The signal voltage will be high when the

engine is cold and low when the engine is hot. By

measuring the voltage, the PCM calculates the engine

coolant temperature. Engine coolant temperature

affects most of the systems that the PCM controls.

Tech 2 displays engine coolant temperature in degrees.

After engine start-up, the temperature should rise

steadily to about 85°C (185°F). It then stabilizes when

the thermostat opens. If the engine has not been run for

several hours (overnight), the engine coolant

temperature and intake air temperature displays should

be close to each other. A hard fault in the engine

coolant sensor circuit will set DTC P0177 or DTC

P0118. An intermittent fault will set a DTC P1114 or

P1115.

0016

Electrically Erasable Programmable Read

Only Memory (EEPROM)

The electrically erasable programmable read only

memory (EEPROM) is a permanent memory chip that is

physically soldered within the PCM. The EEPROM

contains the program and the calibration information

that the PCM needs to control powertrain operation.

Unlike the PROM used in past applications, the

EEPROM is not replaceable. If the PCM is replaced,

the new PCM will need to be programmed. Equipment

containing the correct program and calibration for the

vehicle is required to program the PCM.

Fuel Control Heated Oxygen Sensors

The fuel control heated oxygen sensors (Bank 1 HO2S

1 and Bank 2 HO2S 1) are mounted in the exhaust

stream where they can monitor the oxygen content of

the exhaust gas. The oxygen present in the exhaust

gas reacts with the sensor to produce a voltage output.

This voltage should constantly fluctuate from

approximately 100 mV to 900 mV. The heated oxygen

sensor voltage can be monitored with Tech 2. By

monitoring the voltage output of the oxygen sensor, the

PCM calculates the pulse width command for the

injectors to produce the proper combustion chamber

mixture.

• Low HO2S voltage is a lean mixture which will result

in a rich command to compensate.

• High HO2S voltage is a rich mixture which will result

in a lean command to compensate.

An open Bank 1 HO2S 1 signal circuit will set a DTC

P0134 and Tech 2 will display a constant voltage

between 400-500 mV. A constant voltage below 300

mV in the sensor circuit (circuit grounded) will set DTC

P0131. A constant voltage above 800 mV in the circuit

will set DTC P0132. Faults in the Bank 2 HO2S 1 signal

circuit will cause DTC 0154 (open circuit), DTC P0151

(grounded circuit), or DTC P0152 (signal voltage high)

to set.

0012

Intake Air Temperature (IAT) Sensor

The intake air temperature (IAT) sensor is a thermistor

which changes its resistance based on the temperature

of air entering the engine. Low temperature produces a

high resistance of 100,000 ohms at –40°C (–40°F).

High temperature causes low resistance of 70 ohms at

130°C (266°F) . The PCM supplies a 5-volt signal to the

sensor through a resistor in the PCM and monitors the

signal voltage. The voltage will be high when the

incoming air is cold. The voltage will be low when the

incoming air is hot. By measuring the voltage, the PCM

calculates the incoming air temperature. The IAT

sensor signal is used to adjust spark timing according to

the incoming air density.

Tech 2 displays the temperature of the air entering the

engine. The temperature should read close to the

ambient air temperature when the engine is cold and

rise as underhood temperature increases. If the engine

has not been run for several hours (overnight), the IAT

sensor temperature and engine coolant temperature

should read close to each other. A fault in the IAT

sensor circuit will set DTC P0112 or DTC P0113.

0018

Knock Sensor

Insufficient gasoline octane levels may cause

detonation in some engines. Detonation is an

uncontrolled explosion (burn) in the combustion

chamber. This uncontrolled explosion results from a

flame front opposite that of the normal flame front

produced by the spark plug. The rattling sound

normally associated with detonation is the result of two

or more opposing pressures (flame fronts) colliding

within the combustion chamber. Light detonation is

sometimes considered normal, but heavy detonation

could result in engine damage.

A knock sensor system is used to control detonation.

This system is designed to retard spark timing up to 20

degrees to reduce detonation in the engine. This allows

the engine to use maximum spark advance to improve

driveability and fuel economy.

The knock sensor system has two major components:

• The knock sensor (KS) module.

• The knock sensor.

The knock sensor, mounted in the engine block near the

cylinders, detects abnormal vibration in the engine. The

sensor produces an AC output signal of about 10

millivolts. The signal amplitude and frequency are

dependent on the amount of knock being experienced.

The signal voltage increases with the severity of the

knock. This signal voltage is input to the PCM. The

PCM then retards the ignition control (IC) spark timing

based on the KS signal being received.

The PCM determines whether knock is occurring by

comparing the signal level on the KS circuit with the

voltage level on the noise channel. The noise channel

allows the PCM to reject any false knock signal by

indicating the amount of normal engine mechanical

noise present. Normal engine noise varies depending

on the engine speed and load. If the voltage level on

the KS noise channel circuit is below the range

considered normal, DTC P0327 will set, indicating a

fault in the KS circuit or the knock sensor. If the PCM

determines that an abnormal minimum or maximum

noise level is being experienced, DTC P0325 will set.

The PCM contains a knock sensor (KS) module. The

KS module contains the circuitry which allows the PCM

to utilize the KS signal and diagnose the KS sensor and

the KS circuitry. If the KS module is missing or faulty, a

continuous knock condition will be indicated, and the

PCM will set DTC P0325.

Although it is a plug-in device, the KS module is not

replaceable. If the KS module is faulty, the entire PCM

must be replaced.

0009

Linear Exhaust Gas Recirculation (EGR)

Control

The PCM monitors the exhaust gas recirculation (EGR)

actual position and adjusts the pintle position

accordingly. The PCM uses information from the

following sensors to control the pintle position:

• Engine coolant temperature (ECT) sensor.

