SECTION 6C3-1 - GENERAL INFORMATION -

GEN III V8 ENGINE

IMPORTANT:

Before performing any Service Operation or other procedure described in this Section, refer to Section 00

CAUTIONS AND NOTES in this VX Service Information for correct workshop practices with regards to

safety and/or property damage.

1. GENERAL DESCRI PTION

The engine used in this vehicle uses an Powertrain Control Module (PCM) to control exhaust emissions while

maintaining excellent driveability and fuel economy. The PCM maintains a desired air/fuel ratio at precisely 14.7

to 1. To m aintain a 14.7 to 1 air fuel ratio the PCM monitors the output signal from two oxygen sensors. The PCM

will either add or subtract fuel pulses based on the oxygen sensors output signal. This method of feed back fuel

control is called CLOSED LOOP.

In addition to fuel control, the PCM also controls the following systems.

• The Ignition Dwell

• The Ignition Timing

• The Idle Speed

• The Engine Electric Cooling Fan

• The Fuel Pump

• The Instrument Panel Check Powertrain Lamp (CPL)

• The A/C Compressor Clutch

• The Automatic Transmission Functions

• The Manual Transmission Reverse Inhibit

• Theft Deterrent

The PCM also interfaces with other vehicle control modules, such as the Powertrain Interface Module (PIM),

Instruments, and Body Control Module (BCM). The following diagram contains a list of the various operating

conditions sensed by the PCM, and the various systems controlled. Details of basic operation, diagnosis, and

service are covered in this Section.

The PCM has a built-in diagnostic system that identifies operational problems and alerts the driver by illuminating

the Check Powertrain Lamp (CPL) on the instrument panel. If the lamp illuminates while driving, it does not mean

that the engine should be stopped immediately, but the cause of the lam p illuminating should be checked as soon

as is reas onably pos sible. The PCM has built in bac k-up s ys tems that in all but the most severe faults will allow the

vehicle to operate in a near normal manner until repairs can be made.

Below the instrument panel is a Data Link Connector (DLC) which is used by the assembly plant for a computer

check-out of the powertrain management system. The DLC is also used in service to help diagnose the system

using Tech 2. Refer to Section 6C3-2, DIAGNOSIS of the VX Series Service Information for further details.

The locations of the Engine Management System (EMS) components of the system are shown in the following

Figures 6C3-1-2 through 6C3-1-5.

For the transmission Management System components and their locations, refer to Figure 6C1-1-6 of the VX

Series Service Information.

Note:

Some parameters may travel through one or more controllers for input or output controls.

ENGINE CONTROLS

TRANSMISSION CONTROLS

Figure 6C3-1-1 PCM Operating Conditions Sensed and Systems Controlled

• A/C Pressure Sensor

• A/C Request "ON" or "OFF"

• Battery Voltage

• Camshaft Position (CMP)

• Crankshaft Position (CKP)

• DLC Data Stream Input

• Engine Coolant Level Switch

• Engine Coolant Temperature (ECT)

• Engine Cooling Fan Response

• Engine Knock (KS)

• Engine Speed (RPM)

• Exhaust Gas Oxygen Content

• Intake Air Temperature (IAT)

• Mass Air Flow (MAF)

• Manifold Absolute Pressure (MAP)

• Oil Pressure Sensor

• Spark Retard Signal

• Stop Lamp Switch

• Throttle Position (TP)

• Transmission Gear Position

•

Theft Deterrent Signal

POWERTRAIN

CONTROL

MODULE (PCM)

• Air Conditioning Compressor

Clutch

• Canister Purge Solenoid

• Diagnostics

• - Check Powertrain Lamp (CPL)

• - DLC Data Stream Output

• - Field Service Mode

• Electric Engine Cooling Fan

• Electronic Spark Control (ESC)

• Electronic Spark Timing (EST)

• Fuel Control

- Fuel Injectors

- Fuel Pump

• Idle Air Control

• Torque Management

OPERATING PARAMETERS SENSED SYSTEMS CONTROLLED

• Battery Voltage

• Power/Economy Switch

• Engine Speed (Engine RPM)

• Engine Coolant Temperature (ECT)

• Stop Lamp Switch

• Throttle Position (TP Sensor)

• Transmission Fluid Temperature

(TFT)

• Transmission Gear Position

• Vehicle Speed Sensor (VSS)

• Transmission Fluid Pressure (TFP)

• Switch Assembly

• TCC Enable Solenoid

• 3-2 Shift Solenoid

• 1-2 Shift Solenoid

• 2-3 Shift Solenoid

• Diagnostics

• - Check Powertrain Lamp (CPL)

• - DLC Data Stream Output

• Manual Transmission Reverse

Inhibit

POWERTRAIN

CONTROL

MODULE (PCM)

OPERATING PARAMETERS SENSED SYSTEM CONTROLLED

POWERTRAIN

INTERFACE

MODUL E (PIM)

POWERTRAIN

INTERFACE

MODULE (PIM)

BODY

CONTROL

MODUL E (BC M)

BODY

CONTROL

MODULE (BCM)

T26C3001

151617 18

20 21

Figure 6C3-1-2 Component Locations View GEN III V8 Engine

1. Engine Compartment Fusible Link Housing

2. Battery Harness Fusible Link Housing

3. Engine Compartment Relay Housing

4. Engine Compartment Relay Housing

5. Fuel Pressure Regulator (in Fuel Tank)

6. A/C Accumulator Tank

7. Brake Hydraulic Failure Switch

8. Fuel Injectors (8)

9. Idle Air Control (IAC) Valve

10. Check Powertrain Lamp (CPL)

11. Ignition Coil/Module Right Bank

12. Ignition Coil/Module Left Bank

13. Engine Fans (2)

14. Canister Purge Solenoid

15. Mass Air Flow (MAF) Sensor

16. Engine Coolant Temperature (ECT) Sensor

17. Throttle Position (TP) Sensor

18. Intake Air Temperature (IAT) Sensor

19. Vehicle Speed Sensor (VSS)

20. Camshaft Position (CMP) Sensor

21. Heated Oxygen (HO2S) Sensor (2)

22. Crankshaft Position (CKP) Sensor

23. Knock Sensors (KS) (2)

24. ECC In - Car Air Temperature Sensor

25. A/C Refrigerant Pressure Sensor

26. Powertrain Control Module (PCM)

27. Powertrain Interface Module (PIM) - Inside

vehicle behind left kick panel

28. Diagnostic Link Connector (DLC)

29. Oil Pressure Sensor

30. Manifold Absolute Pressure (MAP) Sensor

A Battery

B ABS

C BCM

D Fuel Tank

E Surge Tank (With Low Coolant Level Switch)

F Air Cleaner

Figure 6C3-1-3 GEN III V8 Engine View Left-Hand Side

1. Right-Hand Ignition Coils/Modules

2. Fuel Pulse Dampener

3. Fuel Rail with Injectors

4. Evaporative Canister Purge Solenoid

5. Crankcase Vent

6. Left-Hand Ignition Coils/Modules

7. Engine Coolant Temperature (ECT) Sensor

8. Fuel Pressure Gauge Test Connector

9. Throttle Position (TP) Sensor

10. Idle Air Control (IAC) Valve

11. Throttle Body

Figure 6C3-1-4 GEN III V8 Engine Front View

1. Idle Air Control (IAC) Valve

2. Throttle Position (TP) Sensor

3. Generator

4. Throttle Body

Figure 6C3-1-5 GEN III V8 Engine Rear View

1. Manifold Absolute Pressure (MAP) Sensor

2. Camshaft Position (CMP) Sensor

3. Oil Pressure Sensor

4. Connector to Knock Sensor Jumper Harness

Figure 6C3-1-6 Automatic Transmission Internal Electronic Component Locations

1. Vehicle Speed Sensor (VSS)

2. Shift Solenoid B (SS) Valve

3. Shift Solenoid A (SS) Valve

4. Automatic Transmission Fluid Pressure (TFP) Manual Valve Position Switch

5. Shift Solenoid (SS) Valve Assembly

6. Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid Valve

7. Torque Converter Clutch (TCC) Solenoid Valve

8. Pressure Control Solenoid (PCS) Valve

Figure 6C3-1-7 Engine Compartment Fuse/Relay Panel

1. Fan 1 Fusible Link FU 15. Start Relay

2. Fan 2 Fusible Link FT 16. Headlamp High Beam Relay

3. Engine Fan Relay (Low Speed) 17. Fuel Pump Relay

4. Lighting Fusible Link FQ 18. Front Wiper Relay

5. ABS Fusible Link FR 19. Headlamp Low Beam Relay

6. Engine Fusible Link FS 20. Injectors / Ignition Fuse F35

7. Main Fusible Link FJ 21. Injectors / Ignition Fuse F34

8. Blower Fusible Link FY 22. Engine Sensors Fuse F33

9. Engine Cont. (EFI) Relay 23. Automatic Transmission Fuse F32

10. Horn Relay 24. Engine Control / BCM Fuse F31

11. A/C Relay 25. LH Headlamp Fuse F30

12. Theft Horn Relay 26. RH Headlamp Fuse F29

13. Fog Lamp Relay 27. Fuel Pump Fuse F28

14. Engine Fan Relay (High Speed) 28. Throttle Relaxer Control Module Fuse F36

1.1 PO WERTRAIN CONTROL MODULE (PCM)

The Powertrain Control Module (PCM), is located

in the engine com partm ent. The PCM is the control

centre of the vehicle. It controls the following:

• Fuel metering system.

• Transmission shifting.

• Ignition timing.

• Knock Sensor (KS).

• Evaporative Emission Control System (EECS)

Purge.

• Cooling fan.

• A/C system.

• Check Powertrain Lamp (CPL).

• Theft Deterrent (Injector control).

The PCM constantly monitors the information from

various sensors, and controls the systems that

affect vehicle performance. The PCM also

perfor ms a diagnos tic function of the syst em. It can

recognise operational problems. The PCM also

alerts the driver through the Check Powertrain

Lamp (CPL) via the Class II serial data

communication line to the Powertrain Interface

Module (PIM). This is where the PIM converts the

Class II serial data communication to Universally

Asynchronous Receiving/Transmitting (UART).

This UART serial data communication is then sent

from the PIM to the Body Control Module (BCM)

then f rom the BCM to the Instr ument Panel Cluster .

When the PCM detects a malfunction, it stores a

Diagnostic Trouble Code (DTC).

GE N 3 0004

Figure 6C3-1-8 Powertrain Control Module

1. Connector J1 BLUE

2. Connector J2 RED

A stored DTC will identify the problem areas. This

will aid the technician in making repairs.

The PCM supplies either 5.0 or 12.0 volts to power

various sensors or switches. This is done through

resistanc e in the PCM. The resistanc e is so high in

value that a test lamp will not illuminate 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 multimeter (DMM) (J 39200)

with at least 10 megaohms input impedance is

required to ensure accurate voltage readings.

The PCM controls output circuits such as the

injector s, IAC, cooling fan relays, etc. by controlling

the earth or the power feed circuits through

transistor s or a device called a “ Driver” in the PCM.

The two exceptions to this are the fuel pump relay

control circuit and the automatic transmission

pressure control solenoid (PCS). The fuel pump

relay is the only PCM controlled circuit where the

PCM controls the +12 volts sent to the coil of the

relay. The earth side of the fuel pump relay coil is

connected to engine earth. The PCM supplies

current to the PCS and m onitors how m uch cur rent

returns to the PCM on a separate terminal. The

PCM also receives and transmits ser ial data via the

Powertrain Interface Module (PIM) and the serial

data bus.

GE N 3 0005

Figure 6C3-1-9 Powertrain Control Module

1. Coolant Surge Tank

2. Powertrain Control Module (PCM)

PCM POWER SUPPLIES

Battery voltage is applied to PCM terminals J1-20

and J1-57 at all times via fuse F31 and ignition

voltage is applied to PCM terminal J1-19 via fuse

F14 whenever the ignition switch is in the ON or

START position. The PCM is earthed from

terminals J1-01, J1-40, J2-01, and J2-40 to earth

points E5 and E15.

PCM FIVE VOLT REFERENCE CIRCUITS

The PCM has two five volt reference circuits. The

five volt reference circuit number one supplies five

volts to the following sensors:

• The Throttle Position (TP) Sensor

• The Manifold Absolute Pressure (MAP) Sensor

• Oil Pressure Sensor

The five volt reference circuit number two supplies

five volts to the following sensor:

• The A/C Pressure Sensor

The PCM monitors the voltage on the 5.0 volt

reference circuit. The following DTCs will set if the

voltage is out of range.

A failure in a f ive volt ref erenc e circ uit will set either

DTC P1635 or P1639.

DTC P1635 FIVE VOLT REFERENCE #1 CIRCUIT

Conditions for running DTC P1635

• The ignition is on.

Conditions for setting DTC P1635

• The five volt reference #1 circuit is out of range.

• All of the above conditions are present for greater than 2 seconds.

Action taken when DTC P1635 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1635

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does

not fail.

• A last test failed (Current DTC) clears when the diagnostic runs and does not fail.

DTC P1639 FIVE VOLT REFERENCE #2 CIRCUIT

Conditions for running DTC P1639

• The ignition is on.

Conditions for setting DTC P1639

• The five volt reference #2 circuit is out of range.

• All of the above conditions are present for greater than 2 seconds.

Action taken when DTC P1639 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1639

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does

not fail.

• A last test failed (Current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-10 PCM Battery, Ignition and Earth Circuits

SERIAL DATA COMMUNICATION (BUS MASTER)

Various devices; system control modules of the vehicle, as well as TECH 2 communicate with each other. The

communication between control m odules and comm unication with the TECH 2 diagnostic scan tool is achieved on

the ser ial comm unication lines us ing serial data. Serial data transf ers inform ation in a linear fashion - over a single

line, one bit at a tim e. The ser ial data line is ref erred to as the ‘data bus’. Exc luding the GEN III V8 PCM, all control

modules communicating on the data bus communicate using UART communication.

Figure 6C3-1-11 System Overview - Serial Communication

UART is a 5 volt data line that toggles the voltage to earth ( 0 volts) at a f ixed bit pulse width during c om m unication.

UART trans mits data at the rate of 8.2 kilobits per sec ond (8192 bits/sec). With UART comm unication, when there

is no communication on the data line, the system voltage will be 5 volts.

G3PCM021PT

PCM

J1-20

J1-57

BATTERY

(1040) O (740)O/B (740)

O (740)

J1-19 IGNITION

BATTERY

R (2H)

LOC . E 1

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

IGNITION SWITCH

P (3)

YE122 YE112

YE123

YB44

F14 P (39)

J1-01

J1-40

J2-01

J2-40

LOC. E5/E15

EARTH

B/R (750)

F31

P/B (39)

The GEN III V8 PCM us es Class 2 comm unication.

This type of communication toggles the data line

from 0 volts to 7 volts at either a s hor t or long puls e

width at a rate of 10.4 kilobits per second

(average). With Class 2 communication, when

there is no communication on the data line, the

system voltage will be 0 volts.

As the ‘Class 2’ communication is different to

UART (different languages), communication

between the modules is incom patible, and as such,

requires a Powertrain Interface Module (PIM) to

convert Class 2 communication into UART, and

UART into Class 2 (a translator).

TECH 2 is able to communicate with both UART

and Class 2 control modules.

On all VX and WH Models, the BCM is the Bus

Master of the serial data communication system.

The BCM periodically polls (surveys) each device

on the data bus and requests status data.

T212J1012

UART

CLASS 2

11 1

111

000 0

000

Figure 6C3-1-12 Serial Data Digital Wave Form

On vehicles fitted with a GEN III V8, the devices (control modules) the BCM polls are:

• Powertrain Interface Module (PIM).

• Instrument cluster (INS).

• Antilock Brake/Electronic Traction Control System (ABS/ETC) Module.

• Supplemental Restraint System (SRS) Sensing and Diagnostic Module (SDM).

• Electronic Climate Control (ECC) Module.

• TECH 2.

The data provided by each device may be utilised by any device connected to the bus.

Each device has a unique response Message Identifier Word (MIW) for ease of identification.

The bus master ( BCM) polls each device with a serial data m essage which includes that devic es MIW . The device

responds by putting a s erial data m ess age onto the bus which includes its MIW and data, of which is retrieved and

utilised by any device requiring it.

The BCM polls each device for a status update, once every 300 milliseconds. The exception to this being the PIM

(GEN III V8) which is polled twice every 300 milliseconds. The PIM will construct a serial data message from

inform ation requested from the PCM via the Class 2 com munication. T his construc ted serial data mes sage is then

placed on the serial data bus.

When the ignition switch is turned from the OFF position to the ON position, the BCM will communicate with the

PCM via the PIM for theft deterrent purposes. If the BCM does not receive an OK TO START message from the

PIM within 0.5 seconds of ignition on, the auxiliary data bus is isolated via switching from the BCM.

The isolation of the auxiliary data bus during this period eliminates the possibility of a device failure other than the

BCM, or PIM, causing a problem on the serial data bus and inhibiting theft deterrent communications.

This period (short loop time) continues until the PIM responds with an acknowledgment or for a maximum of five

seconds after which the BCM will switch to the standard polling sequence and a no start condition will occur.

Following succ essful thef t deterrent com munications, the BCM begins sequential polling of devices on the bus and

normal system operation is established.

When the ignition switch is in the OFF position, the BCM continues to poll, allowing for TECH 2 communications

and external control of the bus prior to the ignition being switched on.

DIAGNOSTIC INFORMATION

The diagnostic tables and functional checks in the Service Information are designed to locate a faulty circuit or

component through logic based on the process of elimination. The tables in the Service Information are prepared

with the understanding that the vehicle:

• Functioned correctly at the time of assembly.

• There are no multiple faults.

• The problem currently exists.

The PCM perf orms a continual self-diagnosis on certain control functions. The PCM indicates the source of a fault

through the use of Diagnostic Trouble Codes (DTCs). The DTCs are four digit codes (P0XXX or P1XXX). W hen a

fault is detected by the PCM, a DTC will be set and stored in the memory of the PCM and the Check Powertrain

Lamp may illuminate.

RECORDING TEST RESULTS (DIAGNOSTIC EXECUTIVE)

The Diagnostic Exec utive is a unique segm ent of the PCM sof tware which is designed to co-or dinate and prioritise

the diagnostic procedures as well as define the protocol for recording and displaying their results. The main

responsibilities of the Diagnostic Executive are:

• DTC Information

DTC Information indicates the status of the diagnostic testing for a specific DTC. It contains information on

pass / fail status of the test, when the diagnostic test failed and if the DTC is requesting the illum ination of the

Check Powertrain Lamp.

• Freeze Frame / Failure Records

Freeze fram e / failur e records ar e stored any time a diagnostic tes t fails. T he PCM has the ability to store up to

six freeze frame / failure records. When a diagnostic test fails, records are stored in the first fail position. If a

different diagnostic test fails, a second fail record position. Additional failed diagnostic tests for different DTCs

also store fail records until the fail record memory is full. The PCM has the ability to store six freeze frame /

failure r ecords, if m ore than six DT C freeze fram e failure recor ds are stored, the f ail records are replaced on a

first in, first out basis.

The freeze frame / failure records data list has 32 parameters for data capture. W hen a DTC is set, the PCM

will capture all 32 parameters at the time the DTC is logged.

In addition to the regular data list parameters found in the freeze frame / failure records data list, there is

additional information available about the DTC diagnostics:

• First Odometer - Vehicle kilometre value when the DTC failure first recorded.

• Last Odometer - Vehicle kilometre value when the DTC fail is recorded.

• Fail Counter - Number of ignition cycles with failure (DTC was set).

• Pass Counter - Number of ignition cycles with diagnostic passes (DTC was not set again).

• Not Run Counter - Number of ignition cycles without diagnostic run (DTC conditions were not tested).

• System Status

T he System Status (I/M Flag) stores inf orm ation on which diagnostic s have run. If a system diagnostic has run,

the system status flag (yes/no) will be set.

• Warm-Up Cycles

Records the number of warm-up cycles that have been achieved since the DTC was set

GENIIIGB006

FREEZE FRAME

FAILURE RECORDS

PASS/FAIL REPORTS CHECK POWERTRAIN

LAMP CONTROL

OPERATING CONDITIONS DTC

IGNITION COUNTER D TC INFO RMAT ION

DTC STATUS

WARM-UPS

TRIPS

D TC INFO RMAT ION

SYSTEM STATUS

1COUNTER

0-40

COUNTER

0-80

History

MIL SVS or Message Requested

Last Test Failed

Test Failed Since Cleared

Not Run Since Cleared

Failed This Ignition

Oxygen Senors

Knock Sensors

Cooling Fan

Vehicle Speed

Idle Speed Control

A/C System

System Voltage

DIAGNOSTIC EXECUTIVE

Figure 6C3-1-13 Diagnostic Executive

TECH 2 SCAN TOOL: FREEZE FRAME / FAILURE RECORDS DATA DISPLAY

SCAN POSITION Q UNITS DISPLAYED R DATA VALUE S

ENGINE SPEED RPM 0 RPM

DESIRED IDLE SPEED RPM 0 RPM

ENG. COOLANT TEMP (E CT) DEGREES C VARIES

START UP ECT DEGREES C VARIES

THROTTLE POSI TI ON 0-100 % 0 %

ENGINE LOAD % %

BARO kPa kPa

BARO SENSOR VOLTS VOLTS VOLTS

MAP SENSOR kPa kPa

MAP SENSOR VOLTS VOLTS VOLTS

MASS AIR FLOW GRAM /SEC GRAM /SEC

FUEL SYSTEM STATUS OPEN LOOP/

CLOSED LOOP OPEN LOOP/

CLOSED LOOP

LEFT SHORT TERM FUEL TRIM

(BANK 1) % +0% to -0%

RIGHT SHORT TERM FUEL TRIM

(BANK 2) % +0% to -0%

LEFT LONG TERM FUEL TRIM

(BANK 1) % +0% to -0%

RIGHT LONG TERM FUEL TRIM

(BANK 2) % +0% to -0%

INJECTION PULSE BANK 1 mS mS

INJECTION PULSE BANK 2 mS mS

AIR FUEL RA TI O % 14.7:1

TRANSMISSION RANGE PARK, REVERSE,

NEUTRAL, DRIVE 4

OD, DRIVE 3 / D,

DRIVE 2, DRIVE 1,

INVALID

PARK, REVE RS E, NEUTRAL, DRIV E 4 OD, DRIV E 3 / D, DRI VE

2, DRIVE 1, INV A LID

CURRENT GEAR 1,2,3,4 1,2,3,4

AT Output S peed ( Auto Trans) RPM RPM

TCC BRAKE SWITCH ON / OFF ON / OFF

TCC SOLENOID ON / OFF ON / OFF

TCC PWM ON / OFF ON / OFF

VEHICLE SPEED km/h km/h

TIME FROM START TIME 0:00:00

FIRST ODOMETER km km

LAST ODOMETER km km

FAIL COUNT E R # #

PASS COUNTER # #

NOT RAN COUNTER # #

PCM PROGRAMMING

The PCM for this vehicle application does not

contain a removable PROM, instead it uses an

EEPROM (Flash Memory) which is non removable.

From the factory, the PCM is programmed with the

proper calibrations for vehicle operation. In the

event that the PCM is replaced, or an updated

calibration is required to correct a vehicle's

operating condition, the new PCM or the new

calibration will require the use of the Tech 2 scan

tool for down loading to the EEPROM (Flash

Memory). Down loading is accomplished through

the vehicle Data Link Connector (DLC) using the

Tech 2 scan tool.

The service replacement PCM EEPROM (Flash

Memory) will not be programmed. DTC P0601 and

P0602 indicates the Flash Memory is not

programmed or has malfunctioned.

NOTE: The PCM used in this vehicle application is

not interchangeable with any other V8 GEN III

program. Only the PCM part number for this

vehicle must be used.

Refer to Section 6C3-3 of the VX Series Service

Information for this service programming

procedure.

GE N 3 0005

Figure 6C3-1-14 Powertrain Control Module Location

1. Coolant Surge Tank

2. Powertrain Control Module (PCM)

DTC P0601 POWERTRAIN CONTROL, MODULE (PCM) MEMORY

Conditions for running DTC P0601

• The ignition switch is in the crank position or the run position.

Conditions for setting DTC P0601

• The PCM is unable to correctly read data from the EEPROM (flash memory).

Action taken when DTC P0601 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0601

• A last test failed (Current DTC) clears when the diagnostic runs and does not fail.

• A History DTC clears after fourty consecutive warm-up cycles, if this or any other emission related

diagnostic does not report any failures.

• Use a Tech 2 tool in order to clear the CPL/DTC.

DTC P0602 POWERTRAIN CONTROL MODULE (PCM) NOT PROGRAMMED

Conditions for running DTC P0602

• The ignition switch is in the run position.

Conditions for setting DTC P0602

• No software data is present in the PCM.

Action taken when DTC P0602 Sets

• The PCM illuminates the Check Powertrain Lamp (CPL) when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0602

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does

not fail.

• A last test failed (Current DTC) clears when the diagnostic runs and does not fail.

• A History DTC clears after fourty consecutive warm-up cycles, if this or any other emission related

diagnostic does not report any failures.

• Use a Tech 2 tool in order to clear the CPL/DTC.

Techline

PCM/PIM/BCM SECURITY LINK

Once the PCM, PIM and or BCM have been replaced, the new module(s) m ust be security linked to each other

using the Tech 2 and TIS. If the procedure is not performed, the engine will not crank or run.

This linking procedure is found under the BODY CONTROL MODULE of TECH 2 and has to be performed as

follows:

Connect TECH 2 to DLC and select:

Diagnostic / (X) 2000 / VX Commodore / Body / Body Control Module / Security / BCM Link to PCM/PIM.

The proc edure ”BCM Link to PCM/PIM” will first ask to selec t the installed engine. If Gen III V8 is selec ted a T IS

program approval is required.

Connect TECH 2 to TIS terminal and select ”Program Approve”. After returning to the vehicle select again the

linking procedure. Now first BCM and PIM are linked and afterwards the PCM – PIM linking is performed

automatically.

For additional information regarding TECH 2 and TECH 2 test modes (including this linking procedure), refer to

TECH 2 DIAGNOSIS FOR BCM in Section 12J-1 LOW SERIES BCM or Sectio n 12J- 2 HIGH SERIES BCM in

the VX Service Information.

PCM MEMORY FUNCTIONS

The following list contain the two types of memory within the PCM.

• RAM

• EEPROM (Flash Memory)

RAM

Random Access Memory (RAM) is the microprocessor scratch pad. The processor can write into, or read from

this m emor y as needed. T his m em ory is volatile and needs a constant s upply of B+ voltage to be retained. If the

B+ voltage is lost, the memory is lost.

EEPROM (FLASH MEMORY)

A new Service Programming System (SPS) has been incorporated with this Gen III PCM. This SPS enables

technicians to directly update the data stored in the Powertrain Control Module (PCM). The part of the PCM

which contains the specif ic calibration data f or a particular vehicle and engine com bination is com m only ref erred

to as the EEPROM. EEPROM is an acronym for Electrically Erasable Programmable Read Only Memory. In

effect, the data in the memory matches the PCM to the vehicle to provide optimum performance, driveability,

and emissions control.

Sometim es EEPROM data is updated to modify engine operations. For example, the EEPROM calibration data

may be changed to adjust ignition timing in order to eliminate a potential detonation condition or improve idle

quality. Before the SPS was implemented, the procedure for updating EEPROM data was to simply replace the

PCM EEPROM unit.

The relative ease of changing engine data has led to increased use of aftermarket EPROMs designed to

enhance performance. Unfortunately, such HOT EEPROMs often cause engine emissions to exceed regulated

standards. In s uch ins tances, ins tallation of an af term ar ket EEPRO M is c onsidered tam pering. Governing bodies

ruled that emission-related control modules must be tamper resistant. These tamper-resistant EEPROMs are

soldered in place as an integral part of the PCM. Updating the EEPROM data is accomplished through flash

programming.

Flash programming refers to the SPS used to transfer (or download) PCM data from a computer terminal and

compact disk-read only memory (CD-ROM) to the vehicle’s PCM. The system is designed so that the vehicle

verification procedures are required to eliminate EEPROM tampering that could increase engine emission levels.

There are three main flash programming techniques listed below:

1. Direct Programming

This is where the vehicle’s Data Link Connector (DLC) is connected directly to a computer terminal. On

screen directions are then followed for downloading.

2. Remote Programming

Reprogramming information is downloaded from a computer terminal to a Tech 2 scan tool. The Tech 2

scan tool is then connected to the vehicle’s Data Link Connector (DLC). On screen directions are then

followed for downloading.

3. Off-Board Programming

The off-board programming method is used when a reprogrammable PCM must be programmed separate

from the vehicle. For example, an independent repair facility may find it necessary to replace a faulty PCM.

On flash programming equipped vehicles, the replacement PCM must be programmed with data for the

specific Vehicle Identification Number (VIN) or the vehicle may not operate properly.

1.2 PO WERTRAIN INTERFACE MODULE (PIM)

The Powertrain Interface Module (PIM), is located

in the passenger compartment behind the left kick

panel. The PIM ac ts as a comm unication translator

between the PCM and other control modules that

use a different serial data protocol. T he GEN III V8

PCM uses Class II serial data to communicate,

while other control modules in the vehicle are

designed to transmit serial data via the

conventional Universal Asynchronous Receive and

Transmit (UART) protocol. Since these two types

of serial data are not compatible, the PIM is

required to transmit data in either direction

between the PCM and other control modules. The

PIM will interpret the serial data information and

translate UART to Class II or Class II to UART to

support the appropriate vehicle control module

operation. The PIM is also used to control the

operation of the starter relay.