• Throttle position (TP) sensor.

• Mass air flow (MAF) sensor.

Mass Air Flow (MAF) Sensor

The mass air flow (MAF) sensor measures the

difference between the volume and the quantity of air

that enters the engine. “Volume”means the size of the

space to be filled. “Quantity”means the number of air

molecules that will fit into the space. This information is

important to the PCM because heavier, denser air will

hold more fuel than lighter, thinner air. The PCM adjusts

the air/fuel ratio as needed depending on the MAF

value. Tech 2 reads the MAF value and displays it in

terms of grams per second (gm/s). At idle, Tech 2

should read between 4-7 gm/s on a fully warmed up

engine. Values should change quickly on acceleration.

Values should remain stable at any given RPM. A

failure in the MAF sensor or circuit will set DTC P0101,

DTC P0102, or DTC P0103.

0007

Manifold Absolute Pressure (MAP) Sensor

The manifold absolute pressure (MAP) sensor responds

to changes in intake manifold pressure (vacuum). The

MAP sensor signal voltage to the PCM varies from

below 2 volts at idle (high vacuum) to above 4 volts with

the ignition ON, engine not running or at wide-open

throttle (low vacuum).

The MAP sensor is used to determine the following:

•Manifold pressure changes while the linear EGR flow

test diagnostic is being run.

• Engine vacuum level for other diagnostics.

• Barometric pressure (BARO).

If the PCM detects a voltage that is lower than the

possible range of the MAP sensor, DTC P0107 will be

set. A signal voltage higher than the possible range of

the sensor will set DTC P0108. An intermittent low or

high voltage will set DTC P1107 or DTC P1106,

respectively. The PCM can detect a shifted MAP

sensor. The PCM compares the MAP sensor signal to a

calculated MAP based on throttle position and various

engine load factors. If the PCM detects a MAP signal

that varies excessively above or below the calculated

value, DTC P0106 will set.

055RW004

Powertrain Control Module (PCM)

The powertrain control module (PCM) is located in the

passenger compartment below the center console. The

PCM controls the following:

• Fuel metering system.

• Transmission shifting (automatic transmission only).

• Ignition timing.

• On-board diagnostics for powertrain functions.

The PCM constantly observes the information from

various sensors. The PCM controls the systems that

affect vehicle performance. The PCM performs the

diagnostic function of the system. It can recognize

operational problems, alert the driver through the MIL

(Service Engine Soon lamp), and store diagnostic

trouble codes (DTCs). DTCs identify the problem areas

to aid the technician in making repairs.

This engine uses 2 different control modules:

• IPCM-6KT for automatic transmission-equipped

vehicles.

• ISFI-6 for manual transmission-equipped vehicles.

PCM Function

The PCM supplies either 5 or 12 volts to power various

sensors or switches. The power is supplied through

resistances in the PCM which are so high in value that a

test light will not light when connected to the circuit. In

some cases, even an ordinary shop voltmeter will not

give an accurate reading because its resistance is too

low. Therefore, a digital voltmeter with at least 10

megohms input impedance is required to ensure

accurate voltage readings. Tool J 39200 meets this

requirement. The PCM controls output circuits such as

the injectors, IAC, cooling fan relays, etc., by controlling

the ground or the power feed circuit through transistors

of following device.

• Output Driver Module (ODM)

0005

PCM Components

The PCM is designed to maintain exhaust emission

levels to government mandated standards while

providing excellent driveability and fuel efficiency. The

PCM monitors numerous engine and vehicle functions

via electronic sensors such as the throttle position (TP)

sensor, heated oxygen sensor (HO2S), and vehicle

speed sensor (VSS). The PCM also controls certain

engine operations through the following:

•Fuel injector control

•Ignition control module

•Knock sensor

•Automatic transmission shift functions

•Cruise control

•A/C clutch control

PCM Voltage Description

The PCM supplies a buffered voltage to various

switches and sensors. It can do this because

resistance in the PCM is so high in value that a test light

may not illuminate when connected to the circuit. An

ordinary shop voltmeter may not give an accurate

reading because the voltmeter input impedance is too

low. Use a 10-megohm input impedance digital

voltmeter (such as J 39200) to assure accurate voltage

readings.

The input/output devices in the PCM include

analog-to-digital converters, signal buffers, counters,

and special drivers. The PCM controls most

components with electronic switches which complete a

ground circuit when turned “ON.” These switches are

arranged in groups of 4 and 7, called either a

surface-mounted quad driver module (QDM), which can

independently control up to 4 output terminals, or QDMs

which can independently control up to 7 outputs. Not all

outputs are always used.

PCM Input/Outputs

Inputs – Operating Conditions Read

•Air Conditioning “ON” or “OFF”

•Engine Coolant Temperature

•Crankshaft Position

•Exhaust Oxygen Content

•Electronic Ignition

•Manifold Absolute Pressure

•Battery Voltage

•Throttle Position

•Vehicle Speed

•Fuel Pump Voltage

•Power Steering Pressure

•Intake Air Temperature

•Mass Air Flow

•Engine Knock

•Camshaft Position

Outputs – Systems Controlled

•Exhaust Gas Recirculation (EGR)

•Ignition Control

•Fuel Control

•Idle Air Control

•Electric Fuel Pump

•Air Conditioning

•Diagnostics

–Malfunction Indicator Lamp (Service Engine Soon

lamp)

–Data Link Connector (DLC)

–Data Output

•Transmission Control Module

•Alternator Gain Control

PCM Service Precautions

The PCM is designed to withstand normal current draws

associated with vehicle operation. Avoid overloading

any circuit. When testing for opens and shorts, do not

ground or apply voltage to any of the PCM's circuits

unless instructed to do so. These circuits should only

be tested Tech-2. The PCM should remain connected

to the PCM or to a recommended breakout box.