Figure 6C3-1-15 PIM location

Figure 6C3-1-16 PIM Communication

POWERTRAIN

CONTROL MODULE POWERTRAIN

INTERFACE MODULE

STARTER

RELAY

ENGINE SPEED

COOLANT TEMPERATURE

BAROMETRIC PRESSURE

VEHICLE SPEED

A/C CLUTCH

A/C PRESSURE

LOW SPEED FAN REQUEST

LOW FAN RUN ON

THEFT STATUS

PCM DTC STATUS

CHECK POWERTRAIN LAMP

THROTTLE FAILURE

MAP FAILURE

FUEL USED

FUEL FLOW RATE (INSTANTANEOUS)

ENGINE TYPE

TRANSMISSION CODING

FUEL TYPE

ENGINE OIL CHANGE

TRANSMISSIN OIL CHANGE

SHIFT PATTERN

THROTTLE POSITION

HIGH COOLANT TEMPERATURE

LOW COOLANT LEVEL

OIL PRESSURE SWITCH

PRNDL SWITCH

COMMANDED GEAR

PCM CHIME

THEFT DETERRENT SIGNAL

PRIORITY KEY USER

A/C REQUEST

CRUISE CONTROL STATUS

ETC EQUIPPED

A/C REQUEST

CRUISE CONTROL

ENGAGED

SRS DEPLOYED

THIS IGNITION CYCLE

GEN321

BODY CONTROL

MODULE

ABS/ETC

MODULE

ECC

MODULE

INSTRUMENT

SRS SENSING AND

DIAGNOSTIC MODULE

PIM DIAGNOSTIC TROUBLE CODES

A PIM malfunction may affect vehicle operation and may interrupt starter motor operation. For PIM diagnosis

refer to Section 6C3-2A of this Service Information for PIM DTC diagnosis. There are four (4) PIM DTCs that

will set. Each of these DTCs have corresponding diagnostic tables.

The PIM does not have the mem ory to store any DTC information, so only a current DTC with the Tech 2 scan

tool can be displayed. Once the fault is corrected, the DTC is no longer active.

DTC DTC DESCRIPTION

B2002 Low Speed Fan No BCM Response

B2006 No Serial Data From PCM

B2007 Starter Relay Voltage High

B2009 EEPROM Checksum Error

There are twenty (20) other PIM DTCs that will also set whenever DTC B2006 sets. These DTCs indicate the

loss of part of the Class II serial data. If ther e is a problem with the Class II serial data circ uit, and the PIM does

not receive any of this information a DTC B2006 will set. The Powertrain On Board Diagnostic (OBD) System

Check will identify a problem with the serial data circuit or other circuits, and direct the technician in the proper

direction for diagnosis. There are no PIM DTC tables associated with these twenty (20) PIM DTCs, so always

diagnose the PCM first.

DTC DTC DESCRIPTION

B2017 No Throttle Position Sensor (TPS) Information

B2018 No A/C Clutch Information

B2019 No Engine Speed Information

B2020 No Vehicle Speed Information

B2021 No Commanded Gear Information

B2022 No Transmission Type

B2023 No Low Speed Fan Run On Information

B2024 No Low Speed Fan Request Information

B2025 No Engine Coolant Temp (ECT) Information

B2026 No Fuel Flow Rate Information

B2027 No Fuel Used Counter Information

B2028 No A/C Pressure Information

B2029 No PRNDL Information

B2030 No Engine Oil Information

B2031 No Oil Pressure Information

B2032 No Shift Information

B2033 No Check Powertrain Lamp Information

B2034 No Low Coolant Level Information

B2035 No Barometric Pressure Information

B2036 No PCM Information

STARTER RELAY

The PIM also controls the operation of the starter relay. When the ignition switch is turned to on, the PIM will

enable the starter relay for one second, if the PIM does not receive the correct security code it will disable the

starter relay. If the PIM receives the correct security code from the BCM, the PIM will continue to enable the start

relay. Once the engine has started and the engine speed is above 500 RPM the PIM will disable the starter relay,

preventing starter engagement while the engine is running.

If the ser ial data bus between the BCM and the PIM should fail ( no polling from the BCM f or m ore than 10 minutes )

after s ucces sf ul theft deter rent com m unic ations, the PIM will allow subsequent star ts, however there will be a crank

delay of one second. If the PIM receives valid communication, normal operation will resume.

If the Class II serial data bus between the PIM and the PCM should fail (no communications for 20 seconds) after

successful theft deterrent communications, the PCM will allow subsequent starts, however there will be a crank

delay of one second. If communications between the PCM and the PIM are re-established, normal operation will

resume.

Figure 6C3-1-17 Starter Circuit

BATTERY MAIN POWER

HIGH SERIES

BCM TERMINALS

NOMINA TED FIRST

BCM

REMOTE

CODED KEY

V/R (229) E1/D12 KEY R EADER

BATTERY

LOC.

LOC. G1

F31

A5/A6O/B (740)

(1040)

REMOTE KEY

RECEIVER

Y (266) E8/D1 RECEIVER DATA

BR/G (271) E7/D11 RECE IVER EARTH

O/B

(740)

GY/BLU

(1434)

G3PCM040PT

THEFT DETERRENT

ALERT INDICA TOR

R/B

(1221)

E2/D2 SERIAL DATA

R (2H)

E20/D6 IGNITION

NEUTRAL ST ART

BACK-UP SW.

(FOR AUTO TRANS)

(FOR MANUAL

TRANS)

(434)

R (1)

V/W (6)

F14

START

RELAY

IGN ITIO N SWITC H

15a 15 50

30 ACC

IGN

START

V (5) P (3) P/B

(39)

A6/A8

LBLU

(263) THE FT LED

B/Y

(155)

LOC. E3

B/G

(151) B10/B11 HIGH CURRENT

EARTH

B/Y

(155) ELECTRONIC EARTH

A1/A5

LOC. E3

PIM

UART

SERIAL

DATA

START

RELAY

CLASS 2

SERIAL DATA

B/R (750)

LOC. E5/E15

R/B

(1221)

PCM

J1-58 CLASS 2

SERIAL DATA

Y (1049)

(1049)

STARTER

MOTOR

YB215

YE112

YB35

YE104

YE8

YB35

YE114 YB56 YB56

YE49

YB44

YE49

YB44

YB95

YB175

YB164

YB176

YB165

YB175

YB164

YB175

YB164

YB174

YB163

YE114

YE114 YB176

YB165

YE122

YB176

YB165

YB95

DTC B2002 LOW SPEED FAN NO BCM RESPONSE

Conditions for running DTC B2002

• The ignition is on.

Conditions for setting DTC B2002

• The PIM sends a Low Speed request signals to the BCM , with no response back from the BCM.

Action taken when DTC B2002 Sets

• The PIM will display the DTC only when current.

• The Check Powertrain Lamp (CPL) will not illuminate.

Conditions for clearing DTC B2002

• A current DTC will clear when the PIM receives a Low Speed Fan Response from the BCM.

Figure 6C3-1-18 Cooling Fan Circuit

R/B (1221) E2/D2

IGNITION

LOW

SPEED FAN

BATTERY MAIN POWER

HIGH SERIES

BCM TERMINALS

NOMINATED FIRST

BCM

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

G3PCMO42PT

E20/D6

B7/B7

P (3)

IGNITION SWITCH

O/B (473)

87A

ENGINE

COOLING

FAN 1

ENGINE

COOLING

FAN RELAY

(LOW SPEED)

ENGINE

COOLING

FAN RELAY

(HIGH SPEED)

P/B (39)

O/Y

(250)

F14

BLU/W (304)

R/B (1049)

HIGH

CURRENT EARTH

B/Y

(155) A1/A5 ELECTRONIC EARTH

B/G

(151)

LOC.

E2 LOC.

B10/B11

B/R (157)

J1-58

GEN III PCM

PIM

J2-33

HIGH

SPEED FAN

BLUE

FUSIBLE

LINK

LOC.

F31

A5/A6

O/B (740)

ENGINE

COOLING

FAN 2

BATTERY

FT FAN 2

FU FAN 1

(1040)

(203)

(001)

O/B

(208)

O/BLU

(204)

(001)

(2H)

CLASS 2 SERIAL DATA

UART SERIAL DATA

CLASS 2

SERIAL DA TA

SERIAL

DATA

GY /B (455)

J1-74 Y (41O)

COOLANT TEMP

SENSOR

ETC SENSOR

SIGNAL

A/C

PRESSURE

SIGNAL

348

Ω

J1-80

SENSOR

EARTH

SENSOR

EARTH

J2-21

J2-20

EHICLE SPEED

SENSOR

BLU/W (831)

T (832)

V/W (415)

J2-57

J2-14

J1-45

G/O (469)

G/B (259)

/C PRESSURE

SENSOR

P/B (39)

BLU/Y

(533)

YB176

YE118

YE104

YE43

YB175

YB164

YB175

YB174

YB176

YB165

YB195

YE113

YE65 YE65

YE123

YE122

YE123

YE122

YE123

YB44

YE119

YE140

YE139

YB44

YE104

YE118

YB215 YB215

YB163

YB164

YE43

DTC B2006 NO SERIAL DATA FROM PCM

Conditions for running DTC B2006

• The ignition switch is on.

• The ignition voltage is between 5.0 and 17 volts.

Conditions for setting DTC B2006

• PIM does not receive any serial data communication from the PCM.

Action taken when DTC B2006 Sets

• The PIM will display the DTC only when current.

• The Check Powertrain Lamp (CPL) will not illuminate.

Conditions for clearing DTC B2006

• A current DTC will clear when the PIM receives serial data from the PCM.

Figure 6C3-1-19 Serial Data Circuit

B/Y

(155)

(150)

LOC. E3

642516 9 1

G3PCM039PT

INSTRUMENTS

ABS/ETC

SRS

ECC

BCM

DATA LINK

CONNECTOR

SERIAL

DATA

SERIAL

DATA SERIAL

DATA

5V 5V

BATTERY

F31

A5/A6

O/B (740)

(1040)

BATTERY MAIN POWER

HIGH SERIES

BCM TERMINALS

NOMINATED FIRST

LOC. E1

R (2)

F14

E20/D6

P/B

(39) IGNITION ON

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

IGNITION SWITCH

(3)

B/Y (155)

B/G (151)

LOC. E3

R/B (1221)

G/W (1220)

LOC.G11

LOC.E3

LOC.E2

LOC.E3 EARTH

SERIAL

DATA

B (305)

B/Y (155) 2

B (150)

B/O

(154) B/R

(157)

B/Y(155)

B/R ( 750)

W/B (451)

R/B (1221)

Y (1049)

PIM

UART

SERIAL

DATA

12V

ELECTRONIC EARTH

HIGH CURRENT

EARTH

A1/A5

B10/B11

E2/D2

E9/D3

E3/D13

SERIAL

DATA

MAIN

SERIAL

DATA AUX.

DIAG. ENABLE

CL ASS 2

SERIAL DATA

LOC. E5/E15

GEN III V8 PCM

J1-58

J2-01

J2-40

J1-40

J1-01

CL ASS 2

SERIAL DATA

B/R ( 750)

YB176

YB165

YB175

YB164

YB174

YB163

YB176

YB165

YB190

YB189

YB89

YE114

YB98

YB66

YE114

YB215

YE122

YE123

YB87

YE114

YB44

DTC B2007 STARTER RELAY VOLTAGE HIGH

Conditions for running DTC B2007

• The ignition switch is in the crank position.

• The ignition voltage is between 5.0 and 17 volts.

Conditions for setting DTC B2007

• PIM detects high voltage on the starter relay control circuit.

Action taken when DTC B2007 Sets

• The PIM will display the DTC only when current.

• The Check Powertrain Lamp (CPL) will not illuminate.

Conditions for clearing DTC B2007

• A current DTC will clear when the PIM no longer detects a high voltage on the starter relay circuit.

Figure 6C3-1-20 Starter Relay Circuit

BATTER Y MAIN POWE R

HIGH SERIES

BCM TERMINALS

NOMINA TED FIRST

BCM

REMOTE

CODED KEY

V/R (229) E1/D12 KEY R EADER

BATTERY

LOC.

LOC. G1

F31

A5/A6O/B (740)

(1040)

REMOTE KEY

RECEIVER

Y (266) E8/D1 RECEIVER DATA

BR/G (271) E7/D11 RECE IVER EARTH

O/B

(740)

GY/BLU

(1434)

G3PCM040PT

THEFT DETERRENT

ALERT INDICA TOR

R/B

(1221)

E2/D2 SERIAL DATA

R (2H)

E20/D6 IGNITION

NEUTRAL ST ART

BACK-UP SW.

(FOR AUTO TRANS)

(FOR MANUAL

TRANS)

(434)

R (1)

V/W (6 )

F14

START

RELAY

IGN ITIO N SWITC H

15a 15 50

30 ACC

IGN

START

V (5) P (3) P/B

(39)

A6/A8

LBLU

(263) THE FT LED

B/Y

(155)

LOC. E3

B/G

(151) B10/B11 HIGH CURRENT

EARTH

B/Y

(155) ELECTRONIC EARTH

A1/A5

LOC. E3

PIM

UART

SERIAL

DATA

START

RELAY

CLASS 2

SERIAL DATA

B/R (750)

LOC. E5/E15

R/B

(1221)

PCM

J1-58 CLASS 2

SERIAL DATA

Y (1049)

(1049)

STARTER

MOTOR

YB215

YE112

YB35

YE104

YE8

YB35

YE114 YB56 YB56

YE49

YB44

YE49

YB44

YB95

YB175

YB164

YB176

YB165

YB175

YB164

YB175

YB164

YB174

YB163

YE114

YE114 YB176

YB165

YE122

YB176

YB165

YB95

DTC B2009 PIM EEPROM CHECKSUM ERROR

Conditions for running DTC B2009

• The ignition switch is in the crank position or run position.

Conditions for setting DTC B2007

• The PIM is unable to correctly read data from its memory.

Action taken when DTC B2007 Sets

• The PIM will display the DTC only when current.

• The Check Powertrain Lamp (CPL) will not illuminate.

Conditions for clearing DTC B2007

• A current DTC will clear when the PIM is able to correctly read data.

The only action taken if this DTC B2009 is set, is

replacement of the PIM assembly .

GE N 3 0006

Figure 6C3-1-21 Powertrain Interface Module (PIM)

1. Throttle Relaxer Control Module

2. Powertrain Interface Module

3. Left ‘A’ pillar

1.3 ENGINE INFORMATION SENSORS AND SIGNALS

ENGINE COOLANT TEMPERATURE (ECT) SENSOR

The Engine Coolant Temperature (ECT) sensor is

a thermistor, (a resistor that changes value based

on temperature) mounted in the engine coolant

stream. Low engine coolant temperature produces

a high sens or res istance (29k ohm s at -20°C) while

high engine coolant temperature causes low

sensor resistance (180 ohms at 100°C).

The PCM supplies a 5 volt signal voltage to the

sensor through a resistor network in the PCM, and

monitors the circuit voltage, which will change

when connected to the sensor.

The circuit voltage will vary depending on the

resistance of the coolant temperature sensor. The

circuit voltage will be close to the 5 volt level when

the sensor is cold, and will decrease as the sensor

warms. Engine coolant temperature affects most

systems controlled by the PCM.

The PCM uses a dual pull up resistor network to

increase the r esolution through the entire operating

range of engine coolant temperature. When the

coolant temperature is less than 51°C both the 4K

and 348 ohm resistors ar e used. W hen the coolant

temperature reaches 51°C. The PCM switches a

short across the 4K resistor and only the 348 ohm

resistor is used.

As the engine warms, the sensor resistance

becomes less and the voltage at the PCM coolant

temperature sensor signal terminal should

decrease from approximately 4.5 volts when cold

to 0.9 volts at 51°C. At this temperature the PCM

switches the short across the 4k resistor, the

voltage will then rise to 3.5 volts. The voltage will

again decrease as the coolant temperature

increases until at normal engine operating

temperature (95°C), the voltage should be less

than 2.0 volts.

GE N 3 0008

Figure 6C3-1-22 Engine Coolant Temperature

(ECT) Sensor

1. ECT Electrical Connector

2. Connector Tab

3. Engine Coolant Temperature (ECT) Sensor

The following DTCs will set when the PCM detects

a malfunction in the engine coolant temperature

sensor circuit:

DTC P0117: ECT Sensor Circuit Low Voltage.

DTC P0118: ECT Sensor Circuit High Voltage.

DTC P0125: ECT Excessive Time to Closed Loop

Fuel Control.

DTC P1114: ECT Sensor CKT Intermittent Low

Voltage.

DTC P1115: ECT Sensor CKT Intermittent High

Voltage.

DTC P1258: Engine Coolant Over Temp Fuel

Disable

5.72

4.90

4.48

4.16

3.84

3.52

3.20

2.58

2.88

2.24

1.92

1.60

1.28

0.96

0.64

0.32

0.00 -28 -16 -4 7 19 31 49 55 79 91 115 127 139103 15167-40

4210

ECT Temperature vs Voltage

1. Engine Coolant Temperature Vs. Voltage Table

2. Sensor Voltage Above 50°C

3. Temperature °C

4. Sensor Voltage Below 50°C

5. Volts

Section 6C3-4 of this Service Information contains

a table to check for sensor resistance values

relative to temperature.

T6B3047

Figure 6C3-1-23 Engine Coolant Temperature

(ECT) Sensor Location

1. ECT Sensor

2. Left Cylinder Head

DTC P0117 ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW VOLTAGE

Conditions for running DTC P0117

• The engine run time is greater than 10 seconds.

Conditions for setting DTC P0117

• The engine coolant temperature is greater than 139°C.

• All conditions met for at least 45 seconds.

Action taken when DTC P0117 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM will substitute a coolant temperature default value.

The PCM arrives at this default value, by using current intake air temperature, then counting upward to 116°C

at a rate of approximately 7 degrees per minute.

• The PCM will turn on the electric engine cooling fans. This is a FAIL-SAFE action by the PCM to prevent a

possible engine overheat condition, since the DTC indicates an unknown actual coolant temperature.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0117

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0118 ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT HIGH VOLTAGE

Conditions for running DTC P0118

• The engine run time is greater than 10 seconds.

Conditions for setting DTC P0118

• The engine coolant temperature is greater than –38.9°C.

• All conditions met for at least 45 seconds.

Action taken when DTC P0118 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM will substitute a coolant temperature default value.

The PCM arrives at this default value, by using current intake air temperature, then counting upward to 116°C

at a rate of approximately 7 degrees per minute.

• The PCM will turn on the electric engine cooling fans. This is a FAIL-SAFE action by the PCM to prevent a

possible engine overheat condition, since the DTC indicates an unknown actual coolant temperature.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0118

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0125 ENGINE COOLANT TEMPERATURE SENSOR EXCESS TIME TO CLOSED LOOP FUEL

CONTROL

Conditions for running DTC P0125

• DTCs P0112, P0113, O0117, P0118 are not set.

• The engine is operating.

• The engine coolant temperature is between -36°C and 40°C at engine start-up.

• The intake air temperature is greater than -7°C.

• The vehicle speed is greater than 1.6 km/h.

Conditions for setting DTC P0125

• The closed loop coolant temperature of 34°C is not reached within a predetermined time. The maximum

allowable time depends on the start-up coolant temperature and the amount of airflow into the engine. The

range for the time is from 2 minutes and 20 seconds to 22 minutes and 30 seconds.

Action taken when DTC P0125 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0125

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1114 ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT INTERMITTENT LOW VOLTAGE

Conditions for running DTC P1114

• The engine run time is greater than 10 seconds.

Conditions for setting DTC P1114

• The engine coolant temperature is greater than 139°C fore at least one second.

Action taken when DTC P1114 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1114

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1115 ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT INTERMITTENT HIGH VOLTAGE

Conditions for running DTC P1115

• The engine run time is greater than 60 seconds.

Conditions for setting DTC P1115

• The engine coolant temperature is less than -35°C for at least one second.

Action taken when DTC P1115 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1115

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1258 ENGINE COOLANT OVER TEMP FUEL DISABLED

Conditions for running DTC P1258

• DTCs P0117, P0118, are not set.

• The engine is running.

Conditions for setting DTC P1258

• The engine coolant temperature is greater than 132°C.

• The above conditions present for greater than 10 seconds.

Action taken when DTC P1258 Sets

• The PCM will randomly disable several injectors.

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1258

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-24 Engine Coolant Temperature (ECT) Sensor Circuit

ENGINE COOLANT LEVEL SWITCH

The engine coolant level switch is used to inform

the PCM when the coolant level is at a calibrated

low level.

The engine coolant level switch is a reed switch

and is used to inform the PCM when the coolant

level is at a calibrated low level. When the engine

coolant is at norm al operating level, the float inside

the surge tank will rise, the magnet in the float will

cause the reed s witc h contacts to close, pulling the

PCM supplied voltage low. When the coolant level

is low, the float will fall, the reed switch contacts

will open, causing the PCM voltage signal to go

high. The PCM will then send a serial data

mes sage to the instrum ent panel cluster instructing

the instrument panel cluster to turn ON the Low

Coolant Warning Lamp.

For diagnosis of the engine coolant level switch,

refer to Section 6C3-2C in this Service

Information.

The engine coolant level switch is located in the

coolant s urge tank. T he engine coolant level switch

is serviceable only by replacing the surge tank.

Refer to Section 6B3 Engine Cooling in VX

Service Information, for surge tank replacement.

GE N 3 0153

Figure 6C3-1-25 Engine Coolant Level Switch Location

1. Engine Coolant Level Switch Electrical Connector

2. Powertrain Control Module (PCM)

Figure 6C3-1-26 Engine Coolant Level Switch Circuit

G3PCM004PT

J1-80

J1-74

ENGINE COOLANT

TEMPERATURE SENSOR

SENSOR EARTH

ETC SENSOR SIGNAL

348

Ω

Y (41 0)

GY/B (455)

YE65 YE122

G3PCM013PT

J1-30

LOW COOLANT

LEVEL SWITCH

LOW COOLANT LEVEL

SWITCH SIGNAL

PCM

G (69)B/R (750)

LOC. E5/E15

YE122

YE131

MASS AIR FLOW (MA F) SENSOR

The Mass Air Flow (MAF) sensor utilises a heated

element type of operation. A heated element in the

MAF is placed in the air flow stream of the engine

intake system. The heating element is maintained

at a constant temperature differential above the air

temperature. The amount of electrical power

required to maintain the heated element at the

proper tem perature is a direct function of the mass

flow rate of the air past the heated element.

The following DTCs are set when the PCM detects

a malfunction in the MAF sensor circuit:

• DTC P0101: Mass Air Flow System

Performance.

• DTC P0102: MAF Sensor Circuit Low

Frequency.

• DTC P0103: MAF Sensor Circuit High

Frequency.

Figure 6C3-1-27 Mass Air Flow (MAF) Sensor

Three sensing elements are used in this system.

One senses am bient air temperature and uses two

calibrated resistors to establish a voltage that is

always a function of ambient temperature. This

ambient sensor is mounted in the lower half of the

sensor housing. The other two sensing elements

are heated to a predetermined temperature that is

significantly above ambient air temperature. The

two heated elements are connected electrically in

parallel and mounted directly in the air flow stream

of the sens or housing. O ne sensor is in the top and

the other sensor is in the bottom of the sensor

housing. This is done so that the air meter is less

sensitive to upstream ducting configurations that

could skew the flow of air through the housing.

GE N 3 0010

Figure 6C3-1-28 Sensing Elements

1. Heater Sensing Elements

2. Ambient Temperature Sensor

As air passes over the heated elements during

engine operation they begin to cool. By measuring

the amount of electrical power required to maintain

the heated elements at the predetermined

temperature above ambient temperature the mass

air flow rate can be determined.

Once the mass air flow sensor has developed an

internal signal related to the mass air flow rate, it

must send this information to the PCM. In order to

preserve the accuracy and resolution of the small

voltage signal in the mass air flow sensor, it is

converted to a frequency signal by a voltage

oscillator and sent to the PCM.

T26C3002

Figure 6C3-1-29 MAF Sensor Location

1. Air Cleaner Housing

2. Mass Air Flow (MAF) Sensor

The s ignal that is sent from the MAF sensor is sent

in the form of a frequency output. A large quantity

of air passing through the sensor (such as when

accelerating) will be indicated as a high frequency

output. A small quantity of air passing through the

sensor will be indicated as a low frequency output

(such as when decelerating or at idle). The Tech 2

scan tool displays MAF sensor information in

frequency, and in grams per second. At idle the

readings should be low and increase with engine

RPM.

If a problem occurs in the MAF sensor circuit, the

PCM will store a DTC in its mem ory. The PCM will

turn on the Check Powertrain Lamp, indicating

there is a problem. If this occurs, the PCM will

calculate a s ubstitute mas s air f low signal based on

speed density RPM, MAP and IAT.

No field service adjustment is necessary or

possible with this MAF sensor.

Figure 6C3-1-30 MAF Sensor Identification

Figure 6C3-1-31 MAF Sensor Simplified Schematic Circuit

DTC P0101 MASS AIR FLOW SYSTEM PERFORMANCE

Conditions for running DTC P0101

• DTCs P0102, P0103, P0107, P0108, P0121, P0122, P0123 are not set.

• The engine is running.

• The throttle position angle is less than 50% and the engine vacuum (BARO-MAP) is greater than 65 kPa.

• The system voltage is greater than 11 volts but less than 16 volts.

• The change in throttle position is less than 3%.

• All above conditions stable for two seconds.

Conditions for setting DTC P0101

• The MAF frequency is 50% different from the speed density calculation.

• The conditions met for at least five seconds.

Action taken when DTC P0101 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• The PCM utilises speed density (RPM, MAP, IAT) for fuel management.

Conditions for clearing the Check Powertrain Lamp and DTC P0101

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

G3PCM006A

J2-31

J1-01

PCM

MASS AIR FLOW

INPUT SIGNAL

EARTH

5 V

EFI

RELAY

F33

BR/ W (792)

B/R (750)

LOC. E5/ E15

MASS AIR FLOW SENSOR

P (439)

DTC P0102 MA SS AIR FLOW SENSOR CIRCUIT LOW FREQUENCY

Conditions for running DTC P0102

• The engine speed is greater than 300 RPM.

• The system voltage is at least 110 volts.

Conditions for setting DTC P0102

• The MAF frequency is 50% different from the speed density calculation.

• The conditions met for at least five seconds.

Action taken when DTC P0102 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM utilises speed density (RPM, MAP, IAT) for fuel management.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• The PCM utilises speed density (RPM, MAP, IAT) for fuel management.

Conditions for clearing the Check Powertrain Lamp and DTC P0102

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0103 MA SS AIR FLOW SENSOR CIRCUIT HIGH FREQUENCY

Conditions for running DTC P0103

• The engine speed is greater than 300 RPM.

• The system voltage is at least 110 volts.

Conditions for setting DTC P0103

• The MAF frequency is greater than 11,250 Hz.

• The conditions met for at least one seconds.

Action taken when DTC P0103 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM utilises speed density (RPM, MAP, IAT) for fuel management.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• The PCM utilises speed density (RPM, MAP, IAT) for fuel management.

Conditions for clearing the Check Powertrain Lamp and DTC P0103

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-32 Mass Air Flow Sensor Circuit

G3PCM006PT

CIRCUIT

MASS AIR FLOW SENSOR

J2-31

J1-01

PCM

CBA

AIR FLOW

FROM

AIR FILTER

AIR FLOW

THROTTLE BODY

EFI

RELAY

F33

P (43 9)

YE100

YE122

YE123

YE111

BR/W (792)

MASS AIR FLOW

INP U T SIG NAL

EARTH

B/R (750)

LOC. E5/E15

INTAKE AIR TEMPERATURE (IAT) SENSOR

The Intake Air Temperature (IAT) sensor is a

thermistor, (a resistor that changes resistance with

changes in temperature) mounted in the air c leaner

housing of the intake system. Low intake air

temperature produces high resistance in the

sensor, approximately 101k ohms at -40°C, while

high intake air temperature causes low sensor

resistance, approximately 80 ohms at 130°C.

The PCM:

1. Supplies a 5 volt signal voltage to the sensor

through a resistor in the PCM, and

2. Monitors the intake air temperature circuit

voltage, which will change when connected to

the intake air temperature sensor.

The circuit voltage will vary depending on the

resistance of the IAT sensor. The voltage will be

close to the 5 volt level when the sensor is cold,

and will decrease as the sensor warms.

The IAT sensor signal voltage is used by the PCM

to assist in calculating the fuel injector pulse width,

idle speed, canister purge and electronic spark

timing.

The following DTCs are set if the PCM detects a

malfunction in the IAT sensor circuit:

• DTC P0112: IAT Sensor Circuit Low Voltage.

• DTC P0113: IAT Sensor Circuit High Voltage.

• DTC P1111: IAT Sensor CKT Intermittent High

Voltage.

• DTC P1112: IAT Sensor CKT Intermittent Low

Voltage.

Figure 6C3-1-33 Intake Air Temperature (IAT) Sensor

T26C3004

Figure 6C3-1-34 IAT Sensor Location

1. Air Cleaner Housing

2. Intake Air Temperature (IAT) Sensor

3. A/C Refrigerant Pressure Sensor

DTC P0112 INTAKE AIR TEMPERATURE SENSOR CIRCUIT LOW VOLTAGE

Conditions for running DTC P0112

• DTC(s) P0101, P0102, P0103, P0117, P0118, are not set.

• The engine run time is greater than 30 seconds.

• The vehicle speed is less than 40 km/h.

Conditions for setting DTC P0112

• The Intake Air Temperature is greater than 139°C.

• The conditions met for at least 20 seconds.

Action taken when DTC P0112 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM will substitute a default Intake Air Temperature value of 25°C.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0112

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0113 INTAKE AIR TEMPERATURE SENSOR CIRCUIT HIGH VOLTAGE

Conditions for running DTC P0113

• DTC(s) P0101, P0102, P0103, P0117, P0118, are not set.

• The engine run time is greater than 100 seconds.

• The engine coolant temperature is greater than 0°C.

• The vehicle speed is less than 11 km/h.

Conditions for setting DTC P0113

• The Intake Air Temperature is at or below -35°C.

• The conditions met for at least 20 seconds.

Action taken when DTC P0113 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM will substitute a default Intake Air Temperature value of 25°C.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0113

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1111 INTAKE AIR TEMPERATURE SENSOR CIRCUIT INTERMITTENT HIGH VOLTAGE

Conditions for running DTC P1111

• DTC(s) P0101, P0102, P0103, P0117, P0118, are not set.

• The engine run time is greater than 100 seconds.

• The engine coolant temperature is greater than 0°C.

• The vehicle speed is less than 11 km/h.

• The Mass Air Flow is less than 15 g/s.