Reprogramming The PCM

The Service Programming System (SPS) allows

reprogramming of the PCM without removing it from the

vehicle . This provides a flexible and cost-effective

method of making changes in software calibrations.

The service programming system (SPS) will not allow

incorrect software programming or incorrect calibration

changes.

Refer to Sections 0C1 - Service Programming System

and 11A1 - 6VE1 Immobiliser.

Throttle Position (TP) Sensor

The throttle position (TP) sensor is a potentiometer

connected to the throttle shaft on the throttle body. The

PCM monitors the voltage on the signal line and

calculates throttle position. As the throttle valve angle is

changed (accelerator pedal moved), the TP sensor

signal also changes. At a closed throttle position, the

output of the TP sensor is low. As the throttle valve

opens, the output increases so that at wide open throttle

(WOT), the output voltage should be above 4 volts.

The PCM calculates fuel delivery based on throttle

valve angle (driver demand). A broken or loose TP

sensor may cause intermittent bursts of fuel from an

injector and unstable idle because the PCM thinks the

throttle is moving. A hard failure in the TP sensor 5-volt

reference or signal circuits will set a DTC P0123. A

hard failure with the TP sensor ground circuit may set

DTC P0123. Once a DTC is set, the PCM will use an

artificial default value based on engine RPM and mass

air flow for the throttle position, and some vehicle

performance will return. A high idle may result when

DTC P0123 is set. The PCM can also detect a shifted

TP sensor. The PCM monitors throttle position and

compares the actual TP sensor reading to a predicted

TP value calculated from engine speed. If the PCM

detects an out-of-range condition, DTC P0121 will be

set.

0021

Transmission Fluid Temperature (TFT)

Sensor

The transmission fluid temperature sensor is a

thermistor which changes its resistance based on the

temperature of the transmission fluid. For a complete

description of the TFT sensor, refer to 4L30-E

Automatic Transmission Diagnosis.

A failure in the TFT sensor or associated wiring will

cause DTC P0712 or DTC P0713 to set. In this case,

engine coolant temperature will be substituted for the

TFT sensor value and the transmission will operate

normally.

Transmission Range Switch

Important: The vehicle should not be driven with the

transmission range switch disconnected; idle quality will

be affected.

The four inputs from the transmission range switch

indicate to the PCM which position is selected by the

transmission selector lever. This information is used for

ignition timing, EVAP canister purge, EGR and IAC

valve operation.

For more information on the transmission on the

transmission range switch, refer to 4L30-E Automatic

Transmission.

Vehicle Speed Sensor (VSS)

The PCM determines the speed of the vehicle by

converting a plusing voltage signal from the vehicle

speed sensor (VSS) into miles per hour. The PCM uses

this signal to operate the cruise control, speedometer,

and the TCC and shift solenoids in the transmission. For

more information on the TCC and shift solenoids, refer

to 4L30-E Automatic Transmission.

0008

Use of Circuit Testing Tools

Do not use a test light to diagnose the powertrain

electrical systems unless specifically instructed by the

diagnostic procedures. Use Connector Test Adapter Kit

J 35616 whenever diagnostic procedures call for

probing connectors.

Aftermarket Electrical and Vacuum

Equipment

Aftermarket (add-on) electrical and vacuum equipment

is defined as any equipment which connects to the

vehicle's electrical or vacuum systems that is installed

on a vehicle after it leaves the factory. No allowances

have been made in the vehicle design for this type of

equipment.

NOTE: No add-on vacuum equipment should be added

to this vehicle.

NOTE: Add-on electrical equipment must only be

connected to the vehicle's electrical system at the

battery (power and ground).

Add-on electrical equipment, even when installed to

these guidelines, may still cause the powertrain system

to malfunction. This may also include equipment not

connected to the vehicle electrical system such as

portable telephones and radios. Therefore, the first step

in diagnosing any powertrain problem is to eliminate all

aftermarket electrical equipment from the vehicle. After

this is done, if the problem still exists, it may be

diagnosed in the normal manner.

Electrostatic Discharge Damage

Electronic components used in the PCM are often

designed to carry very low voltage. Electronic

components are susceptible to damage caused by

electrostatic discharge. Less than 100 volts of static

electricity can cause damage to some electronic

components. By comparison, it takes as much as 4000

volts for a person to feel even the zap of a static

discharge.

TS23793

There are several ways for a person to become

statically charged. The most common methods of

charging are by friction and induction.

•An example of charging by friction is a person sliding

across a vehicle seat.

•Charge by induction occurs when a person with well

insulated shoes stands near a highly charged object

and momentary touches ground. Charges of the

same polarity are drained off leaving the person

highly charged with the opposite polarity. Static

charges can cause damage, therefore it is important

to use care when handling and testing electronic

components.

NOTE: To prevent possible electrostatic discharge

damage, follow these guidelines:

•Do not touch the PCM connector pins or soldered

components on the PCM circuit board.

•Do not touch the knock sensor module component

leads.

•Do not open the replacement part package until the

part is ready to be installed.

•Before removing the part from the package, ground

the package to a known good ground on the vehicle.

•If the part has been handled while sliding across the

seat, while sitting down from a standing position, or

while walking a distance, touch a known good ground

before installing the part.

Upshift Lamp

Refer to Manual Transmission.

General Description (Air Induction)

Air Induction System

The air induction system filters contaminants from the

outside air, and directs the progress of the air as it is

drawn into the engine. A remote-mounted air cleaner

prevents dirt and debris in the air from entering the

engine. The air duct assembly routes filtered air to the

throttle body. Air enters the engine by to following

steps:

1. Through the throttle body.

2. Into the common chamber.

3. Through the cylinder head intake ports.

4. Into the cylinders.

055RV010

General Description (Fuel Metering)

Acceleration Mode

The PCM provides extra fuel when it detects a rapid

increase in the throttle position and the air flow.