Conditions for setting DTC P1111

• The Intake Air Temperature is at or below -35°C.

• The conditions present for 0.3 seconds.

Action taken when DTC P1111 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM will substitute a default Intake Air Temperature value of 25°C.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1111

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1112 INTAKE AIR TEMPERATURE SENSOR CIRCUIT INTERMITTENT LOW VOLTAGE

Conditions for running DTC P1112

• DTC(s) P0101, P0102, P0103, P0117, P0118, are not set.

• The engine run time is greater than 30 seconds.

• The vehicle speed is less than 40 km/h.

Conditions for setting DTC P1112

• The Intake Air Temperature is at or below 139°C.

• The conditions present for 0.3 seconds.

Action taken when DTC P1112 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM will substitute a default Intake Air Temperature value of 25°C.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1112

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-35 Intake Air Temperature Sensor Circuit

G3PCM002PT

J2-57

J2-25

INTAKE AIR

TEMPERATURE SENSOR

SENSOR EARTH

IAT SENSOR SI G NAL

PCM

BR (47 2 )

G/O (469)

YE23 YE123

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR

The Manifold Absolute Pressure (MAP) sensor

measures the changes in the intake manifold

pressure which result from engine load (intake

manifold vacuum) and RPM changes and converts

these into a voltage output.

The control module sends a 5-volt supply voltage

to the MAP sensor. As the manifold pressure

changes, the output voltage of the sensor also

changes. By monitoring the sensor output voltage,

the control module knows the manifold pressure.

A closed throttle during engine coast down would

produce a relatively low MAP output, while a wide

open throttle would produce a high output. This

high output is produced because the pressure

inside the manifold is the same as outside the

manifold during wide open throttle, so it measures

100% of outside air pressure (atmospheric

pressure). The MAP sensor is also used, to

measure barometric pressure, allowing the control

module to m ak e adjustm ents f or differ ent operating

altitudes.

With the engine running, the MAP output voltage

signal should vary from about 1.0 to 1.5 volts at

idle, to about 4.0 to 4.5 volts at wide open throttle.

This MAP output voltage signal is sent to the

control module MAP sensor input signal terminal.

With ignition on and engine stopped, the manifold

pressure is equal to atmospheric (or barometric)

pressure and the signal voltage output will be high,

close to 5 volts at s ea level. T his voltage is us ed by

the PCM as an indication of engine load and

atmos pheric pr essure, altitude and is referr ed to as

BARO.

Figure 6C3-1-36 Manifold Absolute Pressure (MAP)

Sensor Location

1. Manifold Absolute Pressure (MAP) Sensor

2. Camshaft Position (CMP) Sensor

3. Oil Pressure Sensor

4. Connector to Knock Sensor Jumper Harness

The MAP sensor is used for the following:

• Altitude determination.

• Ignition timing control.

• Speed density fuel management default.

MANIFOLD

ABSOLUTE

PRESSURE

SENSOR

GEN30011GB

Figure 6C3-1-37 Manifold Absolute Pressure (MAP) Sensor

1. MAP Sensor

SPEED DENSITY SYSTEM

Three specific data sensors provide the PCM with

the basic information for the fuel management

portion of its operation. That is three specific

signals to the PCM establish the engine speed and

air dens ity factor s. The engine speed s ignal comes

from the ignition system. The PCM uses this

information to determine engine speed (RPM). Air

density is derived from IAT and MAP sensor inputs.

The IAT sensor measures the air temperature that

is entering the engine. The IAT signal works in

conjunction with the MAP sensor to determine air

density. As the intake manifold also increases and

additional f uel is r equir ed. T his inf or mation f r om the

IAT and MAP sensors is used by the PCM to

control injector pulse width.

The speed density system is only needed when

there is a Mass Air Flow (MAF) sensor m alfunc tion.

If the PCM detects a malfunction with the MAF

sensor circuit, the PCM will default to Speed

Density fuel management.

The following DTCs are set if the PCM detects a

malfunction in the MAP sensor circuit:

• DTC P0107: MAP Sensor Circuit Low Voltage.

• DTC P0108: MAP Sensor Circuit High

Voltage.

Figure 6C3-1-38 Manifold Absolute Pressure (MAP)

Sensor Location

1. Manifold Absolute Pressure (MAP) Sensor

2. MAP Sensor Harness Connector

DTC P0107 MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW VOLTAGE

Conditions for running DTC P0107

• No TP or ECT sensor DTCs are set.

• The engine is running.

• The TP angle is above 20% when the engine speed is greater than 1200 RPM.

• The TP angle is below 18% when the engine speed is below 1000 RPM.

Conditions for setting DTC P0107

• The MAP sensor voltage is less than 0.10 volts..

• The conditions met for at least two seconds.

Action taken when DTC P0107 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0107

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0108 MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT HIGH VOLTAGE

Conditions for running DTC P0108

• No TP or ECT sensor DTCs are set.

• The engine is running.

• The TP angle is above 20% when the engine speed is greater than 1000 RPM.

• The TP angle is below 18% when the engine speed is below 1200 RPM.

Conditions for setting DTC P0108

• The MAP sensor voltage is greater than 4.3 volts.

• The conditions met for at least four seconds.

Action taken when DTC P0108 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0108

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-39 MAP Sensor Circuit

G3PCM010PT

PCM

J2-32

J1-54

MANIFOLD

ABSOLUTE

PRESSURE SENSOR

J1-48

YE27 YE122

YE122

SENSOR EARTH

MAP SENSOR

SIGNAL

REFERENCE

VOLTAGE

V/W (414)

B (42 1)

LG (432)

YE123

HEATED OXYGEN SENSORS (HO2S)

The GEN III V8 engine incorporates the use of

Heated Exhaust Gas Oxygen Sensors (HO2S).

The ox ygen sens ors are the k ey to closed-loop fuel

control. The PCM uses information from the

oxygen sensors to precisely fine tune its fuel

injector pulse width calculations, based on the

unused, left-over oxygen content in the exhaust.

The system uses, two four wire heated oxygen

sensors. The oxygen sensors have a Zirconia

element that, when heated to temperatures above

360°C, produces voltages based on the amount of

oxygen content surrounding the tip, as compared

to oxygen in the atmosphere.

The sensors are mounted in the exhaust pipe with

the sensing portion exposed to the exhaust gas

stream. When the sensor has reached an

operating temperature of more than 360°C, it acts

as a voltage generator, producing a rapidly

changing voltage of between 10 - 1000 millivolts.

This voltage output is dependent upon the oxygen

content in the exhaust gas, as compared to the

sensor's atm ospheric oxygen reference cavity. T he

reference cavity of an un-heated oxygen sensor is

exposed to the atm osphere through the body of the

oxygen sensor. The oxygen sensors have an

internal heating element that is used to heat the

Zirconia element faster inside the sensors, thereby

decreasing the amount of time before the fuel

control system can begin running in closed loop.

The heated oxygen sensors have four wires, with

two for the internal Positive Temperature Co-

efficient (PTC) thermistor type heater circuit. One

of these wires has 12 volts continually applied to

the heater elem ent whenever the ignition is on. The

other wire is for the heater element earth. When

the sensor is cold, maximum current

(approximately 4 amps) flows through the heater

circuit and gradually reduces to approximately 0.5

amps as the sensor reaches full operating

temperature. The other two sensor wires are for

the sensor's signal to the PCM, and the sensor

earth.

GEN3 0013

Figure 6C3-1-40 Heated Oxygen Sensor (HO2S) Cutaway

1. Four Wire In-Line Connector

2. Heater Termination

3. Water Shield Assembly

4. Sensor Lead

5. Flat Seat Shell

6. Seat Gasket

7. Outer Electrode and Protective Coating

8. Rod Heater

9. Inner Electrode

10. Zirconia Element

11. Insulator

12. Clip Ring

13. Gripper

The reference cavity of a heated oxygen sensor is

exposed to the atmosphere by the air that passes

between the wire strands and insulation of the

oxygen sensor leads. The signal and heater leads

used on the oxygen sensor are of the stranded

type. Stranded leads have small spaces between

the wire strands and the insulation. These spaces

allow a satisfactory amount of air to pass through

the lead to maintain an adequate air reference.

When the sensor is cold, it produces either no

voltage, or an unusable, slowly changing one. Also

when cold, its internal electrical resistance is

extremely high – many million ohms. The PCM

always supplies a steady 450 millivolt, very low

current bias voltage to the oxygen sensor circuit.

When the sensor is cold and not producing any

voltage, the PCM detects only this steady bias

voltage. As the sensor begins heating, its internal

resistance decreases and it begins producing a

rapidly changing voltage that will overshadow the

PCM's supplied steady bias voltage. When the

PCM detects the changing voltage, it knows the

oxygen sensor is hot and its output voltage can be

used for fine-tuning the fuel injector pulse width.

The PCM monitors the oxygen sensor's changing

voltage for going above and below a mid-range

voltage band (approximately 300 - 600 millivolts),

to help decide when to operate in the closed-loop

mode.

When the fuel system is correctly operating in the

closed-loop mode, the oxygen sensor voltage

output is rapidly changing several times per

second, fluctuating from approximately 100mV

(high oxygen content – lean mixture) to 900mV

(low oxygen content – rich mixture). The PCM

monitors the changing voltage, and decides the

needed fuel mixture correction.

T6A3079GB

Figure 6C3-1-41 Heated Oxygen Sensor (HO2S) Locations

1. Left Hand Oxygen Sensor Bank 1 Sensor 1

2. Right Hand Oxygen Sensor Bank 2 Sensor 1

The oxygen sensors are mounted in the exhaust

pipes and are referred to as Bank 1 Sensor 1 (left

exhaust pipe) Bank 2 Sensor 1 (right exhaust

pipe).

The following DTCs set when the PCM detects a

HO2S signal circuit that is low:

DTC P0131: Bank 1 Sensor 1 HO2S.

DTC P0151: Bank 2 Sensor 1 HO2S.

The following DTCs set when the PCM detects a

HO2S signal circuit that is high:

DTC P0132: Bank 1 Sensor 1 HO2S.

DTC P0152: Bank 2 Sensor 1 HO2S.

The following DTCs set when the PCM detects no

HO2S activity:

DTC P0134: Bank 1 Sensor 1 HO2S.

DTC P0154: Bank 2 Sensor 1 HO2S.

A fault in the oxygen sensor heater element or its

ignition feed or earth results in an increase in time

to Closed Loop fuel control. This may cause

increased emissions, especially at start-up. The

following DTCs set when the PCM detects a

malfunction in the HO2S heater circuits:

• DTC P0135: Bank 1 Sensor 1 HO2S heater.

• DTC P0155: Bank 2 Sensor 1 HO2S heater.

RESPONSE TIME

Not only is it necessary for the oxygen sensors to produce voltage signals for rich or lean exhaust, it is also

important to respond quickly to changes. If the oxygen sensors respond slowly, the customer may complain of

poor fuel ec onomy, rough idle, surging or lack of perfor mance. T he PCM will s et a DTC that indicates degraded

HO2S performance if a HO2S response switching, transition time, or ratio problem is detected.

DTC P1133: Insufficient Switching Bank 1 Sensor 1.

DTC P1134: Transition Time Ratio Bank 1 Sensor 1.

DTC P1153: Insufficient Switching Bank 2 Sensor 1.

DTC P1154: Transition Time Ratio Bank 2 Sensor 1.

OXYGEN SENSOR CONTAMINANTS

Carbon

Black carbon or soot deposits result from over-rich air-fuel mixtures. However, carbon does not harm an oxygen

sensor. Deposits can be burned off in the vehicle by running the engine at part throttle for at least two minutes.

Silica

Certain RT V silicon gask et ma terials give off vapour as they cure that may contaminate the ox ygen s ensor. This

contam ination is us ually caused by the vapours being pulled from the PCV syst em , into the combus tion chamber

and pass ed on to the exhaust s ystem. T he sand lik e partic les fr om the RTV s ilica em bed in the m olec ules of the

oxygen sensor element and plug up the surface. With the outside of the oxygen sensor element not able to

sense all of the oxygen in the exhaus t system it results in lazy ox ygen sensor response and engine control. The

oxygen sensor will have a whitish appearance on the outside if it has been contaminated.

There is also a possibility of silica contamination caused by silicon in the fuel. Some oil companies have used

silicone to raise the octane rating of their fuel. Careless fuel handling practices with transport containers can

result in unacceptable concentrations of silicone in the fuel at the pump.

Silica contamination can be caused by silicon in lubricants used to install vacuum hoses on fittings. Do not use

silicon sealers on gaskets or exhaust joints.

Lead

Lead glazing of the sens ors can be introduc ed when regular, or leaded fuel is burned. It is diff icult to detect lead

contamination by visual inspection.

Other Substances

Oil deposits will ultimately prevent oxygen sensor operation. The sensor will have a dark brown appearance.

Causes of high oil consumption should be checked.

The additives in ethylene glycol can also affect oxygen sensor performance. This produces a whitish

appearance. If antifreeze enters the exhaust system , you will likely enc ounter other , m ore obvious, sym ptoms of

cooling system trouble. If for example the engine had a head gasket failure where coolant did enter the

combustion chamber it would be a good idea to check the oxygen sensor operation after the head gasket was

repaired.

Multiple Faults

If you encounter multiple or repeated oxygen sensor failures on the same vehicle, consider contamination.

Leaded fuel, silica contamination from uncured, low-grade (unapproved) RTV sealant, and high oil consum ption

are possible causes.

DTC P0131 HEATED OXYGEN SENSOR CIRCUIT LOW VOLTAGE BANK 1 SENSOR 1

Conditions for running DTC P0131

Criteria 1

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The engine coolant temperature is greater than 48°C.

• The ignition voltage is greater than 9.0 volts.

• The fuel system is operating in Closed Loop.

• The fuel trim learn is enabled.

• The air/fuel ratio is between 14.5:1 and 14.7:1.

• The TP angle is between 0% and 70%.

Criteria 2

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The ignition voltage is greater than 9.0 volts.

• The Power Enrichment mode is enabled for at least 0.5 seconds.

Conditions for setting DTC P0131

Criteria 1

• The HO2S signal voltage remains below 200 mV.

• The Criteria 1conditions are present for at least 33 seconds.

Criteria 2

• The HO2S signal voltage remains below 360 mV.

• The Criteria2 conditions are present for at least five seconds.

Action taken when DTC P0131 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• Open Loop Fueling.

Conditions for clearing the Check Powertrain Lamp and DTC P0131

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0132 HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE BANK 1 SENSOR 1

Conditions for running DTC P0132

Criteria 1

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The ignition voltage is greater than 9.0 volts.

• The fuel system is operating in Closed Loop.

• The fuel trim learn is enabled.

• The air/fuel ratio is between 14.5:1 and 14.7:1.

Criteria 2

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The ignition voltage is greater than 9.0 volts.

• Deceleration Fuel Cut-Off mode is enabled for greater than one second.

Conditions for setting DTC P0132

Criteria 1

• The HO2S signal voltage remains below 775 mV.

• The Criteria 1conditions are present for at least 33 seconds.

Criteria 2

• The HO2S signal voltage remains below 540 mV.

• The Criteria2 conditions are present for at least five seconds.

Action taken when DTC P0132 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• Open Loop Fueling.

Conditions for clearing the Check Powertrain Lamp and DTC P0132

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0133 HEATED OXYGEN SENSOR SLOW RESPONSE BANK 1 SENSOR 1

Conditions for running DTC P0133

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The engine coolant temperature is greater than 65°C.

• The ignition voltage is greater than 9.0 volts.

• The fuel system is operating in Closed Loop.

• The engine speed is between 1000 RPM and 2300 RPM.

• The engine air flow is between 20 g/s and 50 g/s.

• The EVAP canister purge duty cycle is greater than 0%.

• The engine run time is greater than 120 seconds.

Conditions for setting DTC P0133

• The Lean to Rich response (below 300 mV to above 600 mV) average time is greater than 100 milliseconds.

• The Rich to Lean response (above 600 mV to below 300 mV) average time is greater than 100 milliseconds.

Action taken when DTC P0133 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• Open Loop Fueling.

Conditions for clearing the Check Powertrain Lamp and DTC P0133

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0134 HEATED OXYGEN SENSOR INSUFFICIENT ACTIVITY BANK 1 SENSOR 1

Conditions for running DTC P0134

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The ignition voltage is greater than 9.0 volts.

• The fuel system is operating in Closed Loop.

• The engine run time is greater than 70 seconds.

• The engine coolant temperature is greater than 48°C.

Conditions for setting DTC P0134

• The HO2S signal voltage is steady between 350 mV and 550 mV.

• The conditions are present for at least 70 seconds.

Action taken when DTC P0134 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• Open Loop Fueling.

Conditions for clearing the Check Powertrain Lamp and DTC P0134

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0135 HEATED OXYGEN SENSOR HEATER CIRCUIT BANK 1 SENSOR 1

Conditions for running DTC P0135

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The intake air temperature and the engine coolant temperature are less than 50°C and are within 8°C of each

other at engine start-up.

• The ignition voltage is between 10.0 volts and 18.0 volts.

• The engine air flow is less than 18 g/s.

Conditions for setting DTC P0135

• The HO2S voltage remains between 300 mV and 700 mV for a predetermined amount of time (depends on

engine coolant temperature and air flow).

Action taken when DTC P0135 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0135

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0151 HEATED OXYGEN SENSOR CIRCUIT LOW VOLTAGE BANK 2 SENSOR 1

Conditions for running DTC P0151

Criteria 1

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The engine coolant temperature is greater than 48°C.

• The ignition voltage is greater than 9.0 volts.

• The fuel system is operating in Closed Loop.

• The fuel trim learn is enabled.

• The air/fuel ratio is between 14.5:1 and 14.7:1.

• The TP angle is between 0% and 70%.

Criteria 2

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The ignition voltage is greater than 9.0 volts.

• The Power Enrichment mode is enabled for at least 0.5 seconds.

Conditions for setting DTC P0151

Criteria 1

• The HO2S signal voltage remains below 200 mV.

• The Criteria 1conditions are present for at least 33 seconds.

Criteria 2

• The HO2S signal voltage remains below 360 mV.

• The Criteria2 conditions are present for at least five seconds.

Action taken when DTC P0151 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• Open Loop Fueling.

Conditions for clearing the Check Powertrain Lamp and DTC P0151

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0152 HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE BANK 2 SENSOR 1

Conditions for running DTC P0152

Criteria 1

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The ignition voltage is greater than 9.0 volts.

• The fuel system is operating in Closed Loop.

• The fuel trim learn is enabled.

• The air/fuel ratio is between 14.5:1 and 14.7:1.

Criteria 2

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The ignition voltage is greater than 9.0 volts.

• Deceleration Fuel Cut-Off mode is enabled for greater than one second.

Conditions for setting DTC P0152

Criteria 1

• The HO2S signal voltage remains below 775 mV.

• The Criteria 1conditions are present for at least 33 seconds.

Criteria 2

• The HO2S signal voltage remains below 540 mV.

• The Criteria2 conditions are present for at least five seconds.

Action taken when DTC P0152 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• Open Loop Fueling.

Conditions for clearing the Check Powertrain Lamp and DTC P0152

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0153 HEATED OXYGEN SENSOR SLOW RESPONSE BANK 2 SENSOR 1

Conditions for running DTC P0153

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The engine coolant temperature is greater than 65°C.

• The ignition voltage is greater than 9.0 volts.

• The fuel system is operating in Closed Loop.

• The engine speed is between 1000 RPM and 2300 RPM.

• The engine air flow is between 20 g/s and 50 g/s.

• The EVAP canister purge duty cycle is greater than 0%.

• The engine run time is greater than 120 seconds.

Conditions for setting DTC P0153

• The Lean to Rich response (below 300 mV to above 600 mV) average time is greater than 100 milliseconds.

• The Rich to Lean response (above 600 mV to below 300 mV) average time is greater than 100 milliseconds.

Action taken when DTC P0153 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• Open Loop Fueling.

Conditions for clearing the Check Powertrain Lamp and DTC P0153

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0154 HEATED OXYGEN SENSOR INSUFFICIENT ACTIVITY BANK 1 SENSOR 1

Conditions for running DTC P0154

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The ignition voltage is greater than 9.0 volts.

• The fuel system is operating in Closed Loop.

• The engine run time is greater than 70 seconds.

• The engine coolant temperature is greater than 48°C.

Conditions for setting DTC P0154

• The HO2S signal voltage is steady between 350 mV and 550 mV.

• The conditions are present for at least 70 seconds.

Action taken when DTC P0154 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• Open Loop Fueling.

Conditions for clearing the Check Powertrain Lamp and DTC P0154

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0155 HEATED OXYGEN SENSOR HEATER CIRCUIT BANK 1 SENSOR 1

Conditions for running DTC P0155

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335, P0336, P0351-

P0358, P1258 are not set.

• The intake air temperature and the engine coolant temperature are less than 50°C and are within 8°C of each

other at engine start-up.

• The ignition voltage is between 10.0 volts and 18.0 volts.

• The engine air flow is less than 18 g/s.

Conditions for setting DTC P0155

• The HO2S voltage remains between 300 mV and 700 mV for a predetermined amount of time (depends on

engine coolant temperature and air flow).

Action taken when DTC P0155 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0155

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0171 FUEL SYSTEM LEAN BANK 1

Conditions for running DTC P0171

• DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335,

P0336, P0351-P0358, P1111, P1112, or P1258 are not set.

• The engine coolant temperature is between 50°C and 115°C.

• The Barometric pressure is greater than 74 kPa.

• The MAF is between 5.0 g/s and 90 g/s.

• The MAP pressure is between 26 kPa and 90 kPa.

• The IAT is between -20°C and 90°C.

• The engine speed is between 400 RPM and 3000 RPM.

• The TP sensor angle is less than 90%.

• The vehicle speed is less than 137 km/h.

Conditions for setting DTC P0171

• The average Long Term Fuel Trim cell values are above a predetermined threshold.

• All the above conditions are present for at least six seconds.

Action taken when DTC P0171 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0171

• The PCM turns the Check Powertrain Lamp OFF after one drive trip that the diagnostic runs and does not fail

within the same conditions that the DTC last failed.

NOTE: If the failure was during a non-typical driving condition, the Check Powertrain Lamp may remain on

longrer than one drive trip. Review the Freeze Frame/Failure Records for the last failure conditions.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0172 FUEL SYSTEM RICH BANK 1

Conditions for running DTC P0172

• DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335,

P0336, P0351-P0358, P1111, P1112, or P1258 are not set.

• The engine coolant temperature is between 50°C and 115°C.

• The Barometric pressure is greater than 74 kPa.

• The MAF is between 5.0 g/s and 90 g/s.

• The MAP pressure is between 26 kPa and 90 kPa.

• The IAT is between -20°C and 90°C.

• The engine speed is between 400 RPM and 3000 RPM.

• The TP sensor angle is less than 90%.

• The vehicle speed is less than 137 km/h.

Conditions for setting DTC P0172

• The average Long Term Fuel Trim cell values are above a predetermined threshold.

• All the above conditions are present for at least 49 seconds.

Action taken when DTC P0172 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0172

• The PCM turns the Check Powertrain Lamp OFF after one drive trip that the diagnostic runs and does not fail

within the same conditions that the DTC last failed.

NOTE: If the failure was during a non-typical driving condition, the Check Powertrain Lamp may remain on

longrer than one drive trip. Review the Freeze Frame/Failure Records for the last failure conditions.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0174 FUEL SYSTEM LEAN BANK 2

Conditions for running DTC P0174

• DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335,

P0336, P0351-P0358, P1111, P1112, or P1258 are not set.

• The engine coolant temperature is between 50°C and 115°C.

• The Barometric pressure is greater than 74 kPa.

• The MAF is between 5.0 g/s and 90 g/s.

• The MAP pressure is between 26 kPa and 90 kPa.

• The IAT is between -20°C and 90°C.

• The engine speed is between 400 RPM and 3000 RPM.

• The TP sensor angle is less than 90%.

• The vehicle speed is less than 137 km/h.

Conditions for setting DTC P0174

• The average Long Term Fuel Trim cell values are above a predetermined threshold.

• All the above conditions are present for at least six seconds.

Action taken when DTC P0174 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0174

• The PCM turns the Check Powertrain Lamp OFF after one drive trip that the diagnostic runs and does not fail

within the same conditions that the DTC last failed.

NOTE: If the failure was during a non-typical driving condition, the Check Powertrain Lamp may remain on

longrer than one drive trip. Review the Freeze Frame/Failure Records for the last failure conditions.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0175 FUEL SYSTEM RICH BANK 2

Conditions for running DTC P0175

• DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335,

P0336, P0351-P0358, P1111, P1112, or P1258 are not set.

• The engine coolant temperature is between 50°C and 115°C.

• The Barometric pressure is greater than 74 kPa.

• The MAF is between 5.0 g/s and 90 g/s.

• The MAP pressure is between 26 kPa and 90 kPa.

• The IAT is between -20°C and 90°C.

• The engine speed is between 400 RPM and 3000 RPM.

• The TP sensor angle is less than 90%.

• The vehicle speed is less than 137 km/h.

Conditions for setting DTC P0175

• The average Long Term Fuel Trim cell values are above a predetermined threshold.

• All the above conditions are present for at least 49 seconds.

Action taken when DTC P0175 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0175

• The PCM turns the Check Powertrain Lamp OFF after one drive trip that the diagnostic runs and does not fail

within the same conditions that the DTC last failed.

NOTE: If the failure was during a non-typical driving condition, the Check Powertrain Lamp may remain on

longrer than one drive trip. Review the Freeze Frame/Failure Records for the last failure conditions.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1133 HEATED OXYGEN SENSOR INSUFFICIENT SWITCHING BANK 1 SENSOR 1

Conditions for running DTC P1133

• DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335,

P0336, P0351-P0358, P1111, P1112, or P1258 are not set.

• The fuel system is operating in Closed Loop.

• The engine run time is greater than 2.0 seconds.

• The engine speed is greater than 1000 RPM but less than 2300 RPM.

• The ignition voltage is greater than 9.0 volts.

• The engine coolant temperature is greater than 65°C.

• The MAF is between 20 g/s and 50 g/s.

• The EVAP purge duty cycle is greater than 0%.

Conditions for setting DTC P1133

• The PCM determines that within 100 seconds the HO2S lean to rich switches are less than 10 and rich to lean

switches are less than 10.

Action taken when DTC P1133 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1133

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1134 HEATED OXYGEN SENSOR TRANSITION TIME RATIO BANK 1 SENSOR 1

Conditions for running DTC P1134

• DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335,

P0336, P0351-P0358, P1111, P1112, or P1258 are not set.

• The fuel system is operating in Closed Loop.

• The engine run time is greater than 2.0 seconds.

• The engine speed is greater than 1000 RPM but less than 2300 RPM.

• The ignition voltage is greater than 9.0 volts.

• The engine coolant temperature is greater than 65°C.

• The MAF is between 20 g/s and 50 g/s.

• The EVAP purge duty cycle is greater than 0%.

Conditions for setting DTC P1134

• The PCM determines that the HO2S transition time ratio is not at the expected value.

Action taken when DTC P1134 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1134

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1153 HEATED OXYGEN SENSOR INSUFFICIENT SWITCHING BANK 2 SENSOR 1

Conditions for running DTC P1153

• DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335,

P0336, P0351-P0358, P1111, P1112, or P1258 are not set.

• The fuel system is operating in Closed Loop.

• The engine run time is greater than 2.0 seconds.

• The engine speed is greater than 1000 RPM but less than 2300 RPM.

• The ignition voltage is greater than 9.0 volts.

• The engine coolant temperature is greater than 65°C.

• The MAF is between 20 g/s and 50 g/s.

• The EVAP purge duty cycle is greater than 0%.

Conditions for setting DTC P1153

• The PCM determines that within 100 seconds the HO2S lean to rich switches are less than 30 and rich to lean

switches are less than 30.

Action taken when DTC P1153 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1153

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1154 HEATED OXYGEN SENSOR TRANSITION TIME RATIO BANK 2 SENSOR 1

Conditions for running DTC P1154

• DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0335,

P0336, P0351-P0358, P1111, P1112, or P1258 are not set.

• The fuel system is operating in Closed Loop.

• The engine run time is greater than 2.0 seconds.

• The engine speed is greater than 1000 RPM but less than 2300 RPM.

• The ignition voltage is greater than 9.0 volts.

• The engine coolant temperature is greater than 65°C.

• The MAF is between 20 g/s and 50 g/s.

• The EVAP purge duty cycle is greater than 0%.

Conditions for setting DTC P1154

• The PCM determines that the HO2S transition time ratio is not at the expected value.

Action taken when DTC P1154 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1154

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-42 Heated Oxygen Sensor (HO2S) Circuits

GY/B (1413)

GY (1412)

RIGHT OXYGEN SENSOR

BANK TWO SENSOR ONE

LEFT OXYGEN SENSOR

BANK ONE SENSOR O NE

LOC. E5/E15

BLU/B (413)

V (412)

P (439)

TO F USE

F33

G3PCM003PT

J1-26

J1-66

J1-01

J1-40

J2-01

J2-40

J1-69

J1-29

PCM

RIGHT

OXYGEN

SENSOR

SIGNAL LO

LEFT

OXYGEN

SENSOR

SIGNAL LO

RIGHT

OXYGEN

SENSOR

SIGNAL HI

EARTH

LEFT

OXYGEN

SENSOR

SIGNAL HI

45 0 mV

B/R (750)

YE95

YE122

YE123

THROTTLE POSITION (TP) SENSOR

The Throttle Position (TP) sensor is connected to

the throttle shaft on the throttle body unit. It is a

potentiometer with one end connected to 5 volts

from the PCM and the other end to PCM earth. A

third wire connects from a sliding contact in the T P

sensor to the PCM allowing the PCM to measure

the voltage from the TP sensor. As the throttle is

moved ( acceler ator pedal m oved), the output of the

TP sensor changes. At a closed throttle position,

the output of the TP sensor is below 1.25V. As the

throttle valve opens, the output increases so that,

at wide-open throttle (WOT), the output voltage

should be about 4 volts.

By monitoring the output voltage from the TP

sensor, the PCM c an determ ine fuel delivery based

on throttle valve angle (driver demand). A broken

or loose T P sensor c an cause intermittent bursts of

fuel from the injectors, and an unstable idle,

because the PCM interprets the throttle is moving.

The TP sens or is not adjustable and ther e is no set

value for voltage at closed throttle because the

actual voltage at closed throttle can vary from

vehicle to vehicle due to tolerances. The PCM has

a special progr am built into it that can adjus t for the

tolerances in the T P sensor voltage reading at idle.

The PCM uses the reading at closed throttle idle

for the zero reading (0% throttle) so no adjustment

is necessary. Even if the TP sensor voltage

reading was to be changed by: tampering, throttle

body coking, sticking cable or any other reason,

the TP sensor will still be 0%. The PCM will learn

what the closed throttle value is every time the

throttle comes back to closed throttle.

Figure 6C3-1-43 Throttle Position (TP) Sensor

1. TP Sensor

2. Throttle Body

3. IAC Valve

The following DTCs are set when the PCM detects

a malfunction with the TP sensor circuits:

• DTC P0121: TP Sensor Circuit Insufficient

Activity.

• DTC P0122: TP Sensor Circuit Low Voltage.

• DTC P0123: TP Sensor Circuit High Voltage.

• DTC P1121: TP Sensor CKT Intermittent High

Voltage.

• DTC P1122: TP Sensor CKT Intermittent Low

Voltage.

GEN 3 00 15

Figure 6C3-1-44 TP Sensor - Typical

1. TP Sensor

2. Throttle Plate

3. Powertrain Control Module (PCM)

DTC P0121 THROTTLE POSITION SENSOR CIRCUIT INSUFFICIENT ACTIVITY

Conditions for running DTC P0121

• No MAP sensor or TP sensor DTCs.

• The engine run time is greater than 10 seconds.

• The engine coolant temperature is greater than 0°C.

• The IAC is between 0 and 255 counts.

• The MAP is less than 55 kPa.

• The MAP is greater than 65 kPa.

• MAP is steady.

Conditions for setting DTC P0121

• The predicted throttle angle does not match the actual throttle angle.

• All conditions are met for at least 20 seconds.

Action taken when DTC P0121 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• The PCM uses a default TP sensor value.

Conditions for clearing the Check Powertrain Lamp and DTC P0121

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0122 THROTTLE POSITION SENSOR CIRCUIT LOW VOLTAGE

Conditions for running DTC P0122

• The ignition switch is ON or in the engine is running.

Conditions for setting DTC P0122

• The TP sensor signal voltage is less than 0.2 volts.

Action taken when DTC P0122 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• The PCM uses a default TP sensor value.

• The transmission TCC will not apply.

• High transmission line pressure.

• Fixed transmission shift points, hard shifts and no fourth gear in hot mode.

Conditions for clearing the Check Powertrain Lamp and DTC P0122

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0123 THROTTLE POSITION SENSOR CIRCUIT HIGH VOLTAGE

Conditions for running DTC P0123

• The ignition switch is ON or in the engine is running.

Conditions for setting DTC P0123

• The TP sensor signal voltage is greater than 4.8 volts.

• Conditions present for at least ten seconds.

Action taken when DTC P0123 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• The PCM uses a default TP sensor value.

• The transmission TCC will not apply.

• High transmission line pressure.

• Fixed transmission shift points, hard shifts and no fourth gear in hot mode.

Conditions for clearing the Check Powertrain Lamp and DTC P0123

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1121 THROTTLE POSITION SENSOR CIRCUIT INTERMITTENT HIGH VOLTAGE

Conditions for running DTC P1121

• The ignition switch is ON.

Conditions for setting DTC P1121

• The TP sensor signal voltage is greater than 4.8 volts.

Action taken when DTC P1121 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1121

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1122 THROTTLE POSITION SENSOR CIRCUIT INTERMITTENT HIGH VOLTAGE

Conditions for running DTC P1122

• The ignition switch is ON or the engine is running.

Conditions for setting DTC P1122

• The TP sensor signal voltage is less than 0.2 volts.

Action taken when DTC P1122 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1122

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-45 Throttle Position Sensor Circuits

G3PCM005PT

SENSOR EARTH

TP SENSOR SIGNAL

TP SEN SOR

REFERENCE

VOLTAGE

PCM

J1-08

J2-24

J1-60

THROTTLE

POSITION SENSOR

GY (416)

YE122

YE122YE30

YE123

BLU (417)

B/Y (452)

THROTTLE RELAXER

MODULE

KNOCK SENSORS (KS)

Varying octane levels in today's petrol may cause

detonation in some engines. Detonation is caused

by an uncontrolled pressure in the combustion

chamber. This uncontrolled pressure could

produce a f lame f r ont oppos ite to 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. Though light detonation is

sometimes considered normal, heavy detonation

could result in engine damage. Light detonation

occurs when the point of maximum pressure has

been exceeded. T o control spark knock , two knoc k

sensors are used on the GEN III V8 engine. This

system is des igned to retard spark tim ing up to 20°

to reduce spark knock in the engine. This allows

the engine to use maximum spark advance to

improve driveability and fuel economy.

The knock sensors detect abnormal mechanical

vibration (spark knocking) in the engine. There are

several calibrations of knock sensors because

each engine produces a different frequency of

mechanical noise. The knock sensor is specifically

chosen for this engine to best detec t engine knock ,

over all the other noises in the engine.

The knock sensor produces an AC output voltage

that increases with the severity of the knock. This

signal voltage inputs to the PCM. This AC signal

voltage to the PCM is proces sed by a Digital Signal

Noise Enhancement Filter (DSNEF) module. This

DSNEF module is used to determine if the AC

signal coming in is noise or actual detonation. This

DSNEF module is part of the PCM and cannot be

replaced.

4254

Figure 6C3-1-46 Knock (KS) Sensor

1. Piezo Crystal

2. Shunt Resister

The processed knock sensor signal is then

supplied to the PCM. The PCM then adjusts the

ignition control system to reduce the spark

advance. How muc h the tim ing is retar ded is based

upon the amount of time knock is detected. After

the detonation stops, the timing will gradually

return to its calibrated value of s park advance. T he

Knock Sensor system will only retard timing after

the following conditions are met:

• The engine run time is greater than 20

seconds.

• The engine speed is greater than 1650 RPM.

• T he engine coolant tem perature is greater than

70°C.

• T he manif old absolute pressur e is less than 60

kPa.

DTC P0325 indicates an internal PCM malfunction

related to the knock sensor system. DTCs P0327

and P0332 indicate that a knock sensor or knock

sensor circuit is malfunctioning.

Figure 6C3-1-47 Knock Sensor Location

1. Front Knock Sensor

2. Rear Knock Sensor

3. Left Cylinder Head

DTC P0325 KNOCK SENSOR SYSTEM

Conditions for running DTC P0325

• The engine run time is greater than 20 seconds.

• The engine speed is between 1650 and 3000 RPM.

• The MAP is at or about 48 kPa.

• The engine coolant temperature is greater than 70°C.

• The throttle angle is greater than 0.5%.

• The TP sensor angle is steady within 1%.

• Battery voltage is between 10 and 16 volts.

Conditions for setting DTC P0325

• A malfunction with the knock sensor system or circuits within the PCM are faulty.

• All above conditions present for at least three seconds.

Action taken when DTC P0325 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0325

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0327 KNOCK SENSOR CIRCUIT FRONT SENSOR

Conditions for running DTC P0327

• The engine run time is greater than 20 seconds.

• The engine speed is between 1650 and 3000 RPM.

• The MAP is at or about 48 kPa.

• The engine coolant temperature is greater than 70°C.

• The throttle angle is greater than 0.5%.

• Battery voltage is between 10 and 16 volts.

Conditions for setting DTC P0327

• The PCM determines that the frequency is less than or greater than the expected amount for at least three

seconds.

Action taken when DTC P0327 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0327

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0332 KNOCK SENSOR CIRCUIT REAR SENSOR

Conditions for running DTC P0332

• The engine run time is greater than 20 seconds.

• The engine speed is between 1650 and 3000 RPM.

• The MAP is at or about 48 kPa.

• The engine coolant temperature is greater than 70°C.

• The throttle angle is greater than 0.5%.

• Battery voltage is between 10 and 16 volts.

Conditions for setting DTC P0332

• The PCM determines that the frequency is less than or greater than the expected amount for at least three

seconds.

Action taken when DTC P0332 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0332

The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-48 Knock Sensor Circuit

G3VX007PT

PCM

DSNEF

FRONT KNOCK

SENSOR SIGNAL I NPUT

REAR KNOCK

SENSOR SIGNAL I NPUT

J1-51

J1-11

REAR

KNOCK

SENSOR

FRONT

KNOCK

SENSOR

BLU (815)

YE19

YE18

YE122

LBLU (826)

PARK, REVERSE, NEUTRAL, DRIVE, LOW (PRNDL) SWITCH

The transmission PRNDL switch is a mulit-signal

switch which sends signals to the PCM to indicate

gear lever position. Park, Reverse, Neutral, Drive,

3, 2, or 1. The PCM will then determine the signal

from the PRNDL switch and sends a command to

the instruments via the PIM and the serial data

normal mode message commanding the

instruments to turn ON the correct gear indicator

lamp for the gear that has been selected.

The PRNDL switch uses four discrete circuits to

pull four PCM voltages low in var ious combinations

to indicate each gear range. The voltage level of

the circuits is represented as CLOSED = earthed

(0V), and OPEN = open (12V). The four states

displayed represents P, A, B, and C inputs.

The Tech 2 scan tool will display all four circuits

(P, A, B, C) and the appr opriate open and c los ed to

represent the gear selected. If the gear selected

does not match the OPEN/ CLOSED state as

displayed in the table or on the scan tool, or the

appropriate instruments gear lamp does not light

up for the gear selected, there is a fault in the

PRNDL select circuit or in the Instrument Panel

(IP) cluster.

The PRNDL operation indicates to the PCM what

gear the shif t s elec tor is in. This inf or mation is used

for the IAC valve operation.

IMPORTANT:

Idle quality will be affected if the vehicle is driven

with the PRNDL switch disconnected. Having the

switch disconnec ted m ay also cause a VSS DT C to

set.

For additional details of the PRNDL switch

location and adjustment, refer to

Section 7C4 Automatic Transmission, On-

Vehicle Servicing in VX Service Information.

The following DTCs are set when the PCM detects

a malfunction with the transmission range switch:

• DTC P0705: Transmission Range Switch

Circuit.

• DTC P0706: Transmission Range Switch

Performance.

DTC P0705 TRANSMISSION RANGE SWITCH CIRCUIT

Conditions for running DTC P0705

• The ignition is on.

Conditions for setting DTC P0705

• The Transmission Range Switch inputs indicate an invalid combination.

• The above condition is present for longer than 30 seconds.

Action taken when DTC P0705 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0705

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

GEAR

POSITION

SELECTED

SCAN TOOL PRNDL DISPLAY

(P, A, B, C)

P A B C

PARK (P) CLOSED

(0V) CLOSED

(0V) OPEN

(12V) OPEN

(12V)

REVERSE (R) OPEN

(12V) CLOSED

(0V) CLOSED

(0V) OPEN

(12V)

NEUTRAL (N) CLOSED

(0V) OPEN

(12V) CLOSED

(0V) OPEN

(12V)

DRIVE 4 (D) OPEN

(12V) OPEN

(12V) CLOSED

(0V) CLOSED

(0V)

DRIVE (3) CLOSED

(0V) CLOSED

(0V)

DRIVE 2 (2) OPEN

(12V) CLOSED

(0V) OPEN

(12V) CLOSED

(0V)

DRIVE 1 (1) CLOSED

(0V) OPEN

(12V) OPEN

(12V) CLOSED

(0V)

Figure 6C3-1-49 Transmiss i on Ra nge / PRNDL Switch

Valid Input Combinations

DTC P0706 TRANSMISSION RANGE SWITCH PERFORMANCE

Conditions for running DTC P0706

• The ignition is on.

Conditions for setting DTC P0706

• The Transmission Range Switch inputs indicate an invalid combination.

• The above condition is present for longer than 30 seconds.

Action taken when DTC P0706 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0706

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

Figure 6C3-1-50 Transmission PRNDL Switch Circuit

G3PCM038PT

PCM

J1-32

J1-72

PRNDL P

PRNDL A

SWITCH P

SWITCH A

SWITCH B

SWITCH C

LOC. E5/E15

P. R. N. D. L. SWITC H

12V

J2-62

J1-34

PRNDL B

PRNDL C

12V

BLU/W (771)

Y (77 2)

GY (773)

W (776)

YE122

YE123

YB20

YB35

B/R (750)

A/C REQUEST SIGNAL A ND A/C CLUTCH CONTROL WITH ECC

The Electronic Climate Control (ECC) module request the PCM to turn the A/C compressor clutch on or off via

the PIM and the s erial data bus nor m al m ode m essage. T he ECC m odule m onitor s inf orm ation fr om it’s s ensors

and switches and determines if the A/C compres sor c lutch s hould be on or off. The ECC contr ol module will then

request the PCM to turn the A/C compressor clutch on or off when required.

The PCM on receiving a request to turn on the A/C compressor will:

1. Adjust the Idle Air Control ( IAC) valve position to c om pensate f or the additional load placed on the engine by

the air conditioning compressor.

2. Energise the A/C compressor relay, to operate the A/C compressor if the pressure in the A/C system is

within the correct operating range.

Low Pressure High Pressure RPM

Cut Out Cut In Cut Out Cut In Off On

180 240 2900 2000 4800 4000

The PCM on rec eiving a request to tur n on the A/C com pres sor, m onitors the A/C pressure, coolant tem perature

and RPM to determine A/C clutch operation.

There are two DTCs associated with the A/C system . DTC P1539 is set when, the PCM detects voltage on the

A/C clutch status terminal when the system has not requested A/C. A short to voltage at any point in the A/C

status circuit, or the A/C relay contacts are stuck.

DTC P1546 is set when the PCM activates the relay, voltage should be present at both the A/C compressor

clutch and the A/C clutch status circuit at the PCM. If the voltage is not present, DTC P1546 will set.

Figure 6C3-1-51 A/C Request Signal With ECC Circuit

G3PCM046PT

BCM

BATTERY

F31

A5/A6O/B (740)

(1040)

BATTERY MAIN POWER

LOC. E1

R (2H)

F14

E20/D6

P/B

(39) IGNITION ON

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

IGNITION SWITCH

(3)

B/Y (155 )

B/G (151)

LOC. E3

R/B (1221)

G/W (1220)

Y (1049)

R/B (1221)

PIM

SERIAL

DATA

ELECTRONIC EARTH

HIGH CURRENT

EARTH

A1/A5

B10/B11

E2/D2

E9/E3

SERIAL

DATA

MAIN

SERIAL

DATA AUX.

16 B/R ( 750)

LOC. E5/E15

CLASS 2

SERIAL DATA

EARTH

ECC

6SERIAL

DATA

LOC. E3

G/W (1220)

B/Y (155 )

PCM

J1-58

CLASS 2

SERIAL DA TA

LG/B

(366)

O/Y

(479)

Y (1049)

J2-43

J2-18

A/C

CLUTCH

CONTROL

A/C RELA Y

STATUS

COMPRESSOR

A/C

RELAY

EFI

RELAY

F33 LOC. E 3

G (59) B/R (750)

YB176

YB165

YB175

YB44

YB44 YB164

YB175

YB164

YB174

YB163

YB176

YB165

YB89

YB87YE114

YE120

YE105

YE39

YE114

YE39

YE101

YE123

YE122

YB215

YE39

YE105

YE120

YE114

A/C REQUEST SIGNAL A ND A/C CLUTCH CONTROL WITHOUT ECC

The BCM request the PCM to turn the A/C compressor on or off via the PIM and the serial data bus normal

mode m essage. T he BCM monitors the voltage at BCM terminal D9 to determ ine the status of the m omentary

A/C Master switch. W hen the A/C master switch is pressed, 12 volts is applied to the BCM terminal D9. The

BCM sees this high voltage as an A/C master switch input signal.

On receiving the A/C m aster switch input signal, the BCM request the PCM to energise the A/C clutch via the

PIM and the serial data bus normal mode message, if the ignition is on and the blower motor is operating. If

the A/C master switch is pressed again the BCM will request the PCM to turn off the A/C compressor.

The operating status of the system will be remembered by the BCM, when the ignition is switched from on to

off or when the blower is switched off. If the blower is off and the A/C master switch is pressed, then the next

time the blower is switched on the air conditioning will be turned on. Turning the ignition off will cancel this

button press function.

The system will reset to off when the battery is disconnected.

The PCM uses this signal to:

1. Adjust the Idle Air Control (IAC) valve position to com pensate for the additional load placed on the engine

by the air conditioning compressor.

2. Energise the A/C compressor relay, to operate the A/C compressor if the pressure in the A/C system is

within the correct operating range.

Low Pressure High Pressure RPM

Cut Out Cut In Cut Out Cut In Off On

180 240 2900 2000 4800 4000

The PCM monitors the A/C pressure Sensor to determine A/C system pressure.

There are two DTCs associated with the A/C system . DTC P1539 is set when, the PCM detects voltage on the

A/C clutch status terminal when the system has not requested A/C. A short to voltage at any point in the A/C

status circuit, or the A/C relay contacts are stuck.

DTC P1546 is set when the PCM activates the relay, voltage should be present at both the A/C compressor

clutch and the A/C clutch status circuit at the PCM. If the voltage is not present, DTC P1546 will set.

Figure 6C3-1-52 Heater and Air Conditioning Controls

Figure 6C3-1-53 A/C Request Signal Without ECC

DTC P1539 A/C CLUTCH STATUS CIRCUIT HIGH VOLTAGE

Conditions for running DTC P1539

• The A/C clutch is not requested.

Conditions for setting DTC P1539

• Voltage is detected on the A/C status circuit for more than 15 seconds after the PCM has disengaged the A/C

clutch relay.

Action taken when DTC P1539 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1539

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

D20

/C MASTER

SWITCH

O (291)

B/R (292)

R/W (248)

R/BR (962)

(4)

(51)

LOC. E3

LOC. E1

BLOWER

MOTOR

RESISTORS

A/C

COMPRESSOR

A/C

RELAY

EFI

RELAY

BLOWER

MOTOR

HEATER AND A/C

CONTROLS

BLOWER

INHIBIT

RELAY

BLOWER

RELAY

DKG/Y (359)

Y/B (52)

R/G (245)

LOC.

E5/E15

R/Y (244)

O/G

(251)

DKG/Y

(359)

BATT ERY MAIN POWER

BATTERY

IGNITION SW ITCH

F31

A5/A6

O/B (740)

(1040)

BCM

IGNITION

DEMIST OUTPUT

DEMIST INPUT

A/C SWITCH INPUT

A/C LED OUTPUT

A/C BLOWER

INPUT

F14

F13

F33

E20/D6

P/B (39)

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

P (3)

R (2H)

R (2A)

P/BLU (44)

G (59)

LOC. E3

B/G (151)

B10/B11 HIGH

CURRENT

EARTH

E2/D2

R/B (1221)

SERIAL

DATA

B/Y (155)

ELECTRONIC

EARTH

A1/A5

PIM

CLASS 2 SERIAL DATA

UART SERIAL DATA

PCM

J1-58

CLASS 2

SERIAL DATA

Y (1049)

J2-43

J2-18

A/C CLUTCH CONTROL

A/C RELAY STA TUS

G3PCM047PT

G (59)

LG/B (366) B (1 50)

YB165

YB164

YB163

YB54

YB50

YB50 YB48

YB48

YB174

YB163

YB175

YB164

YB174

YB163

YB176

YB165

YE114

YB215YE122

YE123

YB2

YB64YE114

YB64

YB14

YB44

YE39

YE101

YE120

YE105

B/R

(750)

YE105

YE114

YB215

YE114

YB165

DTC P1546 A/C CLUTCH STATUS CIRCUIT HIGH VOLTAGE

Conditions for running DTC P1546

• The A/C clutch is requested.

Conditions for setting DTC P1546

• The PCM commands the A/C ON and the PCM does not detect a voltage on the A/C clutch status line for more

than five seconds.

Action taken when DTC P1546 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1546

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-54 A/C Clutch Circuit

4360

PCM

/C RELAY

J2-43

LG/B (366)

YE101

YE105YE105

YE120 YE120

YE101

YE123

A/C CLUTCH

CONTROL

EFI

RELAY

F33

LOC. E5/E15

B/R 750

A/C

COMPRESSOR

J2-18

G (59) A/C RELA Y STATUS

A/C REFRIGERANT PRESSURE SENSOR

The A/C Refrigerant Pressure Sensor is a sealed

gauge reference capacitive pressure sensor with

on board signal conditioning. It provides a 0 to five

volt output and requires a five volt regulated power

supply.

In operation the Sensor senses applied pressure

via the deflection of a two piece c eramic diaphr agm

with one half being a parrel plate capacitor.

Changes in capacitance influenced by the

refrigerant pressure under the ceramic diaphragm

are converted to an analogue output by the

Sensors integral signal electronics.

The pressure Sensor’s electronics are on a flexible

circuit board contained in the upper section of the

Sensor. They provide linear calibration of the

capacitance signal from the ceramic sensing

diaphragm.

Benefits of using the pressure Sensor over a

normal type pressure switch is that the Sensor is

constantly monitoring pressures and sending

signals to the Powertrain Control Module (PCM).

The norm al type pressure s witch only has an upper

and lower cut-out point. The PCM will disengage

the A/C compressor at Low or High refrigerant

pressures and control the operation of the engine

cooling fans.

If there is a failure in the A/C Pressure Sensor

circuit DTC P0530 will set.

T26C3004

Figure 6C3-1-55 A/C Refrigerant Pressure Sensor Location

1. A/C Refrigerant Pressure Sensor.

4347

Figure 6C3-1-56 A/C Refrigerant Pressure Sensor

Cut-Away View

1. Signal Electronics.

2. Pressure Port.

3. Ceramic Diaphragm.

4. Pressure Sensor.

5. High Side Charge Port.

Low Pressure Compressor Cut OFF at 180kPa

ON at 240 kPa

High Pressure Compressor Cut OFF at 2900 kPa

ON at 2400 kPa

Engine Cooling Fan Low ON at 1500 kPa

Speed OFF at 1250 kPa

Engine Cooling Fan High ON at 2600 kPa

Speed OFF at 2300 kPa

DTC P0530 A/C REFRIGERANT PRESSURE SENSOR CIRCUIT

Conditions for running DTC P0530

• The PCM detects an A/C request.

Conditions for setting DTC P0530

• A/C refrigerant pressure Sensor indicates A/C refrigerant pressure is at or below 25 kPa for five seconds.

• A/C refrigerant pressure Sensor indicates A/C refrigerant pressure is at or above 3140 kPa for five seconds.

Action taken when DTC P0530 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0530

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-57 A/C Refrigerant Pressure Sensor Circuit

G3PCM001PT

PCM

J2-14

J2-57

A/C

PRESSURE

SENSOR

J1-45

SENSOR EARTH

A/C PRESSURE

SENSOR SIGNAL

V/W (415)

YE122

YE123YE113

G/O (469)

G/B (259)

IAT SENSOR

VEHICLE SPEED SENSOR (VSS)

The PCM receives vehicle speed information from

then Vehicle Speed Sensor (VSS) located on the

rear of the transmission. The VSS basically

consists of a magnetic core and a coil. As the

output shaft turns, the teeth on the output shaft

concentrate the magnetic field causing the

magnetic flux to increase and then decreases as

the teeth move in and out of the magnetic field,

inducing a voltage into the coil, first in a positive

and then in a negative direction.

This AC voltage produc ed in the VSS sensor circ uit

is fed into the PCM, the PCM filters and shapes

this signal. The PCM then counts the number of

pulses received in a given time, to determine the

vehicle speed.

Once the PCM has calculated the vehicle speed it

then pulses circuit 123 (Violet/W hite wire) to earth,

this will cause the 12 volts at terminal 17 of the

instruments to be pulled down to less than 0.2

volts. The instruments determines the vehicle

speed and the kilometers from the number of

pulses it receives. The PCM also transmits vehicle

speed information to other control modules via the

serial data bus normal mode message.

There are three DTCs associated with the VSS.

DTC P0502 will set when the output from the VSS

is to low. DTC P0503 will set when the VSS signal

is intermittent. DTC P0608 will set when the

commanded state of the

GE N3 0020

Figure 6C3-1-58 Vehicle Speed Sensor To

Reluctor Wheel

1. Reluctor Wheel (Rotor) 3. Electrical Connector

2. O-Ring 4. Magnetic Pickup

VSS output driver and the actual state of the driver

do not match.

Figure 6C3-1-59 VSS Location – Automatic Transmission

1. Vehicle Speed Sensor

Figure 6C3-1-60 VSS Location – Manual Transmission

1. Vehicle Speed Sensor

DTC P0502 VEHICLE SPEED SENSOR CIRCUIT LOW INPUT

Conditions for running DTC P0502

• No MAP sensor DTCs P0107 or P0108.

• No Throttle Position DTCs P0122 or P0123.

• No TFP manual valve position switch DTC P1810.

• The transmission is not in park or neutral.

• The Throttle Position angle is greater than 15%.

• The engine vacuum is 0-105 kPa.

• The engine speed is greater than 3000 RPM.

• The engine torque is between 40 – 543 N.m.

Conditions for setting DTC P0502

• The transmission output speed is less than 150 RPM for at least three seconds.

Action taken when DTC P0502 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM commands first gear only .

• The PCM commands maximum line pressure.

• The PCM inhibits TCC engagement.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0502

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0503 VEHICLE SPEED SENSOR CIRCUIT INTERMITTENT

Conditions for running DTC P0503

• No TFP manual valve position switch DTC P1810.

• The time since the last gear range change is greater than six seconds.

• The engine speed is greater than 300 RPM for five seconds.

• The engine is not in fuel cutoff.

• The transmission output speed rise does not exceed 600 RPM within six seconds.

Conditions for setting DTC P0503

• The transmission output speed drop is greater than 1300 RPM for three seconds when the transmission is not

in park or neutral.

Action taken when DTC P0503 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM commands second gear only.

• The PCM commands maximum line pressure.

• The PCM inhibits 4th gear if the transmission is in hot mode.

• The PCM inhibits TCC engagement.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0503

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0608 VEHICLE SPEED SENSOR OUTPUT CIRCUIT

Conditions for running DTC P0608

• The engine speed is greater than 600 RPM.

• The ignition voltage is between 6.0 and 16.0 volts.

Conditions for setting DTC P0608

• The PCM detects that the commanded state of the driver and the actual state of the control circuit do not

match.

• This condition must be present for at least ten seconds.

Action taken when DTC P0608 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0608

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-61 Vehicle Speed Sensor Circuit

V/W (123)

YB66 YB195

YE123

12V IGN

VEHICLE SPEED

G3PCM016PT

INSTRUMENT

VEHICLE SPEED

PCM

J2-50

J2-21

J2-20

EHICLE SPEED

SENSOR

BLU/W

(831)

(832)

SPEEDOMETER

CRANKSHAFT POSITION (CKP) SENSOR

The Crankshaft Position Sensor (CKP) is mounted

in the right rear of the engine block behind the

starter. The CKP sensor works in conjunction with

a 24X reluctor wheel mounted on the rear of the

crankshaft. The CKP sensor has a battery power

supply, an earth, and a signal circuit.

As the crankshaft rotates, the reluctor wheel teeth

interrupt a magnetic field produced by a magnet

within the sensor. The sensor’s internal circuitry

detects this and produces a signal which the PCM

reads. The PCM uses this signal to accurately

measure crankshaft position and engine speed.

The reluctor wheel is mounted on the rear of the

crankshaft. The 24X reluctor wheel uses two

different width notches (12° and 3°) that are 15°

apart. This pulse width encoded pattern allows

cylinder position identification within 90 degrees of

crankshaft rotation. In some cases, cylinder

identification can be located in 45 degrees of

crankshaft rotation. This reluctor wheel also has

dual track notches that are out of phase. The duel

track design allows for quicker starts and accuracy.

NOTE: The engineer will not run if the PCM does

not receive a CKP signal. W ith no CKP signal, the

PCM will not issue any injector pulses.

Figure 6C3-1-62 Crankshaft Position Sensor (CKP) Location

1. Starter Mounting Pad on Engine Block

2. CKP Sensor

3. CKP Mounting Bolt

The PCM monitors the CKP sensor signal circuit

for m alfunctions. The PCM sets a DTC P0335 or a

DTC P0336 when the CKP sensor is out of the

normal operating range.

T6A3229GB

RELUCTOR

Figure 6C3-1-63 Crankshaft Position Sensor Reluctor

1. Reluctor

CRANKSHAFT POSITION SIGNAL

24X CR AN KS HA FT PO SIT ION SIGN AL A

102 108 123 138 162 177 183 198 222 237 252 258 282 288 312 327 342 357

345 360

1950

12 18 33 48 63 78

15 30 45 60 75 90 105 120 135 150 165 180 210 225 330240255270285300315

Figure 6C3-1-64 Crankshaft Position Sensor Signal

DTC P0335 CRANKSHAFT POSITION SENSOR CIRCUIT

Conditions for running DTC P0335

• DTCs P0101, P0102, P0103, P0341, P0342, P0343 are not set.

• The CMP sensor is transitioning.

• The ignition voltage is between 5 and 17.0 volts.

• The MAF is greater than 3 g/s.

Conditions for setting DTC P0335

• The PCM determines no signal from the CKP sensor for at least three seconds.

Action taken when DTC P0335 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0335

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0336 CRANKSHAFT POSITION SENSOR CIRCUIT PERFORMANCE

Conditions for running DTC P0336

• The ignition voltage is between 5 and 17.0 volts.

• The engine speed is greater than 400 RPM.

Conditions for setting DTC P0336

• The PCM determines no signal from the CKP sensor or the signal is out of range for at least one seconds.

Action taken when DTC P0336 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0336

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0654 ENGINE SPEED OUTPUT CIRCUIT

Conditions for running DTC P0654

• The engine speed is greater than 600 RPM.

• The ignition voltage is between 6.0 and 16.0 volts.

Conditions for setting DTC P0654

• The PCM detects that the commanded state of the driver and the actual state of the control circuit do not

match.

• All of the conditions are present for a minimum of 10.0 seconds.