Accelerator Controls

The accelerator control system is a cable-type system

with specific linkage adjustments.

Refer to Cable Adjustment.

Battery Voltage Correction Mode

When battery voltage is low, the PCM will compensate

for the weak spark by increasing the following:

•The amount of fuel delivered.

•The idle RPM.

•Ignition dwell time.

CMP Signal

The PCM uses this signal to determine the position of

the number 1 piston during its power stroke, allowing

the PCM to calculate true sequential multiport fuel

injection (SFI). Loss of this signal will set a DTC P0341.

If the CMP signal is lost while the engine is running, the

fuel injection system will shift to a calculated sequential

fuel injection based on the last fuel injection pulse, and

the engine will continue to run. The engine can be

restarted and will run in the calculated sequential mode

as long as the fault is present, with a 1-in-6 chance of

being correct.

Clear Flood Mode

Clear a flooded engine by pushing the accelerator pedal

down all the way. The PCM then de-energizes the fuel

injectors. The PCM holds the fuel injectors

de-energized as long as the throttle remains above 80%

and the engine speed is below 800 RPM. If the throttle

position becomes less than 80%, the PCM again begins

to pulse the injectors “ON” and “OFF,” allowing fuel into

the cylinders.

Deceleration Mode

The PCM reduces the amount of fuel injected when it

detects a decrease in the throttle position and the air

flow. When deceleration is very fast, the PCM may cut

off fuel completely for short periods.

Engine Speed Fuel Disable Mode

The PCM monitors engine speed. It turns off the fuel

injectors when the engine speed increase above 6400

RPM. The fuel injectors are turned back on when

engine speed decreases below 6150 RPM.

Fuel Cutoff Mode

No fuel is delivered by the fuel injectors when the

ignition is “OFF.” This prevents engine run-on. In

addition, the PCM suspends fuel delivery if no reference

pulses are detected (engine not running) to prevent

engine flooding.

Fuel Injector

The sequential multiport fuel injection (SFI) fuel injector

is a solenoid-operated device controlled by the PCM.

The PCM energizes the solenoid, which opens a valve

to allow fuel delivery.

The fuel is injected under pressure in a conical spray

pattern at the opening of the intake valve. Excess fuel

not used by the injectors passes through the fuel

pressure regulator before being returned to the fuel

tank.

A fuel injector which is stuck partly open will cause a

loss of fuel pressure after engine shut down, causing

long crank times.

0003

Fuel Metering System Components

The fuel metering system is made up of the following

parts:

• The fuel injectors.

• The throttle body.

• The fuel rail.

• The fuel pressure regulator.

• The PCM.

• The crankshaft position (CKP) sensor.

• The camshaft position (CMP) sensor.

• The idle air control (IAC) valve.

• The fuel pump.

• The fuel pump relay.

Basic System Operation

The fuel metering system starts with the fuel in the fuel

tank. An electric fuel pump, located in the fuel tank,

pumps fuel to the fuel rail through an in-line fuel filter.

The pump is designed to provide fuel at a pressure

above the pressure needed by the injectors. A fuel

pressure regulator in the fuel rail keeps fuel available to

the fuel injectors at a constant pressure. A return line

delivers unused fuel back to the fuel tank. Refer to

Section 6C for further information on the fuel tank, line

filter, and fuel pipes.

Fuel Metering System Purpose

The basic function of the air/fuel metering system is to

control the air/fuel delivery to the engine. Fuel is

delivered to the engine by individual fuel injectors

mounted in the intake manifold near each intake valve.

The main control sensor is the heated oxygen sensor

(HO2S) located in the exhaust system. The HO2S tells

the PCM how much oxygen is in the exhaust gas. The

PCM changes the air/fuel ratio to the engine by

controlling the amount of time that fuel injector is “ON.”

The best mixture to minimize exhaust emissions is 14.7

parts of air to 1 part of petrol by weight, which allows the

catalytic converter to operate most efficiently. Because

of the constant measuring and adjusting of the air/fuel

ratio, the fuel injection system is called a “closed loop”

system.

The PCM monitors signals from several sensors in

order to determine the fuel needs of the engine. Fuel is

delivered under one of several conditions called

“modes.” All modes are controlled by the PCM.

Fuel Pressure Regulator

The fuel pressure regulator is a diaphragm-operated

relief valve mounted on the fuel rail with fuel pump

pressure on one side and manifold pressure on the

other side. The fuel pressure regulator maintains the

fuel pressure available to the injector at three times

barometric pressure adjusted for engine load. It may be

serviced separate.

If the pressure is too low, poor performance and a DTC

P0131, DTC P0151,DTC P0171 or DTC P1171 will be

the result. If the pressure is too high, excessive odor

and/or a DTC P0132, DTC P0152,DTC P0172 or DTC

P0175 will be the result. Refer to Fuel System

Diagnosis for information on diagnosing fuel pressure

conditions.

0011

Fuel Pump Electrical Circuit

When the key is first turned “ON,” the PCM energizes

the fuel pump relay for two seconds to build up the fuel

pressure quickly. If the engine is not started within two

seconds, the PCM shuts the fuel pump off and waits

until the engine is cranked. When the engine is cranked

and the 58 X crankshaft position signal has been

detected by the PCM, the PCM supplies 12 volts to the

fuel pump relay to energize the electric in-tank fuel

pump.

An inoperative fuel pump will cause a “no-start”

condition. A fuel pump which does not provide enough

pressure will result in poor performance.