Action taken when DTC P0654 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0654

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• Use a Tech 2 scan tool to clear the CPL/DTC.

Figure 6C3-1-65 Crankshaft Position Sensor Circuit

CAMSHAFT POSITION (CMP) SENSOR

The Camshaft Position Sensor (CMP) is mounted

through the top of the engine block at the rear of

the valley cover and work s in conj unction with a 1X

reluctor wheel on the cam shaft. The reluctor wheel

is ins ide the engine, im m ediately in front of the r ear

cam bearing. The PCM provides a 12 volt power

supply to the CMP sensor as well as a earth and a

signal circuit.

The PCM uses the CMP signal in order to

determine whether a cylinder is on a firing or

exhaust stroke. As the camshaft rotates, the

reluctor wheel interrupts a magnetic field produced

by a magnet within the CMP sensor. The CMP

sensor’s internal circuitr y detects this and produces

a signal which the PCM reads. The PCM uses this

1X signal in combination with the Crankshaft

Position Sensor 24X signal in order to determine

the crankshaft position and stroke.

If the PCM is receiving a 24X Crankshaft Position

sensor signal, the engine will start even if there is

no CMP sensor signal. The PCM cannot

dete4rm ine when a particular c ylinder is on either a

firing or ex haust stroke by the 24X signal alone, the

PCM requires the CMP signal in order to determ ine

if the cylinder is on either the firing or exhaust

stroke.

GE N 3 0022

Figure 6C3-1-66 Camshaft Position Sensor (CMP) Location

1. CMP Mounting Bolt

2. CMP Sensor

3. Top Rear of Engine Block

If there is no CMP signal present the system

attempts synchronisation and looks for an increase

in MAF signal indicating the engine started. If the

PCM does not detect a MAF increase, the PCM

assumes if incorrectly synchronised to the exhaust

stroke and re-synchs to the opposite cam position.

A slightly longer cranking time may be a symptom

of this condition.

This diagnostic for the Camshaft Position Sensor

checks for camshaft position sensor signal. The

PCM also monitors the CMP sensor signal circuit

for malfunctions. The following DTCs are set when

the PCM detects a CMP sensor that is out of the

normal operating range:

• DTC P0341: Camshaft Position (CMP) Sensor

Circuit Performance.

• DTC P0342: Camshaft Position (CMP) Sensor

Circuit Low Voltage.

• DTC P0343: Camshaft Position (CMP) Sensor

Circuit High Voltage.

G3PCM012PT

PCM

CRANKSHAFT

POSITION

SENSOR

J1-02LBLU/W (646)

J1-21

SENSOR EARTH

12V

J1-12BLU (643)

CRANKSHAFT POSITION

SENSOR

SIGNAL

MAGNETO

RESISTIVE

INTEGRATED

CIRCUIT

LBLU/B (647)

YE67 YE122

CMP

Figure 6C3-1-67 Camshaft and Crankshaft Position Sensor Signal

DTC P0341 CAMSHAFT POSITION SENSOR CIRCUIT PERFORMANCE

Conditions for running DTC P0341

• The ignition voltage is between 5 and 17.0 volts.

• The engine speed is greater than 400 RPM.

Conditions for setting DTC P0341

• The PCM detects that a CMP to CKP mismatch has occurred for at least 10 seconds.

Action taken when DTC P0341 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0341

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0342 CAMSHAFT POSITION SENSOR CIRCUIT LOW VOLTAGE

Conditions for running DTC P0342

• The ignition voltage is between 5 and 17.0 volts.

• The engine speed is greater than 400 RPM.

Conditions for setting DTC P0342

• The PCM detects the CMP sensor signal is low when the signal should be high for at least one second.

Action taken when DTC P0342 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0342

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0343 CAMSHAFT POSITION SENSOR CIRCUIT HIGH VOLTAGE

Conditions for running DTC P0343

• The ignition voltage is between 5 and 17.0 volts.

• The engine speed is greater than 400 RPM.

Conditions for setting DTC P0343

• The PCM detects the CMP sensor signal is stuck high when the signal should be low for at least one second.

Action taken when DTC P0343 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0343

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-68 Camshaft Position Sensor Circuit

BATTERY VOLTAGE

The PCM continually monitors battery voltage.

When the battery voltage is low, the ignition system

may deliver a weak spark and the injector

mechanical movement takes longer to open the

injector.

The Powertrain Control Module will compensate

by:

1. Increasing the ignition coil dwell time if the

battery voltage is less than 12 volts.

2. Increasing the engine idle RPM if battery

voltage drops below 10 volts.

3. Inc reasing the injector puls e width if the battery

voltage drops below 10 volts.

On vehicles equipped with automatic transmission,

Diagnostic Trouble Code (DTC) P0563 will set

when the ignition is ON and PCM voltage is more

than 17 volts for about 5 seconds.

Diagnostic Trouble Code (DTC) P0562 will set

when the ignition is ON and PCM voltage is less

than 5 volts for about 5 seconds.

DTC P0562 SYSTEM VOLTAGE LOW

Conditions for running DTC P0562

• The engine is running longer than ten seconds.

• The engine speed is greater than 1000 RPM.

• The vehicle speed is greater than 8 km/h.

Conditions for setting DTC P0562

• The PCM senses sy stem voltage below 5.0 volts.

• All of the above conditions are present for five seconds.

Action taken when DTC P0562 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM will command a high idle speed.

• The transmission will default to third gear.

• The PCM will inhibit TCC operation.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0562

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

G3PCM011PT

PCM

CAMSHAFT

POSITION

SENSOR

J2-39W/B(631)

J1-61

SENSOR EARTH

RW(632)

12V

J1-73

BR(633)

CAMSHAFT POSITION

SENSOR

SIGNAL

MAGNETO

RESISTIVE

INTEGRATED

CIRCUIT

YE69 YE122

YE123

DTC P0563 SYSTEM VOLTAGE HIGH

Conditions for running DTC P0563

• The engine is running longer than 10 seconds.

Conditions for setting DTC P0563

• The PCM senses system voltage above 17 volts.

• All of the above conditions are present for five seconds.

Action taken when DTC P0563 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM will disable most outputs.

• The transmission will default to third gear.

• The PCM will inhibit TCC operation.

• The PCM will cycle the cooling fans ON and OFF every few seconds during the time the condition is present.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0563

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-69 Battery Power Supply Circuit

G3PCM021PT

PCM

J1-20

J1-57

BATTERY

(1040) O (740)O/B (740)

O (740)

J1-19 IGNITION

BATTERY

R (2H)

LOC . E 1

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

IGNITION SWITCH

P (3)

YE122 YE112

YE123

YB44

F14 P (39)

J1-01

J1-40

J2-01

J2-40

LOC. E5/E15

EARTH

B/R (750)

F31

P/B (39)

TRANSMISSION POWER/ECONOMY SWITCH

The Power/Economy switch is used to modify

upshifts and shift times. The driver can select

either Economy or Power mode with the switch (1)

located on the centre console. A third mode,

Cruise, is available via a switch located on the

indicator stalk (where fitted).

Two green indicator lamps of 1.2 watts at 12 volts

are located in the instrument cluster and display

POWER or CRUISE when illuminated to inf orm the

driver of the mode that is enabled.

The PCM provides a voltage signal of about 12

volts, and monitors the status of this circuit. In the

Econom y pos ition, the switch is open and the PCM

voltage status signal remains high, about 12 volts.

The PCM does not allow shift point changes in the

Economy mode. When the transmission switch is

pressed to the Power position the switch is

momentarily closed and the PCM voltage status

signal is mom entarily pulled low, to about 0.5 volts.

The PCM senses this voltage momentary voltage

drop and enables Power mode (alternate shift

pattern tables to be utilised).

In the Power mode, the Torque Converter Clutch

(TCC) can be applied in 3rd and 4th gears. When

the TCC is applied in 3rd gear it will stay applied

until the normal 4th gear upshift criteria is met.

When the 3-4 upshift occurs, the TCC will be

released momentarily. Also, in the Power mode

while in D gear select position, the PCM will delay

the 1-2 and 2-3 shift while under light throttle. The

shift patterns will be the same in the Econom y and

Power modes if the T hrottle Position (T P) sensor is

between 80% - 100%. The Power mode should be

used when towing, as applying the TCC in 3rd and

4th gear reduces slippage in the TCC and thus

reduces heat build up.

In Cruise mode operation, when the driver

activates the cruise control, the POW ER lamp and

Power mode will turn OFF (if vehicle was in power

mode) and a CRUISE lamp will illuminate on the

instrum ent panel. T he trans m ission shif t pattern will

switch to cruise shift pattern. W hen in cruise m ode

the PCM will modify the transmission calibration so

that transmission shift activity is reduced.

W hen the k ey is turned O N, the PCM shift m ode is

set to the last mode that was previously selected

(Power/Econom y). The cruise control is set to OFF

at every key ON cycle.

For replacement of the Power/Economy switch,

refer to Section 7C4 Automatic Transmission -

On Vehicle Service in VX Service Information.

GE N 3 0154

Figure 6C3-1-70 Transmission Power/Economy Switch

1. Automatic Transmission Power/Economy Switch

Figure 6C3-1-71 Power/Economy Switch Circuit

THEFT DETERRENT SYSTEM

The theft deterrent system on this Model uses a remote coded key to arm and disarm the system, as well as

electrically lock or unlock all doors and tailgate (station wagon), or operate the boot unlock mechanism (sedan

models).

The thef t deterrent alert indicator LED is us ed to indicate the state of the system . A flashing LED indicates that the

system is ar m ed and consequently the vehicle cannot be started. When the LED is turned off, the BCM is dis arm ed

and the engine can be started. The theft deterrent LED is incorporated into the trip computer module in the

instrument panel facia.

When the ignition switch is turned f rom of f to on, the BCM will trans mit secur ity inform ation to the PIM via the UART

serial data bus, circuit 1221. The PIM compares the received security information with it’s stored security

information and if the information matches, the PIM will enable the starter relay, and supply security information

(password) via Class II serial Data to the PCM. If the password matches the password stored in the PCM, the

system enables the f uel injection. T he PCM will r eturn on OK to start m essage to the BCM via the PIM, which tells

the BCM to switch fr om shor t loop m ode to the long loop m ode. If the PIM does not send a pass word or if the PCM

does not receive it, the vehicle will not star t unless the PCM is in Vehicle T heft Deterrent (VT D) Fail-Enable m ode.

The BCM will only transmit the corr ec t sec ur ity inform ation to the PIM if the BCM has been dis armed via the remote

coded k ey. If the BCM, PIM, or PCM lose com m unication with each other after the system has received the correct

password, the PCM goes into VTD Fail- Enable mode. T his allows the driver to res tart the vehicle on future ignition

cycles until communications between the BCM, PIM or PCM are restored. If the BCM, PIM or PCM lose

communication before the PCM receives the BCM password, the PCM disables the fuel injection until

communication is restored. In both cases DTC P1626 sets. The PCM will not disable the fuel injection once the

PCM enables the fuel within a given ignition cycle in order to prevent stalling as a result of theft deterrent system

faults.

NOTE 1:

Regardless of the engine configuration, it is very important that the remote coded key reader is aligned correctly

with the ignition lock ass embly. Misalignment with the rem ote coded key contact m ay occur resulting in interm ittent

or no engine cranking or starting.

NOTE 2:

Should the engine crank brief ly when the ignition s witch is turned to the START position (ie. due to m isaligned or a

faulty rem ote coded key reader) then pressing the unlock button on the rem ote coded k ey will also disar m the thef t

deterrent system.

Refer to Section 12J-1 Low Series BCM or Section 12J-2 High Series BCM in the VX Service Information for

further information and diagnosis.

4369

INSTRUMENTBCM

12 SERIAL

DATA

POWER

ECONOMY

LAMP

12V

G/W (1220)

YB175

YB164

YB215 YE122

YE114

YE112

YB66

YB30

YB34 YB34

J1-58

CLASS 2

SERIAL DATA

PCM

R/B (1221)

PIM

UART

SERIAL

DATA

Y (1049)

CLASS 2

SERIAL DA TA

E2/D2

E9/D3

SERIAL

DATA

MAIN

SERIAL

DATA AUX.

HIGH SERIES

BCM TERMINALS

NOMINATED FIRST

J1-71

BLU

LOC. E 3

(774)

POWER/ECONOMY

SWITCH

12V

GEN3 0024

11 97

Figure 6C3-1-72 Theft Deterrent System

1. Remote Coded Key

2. Remote Receiver Module

3. Remote Coded Key Reader Assembly

4. Signal from Remote Receiver Module to BCM

5. Signal from Key Reader to BCM

6. Body Control Module (BCM)

7. Starter Relay

8. Starter Motor

9. Signal from PIM to Start Relay

10. Powertrain Interface Module (PIM)

11. Signal from BCM to PIM for Starter

12. Theft Deterrent Alert Indicator LED Control

13. OK to Start from BCM

14. Is It OK To Start Request from PCM

15. Signal from PCM for Injector Control

16. Fuel Injectors (8)

17. Powertrain Control Module (PCM)

DTC P1626 THEFT DETERRENT SYSTEM FUEL ENABLE CIRCUIT

Conditions for running DTC P1626

• The engine is cranking.

Conditions for setting DTC P1626

• The system has reached fuel enable decision point.

• The PCM is in Fail Enable Mode due to loss of communication with the PIM after the system received the

correct password earlier in the ignition cycle.

• The PCM does receive the password message from the PIM prior to the theft deterrent Fuel Decision Point.

Action taken when DTC P1626 Sets

• The PCM enables the fuel injection on future ignition cycles only if the PCM is in Fail-Enable Mode.

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

NOTE: This DTC is usually set if communication is lost. The Check Powertrain Lamp may not operate.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1626

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1630 THEFT DETERRENT POWERTRAIN CONTROL MODULE IN LEARN MODE

Conditions for running DTC P1630

• The PCM is in the learn password mode.

Conditions for setting DTC P1630

• The PCM is ready to learn a new password from the PIM, but the PIM is not sending a valid password or not

sending a password at all.

Action taken when DTC P1630 Sets

• The engine cranks but may not start.

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1630

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P1631 THEFT DETERRENT PASSWORD INCORRECT

Conditions for running DTC P1631

• The ignition is on and the PCM is waiting for the correct password.

Conditions for setting DTC P1631

• The PCM detects an incorrect password from the PIM.

Action taken when DTC P1631 Sets

• The engine cranks but may not start.

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1631

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-73 Theft Deterrent Circuit

BATTERY MAIN POWER

HIGH SERIES

BCM TERMINALS

NOMINA TED FIRST

BCM

REMOTE

CODED KEY

V/R (229) E1/D12 KEY R EADER

BATTERY

LOC.

LOC. G1

F31

A5/A6O/B (740)

(1040)

REMOTE KEY

RECEIVER

Y (266) E8/D1 RECEIVER DATA

BR/G (271) E7/D11 RECE IVER EARTH

O/B

(740)

GY/BLU

(1434)

G3PCM040PT

THEFT DETERRENT

ALERT INDICA TOR

R/B

(1221)

E2/D2 SERIAL DATA

R (2H)

E20/D6 IGNITION

NEUTRAL ST ART

BACK-UP SW.

(FOR AUTO TRANS)

(FOR MANUAL

TRANS)

(434)

R (1)

V/W (6)

F14

START

RELAY

IGN ITIO N SWITC H

15a 15 50

30 ACC

IGN

START

V (5) P (3) P/B

(39)

A6/A8

LBLU

(263) THE FT LED

B/Y

(155)

LOC. E3

B/G

(151) B10/B11 HIGH CURRENT

EARTH

B/Y

(155) ELECTRONIC EARTH

A1/A5

LOC. E3

PIM

UART

SERIAL

DATA

START

RELAY

CLASS 2

SERIAL DATA

B/R (750)

LOC. E5/E15

R/B

(1221)

PCM

J1-58 CLASS 2

SERIAL DATA

Y (1049)

(1049)

STARTER

MOTOR

YB215

YE112

YB35

YE104

YE8

YB35

YE114 YB56 YB56

YE49

YB44

YE49

YB44

YB95

YB175

YB164

YB176

YB165

YB175

YB164

YB175

YB164

YB174

YB163

YE114

YE114 YB176

YB165

YE122

YB176

YB165

YB95

ENGINE OIL PRESSURE SENSOR

The Engine O il Pres s ur e s ensor is sc r ewed into the

oil gallery at the top rear of the engine block. The

sensor has a five volt reference voltage, an earth,

and a signal circuit. The PCM monitors the voltage

on the signal circuit. This voltage will vary

depending on engine oil pressure. T he oil pressure

sensor is used to determine when the oil pressure

is below a certain value. By monitoring the voltage,

the PCM calculates the engine oil pressure and

determines when to turn ON the low oil warning

lamp. The low oil warning lamp will be illuminated

for two seconds when the ignition is first turned on

as a bulb check. The PCM will only command the

instruments to turn the low oil warning lamp ON, if

the oil pressure is below a specified value. This

value increases with RPM. The PCM commands

the instruments to turn on the low oil warning lamp

via the serial data bus normal mode message.

When the PCM detects a malfunction in the oil

pressure sensor circuit, the following DTCs will set:

• DTC P0522: Engine Oil Pressure Circuit Low

Voltage

• DTC P0523 Engine Oil Pressure Circuit High

Voltage

Figure 6C3-1-74 Oil Pressure Sensor

1. Manifold Absolute Pressure (MAP) Sensor

2. Camshaft Position (CMP) Sensor

3. Oil Pressure Sensor

4. Connector to Knock Sensor Jumper Harness

DTC P0522 ENGINE OIL PRESSURE SENSOR LOW VOLTAGE

Conditions for running DTC P0522

• The engine is running.

Conditions for setting DTC P0522

• The engine oil pressure sensor voltage is less than 0.48 volts.

Action taken when DTC P0522 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• Oil warning lamp will illuminate.

Conditions for clearing the Check Powertrain Lamp and DTC P0522

• The PCM battery voltage is interrupted.

• A last test failed (Current DTC) will not clear when the diagnostic runs and does not fail.

DTC P0523 ENGINE OIL PRESSURE SENSOR HIGH VOLTAGE

Conditions for running DTC P0523

• The engine is running.

Conditions for setting DTC P0523

• The engine oil pressure sensor voltage is greater than 4.5 volts.

Action taken when DTC P0523 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

• Oil warning lamp will illuminate.

Conditions for clearing the Check Powertrain Lamp and DTC P0523

• The PCM battery voltage is interrupted.

• A last test failed (Current DTC) will not clear when the diagnostic runs and does not fail.

Figure 6C3-1-75 Oil Pressure Sensor Circuit

MANUAL TRANSMISSION REVERSE INHIBIT SOLENOID

The manual transmission is fitted with a reverse

inhibit mechanism that prevent the selection of

reverse gear when above road speed of 8 km/h. If

the engine is running and the vehicle speed is less

than 8 km/h, the reverse inhibit solenoid is

energised by the PCM, pulling the solenoid plunger

down, this allows the Reverse Inhibit plunger to

move, enabling selection of reverse gear.

Above 8 km /h, the PCM de-energisees the reverse

inhibit solenoid, causing the solenoid plunger to

block the movement of the spring loaded Reverse

Inhibit plunger. When activated, the rear offset

lever is blocked from rotating to the reverse

selection position.

GE N 3 0147

Figure 6C3-1-76 Reverse Inhibit Solenoid

1. Reverse Inhibit Solenoid

2. Reverse Inhibit Harness Connector

G3PCM008APT

PCM

J1-58

INSTRUMENT

SERIAL

DATA

G/W (1220)

Y (1049)

R/B (1221)

12V IGN

OIL PRESSURE

PIM

CLASS 2

UART

CLASS II

SERIAL DA TA

BCM

E2/D2

E9/D3

SERIAL

DATA

MAIN

HIGH SERIES

BCM TERMINALS

NOMINATED FIRST

SERIAL

DATA AUX.

J2-58

J1-63

J1-07

SENSOR EARTH

OIL PRESSURE

SENSOR SIGNAL

BLU/Y (334)

YE32 YE122

YE122

YB215

YB66

YB175

YB164

YB175

YB164

YE122

YE123

G (335)

BR/W (331)

OIL

PRESSURE

SENSOR

Road Speed Less Than 8 km/h Road Speed Greater Than 8 km/h

Figure 6C3-1-77 Reverse Inhibit Solenoid Operation View

1. Reverse Inhibit Solenoid.

2. Solenoid Plunger.

3. Reverse Inhibit Plunger.

4. Rear Offset Lever.

Figure 6C3-1-78 Reverse Inhibit Solenoid Circuit

G3PCM043PT

PCM

J1-19

J2-44

REVERSE INHIBIT

SOLENOID

IGNITION

BATTERY

LOC. E1

(1040)

R (2H)

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

IGNITION SWITCH

REVERSE INHI BIT

SOLENOID

P (3) P/B (3 9) P (39)

YE122

YE39

YB44

YE39

YB125 YB125

YE123

YE114

YE110

B/W

152

O/Y

(479)

EFI

RELAY

F14

F32 LOC. E3

(838)

P/BLU

(339)

BRAKE PEDAL SWITCHES

There are two electrical switches mounted on the

brake pedal support bracket.

Stop Lamp Switch

The stop lamp switch (4) is a normally open switch

that supplies B+ from fuse F5 to the rear brake

lamps when the brake pedal is depressed. It also

supplies 12 volts to the cruise control actuator and

a brake applied 12 volt input signal to terminal 14

of the ABS or ABS/ETC control module.

Whenever the ABS or ABS/ETC control module

does not receive this signal at start up, the ABS or

ABS/ETC self test will begin as soon as vehicle

speed is at approximately 6km/h. If the driver

depresse s the brak e pedal during this initial ABS or

ABS/ETC cycle, the self test will not occur until the

vehicle speed is approximately 18 km/h. Also, if at

any time during Traction Control mode the brakes

are manually applied, this brake switch signals the

ABS or ABS/ETC control module to inhibit brake

intervention and allow for manual braking (engine

torque management may still occur if necessary).

This stop lam p switch 12 volt signal is also used to

signal the cruis e control m odule to dis engage when

the brake pedal is depressed. For all service

operations on the stop lamp switch, refer to

Section 12B Lighting Systems in VX Service

Information.

Cruise Control Release Switch

The cruise electrical release switch (2) is a

normally closed switch, and supplies a 12 volt

signal from the Low Traction Lamp (through a

resistor adjacent to the Low Traction Lamp) to the

PCM, Cruise Control Actuator, and the ABS or

ABS/ETC module. When the brake pedal is

depressed, the 12 volt supply signal is removed

from the PCM and the Cruise Control Actuator.

When the PCM determines that this 12 volt signal

has been removed, the PCM will disengage the

automatic transmission Torque Converter Clutch

(TCC) until this 12 volt signal is re-established to

the PCM. Also, the cruise control actuator will

deactivate the cruise control operation (the cruise

set speed will be retained in memory). Once the

brake pedal is released, the cruise set speed can

be re-established by selecting the cruise resume

switch.

GE N 3 0181

Figure 6C3-1-79 Brake Pedal Switches Location

1. Cruise Electrical Release Switch Connector

2. Cruise Electrical Release Switch

3. Stop Lamp Electrical Connector

4. Stop Lamp Switch

5. Brake Pedal Support Bracket

6. Brake Pedal Arm Assembly

Also, associated on this cruise electrical release switch (2) circuit is the ABS/ETC module Low Traction Lamp

control. The ABS or ABS/ET C m odule will supply an earth signal to the Low Traction Lamp when traction c ontrol

is being requested. When the PCM rec eives this ear th signal the PCM will inhibit TCC oper ation and activate the

engine torque management operation. The cruise control will also deactivate operation.

If there is a problem with the circuit between the Low Traction Lamp and the PCM, DTC P0719 or P0724 will set.

Both switches are used to signal the cruise control module so that if one should fail, the second switch will still

generate a signal to the cruise control module to disengage the cruise control operation. For all service

operations on the cruise electrical release switch, Refer to Section 12E CRUISE CONTROL in the VX Service

Information.

DTC P0719 BRAKE SWITCH CIRCUIT LOW INPUT

Conditions for running DTC P0719

• No VSS assembly DTCs P0502 or P0503.

• The ignition switch is in the RUN position.

Conditions for setting DTC P0719

• The PCM detects an open brake switch circuit (0 volts) for 15 minutes without changing for 2 seconds, and the

following events occur seven times:

- The vehicle speed is less than 8 km/h;

- Then the vehicle speed is 8 – 32 km/h for four seconds;

- Then the vehicle speed is greater than 32 km/h for six seconds.

Action taken when DTC P0719 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM disregards the brake switch input for TCC scheduling.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0719

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough to power down the PCM.

DTC P0724 BRAKE SWITCH CIRCUIT HIGH INPUT

Conditions for running DTC P0724

• No VSS assembly DTCs P0502 or P0503.

• The ignition switch is in the RUN position.

Conditions for setting DTC P0724

• The PCM detects an closed brake switch circuit (12 volts) without changing for 2 seconds, and the following

events occur seven times:

- Then the vehicle speed is greater than 32 km/h for six seconds.

- Then the vehicle speed is 8 – 32 km/h for four seconds;

- The vehicle speed is less than 8 km/h;

Action taken when DTC P0724 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0724

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough to power down the PCM.

Figure 6C3-1-80 Brake Pedal Switches Location

BATTERY MAIN POWER

G3PCM018PT

BATTERY

F21

20O/Y (1340)

R (2H)

F13

IGNITION

19P/BLU ( 44)

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

IGNITION

SWITCH

P (3)

11 LOW

TRACTION

LAMP

LOW

TRACTION

BRAKE

SWITCH

INPUT

SIGNAL

BRAKE

SWITCH

INPUT

SIGNAL

PCM

J1-33 Y/R (88)

STOP LAMP

SWITCH B

(NC)

CRUISE CONTROL

MODULE ABS/ETC

INSTRUMENTS

D20

B/R (86)

YE56

YE122 YB65

YB12

YB44

YB12

YB65 YB66

YE98

1.4 FUEL CONTROL SYSTEM

SYSTEM OVERVIEW

An electric fuel pump, located in the fuel tank with

the fuel sender assembly, pumps fuel through an

in-line fuel f ilter to the fuel r ail assem bly. T he pump

provides fuel at a pressure greater than is needed

by the inj ectors . The f uel pres sure r egulator, part of

the fuel sender assembly, keeps fuel available to

the injectors at a regulated pressure. A separate

pipe returns unused fuel to the fuel tank.

COMPONENTS

Fuel Tank Vent Valve

The f uel tank vent valve is located in the r ear of the

vehicle near the fuel tank. The fuel tank vent valve

is a pressure/vacuum relief valve. When the fuel

tank pressure exceeds a specified pressure, the

valve opens allowing the tank pres sure to bleed off.

When the fuel tank is in a vacuum condition, the

vent valve opens when the vacuum is within a

specified range allowing fresh air to be pulled in.

Fuel Tank

The fuel tank is constructed from a special plastic

and is located under the rear compartment floor. It

is secured to the vehicle by three metal straps that

attach to the frame.

Fuel Tank Filler Pipe

The fuel tank filler pipe has a built-in resistor and

deflector in order to prevent refueling with leaded

fuel.

Fuel Filler Cap

NOTE: If a fuel filler cap requires replacem ent, use

only a fuel filler cap of the same type. Failure to

use the corr ect fuel f iller cap can r esult in a serious

malfunction of the fuel and evaporative systems.

The fuel filler cap incorporates a torque-limiting

device which prevents the cap from being over

tightened. To ins tall the cap, turn the cap clockwise

until you hear three audible clicks. This indicates

that the cap is correctly torqued and fully seated.

Figure 6C3-1-81 Fuel Filler Cap

Fuel Sender Assembly

The fuel sender assembly, mounted inside the fuel

tank, is attached to the top of the fuel tank . The fuel

sender assembly consists of the following major

components:

• The fuel level sensor

• The fuel pump

• The fuel pressure regulator

• The fuel pump strainer

NOTE: T he only serviceable part of the fuel sender

assembly is the fuel lever sensor. All other

components require replacement of the complete

fuel sender assembly.

4354

Figure 6C3-1-82 Fuel Sender Assembly

1. Diverter Pipe. 6. External Filter Screen

2. Jet Pump Filter. 7. Secondary Umbrella Valve.

3. Reservoir. 8. Internal Filter Screen.

4. Primary Umbrella 9. Gerotor Fuel Pump.

Valve. 10. Fuel Pressure Regulator.

5. Jet Pump

Fuel Pump

The Gerotor fuel pump attaches to the fuel sender

assembly inside the fuel tank and is an electric

high pressure gear Gerotor fuel pump. The fuel

pump provides fuel to the fuel rail assembly at a

specified flow and pressure. Excess fuel returns to

the fuel tank by the return pipe.

The fuel pump delivers a constant flow of fuel to

the engine even during low fuel conditions and

aggressive vehicle manoeuvres. The PCM controls

the electric fuel pump operation through a fuel

pump relay. The fuel pump flex pipe has a quick-

connect f itting. The fuel return hose attaches to the

fuel pressure regulator. The fuel pump flex pipe

acts to dampen the fuel pulses and noise

generated by the fuel pump.

Figure 6C3-1-83 Gerotor Fuel Pump

1. Shell

2. Pump Inlet Seal

3. Umbrel l a Check Valve

4. Pump Inlet Body

5. Pilot Pin

6. Impeller

7. Driver

8. Inlet Plate

9. Gerotor Assembly

10. Alignment Pi n

11. O-Ring

12. End Cap

13. Relief Valve Ball

14. Check Valve Ball

15. Valve Seat

16. Relief Valve Spring

17. Relief Valve Retainer

18. Carrier Assem b l y

19. Field Magnet Assembl y

20. Armature

21. Bushing

22. Plat e & Ring

Assembly

Fuel Pressure Regulator Assembly

The fuel pressure regulator located on the fuel

modular sender and is a diaphragm operated relief

valve with fuel pump pressure on one side and

atmospheric pressure combined with mechanical

spring pressure on the other. The function of the

regulator is to maintain a regulated pressure at the

injectors at all times by controlling the flow into the

return line. With the ignition ON and the engine

OFF, system fuel pressure at the pressure test

connection should be 380-440 kPa

(55-62 psi).