Fuel Rail

The fuel rail is mounted to the top of the engine and

distributes fuel to the individual injectors. Fuel is

delivered to the fuel inlet tube of the fuel rail by the fuel

lines. The fuel goes through the fuel rail to the fuel

pressure regulator. The fuel pressure regulator

maintains a constant fuel pressure at the injectors.

Remaining fuel is then returned to the fuel tank.

055RW009

Idle Air Control (IAC) Valve

The purpose of the idle air control (IAC) valve is to

control engine idle speed, while preventing stalls due to

changes in engine load. The IAC valve, mounted in the

throttle body, controls bypass air around the throttle

plate. By moving the conical valve (pintle) in (to

decrease air flow) or out (to increase air flow), a

controlled amount of air can move around the throttle

plate. If the RPM is too low, the PCM will retract the IAC

pintle, resulting in more air moving past the throttle plate

to increase the RPM. If the RPM is too high, the PCM

will extend the IAC pintle, allowing less air to move past

the throttle plate, decreasing the RPM.

The IAC pintle valve moves in small steps called counts.

During idle, the proper position of the IAC pintle is

calculated by the PCM based on battery voltage,

coolant temperature, engine load, and engine RPM. If

the RPM drops below a specified value, and the throttle

plate is closed, the PCM senses a near-stall condition.

The PCM will then calculate a new IAC pintle valve

position to prevent stalls.

If the IAC valve is disconnected and reconnected with

the engine running, the idle RPM will be wrong. In this

case, the IAC must be reset. The IAC resets when the

key is cycled “ON” then “OFF.” When servicing the IAC,

it should only be disconnected or connected with the

ignition “OFF.”

The position of the IAC pintle valve affects engine

start-up and the idle characteristics of the vehicle. If the

IAC pintle is fully open, too much air will be allowed into

the manifold. This results in high idle speed, along with

possible hard starting and a lean air/fuel ratio. DTC

P0507 or DTC P1509 may set. If the IAC pintle is stuck

closed, too little air will be allowed in the manifold. This

results in a low idle speed, along with possible hard

starting and a rich air/fuel ratio. DTC P0506 or DTC

P1508 may set. If the IAC pintle is stuck part-way

open, the idle may be high or low and will not respond to

changes in the engine load.

0006

Run Mode

The run mode has the following two conditions:

• Open loop

• Closed loop

When the engine is first started the system is in “open

loop” operation. In “open loop,” the PCM ignores the

signal from the heated oxygen sensor (HO2S). It

calculates the air/fuel ratio based on inputs from the TP,

ECT, and MAF sensors.

The system remains in “open loop” until the following

conditions are met:

• The HO2S has a varying voltage output showing that

it is hot enough to operate properly (this depends on

temperature).

• The ECT has reached a specified temperature.

• A specific amount of time has elapsed since starting

the engine.

• Engine speed has been greater than a specified RPM

since start-up.

The specific values for the above conditions vary with

different engines and are stored in the programmable

read only memory (PROM). When these conditions are

met, the system enters “closed loop” operation. In

“closed loop,” the PCM calculates the air/fuel ratio

(injector on-time) based on the signal from the HO2S.

This allows the air/fuel ratio to stay very close to 14.7:1.

Starting Mode

When the ignition is first turned “ON,” the PCM

energizes the fuel pump relay for two seconds to allow

the fuel pump to build up pressure. The PCM then

checks the engine coolant temperature (ECT) sensor

and the throttle position (TP) sensor to determine the

proper air/fuel ratio for starting.

The PCM controls the amount of fuel delivered in the

starting mode by adjusting how long the fuel injectors

are energized by pulsing the injectors for very short

times.

Throttle Body Unit

The throttle body has a throttle plate to control the

amount of air delivered to the engine. The TP sensor

and IAC valve are also mounted on the throttle body.

Vacuum ports located behind the throttle plate provide

the vacuum signals needed by various components.

Engine coolant is directed through a coolant cavity in

the throttle body to warm the throttle valve and to

prevent icing.

0019

General Description (Electronic Ignition

System)

Camshaft Position (CMP) Sensor

As the camshaft sprocket turns, a magnet in the

sprocket activates the Hall-effect switch in the CMP

sensor. When the Hall-effect switch is activated, it

grounds the signal line to the PCM, pulling the camshaft

position sensor signal circuit's applied voltage low. This

is a CMP signal. The CMP signals is created as piston

#1 is approximately 25° after top dead counter on the

power stroke. If the correct CMP signal is not received

by the PCM, DTC P0341 will be set.

0014

Crankshaft Position (CKP) Sensor

The crankshaft position (CKP) sensor provides a signal

used by the powertrain control module (PCM) to

calculate the ignition sequence. The sensor initiates

the 58X reference pulses which the PCM uses to

calculate RPM and crankshaft position.

Electronic Ignition

The electronic ignition system controls fuel combustion

by providing a spark to ignite the compressed air/fuel

mixture at the correct time. To provide optimum engine

performance, fuel economy, and control of exhaust

emissions, the PCM controls the spark advance of the

ignition system. Electronic ignition has the following

advantages over a mechanical distributor system:

• No moving parts.

• Less maintenance.

• Remote mounting capability.

• No mechanical load on the engine.

• More coil cooldown time between firing events.

• Elimination of mechanical timing adjustments.

• Increased available ignition coil saturation time.

0013

Ignition Coils

A separate coil-at-plug module is located at each spark

plug. The coil-at-plug module is attached to the engine

with two screws. It is installed directly to the spark plug

by an electrical contact inside a rubber boot. A

three-way connector provides 12-volt primary supply

from the 15-amp ignition fuse, a ground-switching

trigger line from the PCM, and a ground.

0001

Ignition Control

The ignition control (IC) spark timing is the PCM's

method of controlling the spark advance and the ignition

dwell.

The IC spark advance and the ignition dwell are

calculated by the PCM using the following inputs:

• Engine speed.