If the pressure is too low, poor performance could

result. If the pressure is too high, excessive odor

and Diagnostic Trouble Codes (DTC) P0132,

P0152, P0172, or P0175 may result. Refer to Fuel

System Diagnosis in Section 6C3-2A of the VX

Series Service Information, for information on

diagnosing fuel pressure conditions.

Figure 6C3-1-84 Fuel Pressure Regulator

Fuel Pump Strainer

The f uel pump s trainer attaches to the lower end of

the fuel pump and the lower end of the fuel return

pipe. The fuel pump strainer is made of woven

plastic. T he f unctions of the f uel pum p st rainer is to

filter contaminants and to wick fuel.

The fuel pump strainer is self-cleaning and

normally requires no maintenance. Fuel stoppage

at this point indicates that the fuel tank contains an

abnormal amount of sediment or water. Clean the

fuel tank and replace fuel sender assembly.

4354

Figure 6C3-1-85 Fuel Sender Assembly

1. Diverter Pipe. 6. External Filter Screen

2. Jet Pump Filter. 7. Secondary Umbrella Valve.

3. Reservoir. 8. Internal Filter Screen.

4. Primary Umbrella 9. Gerotor Fuel Pump.

Valve. 10. Fuel Pressure Regulator.

5. Jet Pump

In-Line Fuel Filter

The fuel feed pipe has a steel f ilter installed ahead

of the fuel injection system. The paper filter

element (2) traps particles in the fuel that may

damage the injection system. T he filter housing (1)

is made to withstand maximum fuel system

pressure, exposure to fuel additives, and changes

in temperature. The inlet fitting is a quick-

disconnect and a the outlet is a threaded fitting

which is sealed with an O-ring. The fuel filter is to

be changed at prescribed service intervals, refer to

Section OB, Lubrication & Service in VX Service

Information. A restricted fuel filter should be

replaced.

Fuel Feed and Retur n Pipes

The fuel feed pipe c arries fuel f rom the fuel tank to

the fuel rail assembly. The fuel return pipe carries

fuel f rom the T -connec tor located on the outlet side

of the f uel f ilter back to the f uel tank. T he f uel pipes

consist of three sections:

• T he rear f uel pipe assem blies are located f rom

the top of the fuel tank to the chassis fuel

pipes. The rear fuel pipes are constructed of

nylon.

Figure 6C3-1-86 In-line Fuel Filter

1. Fuel Filter Housing

2. Paper Filter Element

• The chassis fuel pipes are located under the

vehicle and connect the rear fuel pipes to the

engine compartment connecting fuel pipe.

These pipes are constructed of steel.

• The engine compartment connecting fuel pipe

connects the chassis fuel pipe to the engine

fuel rail. This fuel pipe is constructed of nylon

Nylon Fuel Pipes

IMPORTANT:

In order to Reduce the Risk of Fire and

Personal Injury:

• If nylon fuel pipes are nicked, scratched or

damaged during installation, Do Not

attempt to repair the sections of the nylon

fuel pipes. Replace them.

• When installing new fuel pipes, Do Not

hammer directly on the fuel harness body

clips as it may damage the nylon pipes

resulting in a possible leak.

• Always cover nylon vapour pipes with a wet

towel before using a torch near them. Also,

never expose the vehicle to temperatures

higher th an 115°C ( 239°F) fo r more t han on e

hour, or more than 90°C (194°F) for any

extended period.

• Before connecting fuel pipe fittings, always

apply a few drops of clean engine oil to the

male pipe ends. This will ensure proper

reconnection and prevent a possible fuel

leak. During normal operation, the O-rings

located in the female connector will swell

and may prevent proper reconnection if not

lubricated.

Nylon fuel pipes are designed to perform the sam e

job as the steel or flexible fuel pipes or hoses that

they replace. Nylon pipes are constructed to

withstand maximum fuel system pressure,

exposure to fuel additives, and changes in

temperature. There are three sizes of nylon pipes

used: 3/8” ID for the fuel feed, 5/16” ID for the fuel

return, and 1/2" ID for the vent

Heat resistant rubber hose and/or corrugated

plastic conduit pr otect the sec tions of the pipes that

are exposed to chafing, high temperature or

vibration.

NOTE:

Nylon fuel pipes are somewhat flexible and can be

formed around gradual turns under the vehicle.

However, if nylon fuel pipes are forced into sharp

bends, the pipes will kink and restrict the fuel flow.

Also, once exposed to fuel, nylon pipes may

become stiffer and are more likely to kink if bent

too far. Take special care when working on a

vehicle with nylon fuel pipes.

Figure 6C3-1-87 Fuel Filter Location View

1. Quick Connect, Fuel Tank Vapour Line to Canister

2. Hose, Filler Neck Breather

3. Flexible Line, Fuel Feed to Engine

4. Quick Connect, Fuel Feed Line

5. Quick Connect, Fuel Filter T-piece

6. Retaining Tangs, Fuel Filter Strap

7. Filter, Fuel

8. Quick Connect, Fuel Feed Line from Fuel Tank

Quick-Connect Fittings

Quick -connect f ittings provide a simplif ied means of installing and connecting f uel system com ponents. The fittings

consist of a unique female connector and a compatible male pipe end. O-rings, located inside the female

connector, provide the fuel seal. Integral locking tabs or fingers hold the fittings together.

Fuel Pipe O-Rings

O-rings seal the threaded connec tions in the f uel s ystem and ar e made of spec ial material. Ser vice the O -r ing seals

with the correct service part.

Evaporative Pipes and Hoses

The evaporative pipes extend from the fuel sender assembly and the evaporative canister vent solenoid to the

evaporative canister. The evaporative purge pipe extends from the evaporative canister to the evaporative purge

valve in the engine compartment. The rear pipes and the engine compartment pipe are constructed of nylon. The

chassis evaporative purge pipe is constructed of steel.

Figure 6C3-1-88 Fuel Lines

1. Fuel Tank.

2. Vent Tube.

3. Fuel Filter.

4. Vapour Tube.

5. Fuel Pump Harness Connector.

6. Fuel Pump.

FUEL METERING MODES OF OPERATION

Modes Of Operation

The PCM looks at voltages from several sensors to determine how much fuel to give the engine. The fuel is

delivered under one of several conditions called modes. The PCM controls all modes.

Starting Mode

W ith the ignition s witch in the ON position (bef ore engaging the starter) , the PCM energises the fuel pump relay for

two seconds, allowing the fuel pum p to build system pressure. The PCM first checks speed density, then switches

to the Mass Air Flow (MAF) sensor. The PCM also uses the Engine Coolant T emperature (ECT ), Throttle Position

(TP) , and Manifold Absolute Press ure (MAP) sensor s to determine the proper air/fuel ratio for star ting. T his ranges

from 8.5:1 to 14.7:1 depending on coolant temperature. The PCM controls the amount of fuel delivered in the

starting mode by changing the pulse width of the injectors. This is done by pulsing the injectors for very short times.

4355

Sequential Fuel Inje ction Mode

When the engine is first cranked over, all injectors will be energised simultaneously. After the engine has been

started and a good camshaft signal has been processed, the PCM will energise each individual injector in the

normal firing order. This mode of operation helps to stabilise idle, reduce emissions and reduce fluctuations in the

fuel pressure.

Clear Flood Mode

If the engine floods, c lear the engine by pres sing the accelerator pedal down all the way. The PCM then pulses the

injectors at an air /fuel r atio of 20:1. T he PCM holds this injector rate as long as the throttle stays wide open and the

engine speed is below 300 RPM. If the throttle position becomes less than 80 percent, the PCM returns to the

starting mode.

Run Mode

The run mode has two conditions called O pen Loop, and Closed Loop. When the engine is fir st star ted, and engine

speed is above a predetermined RPM, the system begins Open Loop operation. The PCM ignores the signal from

the Heated O xygen Sensor (HO2S) and calculates the air/f uel ratio based on inputs from the ECT , MAF, MAP, and

TP sensors. The system stays in Open Loop until meeting the following conditions:

• Both HO2S have varying voltage output, showing that they are hot enough to operate properly. (This depends

on temperature.)

• The Engine Coolant Temperature (ECT) sensor is above a specified temperature.

• A specific amount of time has elapsed after starting the engine.

Specific values for the above conditions exist for each different engine, and are stored in the Electrically Erasable

Programmable Read Only Memory (EEPROM).

The system begins closed loop operation after reaching these values. In Closed Loop, the PCM calculates the

air/fuel ratio (injector on-time) based on the signal from various sensors, but mainly the HO2S. This allows the

air/fuel ratio to stay very close to 14.7:1.

Acceleration Mode

W hen the driver press es on the accelerator pedal, air flow into the cylinders increases rapidly, while f uel flow tends

to lag behind. To prevent possible hesitation, the PCM increases the pulse width to the injectors to provide extra

fuel acceleration. The PCM determines the amount of fuel required based on Throttle Position, Coolant

Temperature, Manifold Air Pressure, Mass Air Flow and Engine Speed.

Catalyst Protection Mode

During sustained heavy loads the PCM increases the pulse width to the injectors to provide extra fuel, to prevent

the catalytic converter from overheating.

Deceleration Mode

When the driver releases the accelerator pedal, air flow into the engine is reduced. The PCM looks at the

corresponding changes in Throttle Position, Manifold Air Pressure and Mass Air Flow. The PCM shuts OFF fuel

com pletely if the deceleration is very rapid, or f or long periods (suc h as long closed throttle coast- down) . The fuels

shuts OFF in order to protect the warm-up three-way catalytic converters.

Power Enrichment Mode

When battery voltage is low, the PCM compensates for the weak spark delivered by the ignition system in the

following ways:

• Increasing the amount of fuel delivered.

• Increasing the idle RPM.

• Increasing ignition dwell time.

Fuel Cut OFF Mode

To prevent possible engine damage from over-speed, the PCM cuts off fuel from the injectors when the engine

speed is above approximately 6200 RPM. Also, see Rapid Deceleration in Deceleration Mode.

Open Loop Mode

After the engine is running, the PCM will operate the fuel control system in the open loop mode. In open loop, the

PCM ignores the signal from the oxygen sensors, and calculates the air/fuel ratio injector pulse width based on

inputs from the CKP signal (RPM input) and these sensors: MAF, MAP, IAT, ECT and TP sensor.

The system will stay in the open loop mode until all the closed loop mode criteria have been met, or not at idle,

refer to open loop idle mode description.

In open loop, the calculated puls e width may give an air/fuel ratio other than 14.7 to 1. An example of this would be

when the engine is cold, because a richer mixture is needed to ensure good driveability.

Closed Loop Mode

In closed loop m ode, the PCM initially calculates injector pulse with based on the sam e sensors used in open loop.

The dif f er enc e is that in c losed loop, the PC M us es the ox ygen sensor signals to modif y and precisely fine tune the

fuel pulse width calculations in order to precisely maintain the 14.7 to 1 air/fuel ratio that allows the catalytic

converter to operate at its maximum conversion efficiency.

Power Enrichment (PE) Mode

The power enrichment mode delivers a rich mixture to the cylinders during a large throttle position change

command from the driver. During the power enrichment mode, the PCM will not make fueling changes based on

the oxygen sensor signals.

Battery Voltage Correction Mode

When battery voltage is low, the PCM compensates for the weak spark delivered by the ignition system in the

following ways:

• Increasing the amount of fuel delivered.

• Increasing the idle RPM.

• Increasing ignition dwell time.

Adaptive Learning

Adaptive learning is the ability of the PCM to determine and remember its most recent operating experience. The

PCM uses this remembered information to learn from experience and to m ake adjustm ents with respect to what it

learnt. If the engine were to develop a restricted fuel filter, the PCM will change the fuel injector pulse width richer

to com pensate f or this condition and will rem em ber to k eep this fuel inj ection puls e in m em ory until the res triction is

corrected. After the restriction has been fixed, the PCM will eventually go back to the original preprogrammed fuel

injection pulse. Adaptive learning is an on-going process that continues throughout the life of the engine.

Short Term Fuel Trim

Short T erm Fuel Trim (STFT) represents short term corrections to the fuel injector pulse width calculations, based

on the oxygen sensor input signals to the PCM.

When the engine is started cold, in open loop, the PCM will control the fuel injection pulse width based upon

various sensor inputs such as RPM, ECT, IAT, MAP, MAF and TP sensor until the oxygen sensors become hot

enough to operate properly. During this open loop period, both Short T erm Fuel T rim (STFT) and Long Term Fuel

Trim (LTFT) are disabled and will read 0% on a Tech 2 scan tool.

When the oxygen sensors have reached normal operating temperature, they will produce a varying voltage to the

PCM and provide a good indication of what has happened in the combustion chambers.

At this time the PCM will switch from open loop to closed loop and the STFT will start to constantly monitor the

oxygen sensor signals, so that the PCM can modify fuel injector pulse width with greater accuracy than in open

loop.

STFT monitors the oxygen sensor signals so that it can adjust the fuel injector pulse width to maintain an air/fuel

ratio of 14.7 to I f or m ax im um catalytic converter ef fic iency. An STFT value of 0% is equivalent to an air/f uel ratio of

14.7 to I and an average oxygen sensor signal voltage of 450 mV.

The normal position for STFT is 0%, any change from this value indicates the STFT is changing the fuel injector

pulse width. The amount of pulse width change depends upon how far the STFT value is from 0%. If the STFT

value is above 0%, the fuel injector pulse width is being increased, thus adding more fuel. If the STFT value is

below 0%, the fuel injector pulse width is being decreased, thus removing fuel.

If an engine has a r est ric ted f uel f ilter , the low fuel pr es s ure will res ult in les s f uel being inj ect ed and allows more air

into the charge than is needed to ignite the amount of fuel the fuel injector has injected, therefore, a lean air/fuel

ratio exists in the combustion chamber. After combustion has taken place, the exhaust gases still contain more

oxygen content than nor mal and the oxygen sensors r ead this as low voltage, say 200 m V. The STF T detects that

the oxygen sensor signals are low and will increase the value to richen up the air/fuel mixture. On a Tech 2 scan

tool it will display ST FT as a value above 0%. This STFT c hange will inc rease the injector pulse width allowing the

fuel injectors to stay open longer and inject more fuel.

If the additional fuel was injected and the oxygen sensor signal voltages are still low, the STFT will continue to

increase its value until the oxygen sensor signal voltages go above 450 mV. If the STFT continues to detect low

oxygen sensor signal voltages it will continue to try and compensate for the lean exhaust condition until it runs out

of its authority in the particular Long Term Fuel Trim (LTFT) cell it's operating in. At this point, the PCM will reset

STFT to 0% and go through this procedure again until it can control the system.

If after a specif ied am ount of resets have been tr ied and failed, the PCM k nows that it cannot control f or the failure

and the STFT will remain at its maximum value.

STFT values are based on the oxygen sensor signal voltage readings, therefore, STFT is used by the PCM to

make quick changes to the fuel injector pulse width over a short period of time.

Long Term Fuel Trim

LTFT is used to adjust for engine to engine variation and to adjust for engine aging. LT FT is a portion of the PCM

memor y used to adjust f uel delivery across all operating c onditions of the engine. The PCM m onitor s the ST FT and

will adjust the long term trend of the f uel injector pulse width if the STF T has been at a value f or a certain period of

time. LTFT is used to change the long term fuel injector pulse width and is only operational when the fuel control

system is in Closed Loop. A normal LTFT value is 0% and should follow the STFT value.

If an engine has a restricted f uel filter, the low fuel pres sure will result in less f uel being injected and will cause the

STFT value to go higher than 0%, say 2%. If this STFT value change does not compensate for the restricted fuel

filter, the PCM will continue to increase the STFT value. The STFT may climb as high as its maximum calibrated

value if there is a severe restriction. The PCM will continue to monitor STFT as it climbs, but it will not make any

changes to the f uel injector puls e width for a specif ic period of time. Af ter a specific period of time has elapsed and

the STFT value has remained above say +8%, the LTFT will move up to say 4% and wait again to detect if the

STFT has dr opped bac k down to 0%. If not, the ST F T will gradually move toward its m a ximum calibr ated value limit

until it gains control of the fuel injection system. If STFT and LTFT are both set at their maximum value limit, the

fuel control system is out of the limits of control and will set a Diagnostic Trouble Code and go into open loop

operation.

The PCM will k eep the latest LT FT values s tored in its LT FT m em or y' cells. MAP sensor r eadings and engine RPM

are used by the LTFT to determ ine what cell to read. LTFT values are stored in the PCM's long term m emory, for

use each time the engine's RPM and load matches one of the LTFT cells. All LTFT values are reset to 0% when

the PCM's long term memory power supply is disc onnected. The T ec h 2 sc an tool als o has the ability to reset LTF T

to 0% with a special command.

Long Term Fuel Trim Cell

The LTFT function of the PCM is divided up into cells 0-22 arranged by MAP sensor readings and Engine RPM.

Each cell corresponds to a region on a MAP vs. RPM table. Each region is calibrated to a LTFT value of 0%. A

value of 0% in a given block indicates no fuel adjustment is needed for that engine load condition. A higher

number, say + 4%, indicates that the PCM has detected a lean exhaust indication under those conditions, and is

adding fuel (increasing fuel injector pulse width) to compensate. Conversely, a lower number, say -6%, indicates

that the PCM has detected a rich exhaust indication under those load conditions, and is subtracting fuel

(decreasing fuel injector pulse width) to compensate.

As the vehicle is driven from a standing start and accelerated or decelerated from various engine speeds, the

engine's LTFT calibration will change from one cell to another cell. As the LTFT changes cell so does STFT,

however, STFT will only make short term corrections in whatever LTFT cell the engine is operating in. W hen the

engine is idling, it can be in one of two cells. Depending upon canister purge, the engine will idle in cell 20. If the

engine was running at idle and the canister purge was on, we would be in cells 16-19 depending on AC clutch

status and PRNDL position.

Whatever cell the engine is operating in, the PCM will read that cell's particular LTFT value and electronically adjus t

the fuel injector base pulse width to compensate for a rich or lean condition in the engine. If an engine has a

restricted fuel filter and the customer has driven the vehicle lik e this for quite som e time, the LTFT value would be

high, and the PCM would be compensating for this condition by adding more fuel. Because the STFT value is

above 0%, LTFT will also be greater than 0% in most of the cells to compensate for the lean exhaust. If you

suspect a driveability problem associated with an over rich or over lean condition, then use the STFT value to

detect what the fuel control system is doing at the present time. Use the LTFT to identify what the system has

learned over a greater period of time to compensate for the condition.

Use the LTFT cells to determine if the fuel control system is commanding rich or lean throughout the operating

range. If it is only rich or lean at idle or part throttle, look for components that would cause problems in these areas.

All LTFT cell values are reset to 0% when long term memory power to the PCM is removed

The Tech 2 scan tool has the ability to reset all LTFT cells to 0%.

FUEL METERING SYSTEM COMPONENT DESCRIPTION

The fuel metering systems consists of the following parts:

• The fuel supply components(fuel tank, pump, pipes).

• The fuel pump electrical circuit.

• The fuel rail.

• The fuel injectors.

• The fuel pressure regulator.

• The throttle body.

• The Idle Ai r Control (IAC) valve.

• The Throttle Position (TP) Sensor.

System Overview

An electric fuel pump, located in the fuel tank with the fuel sender assembly, supplies fuel through an in-line fuel

filter at a pressure greater than is needed by the injectors. The fuel pressure regulator, part of the fuel sender

assembly, keeps fuel available to the injectors at a regulated pressure.

Fuel Pump Electrical Circuit

When the ignition switch is turned to the on or

crank position after having been off for at least 10

seconds, the PCM will immediately energise the

fuel pump relay to operate the fuel pump. This

builds up the fuel pressure quickly. If the engine is

not cranked within two seconds, the PCM will shut

the fuel pump relay off and wait until the engine is

cranking. As soon as the engine begins cranking,

the PCM will sense the engine turning from the

crankshaft position signal, and turn the relay on

again to run the fuel pump.

If there is a fault with the fuel pump relay control

circuit, DTC P0230 will set.

Figure 6C3-1-89 Fuel Pump Relay Location

1. Fuel Pump Relay

DTC P0230 FUEL PUMP CONTROL CIRCUIT

Conditions for running DTC P0230

• The engine speed is greater than 400 RPM.

• The ignition voltage is between 6.0 volts and 16.0 volts.

Conditions for setting DTC P0230

• The PCM detects that the commanded state of the circuit and the actual state of the circuit do not match.

• All of the above conditions present for at least ten seconds..

Action taken when DTC P0230 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0230

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does not

fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-90 Fuel Pump Relay Circuit

Fuel Rail Assembly

The fuel rail assembly attaches to the engine

intake manifold and performs the following

functions:

• It positions the injectors (1) in the intake

manifold.

• It distributes fuel evenly to the injectors.

• It integrates the fuel pulse dampener into the

fuel metering system.

GE N 3 0029

Figure 6C3-1-91 Fuel Rail Assembly

1. Fuel Injector

2. Fuel Pulse Dampener

3. Fuel Rail

Fuel Injectors

The fuel injectors are electrically operated flow

control valves. They are supplied with battery

voltage from the ignition switch via fuse F14, the

EFI relay and fuse F34 and F35. The injectors are

controlled by the PCM providing the earth circuit.

The injectors are never fully energised on, as that

would flood the engine with too much fuel. The

PCM supplies the earth circuit in short pulses. The

longer the duration of the pulses (pulse width), the

more fuel in injected into the engine. Inside, the

injector s have a coil of electr ical wire that becom es

an electromagnet when energised. The resistance

of these windings is important for the PCM to

operate correctly.

The top-feed fuel injector assembly is a solenoid

operated device, controlled by the PCM, that

meter s press urised fuel to a single engine cylinder.

The PCM energises the injector solenoid, which

opens a ball valve, allowing fuel to flow past the

ball valve, and through a recessed flow director

plate.

GE N 3 0030

Figure 6C3-1-92 Fuel Injector

J2-09 FUEL PUMP RELAY

CONTROL

G3PCM022PT

B/BLU

YR32 YR32 YB39 YE114

YE110

YE123

YE96

YR44 YR44

(156)

LOC. E7 LOC. E3

IN - TANK

FUEL PUMP

RELAY

G/W (465)

PCM

12V

BATTERY

LOC. E1

F28

(1040) O (240)

V (12 0)

B/W(152)

The director plate has multiple machine holes that

control the fuel flow, generating a conical spray

pattern of finely atomised fuel at the injector tip.

Fuel is directed at the intake valve, causing it to

become further atomised and vaporised before

entering the combustion c hamber. An injec tor s tuck

partly open can cause a loss of pressure after

engine shutdown. Consequently, longer cranking

time may result. There are no DTCs associated

with the injectors. Refer to Fuel Injector Balance

Test in Section 6C3-2C of the VX Series Service

Information for diagnosis of the injectors.

Figure 6C3-1-93 Fuel Injector Circuit

G3PCM017PT

PCM

J1-19

J1-36

J1-04

J1-03

J1-44

J1-76

J1-37

J1-20

J1-43

J1-77

J1-57

INJECTOR 1

INJECTOR 2

INJECTOR 7

INJECTOR 8

BATTERY

INJECTOR 5

INJECTOR 6

INJECTOR 3

INJECTOR 4

IGNITION

BATTERY

(1040)

O/Y

(479)

B/W

(152)

LOC. E1

LOC. E3

R (2H)

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

IGNITION SWITCH

P (3) P/B (39) P (39)

EFI

RELAY

F14

F35

F34F31 BLU

(841)

(843)

(845)

P/B

(847)

(842)

BR/Y

(844)

(846)

(848)

O (740)

O/B

(740)

(481)

L/G

(482)

YE39

YB44

YE111

YE112

YE122

YE39

YE77 YE77

YE79 YE79

YE83 YE83

YE78 YE78

YE80 YE80

YE82 YE82

YE84 YE84

YE81 YE81

YE114

Fuel Pulse Dampener

The f uel pulse dam pener attaches inside a housing

on the fuel rail assembly. The fuel pulse dampener

is diaphragm operated, with fuel pump pr essure on

one side and spr ing pressur e of the other side. The

function of the dampener is to reduce fuel

pulsation.

NOTE: The procedure detailed in the Service

Information f or filter replac ement, must be f ollowed,

both in the sequence of removal and installation of

a replacement filter. Failure to observe these

instructions will most probably result in permanent

damage to the flexible line, resulting in

unnecessary parts replacement and expense.

GEN3 0031

Figure 6C3-1-94 Fuel Pulse Dampener

Accelerator Controls

The accelerator control system is cable operated.

Two different type of accelerator control cable

systems are used, one where Electronic Traction

Control (ETC) is fitted and the other without ETC.

Therefore use the specific cable for each

application. Cable adjustment is provided on the

throttle cable, refer to Section 6C3-3 of the VX

Series Service Information.

Throttle Body Assembly

The throttle body assembly attaches to the intake

manifold and controls air flow into the engine,

thereby controlling engine output. The driver opens

the throttle valve within the throttle body through

the accelerator controls. During engine idle, the

throttle valves are alm os t clos ed. A fixed air bypass

orifice and the Idle Air Control (IAC) valve (3)

control the air flow.

Engine coolant flows thr ough a coolant cavity in the

bottom of the throttle body and prevents throttle

valve icing during cool weather operation. The

throttle body also provides the location for

mounting the Throttle Position (TP) sensor (1).

Figure 6C3-1-95 Throttle Body Assembly

1. TP Sensor

2. Throttle Body Assembly

3. IAC Valve

Throttle Position (TP) Sensor

The T hrottle Pos ition (T P) sens or is mounted to the

throttle shaf t on the throttle body. The T P sensor is

a potentiometer which is supplied a 5 volt

reference and an earth circuit from the PCM. The

signal circuit connects from a sliding contact in the

TP sensor to the PCM. This allows the PCM to

measure the voltage from the TP sensor. As the

throttle is depressed, the output of the TP sensor

changes. At a closed throttle position, the output of

the TP sensor is below 1.25V. As the throttle valve

opens, the output increases. At a wide-open

throttle, the TP sensor output voltage should be

greater than 4 volts.

Speed Density System Description

Three specific data sensors provide the PCM with

the basic information for the fuel management

portion of its operation. That is, three specific

signals to the PCM establish the engine speed and

air dens ity factor s. The engine speed s ignal comes

from the ignition system.

The PCM uses this information to determine

engine speed (RPM). Air density is derived from

IAT and MAP sensor inputs. The IAT sensor

measures the air temperature that is entering the

engine. The IAT signal works in conjunction with

the MAP sensor to determine air density. As the

intake manifold also increases and additional fuel

is r equired. This inform ation from the IAT and MAP

sensors is used by the PCM to control injector

pulse width.

The speed density system is used to:

1. Monitor Mass Air Flow (MAF) sensor operation

(to determine if there is a MAF sensor

malfunction).

2. Tak e over fueling m anagement oper ation when

there is a Mass Air Flow (MAF) sensor

malfunction.

GE N 3 0032

Figure 6C3-1-96 Throttle Position (TP) Sensor

1. Throttle Body

2. IAC Valve O-Ring

3. IAC Valve

4. IAC Valve Attaching Screws

5. TP Sensor Attaching Screws

6. TP Sensor

7. TP Sensor Seal

1.5 IDLE AIR CONTROL (IAC) VALVE

The purpos e of the Idle Air Contr ol (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 a portion of

the bypas s air. An or ific e located in the throttle body

also supplies a constant amount of bypass air.

By moving a conical valve, known as a pintle, in

towards the seat (to decrease air f low); or out away

from the seat (to increase air flow), a controlled

amount of air can be bypassed. If engine speed is

too low, more air is bypassed to increase RPM. If

engine speed is too high, less air is bypassed to

decrease RPM.

The PCM moves the IAC valve in small steps,

called counts. These can be measured and

displayed by a Tech 2 scan tool, which plugs into

the Data Link Connector (DLC). The PCM

calculates the proper position of the IAC valve

during idle, based on battery voltage, coolant

temperature, engine load, and engine RPM. If the

RPM drops below specification and the throttle

valve is closed, the PCM senses a near stall

condition and calculates a new valve position in

order to prevent stalling.

• Engine idle speed is a function of total air flow

into the engine. Idle speed is based on IAC

valve pintle position + crankcase ventilation

valve flow + throttle valve opening + bypass

orifice air flow + calibrated vacuum loss

through accessories.

• Controlled idle speed is programmed into the

PCM, which determines the correct IAC valve

pintle position to maintain the desired idle

speed for all engine operating conditions and

loads.

GE N 3 0033

Figure 6C3-1-97 Idle Air Control (IAC) Valve Air Flow

1. IAC Valve

2. Throttle Plate

3. IAC Valve Pintle

• The minimum idle air rate is set at the factory

with a stop screw. This setting allows enough

air flow by the throttle valve to cause the IAC

valve pintle to be positioned a calibrated

number of s teps (c ounts), f rom the seat, dur ing

controlled idle operation.

IDLE AIR VALVE POSITION RESET

If the IAC valve is disconnected and reconnected

with the engine running, the idle speed may be

wrong. If this occurs, reset the IAC valve by

depressing the accelerator pedal slightly, start and

run the engine for five seconds, then turn the

ignition OFF for ten seconds.

Figure 6C3-1-98 IAC Valve Location

1. TP Sensor

2. Throttle Body

3. IAC Valve

DTC P0506 IDLE SPEED LOW

Conditions for running DTC P0506

• DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0171, P0172, P0174, P0175,

P0443, are not set.

• The engine run time is greater than 60 seconds.

• The engine coolant temperature is greater than 60°C.

• The intake air temperature is greater than -10°C.

• The barometric pressure is greater than 65 kPa.

• The ignition voltage is between 9.0 and 17.0 volts.

• The vehicle speed is no more than 2 km/h.

Conditions for setting DTC P0506

• The actual idle speed is 100 RPM less than the desired idle speed.

• All of the above conditions are present for 15 seconds.

Action taken when DTC P0506 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0506

• The PCM turns the Check Powertrain Lamp OFF after the first ignition cycle that the diagnostic runs and does

not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0507 IDLE SPEED HIGH

Conditions for running DTC P0507

• DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0171, P0172, P0174, P0175,

P0443, are not set.

• The engine run time is greater than 60 seconds.

• The engine coolant temperature is greater than 60°C.

• The intake air temperature is greater than -10°C.

• The barometric pressure is greater than 65 kPa.

• The ignition voltage is between 9.0 and 17.0 volts.

• The vehicle speed is no more than 2 km/h.

Conditions for setting DTC P0507

• The actual idle speed is 100 RPM more than the desired idle speed.

• All of the above conditions are present for 15 seconds.

Action taken when DTC P0507 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0507

• The PCM turns the Check Powertrain Lamp OFF after the first ignition cycle that the diagnostic runs and does

not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-99 IAC Valve Circuits

G3PCM020PT

PCM

J2-77

J2-78

J2-79

J2-76

LG/B (444)

YE36

YE123

IAC VALVE

IAC

COIL B HI

IAC

COIL A HI

IAC

COIL B LO

IAC

COIL A LO

12V

LG/W (443)

LBLU/B (442)

LBLU (441)

1.6 ELECTRONIC IGNITION SYSTEM

The ignition system on the GEN III V8 engine features a multiple coil ignition and is known as coil near plug. The

spark plug leads are short compared with a distributor ignition system. Eight ignition coils/modules are individually

mounted above each cylinder on the rocker covers and fire s equentially. Ther e is an Ignition Control (IC) circ uit for

each ignition coil/module. The eight ignition control circuits are connected to the PCM. All timing decisions are

made by the PCM, which triggers each coil/module individually. Each ignition coil/module has a power feed, an

earth circuit and a reference low circuit.

IGNITION SYSTEM OVERVIEW

The electronic ignition system provides a spark to ignite the compressed air/fuel mixture at the correct time. To

provide optim um engine perf orm ance, f uel econom y, and control of ex haust em is sions, the PCM contr ols the spar k

advance of the ignition system.

The electronic ignition system does not use the

conventional distributor and coil. The ignition system

consists of the following components/circuits:

• Eight ignition coils/modules

• Eight Ignition Control (IC) circuits

• Camshaft Position (CMP) sensor

• 1X Camshaft reluctor wheel

• Crankshaft Position (CKP) sensor

• 24X Crankshaft reluctor wheel

• Related connecting wires

• Powertrain Control Module (PCM)

COMPONENTS

Crankshaft Position Sensor (CKP) and Reluctor Wheel

The Crank shaft Position (CKP) Sensor is located in

the right rear of the engine, behind the starter and

is a dual magneto resistive type sensor. This

sensor is not speed dependent. The dual micro

switches monitor both notches of the reluctor wheel

for greater accuracy. The CKP sensor works in-

conjunction with a 24X reluctor wheel.

The reluctor wheel is mounted on the rear of the

crankshaft. The 24X reluctor wheels use two

different width notches that are 15 degrees apart.

This pulse width encoded pattern allows cylinder

position identification within 90 degrees of

crankshaft rotation. In some cases, cylinder

identification can be located in 45 degrees of

crankshaft rotation. This reluctor wheel also has

dual track notches that are 180 degrees out of

phase. The dual track design allows for quicker

starts and accuracy.

The PCM also receives a 4X signal from the

Crankshaft Position Sensor. The PCM utilises the

4X signal for the following:

• Misfire

• Tachometer output

• Spark control

• Fuel Control

• Certain diagnostics

Figure 6C3-1-100 Crankshaft Position Sensor and

Reluctor Wheel

1. CKP Sensor

2. Reluctor Wheel

The CKP signal must be available for the engine to

start. The CMP signal is not needed to start and

operate the engine. The PCM can determine when

a particular cylinder is on either a firing or exhaust

stroke by the 24X signal. The CMP sensor is to

determ ine what strok e the engine is on. The system

will attem pt to synchronise and look for an increas e

in the MAF signal. An increase in the MAF signal

indicates the engine has started. If the PCM does

not detect an increase in the MAF signal, a re-sync

will occur to the opposite cam position. A slightly

longer cranking time may be a symptom of this

condition.

Camshaft Position Sensor (CMP)

The Camshaft Position (CMP) Sensor is mounted

through the top of the engine block at the rear of

the valley cover. The CMP sensor works in-

conjunction with a 1X reluctor wheel. The reluctor

wheel is located at the rear of the camshaft. The

CMP sensor is used to determine whether a

cylinder is on the firing or the exhaust stroke. As

the camshaft rotates, the reluctor wheel interrupts

a magnetic field produced by a magnet within the

sensor. The CMP sensor ’s internal circuitry detects

this and produces a signal which is used by the

PCM. The PCM uses this signal in combination

with the CKP 24X signal to determ ine to crank shaft

position and stroke.

The CKP signal m ust be available for the engine to

start. The CMP signal is not needed to start and

operate the engine. The PCM can determine when

a particular cylinder is on either a firing or exhaust

stroke by the 24X signal. The CMP sensor is to

determine what stroke the engine is on. The

system will attempt to synchronise and look for an

increase in the MAF signal. An increase in the MAF

signal indicates the engine has started. If the PCM

does not detect an increase in the MAF signal, a

re-sync will occur to the opposite cam position. A

slightly longer cranking time may be a symptom of

this condition.

GE N 3 0022

Figure 6C3-1-101 Camshaft Position (CMP) Sensor

1. CMP Mounting Bolt

2. CMP Sensor

3. Top Rear of Engine Block

Ignition Coils/ Module

The ignition system on this engine features a

m ultiple coil ignition and is k nown as coil near plug.

The secondary ignition wires are short compared

with a distributor ignition system wire. Eight ignition

coils/modules are individually mounted above each

cylinder on the rocker covers and fire sequentially.

There is an Ignition Control (IC) circuit for each

ignition coil/module. The eight ignition control

circuits are connected to the PCM. All timing

decisions are made by the PCM, which triggers

each coil/module individually.

The ignition coil/ modules are supplied with the

following circuits:

• Ignition feed circuit

• Ignition control circuit

• Earth circuit

• Reference low circuit

Figure 6C3-1-102 Ignition Coils/Module Location

Ignition Coils

The ignition feed circuits are fused separately for

each bank of the engine. The two f uses also s upply

the injectors for that bank of the engine. Each

coil/module is serviced separately.

This system puts out very high ignition energy for

plug firing. Because the ignition wires are shorter,

less energy is lost to ignition wire resistance. Also,

since the f iring is sequential, each coil has far mor e

time to saturate as opposed to the three in a waste

spark arrangement. Furthermore, no energy is lost

to the resistance of a waste spark system.

CIRCUITS AFFECTING IGNITION CONTROL

To properly control ignition timing, the PCM relies

on the following information:

• Mass Air Flow

• Engine Load (manifold pressure or vacuum)

• Atmospheric (Barometric) Pressure

• Engine Coolant Temperature

• Intake Air Temperature

• Throttle Position Sensor

• Crankshaft Position Sensor

• Engine Speed

• Automatic Transmission Range from the

Transmission Range Switch

The PCM is responsible for maintaining correct

spark and fuel injection timing for all driving

conditions. To provide optimum driveability and

emissions. The PCM calculates the desired spark

advance from information received from the

sensors and triggers the appropriate ignition

coil/modules at the desired time to provide the

spark advance needed.

RESULTS OF INCORRECT OPERATION

An ignition control circuit that is open, earthed, or

short circuited will set an ignition control circuit

DTC. If a fault occurs in the IC output circuit when

the engine is running, the engine will experience a

misfire. DTC P0351 through DTC P0358 will set

when a malfunction is detected with an Ignition

Control circuit.

If the engine cranks but will not run or immediately

stalls, Engine Cranks But Will Not Run diagnostic

table must be used to determine if the failure is in

the ignition system or the fuel system. If DTC

P0341, P0342, P0343, P0335, P0336 is set, the

appropriate diagnostic trouble code table must be

used for diagnosis.

Figure 6C3-1-103 Ignition Coils/Modules

1. Ignition Coils/Modules

2. Engine Valve Cover

NOTEWORTHY IGNITION INFORMATION

There ar e im portant c onsiderations to point out when servicing the ignition sys tem . The following inform ation will list

some of these to help the technician in servicing the ignition system.

• The ignition coil’s secondar y voltage output capability is very high - more than 40,000 volts . Avoid body c ontact

with ignition high voltage secondary components when the engine is running, or personal injury may result.

• The 24X crank shaft position sensor is the m ost critic al part of the ignition system. If the sensor is dam aged so

that pulses are not generated, the engine will not start.

• Crankshaft position sensor clearance is very important. The sensor must not contact the rotating interrupter

ring at any time or sensor damage will result. If the interrupter ring is bent, the interrupter ring blades will

destroy the sensor.

• Ignition timing is not adjustable. There are no timing marks on the crankshaft balancer or timing chain cover.

• Be car eful not to dam age the s econdary ignition wires or boots when servicing the ignition s ystem. Rotate each

boot to dislodge it fr om the plug or c oil tower before pulling it f rom either a spark plug or the ignition coil. Never

pierce a sec ondary ignition wire or boot f or any testing pur poses! F uture problems will oc cur if pinpoints or test

lights are pushed through the insulating for testing.

DTC P0351 IGNITION CONTROL #1 CIRCUIT DTC P0352 IGNITION CONTROL #2 CIRCUIT

DTC P0353 IGNITION CONTROL #3 CIRCUIT DTC P0354 IGNITION CONTROL #4 CIRCUIT

DTC P0355 IGNITION CONTROL #5 CIRCUIT DTC P0356 IGNITION CONTROL #6 CIRCUIT

DTC P0357 IGNITION CONTROL #7 CIRCUIT DTC P0358 IGNITION CONTROL #8 CIRCUIT

Conditions for running DTC P0351 – P0358

• The ignition voltage is between 9.0 and 17.0 volts

Conditions for setting DTC P0351 – P0358

• The PCM detects the ignition control circuit is earthed, open or shorted to a voltage.

• All conditions met for at least 15 seconds.

Action taken when DTC DTC P0351 – P0358 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC DTC P0351 – P0358

• The PCM turns the Check Powertrain Lamp OFF when the diagnostic runs and does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-104 Ignition System Circuits

G3PCM037PT

PCM

J1-19

J2-67

J2-26

J2-61

J2-60

J2-29

J2-69

J2-28

J2-68

J2-66

J2-27

CYL. 2

IGNITION

REFERENCE LOW

IGNITION

REFERENCE LOW

CYL. 8

CYL. 6

CYL. 4

IGNITION

BATTERY

LOC. E3

(1040)

R (2)

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

IGNITION SWITCH

P (3)

CYL 8

CYL 7

CYL 2

CYL 1

CYL 6

CYL 5

R.H IGNITION MODULE

L.H IGNITION MODULE

CYL 4

CYL 3

LOC.

E5/E15

LOC.

E5/E15

V (95 9)

BR (958)

Y/B (972)

W (971)

W (974)

BLU (973)

L/G (976)

G (975)

LBLU (978)

Y (97 7)

EFI

RELAY

F14

F35

F34

(481)B/W

(152)

L/G

(482)

SPARK PLUGS

12V

CYL. 1

CYL. 7

CYL. 5

CYL. 3

12V

YE122

YE39

YB44

YE39

YE114

YE111

YE124

YE125

YE111

YE123

1.7 CRANKCASE VENTILATION SYSTEM

A closed crankcase ventilation system is used to

provide a more complete scavenging of crankcase

vapours. Fresh air from the throttle body is

supplied to the crankcase, mixed with blow-by

gases and then passed through a crankcase

ventilation valve into the intake manifold.

The primary control is through the crankcase

ventilation valve which meters the flow at a rate

depending on manifold vacuum. To maintain idle

quality, the crankcase ventilation valve restricts the

flow when intake manifold vacuum is high. If

abnormal operating conditions arise, the system is

designed to allow excessive amounts of blow-by

gases to back flow through the crankcase vent

tube into the engine air inlet to be consumed by

normal combustion.

The engine ventilation system was developed to

minimise oil consumption and ensure that oil

ingestion could not occur during high speed

cornering manoeuvres. Filtered fresh air is routed

from up stream of the throttle blade to the front of

the right rocker cover via a formed rubber hose.

To reduce the potential of oil pullover into the

throttle bore area due to bac k f low of the ventilation

system, the fitting in the right side rocker cover is

located between a shield from the rocker arms.

Blow-by gases are routed from the rear of both

rock er covers , through m oulded nylon lines to a tee

fitting located on the centreline of the engine at the

rear of the intake manifold. From there, a single

nylon line carries the gases through an externally

mounted, horizontal PCV valve and enters the

intake manifold behind the throttle body.

The dual draw system was developed to meet

vehicle manoeuvre requirements. During sustained

max imum lateral acc eler ations, the outboar d r ocker

cover may fill with oil. The dual draw system

passively switches, allowing the PCV valve to draw

on the rocker cover with the least resistance. This

results in the system drawing on the air filled, or

inboard rocker cover and eliminates oil pullover

due to drawing on the oil-filled outboard rocker

cover.

T20B009

Figure 6C3-1-105 Crankcase Ventilation System Routing

1. PCV Valve

2. Throttle Body

3. Fresh air

4. Return air

1 4

RESULTS OF INCORRECT OPERATION

A plugged PCV valve or hose may cause:

• Rough idle.

• Stalling or slow idle speed.

• Oil leaks.

• Sludge in engine.

A leaking valve or hose would cause:

• Rough idle.

• Stalling.

• High idle speed.

For replac ement of the PCV and related crank case

hoses, refer to Section 6E3 Emission Control -

GEN III V8 Engine in VX Service Information.

GE N 3 0038

Figure 6C3-1-106 PCV Cutaway

1. Check Valve

1.8 EVAPORATIVE EMISSION CONTROL SYSTEM

The Evaporative Emission Control System (EECS)

used on this vehicle is the charcoal canister

storage method. This method transfers fuel vapour

from the fuel tank to an activated carbon (charcoal)

storage device (canister located under the rear of

the vehicle) to hold the vapours when the vehicle is

not operating. W hen the engine is running, the fuel

vapour is purged from the carbon element by

intake air flow and consumed in the normal

combustion process.

The EECS purge solenoid valve allows manifold

vacuum to purge the canister. The Powertrain

Control Module (PCM) supplies an earth signal to

energise the EECS purge solenoid valve (purge

ON). The EECS purge solenoid control is Pulse

Width Modulated (PWM) or turned ON and OFF

several times a second.

The PCM controlled PWM output is commanded

when the appropriate conditions have been met:

• Engine coolant temperature is below 30°C at

cold start up.

• Engine has been running longer than

2 minutes.

• Engine coolant temperature is above 30°C at

warm start up.

• Engine has been running longer than

30 seconds.

• Engine is not in Decel Fuel Cutoff Mode.

• Throttle opening is less than 96%.

• Engine is in Closed Loop mode or Open Loop

mode.

A higher purge rate is used under conditions that

are likely to produce large amounts of vapour,

when the following conditions have been met:

GE N 3 0039

Figure 6C3-1-107 Fuel Vapour Canister

1. Air Vent Port

2. Canister Purge Port

3. Vapour From Fuel Tank Port

4. Vapour Canister

• Intake Air Temperature (IAT) is above 50°C.

• Engine Coolant Temperature (ECT) is above

100°C.

• Engine has been running for more than

15 minutes.

EECS purge PWM duty cycle varies according to

operating conditions determined by mass air flow,

fuel trim and intake air temperature. The EECS

purge will be re-enabled when TP angle decreases

below 96%.

The canister (located under the rear of the vehicle)

cannot be repaired, and is serviced only as an

assembly. Periodically check the canister at the

time or distance intervals specified in

Section OB Lubrication & Service in VX Service

Information or the Owner’s Handbook.

Figure 6C3-1-108 Canister Purge Solenoid Location

1. Evaporative Purge Solenoid

The fuel vapour canister is mounted in a bracket

underneath the vehicle, located by the fuel filter.

This canister is a three port design. Fuel vapour is

absorbed by the char coal within the canister. When

the engine is running at idle speed and above idle,

air is drawn into the canister through the air vent

port (atmospheric port) at the top of the canister

assembly. The air mixes with the fuel vapour and

the mixture is dr awn into the intak e manifold via the

canister purge line.

The upperm ost port on the c anister is controlled by

a PCM controlled canister purge solenoid. The

canister purge solenoid controls the manifold

vacuum signal from the throttle body. The port

below the canister purge port is the vapour inlet

from the fuel tank. The fresh air inlet port (air vent

port) on the canister is open to the atm osphere via

a hose that vents under the vehicle.

RESULTS OF INCORRECT OPERATION

• Poor idle, stalling and poor driveability can be

caused by:

- Inoperative canister purge solenoid

- Damaged canister.

- Hoses split, cracked and/or not connected to

the proper tubes.

- Throttle body and canister hoses

interchanged on the purge solenoid

connections.

NOTE: The canister connection is marked with

CAN.

• Evidence of fuel loss or fuel vapour odour can

be caused by:

- Liquid fuel leaking from fuel lines.

- Cracked or damaged canister.

- Disconnected, incorrectly routed, kinked,

deteriorated or damaged vapour hoses, or

control hoses.

Figure 6C3-1-109 Canister Location

1. Evaporative Canister (Under Vehicle by Fuel Tank)

2. Fuel Filter

If the solenoid is stuc k open, or the control c ircuit is

shorted to earth, the canister will purge to the

intake manifold all the time. This can allow extra

fuel at idle or during warm-up, which can cause

rough or unstable idle or a rich fuel operation.

If the canister purge solenoid is always closed, the

canister can become over loaded with fuel,

resulting in fuel odour.

A failure in the Evaporative Canister purge

solenoid or Circuit will result in DTC P0443.

GEN 03 0042

123

Figure 6C3-1-110 Sectioned View of Canister

1. Air Vent Port

2. Canister Purge Port

3. Vapour From Fuel Tank Port

4. Evaporative Canister

5. Volume Compensator

6. Charcoal Bed

DTC P0443 EVAP PURGE SOLENOID CONTROL CIRCUIT

Conditions for running DTC P0443

• The engine speed is greater than 400 RPM.

• The ignition voltage is between 6.0 and 16.0 volts.

Conditions for setting DTC P0443

• The PCM detects that the commanded state of the circuit and the actual state of the circuit Dec not match.

• The conditions are present for at least ten seconds.

Action taken when DTC P0443 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0443

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does

not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-111 Evaporative Emission Control Schematic

G3PCM026PT

THROTTLE BODY

CANISTER PURGE

SOL EN OID VALVE

CARBON CANISTER

FUEL TANK

PCM

CANISTER PURGE

F33

F14

IGN SW

EFI

RELAY

BATTERY

P (3 ) P/B

(39)

R (2H)

(1040)

P (439)

O/Y

(479)

YE99

YE39YE39

YE114

YB44 YB44 YE123

YE111

1.9 ELECTRIC COOLING FANS

The PCM determines operation of the two speed

engine cooling fans based on A/C request, A/C

system pressure, engine coolant temperature and

vehicle speed signal inputs. Each engine cooling

fan m otor has four term inals, two negative and two

positive terminals. The two negative terminals are

the relay controlled circuits for the fan operation.

The two positive terminals are the direct power

feed from a f usible link to the fan m otors. When an

earth signal is applied to one of the negative

term inals, the fan m otors will operate at low speed.

When an earth signal is applied to both negative

terminals, both fan will operate at high speed. The

engine cooling fan high s peed relay is controlled by

the PCM. The PCM controls the earth path for the

engine cooling fan high speed relay. Cooling fan

low speed is controlled by the PCM via the PIM

and serial data bus to the BCM.

The BCM controls the earth path for the engine

cooling fan low speed r elay. The engine cooling fan

high speed and the engine cooling fan low speed

relays are used to control the earth signal to the

electric motors that drive the fans. The PCM

determines operation of the two, two speed engine

cooling fans based on A/C request, engine coolant

temperature, A/C Refrigerant Pressure Sensor and

vehicle speed signal inputs.

There are also four (4) suppression capacitors

incorporated into the fan motor wiring circuits.

These suppression capacitors help eliminate fan

motor noise through the radio speakers. If these

capacitors are open, then noise will be present

through the radio speakers. If shorted to earth, the

fan motors could continuously run, or the fuse or

fusible link could fail.

4351

Figure 6C3-1-112 Engine Cooling Fan Assembly

1. Engine Cooling Fan Motor Connector

2. Engine Cooling Fusible Link Housing

3. Main W iring Harness

4. Engine Cooling Fan Assembly

ENGINE COOLING FA N LOW SPEED

The engine cooling fan low speed relay is

energised by the BCM.

The cooling fan low speed relay will be turned ON

when:

• The A/C request indicated (YES) and either:

• the vehicle speed is less than 30 km/h.

• A/C pressure is greater than 1500 kPa

• The coolant temperature is greater than 98°C.

• If the coolant temperature is greater than

113°C, when the ignition is switched off, the

relay is energised for approximately four

minutes, this is known as Low Fan Run On.

• If an engine coolant tem perature s ensor f ault is

detected and a DTC such as DTC P0117,

P0118, P01114 or P01115 is set.

The c ooling fan low speed relay will be turned OFF

when any of the following conditions have been

met:

• An A/C request is not indicated (NO) and the

coolant temperature is less than 95°C.

• An A/C request is indicated (YES) and the

vehicle speed is greater than 50 km /h and A/C

pressur e is less than 1170 k Pa and the coolant

temperature is less than 98°C.

NOTE: The low speed cooling fan has a minimum,

run on time of 30 seconds.

Figure 6C3-1-113 Engine Fan Low Speed Relay Location

1. Engine Fan Low Speed Relay

2. Engine Fan High Speed Relay

ENGINE COOLING FAN HIGH SPEED

• The engine cooling fan high speed relay is controlled by the PCM. The PCM will only turn ON' the engine

cooling fan high speed relay fan if the engine cooling fan low speed relay has been "ON" for two seconds

and the following conditions are satisfied.

• There is a BCM message response fault which will cause a PIM DTC B2002.

• An engine coolant tem perature sensor fault is detected and a DT C such as DTC P0177, P0188, P01114 or

P01115 is set.

• Coolant temperature greater than 108°C.

• The A/C refrigerant pressure is greater than 2400 kPa.

If the low speed fan was OFF when the criteria was met to turn the high speed fan ON, the high speed fan will

com e O N 5 s ec onds after the low s peed f an is turned O N. If both the engine cooling f an relays are ON, the PCM

will turn OFF the high speed relay when:

• The engine coolant temperature is less than 102°C.

• A/C request not indicated (NO).

• A/C request indicated (YES) and A/C pressure is less than 1900 kPa.

Note: All cooling fans will be turned off if the vehicle speed is greater than 104 kph.

LOW SPEED RESPONSE

The engine cooling fan Low Speed Relay is energised by the BCM. When the PCM determines that the low

speed fan relay should be enabled, the PCM will send a message on the Class II serial data circuit to the PIM.

The PIM will intern convert the PCM Class 2 message to a UART message and supply this UART message to

the BCM. This message will request the BCM to supply the needed earth signal for the Low Speed Relay to

operate. After the BCM provides the earth signal for the Low Speed Relay, the BCM will send a message back

to the PIM conf irm ing that the earth s ignal was c om m anded. A failur e in this res ponse co m m unication will cause

a PIM DTC B2002 to set.

DTC P0481 COOLING FAN HIGH SPEED RELAY CONTROL

Conditions for running DTC P0481

• The engine speed is greater than 600 RPM.

• The ignition voltage is between 6.0 and 16.0 volts.

Conditions for setting DTC P0481

• The PCM detects that the commanded state of the driver and the actual state of the control circuit do not

match.

• The conditions must be present for a minimum of 10 seconds.

Action taken when DTC P0481 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0481

• The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs and does

not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC B2002 LOW SPEED FAN NO BCM RESPONSE

Conditions for running DTC B2002

• The ignition is on.

Conditions for setting DTC B2002

• The PIM sends a Low Speed request signals to the BCM , with no response back from the BCM.

Action taken when DTC B2002 Sets

• The PIM will display the DTC only when current.

• The Check Powertrain Lamp (CPL) will not illuminate.

Conditions for clearing the Check Powertrain Lamp and DTC B2002

• A current DTC will clear when the PIM receives a Low Speed Fan Response from the BCM.

Figure 6C3-1-114 Engine Cooling Fan Circuit

R/B (1221) E2/D2

IGNITION

LOW

SPEED FAN

BATTERY MAIN POWER

HIGH SERIES

BCM TERMINALS

NOMINATED FIRST

BCM

15a 15 50

30 OFF/ON

LOCK

ACC

IGN

START

G3PCMO42PT

E20/D6

B7/B7

P (3)

IGNITION SWITCH

O/B (473)

87A

ENGINE

COOLING

FAN 1

ENGINE

COOLING

FAN RELAY

(LOW SPEED)

ENGINE

COOLING

FAN RELAY

(HIGH SPEED)

P/B (39)

O/Y

(250)

F14

BLU/W (304)

R/B (1049)

HIGH

CURRENT EARTH

B/Y

(155) A1/A5 ELECTRONIC EARTH

B/G

(151)

LOC.

E2 LOC.

B10/B11

B/R (157)

J1-58

GEN III PCM

PIM

J2-33

HIGH

SPEED FAN

BLUE

FUSIBLE

LINK

LOC.

F31

A5/A6

O/B (740)

ENGINE

COOLING

FAN 2

BATTERY

FT FAN 2

FU FAN 1

(1040)

(203)

(001)

O/B

(208)

O/BLU

(204)

(001)

(2H)

CLASS 2 SERIAL DATA

UART SERIAL DATA

CLASS 2

SERIAL DA TA

SERIAL

DATA

GY /B (455)

J1-74 Y (41O)

COOLANT TEMP

SENSOR

ETC SENSOR

SIGNAL

A/C

PRESSURE

SIGNAL

348

Ω

J1-80

SENSOR

EARTH

SENSOR

EARTH

J2-21

J2-20

EHICLE SPEED

SENSOR

BLU/W (831)

T (832)

V/W (415)

J2-57

J2-14

J1-45

G/O (469)

G/B (259)

/C PRESSURE

SENSOR

P/B (39)

BLU/Y

(533)

YB176

YE118

YE104

YE43

YB175

YB164

YB175

YB174

YB176

YB165

YB195

YE113

YE65 YE65

YE123

YE122

YE123

YE122

YE123

YB44

YE119

YE140

YE139

YB44

YE104

YE118

YB215 YB215

YB163

YB164

YE43

1.10 A/C CLUTCH CONTROL

This vehicle uses two types of A/C clutch controls;

one with standard A/C and the other uses an

Electronic Climate Control (ECC) module.

ECC SYSTEM

With the ECC system, when the A/C is requested

the electronic climate control module will supply a

signal to the BCM. T he BCM will then send a serial

data request to the PCM. W hen the PCM receives

the serial data request on PCM terminal J1-58, it

indicates that air conditioning has been requested

and approximately 1/2 second after the PCM

receives this signal, it will energise the A/C control

relay. This serial data signal to the PCM is also

used to adjus t the idle speed bef ore turning O N the

A/C compressor relay. If this signal is not available

to the PCM, the A/C compressor will be

inoperative.

The BCM also supplies the earth signal from BCM

terminal 7 to the low speed cooling fan relay.

This A/C system also incorporates a A/C

Refrigerant Pressure Sensor. The A/C Refrigerant

Pressure Sensor signal indicates high side

refrigerant pressure to the PCM. The PCM uses

this inf or mation to adj ust the idle air c ontrol valve to

compensate for the higher engine loads present

with high A/C refrigerant pressures. A fault in the

A/C Refrigerant Pressure Sensor signal will cause

DTC P0530 to set.

The PCM will not energise the A/C control relay if

any of the following conditions are present:

• High coolant temperature

• Low A/C system pressure

• High A/C system pressure

• Wide open throttle

• High engine RPM

T26C3004

Figure 6C3-1-115 A/C Refrigerant Pressure

Sensor Location

1. A/C Refrigerant Pressure Sensor

STANDARD A/C SYSTEM

On vehicles equipped with non ECC systems the

power flow is different. With the blower fan

switched ON and the air conditioning switched ON,

switched ignition voltage is supplied from fuse F13

through the A/C master switch and then to the

BCM. The BCM will then supply a ser ial data signal

to the PCM requesting A/C. If the BCM does not

receive a earth signal from the blower switch to

BCM terminal 3, the BCM will not supply the serial

data request for A/C. Once the PCM receives this

serial data signal, the PCM will energise the A/C

com pres sor relay. The BCM also supplies the earth

signal from BCM terminal 7 to the low speed

cooling fan relay.

This serial data signal to the PCM is also used to

adjust the idle speed before turning ON the A/C

compressor relay. If this signal is not available to

the PCM, the A/C compressor will be inoperative.

This system, like on the ECC system also

incorporates a A/C Refrigerant Pressure Sensor.

The A/C Refrigerant Pressure Sensor signal

indicates high side refrigerant pressure to the

PCM. The PCM uses this information to adjust the

idle air control valve to compensate for the higher

engine loads present with high A/C refrigerant

pressures. A fault in the A/C Refrigerant Pressure

Sensor signal will cause DTC P0530 to set.

Figure 6C3-1-116 A/C Relay Location

1. A/C Relay

1.11 ELECTRONIC TRACTION CONTROL

When the ABS/ETC control module senses spin

from the drive wheels due to too much engine

torque for the road conditions, it enters the traction

control mode.

The ABS/ETC m odule monitors both front and rear

wheel speeds through the wheel speed sensors. If

at any time during acceleration the ABS/ETC

module detects drive wheel slip, it will request:

• The PCM, via the spark retard circuit, to retard

the amount of spark advance.

• The PCM, to restrict transmission downshifting.

• The throttle relaxer control module to reduce

the engine throttle opening by a certain

percentage to bring engine torque into a

specific range.

The throttle relaxer control module accomplishes

this by commanding the throttle relaxer to override

the accelerator pedal cable and physically reduce

the throttle body butterfly opening by winding the

throttle cable back.

This is achieved via two high speed Pulse Width

Modulated (PWM) circuits between the ABS/ETC

module and the thr ottle relaxer control m odule. T he

ABS/ETC control module sends a message to the

throttle relaxer control module on the requested

throttle position (DKR) circuit. The throttle relaxer

control module then reports the modified throttle

position opening back to the ABS/ETC control

module via the actual throttle position (DKI) circuit.