• Crankshaft position (58X reference).

• Camshaft position (CMP) sensor.

• Engine coolant temperature (ECT) sensor.

• Throttle position (TP) sensor.

• Knock signal (knock sensor).

• Park/Neutral position (PRNDL input).

• Vehicle speed (vehicle speed sensor).

• PCM and ignition system supply voltage.

• The crankshaft positron (CKP) sensor sends the

PCM a 58X signal related to the exact position of the

crankshaft.

TS22909

• The camshaft position (CMP) sensor sends a signal

related to the position of the camshaft.

TS22910

• The knock sensor tells the PCM if there is any

problem with pre-ignition or detonation. This

information allows the PCM to retard timing, if

necessary.

TS24037

Based on these sensor signals and engine load

information, the PCM sends 5V to each ignition coil.

060RW015

The PCM applies 5V signal voltage to the ignition coil

requiring ignition. This signal sets on the power

transistor of the ignition coil to establish a grounding

circuit for the primary coil, applying battery voltage to

the primary coil.

At the ignition timing, the PCM stops sending the 5V

signal voltage. Under this condition the power transistor

of the ignition coil is set off to cut the battery voltage to

the primary coil, thereby causing a magnetic field

generated in the primary coil to collapse. On this

moment a line of magnetic force flows to the secondary

coil, and when this magnetic line crosses the coil, high

voltage induced by the secondary ignition circuit to flow

through the spark plug to the ground.

TS24047

Ignition Control PCM Output

The PCM provides a zero volt (actually about 100 mV to

200 mV) or a 5-volt output signal to the ignition control

(IC) module. Each spark plug has its own primary and

secondary coil module ("coil-at-plug") located at the

spark plug itself. When the ignition coil receives the

5-volt signal from the PCM, it provides a ground path for

the B+ supply to the primary side of the coil-at -plug

module. This energizes the primary coil and creates a

magnetic field in the coil-at-plug module. When the

PCM shuts off the 5-volt signal to the ignition control

module, the ground path for the primary coil is broken.

The magnetic field collapses and induces a high voltage

secondary impulse which fires the spark plug and

ignites the air/fuel mixture.

The circuit between the PCM and the ignition coil is

monitored for open circuits, shorts to voltage, and shorts

to ground. If the PCM detects one of these events, it will

set one of the following DTCs:

• P0351: Ignition coil Fault on Cylinder #1

• P0352: Ignition coil Fault on Cylinder #2

• P0353: Ignition coil Fault on Cylinder #3

• P0354: Ignition coil Fault on Cylinder #4

• P0355: Ignition coil Fault on Cylinder #5

• P0356: Ignition coil Fault on Cylinder #6

Knock Sensor (KS) PCM Input

The knock sensor (KS) system is comprised of a knock

sensor and the PCM. The PCM monitors the KS

signals to determine when engine detonation occurs.

When a knock sensor detects detonation, the PCM

retards the spark timing to reduce detonation. Timing

may also be retarded because of excessive mechanical

engine or transmission noise.

Powertrain Control Module (PCM)

The PCM is responsible for maintaining proper spark

and fuel injection timing for all driving conditions. To

provide optimum driveability and emissions, the PCM

monitors the input signals from the following

components in order to calculate spark timing:

•Engine coolant temperature (ECT) sensor.

•Intake air temperature (IAT) sensor.

•Mass air flow (MAF) sensor.

•PRNDL input from transmission range switch.

•Throttle position (TP) sensor.

•Vehicle speed sensor (VSS) .

•Crankshaft position (CKP) sensor.

Spark Plug

Although worn or dirty spark plugs may give satisfactory

operation at idling speed, they frequency fail at higher

engine speeds. Faulty spark plugs may cause poor fuel

economy, power loss, loss of speed, hard starting and

generally poor engine performance. Follow the

scheduled maintenance service recommendations to

ensure satisfactory spark plug performance. Refer to

Maintenance and Lubrication.

Normal spark plug operation will result in brown to

grayish-tan deposits appearing on the insulator portion

of the spark plug. A small amount of red-brown, yellow,

and white powdery material may also be present on the

insulator tip around the center electrode. These

deposits are normal combustion by-products of fuels

and lubricating oils with additives. Some electrode wear

will also occur. Engines which are not running properly

are often referred to as “misfiring.” This means the

ignition spark is not igniting the air/fuel mixture at the

proper time. While other ignition and fuel system

causes must also be considered, possible causes

include ignition system conditions which allow the spark

voltage to reach ground in some other manner than by

jumping across the air gap at the tip of the spark plug,

leaving the air/fuel mixture unburned. Misfiring may also

occur when the tip of the spark plug becomes

overheated and ignites the mixture before the spark

jumps. This is referred to as “pre-ignition.”

Spark plugs may also misfire due to fouling, excessive

gap, or a cracked or broken insulator. If misfiring occurs

before the recommended replacement interval, locate

and correct the cause.

Carbon fouling of the spark plug is indicated by dry,

black carbon (soot) deposits on the portion of the spark

plug in the cylinder. Excessive idling and slow speeds

under light engine loads can keep the spark plug

temperatures so low that these deposits are not burned

off. Very rich fuel mixtures or poor ignition system

output may also be the cause. Refer to DTC P0172.

Oil fouling of the spark plug is indicated by wet oily

deposits on the portion of the spark plug in the cylinder,

usually with little electrode wear. This may be caused

by oil during break-in of new or newly overhauled

engines. Deposit fouling of the spark plug occurs when

the normal red-brown, yellow or white deposits of

combustion by products become sufficient to cause

misfiring. In some cases, these deposits may melt and

form a shiny glaze on the insulator around the center

electrode. If the fouling is found in only one or two

cylinders, valve stem clearances or intake valve seals

may be allowing excess lubricating oil to enter the

cylinder, particularly if the deposits are heavier on the

side of the spark plug facing the intake valve.

TS23995

Excessive gap means that the air space between the

center and the side electrodes at the bottom of the

spark plug is too wide for consistent firing. This may be

due to improper gap adjustment or to excessive wear of

the electrode during use. A check of the gap size and

comparison to the gap specified for the vehicle in

Maintenance and Lubrication will tell if the gap is too

wide. A spark plug gap that is too small may cause an

unstable idle condition. Excessive gap wear can be an

indication of continuous operation at high speeds or

with engine loads, causing the spark to run too hot.

Another possible cause is an excessively lean fuel

mixture.

TS23992

Low or high spark plug installation torque or improper

seating can result in the spark plug running too hot and

can cause excessive center electrode wear. The plug

and the cylinder head seats must be in good contact for

proper heat transfer and spark plug cooling. Dirty or

damaged threads in the head or on the spark plug can

keep it from seating even though the proper torque is

applied. Once spark plugs are properly seated, tighten

them to the torque shown in the Specifications Table.

Low torque may result in poor contact of the seats due

to a loose spark plug. Overtightening may cause the

spark plug shell to be stretched and will result in poor

contact between the seats. In extreme cases, exhaust

blow-by and damage beyond simple gap wear may

occur.

Cracked or broken insulators may be the result of

improper installation, damage during spark plug

re-gapping, or heat shock to the insulator material.

Upper insulators can be broken when a poorly fitting

tool is used during installation or removal, when the

spark plug is hit from the outside, or is dropped on a

hard surface. Cracks in the upper insulator may be

inside the shell and not visible. Also, the breakage may

not cause problems until oil or moisture penetrates the

crack later.

TS23994

A broken or cracked lower insulator tip (around the

center electrode) may result from damage during

re-gapping or from “heat shock” (spark plug suddenly

operating too hot).

TS23993

• Damage during re-gapping can happen if the gapping

tool is pushed against the center electrode or the

insulator around it, causing the insulator to crack.

When re-gapping a spark plug, make the adjustment

by bending only the ground side terminal, keeping the

tool clear of other parts.

• "Heat shock" breakage in the lower insulator tip

generally occurs during several engine operating

conditions (high speeds or heavy loading) and may

be caused by over-advanced timing or low grade

fuels. Heat shock refers to a rapid increase in the tip

temperature that causes the insulator material to

crack.

Spark plugs with less than the recommended amount of

service can sometimes be cleaned and re-gapped ,

then returned to service. However, if there is any doubt

about the serviceability of a spark plug, replace it.

Spark plugs with cracked or broken insulators should

always be replaced.

A/C Clutch Diagnosis

A/C Clutch Circuit Operation

A 12-volt signal is supplied to the A/C request input of

the PCM when the A/C is selected through the A/C

control switch.

The A/C compressor clutch relay is controlled through

the PCM. This allows the PCM to modify the idle air

control position prior to the A/C clutch engagement for

better idle quality. If the engine operating conditions are

within their specified calibrated acceptable ranges, the

PCM will enable the A/C compressor relay. This is done

by providing a ground path for the A/C relay coil within

the PCM. When the A/C compressor relay is enabled,

battery voltage is supplied to the compressor clutch coil.

The PCM will enable the A/C compressor clutch

whenever the engine is running and the A/C has been

requested. The PCM will not enable the A/C

compressor clutch if any of the following conditions are

met:

•The throttle is greater than 90%.

•The engine speed is greater than 6315 RPM.

•The ECT is greater than 119°C (246°F).

•The IAT is less than 5°C (41°F).

•The throttle is more than 80% open.

A/C Clutch Circuit Purpose

The A/C compressor operation is controlled by the

powertrain control module (PCM) for the following

reasons:

•It improvises idle quality during compressor clutch

engagement.

•It improvises wide open throttle (WOT) performance.

•It provides A/C compressor protection from operation

with incorrect refrigerant pressures.

The A/C electrical system consists of the following

components:

•The A/C control head.

•The A/C refrigerant pressure switches.

•The A/C compressor clutch.

•The A/C compressor clutch relay.

•The PCM.

A/C Request Signal

This signal tells the PCM when the A/C mode is

selected at the A/C control head. The PCM uses this to

adjust the idle speed before turning on the A/C clutch.

The A/C compressor will be inoperative if this signal is

not available to the PCM.

Refer to A/C Clutch Circuit Diagnosis for A/C wiring

diagrams and diagnosis for A/C electrical system.

General Description (Exhaust Gas

Recirculation (EGR) System)

EGR Purpose

The exhaust gas recirculation (EGR) system is use to

reduce emission levels of oxides of nitrogen (NOx).

NOx emission levels are caused by a high combustion

temperature. The EGR system lowers the NOx

emission levels by decreasing the combustion

temperature.

057RW002

Linear EGR Valve

The main element of the system is the linear EGR

valve. The EGR valve feeds small amounts of exhaust

gas back into the combustion chamber. The fuel/air

mixture will be diluted and combustion temperatures

reduced.

Linear EGR Control

The PCM monitors the EGR actual positron and adjusts

the pintle position accordingly. The uses information

from the following sensors to control the pintle position:

• Engine coolant temperature (ECT) sensor.

• Throttle position (TP) sensor.

• Mass air flow (MAF) sensor.

Linear EGR Valve Operation and Results of

Incorrect Operation

The linear EGR valve is designed to accurately supply

EGR to the engine independent of intake manifold

vacuum. The valve controls EGR flow from the exhaust

to the intake manifold through an orifice with a PCM

controlled pintle. During operation, the PCM controls

pintle position by monitoring the pintle position feedback

signal. The feedback signal can be monitored with

Tech 2 as “Actual EGR Pos.” “Actual EGR Pos.”should

always be near the commanded EGR position ("Desired

EGR Pos."). If a problem with the EGR system will not

allow the PCM to control the pintle position properly,

DTC P1406 will set. The PCM also tests for EGR flow.

If incorrect flow is detected, DTC P0401 will set. If

DTCs P0401 and/or P1406 are set, refer to the DTC

charts.

The linear EGR valve is usually activated under the

following conditions:

• Warm engine operation.

• Above-idle speed.

Too much EGR flow at idle, cruise or cold operation may

cause any of the following conditions to occur:

• Engine stalls after a cold start.

• Engine stalls at idle after deceleration.

• Vehicle surges during cruise.

• Rough idle.

Too little or no EGR flow may allow combustion

temperatures to get too high. This could cause:

• Spark knock (detonation).

• Engine overheating.

• Emission test failure.

• DTC P0401 (EGR flow test).

• Poor fuel economy.

0017

EGR Pintle Position Sensor

The PCM monitors the EGR valve pintle position input

to endure that the valve responds properly to

commands from the PCM and to detect a fault if the

pintle position sensor and control circuits are open or

shorted. If the PCM detects a pintle position signal

voltage outside the normal range of the pintle position

sensor, or a signal voltage that is not within a tolerance

considered acceptable for proper EGR system

operation, the PCM will set DTC P1406.

General Description (Positive Crankcase

Ventilation (PCV) System)

Crankcase Ventilation System Purpose

The crankcase ventilation system is use to consume

crankcase vapors in the combustion process instead of

venting them to the atmosphere. Fresh air from the

throttle body is supplied to the crankcase and mixed

with blow-by gases. This mixture is then passed

through the positive crankcase ventilation (PCV) valve

into the common chamber.

Crankcase Ventilation System Operation

The primary control is through the positive crankcase

ventilation (PCV) valve. The PCV valve meters the flow

at a rate that depends on the intake vacuum. The PCV

valve restricts the flow when the inlet vacuum is highest.

In addition, the PCV valve can seal the common

chamber off in case of sudden high pressure in the

crankcase.

028RV002

While the engine is running, exhaust fuses and small

amounts of the fuel/air mixture escape past the piston

rings and enter the crankcase. These gases are mixed

with clean air entering through a tube from the air intake

duct.

028RW002

During normal, part-throttle operation, the system is

designed to allow crankcase gases to flow through the

PCV valve into the throttle body to be consumed by

normal combustion.

A plugged valve or PCV hose may cause the following

conditions:

• Rough idle.

• Stalling of slow idle speed.

• Oil leaks.

• Sludge in the engine.

A leaking PCV hose would cause:

• Rough idle.

• Stalling.

• High idle speed.

Special Tools

901RW180

EndOFCallout

Legend

(1) PCMCIA Card

(2) RS232 Loop Back Connector

(3) SAE 16/19 Adapter

(4) DLC Cable

(5) TECH–2

ILLUSTRATION TOOL NO.

TOOL NAME

5-8840-0285-0

(J 39200)

High Impedance

Multimeter (Digital

Voltmeter – DVM)

(1) PCMCIA Card

(2) RS232 Loop Back

Connector

(3) SAE 16/19 Adapter

(4) DLC Cable

(5) TECH–2

5-8840-0607-0

(J 34142-B)

Unpowered Test Light

5-8840-0385-0

(J 35616-A/BT-8637)

Connector Test Adapter

Kit

5-8840-0383-0

(J 26792/BT-7220-1)

Spark Tester

5-8840-0279-0

(J 23738-A)

Vacuum Pump with

Gauge or common tool

BT-8515

Exhaust Back Pressure

Tester or common tool

5-8840-2640-0

(J 39194-B)

Heated Oxygen Sensor

Wrench

5-8840-0632-0

(J 35689-A)

Terminal Remover

5-8840-0388-0

(J 28742-A)

Weather Pack II Terminal

Remover

5-8840-2635-0

(J 39021-90)

Injector Switch Box

5-8840-2636-0

(J 39021-65)

Injector Test Light

ILLUSTRATION TOOL NO.

TOOL NAME

1. 5-8840-2607-0 (J-41413)EVAP Pressure/Purge

Diagnostic Station is a multipurpose tool which is

used to perform several diagnostic procedures for

enhanced emission testing. The station will

accommodate a nitrogen gas filled cylinder which is

used to pressurize the vehicle EVAP system for a

leakdown test and leak location test when a vehicle

is repaired for leakage in the enhanced evaporative

emission control system. It also has two additional

gauges (inches of mercury and inches of water)

which are used to measure both source vacuum

and EVAP canister purge vacuum to verify correct

operation and vapor flow within the canister purge

circuit.

2. 5-8840-2608-0 (J-41416) Ultrasonic Leak Detector

is a microprocessor-based device used to detect

leaks in the enhanced evaporative emission control

system. The evaporative system is pressurized to

30 inches of water using the 5-8840-2607-0

(J-41413) EVAP Pressure/Purge Diagnostic

System. Small leaks in the EVAP system will emit

sound at a high frequency undetectable by a human

ear but detectable with the 5-8840-2608-0

(J-41416). The technician traces along the

evaporative system and can pinpoint leaks due to

corroded lines, cracked hoses, or a damaged EVAP

component. The detector includes a high quality

set of headphones to block out surrounding shop

noise and the LED sensitivity meter allows a visual

reference for locating leaks in conjunction with the

audio output heard through the headphones.

5-8840-2607-0

(J 41413)

EVAP Pressure/Purge

Diagnostic Station

5-8840-2608-0

(J 41416)

Ultrasonic Leak Detector

ILLUSTRATION TOOL NO.

TOOL NAME