Simultaneously with engine spark retard and

throttle position intervention, the ABS/ETC control

module will activate the ABS isolation valves, turn

on the ABS pump motor and s upply brake pres s ure

to the over spinning wheel(s).

The isolation valves isolate the front brake

hydraulic circuits from the master cylinder and rear

brake hydraulic circuits. Once the rear brake

hydraulic circuits are isolated, pressure can be

applied to the rear wheels without affecting any

other brake hydraulic circuits. The ASS/ETC

module opens the priming valve, allowing fluid to

be drawn from the master cylinder to the pump

motor, turns on the ABS pump motor to apply

pressure, begins cycling the ABS assembly's inlet

and outlet valves, and closes the switching valve,

ensuring fluid is directed to the wheel not back into

the master cylinder.

The inlet and outlet valve cycling aids in obtaining

maximum road surface traction in the same

manner as the Anti-Lock Brake mode. The

difference between Traction Control and Anti-Lock

Brake mode is that brake fluid pressure is

increased to lessen wheel spin (Traction Control

mode), rather than reduced to allow greater wheel

spin (Anti-Lock Brake mode).

If at any time during Traction Control mode, the

brakes are manually applied, the brake switch

signals the ABS/ETC module to inhibit brake

intervention and allow for manual braking (throttle

reduction and spark retard intervention can still

occur if n ecessary).

Figure 6C3-1-117 ABS/ETC Module Location

1. ABS/ETC Hydraulic Modulator

2. Nut (2 Places) 5.0 - 12.0 N.m

ENGINE SPARK AND THROTTLE POSITION INTERVENTION

Simultaneously to brake intervention, the ABS/ETC

control module communicates with the Powertrain

Control Module (PCM) and the throttle relaxer

control module requesting the PCM to retard the

spark advance and for the throttle relaxer control

module to reduce the throttle opening.

With the engine running, the PCM continually

supplies and m onitors a 12 volt pull- up to the s park

retard circuit. The ABS/ETC control module

requests spark retard by pulling this voltage low.

The PCM then responds by reducing the spark

advance of the engine and restricting transmission

downshifting.

The ABS/ETC control module constantly sends a

Pulse Width Modulated (PWM) signal at 90% with

a frequenc y of IOO HZ to the throttle relaxer control

module on the requested throttle position line

(DKR). This signal is to indicate to the throttle

relaxer control module that the traction control

system (ETC) is in a state of readiness.

With the engine idling, the ABS/ETC control

module constantly sends a Pulse W idth Modulated

(PWM) signal with a duty cycle of 90% to the

throttle relaxer control module via the requested

throttle position line (DKR). The throttle relaxer

control module responds on the actual throttle

position line (DKI) with a PWM signal with a duty

cycle of 9%.

When the ABS/ETC control module determines

that a reduction in throttle is required, it reduces

the PWM signal on the requested throttle position

line (DKR), from 90% (no throttle reduction) to as

low as approximately 14% (maximum throttle

reduction). The throttle relaxer control module then

drives the throttle relaxer motor, overriding the

accelerator pedal command (drivers foot), pulling

the throttle cable back, and thus, closing the

amount of throttle opening.

If there is a malfunction between the ABS/ETC

module and the PCM, an ABS/ET C DTC will set. If

there is a malfunction between the ABS/ETC

module and the throttle relaxer control module,

refer to Section 12L ABS & ABS/ETC in VX

Service Information.

For further description on the Anti-Lock Brake

(ABS) system, Electronic Traction Control (ETC)

system Throttle Relaxer Control Module

operation and DTC diagnosis, refer to

Section 12L ABS & ABS/ETC in VX Service

Information.

GE N 3 0006

Figure 6C3-1-118 Throttle Relaxer Control Module

1. Throttle Relaxer Control Module

2. Powertrain Interface Module

3. Left Front Kick Panel

Figure 6C3-1-119 Throttle Relaxer and ABS/ECT Circuits

G3PCM035PT

HIGH SERIES

BCM TE RMIN ALS

NOMINATED FIRST

12V

E2/D2

E9/D3

REQU ESTED

THROTTL E (DKR)

ACTUAL

THROTTL E (DKI)

O/W (1426)

B/W (1427)

MAIN POWER

ABS/ETC

CONTROL MODULE

BCM

DKR

IGNITION

BATTERY

DKI

MOTO R +

MOTO R -

Y (1049)

5 VOLT REF.

TPS SIGNAL

TPS GROUND

THROTTLE

POSITION SENSOR

THROTTLE

RELAXER

12V

J1-08

J2-53

5 VOLT REF.

SPARK RETARD

TPS SIGNAL

TPS GROUND

J2-24

J1-60

J1-58

CLASS 2

SERIAL DA TA

PIM

CLASS 2 SERIAL DATA

UART SERIAL DATA

SERIAL

DATA

SPARK

RETARD

GY (416)

R/B (466)

R/W (456) AB

BLU (417)

B/Y (452)

R/B (1221)

BATTERY

LOC.

E1 FS

IGNITION

SWITCH

15a 15 50

OFF/ON

LOCK

ACC

IGN

START

F27

F36

P (3)

R (8 55)

TH R OTTLE R ELAX ER

CONTROL MODULE

R (2 H)

(1040)

R/Y

(480)

GY/B (1687)

G/W (1220)

PCM

YB44

YE127

YE30

YE98

YB215

YB215YE122

YE123

YE122

YB170

YE123

YB175

YB164

YE110

YE129

1.12 AIR INTAKE SYSTEM

The air intak e s ystem draws outs ide air through the

front of the air cleaner assembly and filter element

of the forward mounted air cleaner. The air is then

routed through the MAF s ensor and into the throttle

body to the intak e m anif old. T he air is then directed

into the intake manifold runners, through the

cylinder heads and into the cylinders.

If the Mass Air Flow (MAF) Sensor is installed

backwards, the system will run rich. An arrow

marked on the plastic portion of the sensor

indicates correct air flow direction. The arrow must

point toward the engine.

T26C3002

Figure 6C3-1-120 Air Cleaner Location

1. Air Cleaner Housing

2. Mass Air Flow (MAF) Sensor

Figure 6C3-1-121 Air Cleaner Housing Assembly

1. Air Cleaner Housing Upper Body

2. Air Cleaner Housing Top Cover Retaining Screws (3)

3. Air Cleaner Filter

4. Air Cleaner Housing Lower Body

5. Mass Air Flow (MAF) Sensor

6. Air Intake to Throttle Body

7. Air Cleaner Housing Retaining Screws (3)

8. Air Inlet to Air Cleaner Housing Duct

9. Intake Air Temperature (IAT) Sensor

10. Intake Air Temperature (IAT) Sensor Clip

1.13 AUTOMATIC TRANSMISSION SENSORS & SIGNALS

1-2 (A) AND 2-3 (B) SHIFT SOLENOID VALVES

IMPORTANT:

The shift solenoid valve resistance should measure

19-24 ohm s minim um when m easured at 20°C (68°F ).

The shift solenoid current flow should not exceed 0.75

amps. The shift solenoid should energise at a voltage

of 7.5 volts or more (measured across the terminals).

The shift solenoid should de-energise when the

voltage is one volt or less.

If both solenoids lose power, only third gear engages.

The 1-2 and 2-3 shift solenoid valves (also called A

and B solenoids) are identical devices that control the

mo vement of the 1-2 and 2- 3 shift valves (the 3-4 shift

valve is not directly controlled by a shif t solenoid). The

solenoids are normally open exhaust valves that work

in four combinations to shift the transmission into

different gears.

The PCM energises each solenoid by grounding the

solenoid through an internal quad driver. This sends

current through the coil winding in the solenoid and

moves the internal plunger out of the exhaus t position.

When ON, the solenoid redirects fluid to move a shift

valve.

IMPORTANT:

The manual valve can hydraulically override the shift

solenoids. Only in D4 do the shift solenoid states

totally determine what gear the transmission is in. In

the other manual valve positions, the transmission

shifts hydraulically and the shift solenoid states

CATCH UP when the throttle position and the vehicle

speed fall into the correct ranges. Diagnostic trouble

codes P0751, P0753, P0756 and P0758 indicate shift

solenoid performance and circuit voltage faults.

The PCM-controlled shift solenoids eliminate the need

for throttle valve and governor pressures to control

shift valve operation.

8885

Figure 6C3-1-122 A&B Shift Solenoid

DTC P0751 1-2 SHIFT SOLENOID VALVE PERFORMANCE

Conditions for running DTC P0751

• No Throttle Position DTCs P0122 or P0123.

• No VSS assembly DTCs P0502 or P0503.

• No TCC solenoid valve DTC P0740.

• No TCC stuck ON DTC P0742.

• No 1-2 SS valve DTC P0753.

• No 2-3 SS valve DTC P0758.

• No 3-2 SS valve assembly DTC P0785.

• No TFP manual valve position switch DTC P1810.

• No TCC PWM solenoid valve DTC P1860.

• The engine speed is greater than 300 RPM for 5 seconds.

• The engine is not in fuel cutoff.

• The gear range is D.

• The Throttle Position angle is 10-35%.

• The Throttle Position angle is constant +/- 5%.

• The PCM commands a 1-2, 2-3, and 3-4 shift.

• The TCC is commanded ON.

• The vehicle speed is greater than 8 km/h.

• The transmission fluid temperature is 20-130°C.

Conditions for setting DTC P0751

• DTC P0751 sets if the following conditions occur three times:

- Within 2 seconds, the engine speed in 2nd gear is 80 RPM greater than the last speed in 1st gear.

- Within 2 seconds, the engine speed in 3rd gear is 50 RPM less than the last speed in 2nd gear.

- Within 2 seconds, the engine speed in 4th gear is 10 RPM greater than the last speed in 3rd gear.

• All of the above conditions are met and one of the following conditions occurs:

Condition 1

- The speed ratio is 0.95 to 1.2 (speed ratio is engine speed divided by transmission output speed).

- The TCC slip speed is 200-1000 RPM for 4 seconds.

Condition 2

- The speed ratio is 0.65 to 0.8.

- The TCC slip speed is -20 to +40 RPM for 4 seconds.

Action taken when DTC P0751 Sets

• The PCM illuminates the check powertrain lamp (CPL).

• The PCM commands D2 line pressure.

• The PCM inhibits 3-2 downshifts if the vehicle speed is greater than 48 km/h.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0751

• The PCM turns OFF the Check Powertrain Check Powertrain Lamp (CPL) during the first consecutive trip in

which the diagnostic test runs and passes.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0753 1-2 SHIFT SOLENOID CIRCUIT ELECTRICAL

Conditions for running DTC P0753

• The system voltage is between 8.0 and 18 volts.

• The engine speed is greater than 300 RPM for 5 seconds.

• The engine is not in fuel cutoff.

Conditions for setting DTC P0753

• The PCM commands the solenoid ON and the voltage input remains high (12 volts).

• The PCM commands the solenoid OFF and the voltage input remains low (0 volts).

Action taken when DTC P0753 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM commands D2 line pressure.

• The PCM inhibits 3-2 downshift if the vehicle speed is greater than 48 km/h.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0753

• The PCM turns the Check Powertrain Lamp OFF during the first ignition cycle that the diagnostic runs and

does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0756 2-3 SHIFT SOLENOID VALVE PERFORMANCE

Conditions for running DTC P0756

• No Throttle Position DTCs P0122 or P0123.

• No VSS assembly DTCs P0502 or P0503.

• No TCC solenoid valve DTC P0740.

• No TCC stuck ON DTC P0742.

• No 1-2 SS valve DTC P0753.

• No 2-3 SS valve DTC P0758.

• No 3-2 SS valve assembly DTC P0785.

• No TFP manual valve position switch DTC P1810.

• No TCC PWM solenoid valve DTC P1860.

• The vehicle speed is greater than 8 km/h.

• The gear range is D4.

• The engine vacuum is 0-105 kPa.

• The engine torque is 0-542 N.m.

• The Throttle Position angle is 10-50%.

• The Throttle Position angle is constant +/- 7%.

• The PCM commands a 1-2, 2-3, and 3-4 shift.

• The engine speed is greater than 300 RPM for 5 seconds.

• The engine is not in fuel cutoff.

• The transmission fluid temperature is 20-130°C.

Conditions for setting DTC P0756

• DTC P0756 sets if the following conditions occur three times:

- Third gear is commanded for 2 to 6 seconds.

- The speed ratio, in 3rd gear, does not dr op more than 0.3 f rom the last speed ratio, in 2nd gear , (speed ratio

is engine speed divided by transmission output speed).

- The TCC slip speed, in 3rd gear, remains 400 RPM higher than the last TCC slip speed, in 2nd gear.

• All of the above conditions are met for 1.5 seconds and one of the following conditions occurs:

Condition 1

- First gear is commanded for 1.5 seconds.

- The TP angle is greater than 25%.

- The transmission output speed is 400-1500 RPM.

- The speed ratio is 0.7 to 3.0.

- The TCC slip speed is -2000 to 0 RPM for 1.5 seconds.

Condition 2

- Fourth gear is commanded for 1.5 seconds.

- The transmission output speed is 1000-3000 RPM.

- The speed ratio is 1.68 to 3.0.

- The TCC slip speed is 1000 to 3000 RPM for 1 second.

Action taken when DTC P0756 Sets

• The PCM illuminates the check powertrain lamp (CPL).

• The PCM commands 3rd gear only.

• The PCM inhibits TCC engagement.

• The PCM commands maximum line pressure.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0756

• The PCM turns OFF the Check Powertrain Check Powertrain Lamp (CPL) during the first consecutive trip in

which the diagnostic test runs and passes.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

DTC P0758 2-3 SHIFT SOLENOID CIRCUIT ELECTRICAL

Conditions for running DTC P0758

• The system voltage is between 8.0 and 18 volts.

• The engine speed is greater than 300 RPM for 5 seconds.

• The engine is not in fuel cutoff.

Conditions for setting DTC P0758

• The PCM commands the solenoid ON and the voltage input remains high (12 volts).

• The PCM commands the solenoid OFF and the voltage input remains low (0 volts).

Action taken when DTC P0758 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM commands 3rd gear only.

• The PCM commands maximum line pressure.

• The PCM inhibits TCC engagement.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0758

• The PCM turns the Check Powertrain Lamp OFF during the first ignition cycle that the diagnostic runs and

does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-123 Transmission Solenoid Electrical Circuits

4356

PCM

J2-47

J2-48

J1-79

J2-42

J2-04

J2-08

J2-06

TCC PWM

SOLENOID

3-2 CONTROL

SOLENOID

1-2 SHIFT

SOLENOID A

2-3 SHIFT

SOLENOID B

PRESSURE

CONTROL

SOLENOID

LOW

PRESSURE CONTROL

SOLENOID HIGH

YB 129 T RANSMIS SION

PASS-THRU CONNECTOR

TORQUE

CONVERTER

CLUTCH (TCC)

(PWM)

SOLENOID

TORQUE

CONVERTER

CLUTCH (TCC)

ENABLE

SOLENOID

3-2 DOWNSHIFT

CONTROL

SOLENOID

1-2 SHIFT

SOLENOID A

2-3 SHIFT

SOLENOID B

PRESSURE

CONTROL

SOLENOID

P/BLU (339)

TCC ENABLE

SOLENOID

EFI

RELAY

F32

G/W (897)

YE122

YE123

LG (1222)

Y/B (1223)

GY/BLU (1229)

R (1228)

12V

BR (418)

GY/R (422)

YE110

3-2 SHIFT SOLENOID VALVE ASSEMBLY

IMPORTANT:

The 3-2 shift solenoid valve assembly resistance

should be a minimum of 20-24 ohms at 20°C (68°F).

The 3-2 shift solenoid valve assembly is an ON/OFF

solenoid that is used in order to improve the 3-2

downshift. T he s olenoid regulates the release of the 3-

4 clutch and the 2-4 band apply.

If a voltage fault is detected in the 3-2 shift solenoid

circuit, diagnostic trouble code P0785 will set.

325350

Figure 6C3-1-124 3-2 Shift Solenoid

DTC P0785 3-2 SHIFT SOLENOID CIRCUIT ELECTRICAL

Conditions for running DTC P0758

• The system voltage is between 8.0 and 18 volts.

• The engine speed is greater than 300 RPM for 5 seconds.

• The engine is not in fuel cutoff.

Conditions for setting DTC P0758

• The PCM commands the solenoid ON and the voltage input remains high (12 volts).

• The PCM commands the solenoid OFF and the voltage input remains low (0 volts).

Action taken when DTC P0758 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM commands a soft landing to 3rd gear.

• The PCMM commands maximum line pressure.

• The PCM inhibits TCC engagement.

• The PCM inhibit 4th gear if the transmissions in hot mode.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0758

• The PCM turns the Check Powertrain Lamp OFF during the first ignition cycle that the diagnostic runs and

does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-125 Transmission Solenoid Electrical Circuits

4356

PCM

J2-47

J2-48

J1-79

J2-42

J2-04

J2-08

J2-06

TCC PWM

SOLENOID

3-2 CONTROL

SOLENOID

1-2 SHIFT

SOLENOID A

2-3 SHIFT

SOLENOID B

PRESSURE

CONTROL

SOLENOID

LOW

PRESSURE CONTROL

SOLENOID HIGH

YB 129 T RANSMIS SION

PASS-THRU CONNECTOR

TORQUE

CONVERTER

CLUTCH (TCC)

(PWM)

SOLENOID

TORQUE

CONVERTER

CLUTCH (TCC)

ENABLE

SOLENOID

3-2 DOWNSHIFT

CONTROL

SOLENOID

1-2 SHIFT

SOLENOID A

2-3 SHIFT

SOLENOID B

PRESSURE

CONTROL

SOLENOID

P/BLU (339)

TCC ENABLE

SOLENOID

EFI

RELAY

F32

G/W (897)

YE122

YE123

LG (1222)

Y/B (1223)

GY/BLU (1229)

R (1228)

12V

BR (418)

GY/R (422)

YE110

TRANSMISSION PRESSURE CONTROL SOLENOID

IMPORTANT:

Transmission pressure control solenoid resistance

should measure 3-5 ohms when measured at 20°C

(68°F).

The transmission pressure control solenoid is an

electronic pressure regulator that controls pressure

based on the current flow through its coil winding. The

magnetic field produced by the coil moves the

solenoid's internal valve which varies pressure to the

pressure regulator valve.

The PCM controls the pressure control solenoid by

commanding current between 100 and 1100

milliam ps. This c hanges the duty c ycle of the solenoid,

which can range between 5 percent and 95 percent

(typically less than 60 percent). 1100 milliamps

corresponds to minimum line pressure, and 100

milliamps c orr es ponds to max imum line pr es sur e If the

solenoid loses power, the transmission defaults to

maximum line pressure.

The PCM commands the line pressure values, using

inputs such as the throttle position sensor. The

pressure control solenoid takes the place of the

throttle valve or the vacuum modulator that was used

on the past model transmissions.

If the duty cycle drops below 5 percent or rises above

95 percent, DTC P0748 will set.

325352

Figure 6C3-1-126 Pressure Control Solenoid

DTC P0748 PC SOLENOID CIRCUIT ELECTRICAL

Conditions for running DTC P0748

• The system voltage is between 8.0 and 18 volts.

• The engine is running.

Conditions for setting DTC P0748

• The PC solenoid value duty cycle reaches its high limit (approximately 95%) or low limit (approximately 0%) for

200 milliseconds.

Action taken when DTC P0748 Sets

• The PCM does not illuminates the Check Powertrain Lamp.

• The PC solenoid valve is OFF.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0748

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

Figure 6C3-1-127 Transmission Solenoid Electrical Circuits

4356

PCM

J2-47

J2-48

J1-79

J2-42

J2-04

J2-08

J2-06

TCC PWM

SOLENOID

3-2 CONTROL

SOLENOID

1-2 SHIFT

SOLENOID A

2-3 SHIFT

SOLENOID B

PRESSURE

CONTROL

SOLENOID

LOW

PRESSURE CONTROL

SOLENOID HIGH

YB 129 T RANSMIS SION

PASS-THRU CONNECTOR

TORQUE

CONVERTER

CLUTCH (TCC)

(PWM)

SOLENOID

TORQUE

CONVERTER

CLUTCH (TCC)

ENABLE

SOLENOID

3-2 DOWNSHIFT

CONTROL

SOLENOID

1-2 SHIFT

SOLENOID A

2-3 SHIFT

SOLENOID B

PRESSURE

CONTROL

SOLENOID

P/BLU (339)

TCC ENABLE

SOLENOID

EFI

RELAY

F32

G/W (897)

YE122

YE123

LG (1222)

Y/B (1223)

GY/BLU (1229)

R (1228)

12V

BR (418)

GY/R (422)

YE110

TORQUE CONVERTER CLUTCH SOLENOID VALVE

IMPORTANT:

The TCC solenoid resistance should be 21-26 ohms

minimum when measured at 20°C (68°F). If a fault is

detected in the TCC solenoid circuit, code P0740 will

set.

The torque converter clutch solenoid valve is a

normally open exhaust valve that is used to control

torque converter clutch apply and release. When

grounded (energised) by the PCM, the TCC solenoid

valve stops converter signal oil from exhausting. This

causes converter signal oil pressure to increase and

shifts the TCC solenoid valve into the apply position.

The brak e s witch is an input to the PCM, and the PCM

directly controls the TCC apply based on the brake

switch status.

8882

Figure 6C3-1-128

DTC P0740 TCC ENABLE SOLENOID CIRCUIT ELECTRICAL

Conditions for running DTC P0740

• The system voltage is between 8.0 and 18 volts.

• The engine speed is greater than 300 RPM for 5 seconds.

• The engine is not in fuel cutoff.

Conditions for setting DTC P0740

• The PCM commands the solenoid ON and the voltage input remains high (12 volts).

• The PCM commands the solenoid OFF and the voltage input remains low (0 volts).

Action taken when DTC P0740 Sets

• The PCM does not illuminates the Check Powertrain Lamp.

• The PCM inhibits TCC engagement.

• The PCM inhibits 4th gear if the transmission is in hot mode.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0740

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

DTC P0742 TCC SYSTEM STUCK ON

Conditions for running DTC P0742

• No MAP sensor DTCs P0107 or P0108.

• No Throttle Position DTCs P0122 or P0123.

• No VSS assembly DTCs P0502 or P0503.

• No TCC solenoid valve DTC P0740.

• No TFP manual valve position switch DTC P1810.

• No TCC PWM solenoid valve DTC P1860.

• The Throttle Position angle is 10-45%.

• The engine speed is greater than 300 RPM for 5 seconds.

• The engine is not in fuel cutoff.

• The engine speed is 1000-3500 RPM.

• The engine torque is 54-542 N.m.

• The engine vacuum is 0-105 kPa.

• The speed ratio is 0.65-1.30 (the speed ratio is engine speed divided by output speed).

• The vehicle speed is 32-88 km/h.

• The commanded gear is not 1st.

• The gear range is D.

• The gear range does not change within 6 seconds.

• The PCM commands the TCC OFF.

Conditions for setting DTC P0742

• DTC P0742 sets if the following condition occurs three times:

- The TCC slip speed is -20 to +30 RPM for 4 seconds.

Action taken when DTC P0742 Sets

• The PCM illuminates the check powertrain lamp (CPL) during the second consecutive trip in which the

conditions for setting the DTC are met.

• The PCM freezes shift adapts from being updated.

• The PCM stores DTC P0742 in PCM history during the second consecutive trip in which the conditions for

setting the DTC are met.

Conditions for clearing the Check Powertrain Lamp and DTC P0742

• The PCM turns OFF the check powertrain lamp (CPL) during the first trip in which the diagnostic test runs and

passes.

• A scan tool clears the DTC from the PCM history.

• The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without an

emission-related diagnostic fault occurring.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

Figure 6C3-1-129 Transmission Solenoid Electrical Circuits

4356

PCM

J2-47

J2-48

J1-79

J2-42

J2-04

J2-08

J2-06

TCC PWM

SOLENOID

3-2 CONTROL

SOLENOID

1-2 SHIFT

SOLENOID A

2-3 SHIFT

SOLENOID B

PRESSURE

CONTROL

SOLENOID

LOW

PRESSURE CONTROL

SOLENOID HIGH

YB 129 T RANSMIS SION

PASS-THRU CONNECTOR

TORQUE

CONVERTER

CLUTCH (TCC)

(PWM)

SOLENOID

TORQUE

CONVERTER

CLUTCH (TCC)

ENABLE

SOLENOID

3-2 DOWNSHIFT

CONTROL

SOLENOID

1-2 SHIFT

SOLENOID A

2-3 SHIFT

SOLENOID B

PRESSURE

CONTROL

SOLENOID

P/BLU (339)

TCC ENABLE

SOLENOID

EFI

RELAY

F32

G/W (897)

YE122

YE123

LG (1222)

Y/B (1223)

GY/BLU (1229)

R (1228)

12V

BR (418)

GY/R (422)

YE110

TORQUE CONVERTER CLUTCH PWM SOLENOID VALVE

IMPORTANT:

TCC PW M solenoid valve resistance should be 10-11

ohms when measured at 20°C (68°F), and 13-15

ohms when measured at 100°C (212°F).

The torque converter clutch PWM solenoid valve

controls the fluid acting on the converter clutch valve,

which then controls the TCC apply and release. This

solenoid is attached to the control valve body

assembly within the transmission.

The TCC PWM solenoid valve provides smooth

engagement of the torque converter clutch by

operating on a negative duty cycle a variable percent

of ON time.

If a fault is detected in the TCC PWM circuit, code

P1860 will set.

325355

Figure 6C3-1-130 TCC PWM Solenoid

DTC P1860 TCC PWM SOLENOID CIRCUIT

Conditions for running DTC P1860

• The system voltage is between 8.0 and 18 volts.

• The engine speed is greater than 300 RPM for 5 seconds.

• The engine is not in fuel cutoff.

• The PCM commands 1st gear.

• The TCC duty cycle is less than 10% or greater than 90%.

Conditions for setting DTC P1860

• The PCM commands the solenoid ON and the voltage input remains high (12 volts).

• The PCM commands the solenoid OFF and the voltage input remains low (0 volts).

Action taken when DTC P1860 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM inhibits TCC engagement.

• The PCM inhibit 4th gear if the transmission is in hot mode.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1860

• The PCM turns the Check Powertrain Lamp OFF during the first ignition cycle that the diagnostic runs and

does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-131 Transmission Solenoid Electrical Circuits

4356

PCM

J2-47

J2-48

J1-79

J2-42

J2-04

J2-08

J2-06

TCC PWM

SOLENOID

3-2 CONTROL

SOLENOID

1-2 SHIFT

SOLENOID A

2-3 SHIFT

SOLENOID B

PRESSURE

CONTROL

SOLENOID

LOW

PRESSURE CONTROL

SOLENOID HIGH

YB 129 T RANSMIS SION

PASS-THRU CONNECTOR

TORQUE

CONVERTER

CLUTCH (TCC)

(PWM)

SOLENOID

TORQUE

CONVERTER

CLUTCH (TCC)

ENABLE

SOLENOID

3-2 DOWNSHIFT

CONTROL

SOLENOID

1-2 SHIFT

SOLENOID A

2-3 SHIFT

SOLENOID B

PRESSURE

CONTROL

SOLENOID

P/BLU (339)

TCC ENABLE

SOLENOID

EFI

RELAY

F32

G/W (897)

YE122

YE123

LG (1222)

Y/B (1223)

GY/BLU (1229)

R (1228)

12V

BR (418)

GY/R (422)

YE110

TRANSMISSION FLUID PRESSURE (TFP) MANUAL VALVE POSITION SWITCH ASSEMBLY

This gear range sensing device called a

Transmission Fluid Pressure (TFP) manual valve

position switch assembly is used by the PCM to

sense which gear range has been selected by the

vehicle operator. The TFP manual valve position

switch is located on the valve body and consists of

five pressure switches, two normally closed and

three normally open, combined into one unit.

The normally open fluid pressure switches are the

D4, LO and Reverse fluid pressure switches. They

are normally open and electrical current is stopped

at these switches when no fluid pressure is

present. Fluid pressure moves the diaphragm and

contact element until the contact element touches

both the positive contact and the earth contact.

This creates a closed circuit and allows current to

flow from the positive contact, through the switch

and to earth. The normally closed fluid pressure

switches are the D2 and D3 fluid pressure

switches. They are normally closed and electrical

current is free to flow from the positive contact to

the earth contact when no f luid pressur e is pres ent.

Fluid pressure moves the diaphragm to disconnect

the positive and earth contacts. This opens the

switch and stops current from flowing through the

switch.

The PCM applies system voltage to the TFP

manual valve position switch assembly on three

separate wires. An open circuit measures 12 Volts

while an earthed circuit measures 0 Volts. The

switches are opened or closed by fluid pressure.

The combination of which switches are open and

closed is used by the PCM to determine actual

manual valve position. The TFP manual valve

position switch assembly however cannot

distinguish between park and neutral because the

monitored valve body pressures are identical in

both cases.

4352

Figure 6C3-1-132 Transmission Fluid Pressure (TFP)

Manual Valve Position Switch

1. Fluid 5. Normal Open

2. O-Ring 6. Normal Closed

3. Diaphragm 7. Contact Element

4. Contact 8. Body

LO This switch will have hydraulic pressure

applied to it in manual 1st gear only and will

be closed.

REV This switch will have hydraulic pressure

applied to it in reverse only and will be

closed.

D2 This switch will have hydraulic pressure

applied to it in manual 1st and 2nd gear and

will be open.

D3 This switch will have hydraulic pressure

applied to it in m anual 1st, 2nd and 3rd gear

and will be open.

D4 This switch will have hydraulic pressure

applied to it in all drive gears except reverse

and will be closed.

RANGE FLUID PRESSURE

INDICATOR REV D4 D3 D2 LO

PARK

REVERSE X

NEUTRAL

D X

3 X X

2 X X X

1 X X X X

Pressure Applied to TFP Manual Valve Switches

These TFP manual valve position switch inputs are used to help control line pressure, torque converter clutch

apply and shift solenoid operation. To monitor TFP manual valve position switch operation, the PCM compares

the actual voltage com bination of the s witches to a TFP m anual valve position switch c ombination T able stored in

its memory.

There are two possible combinations of the switches within the TFP manual valve position switch assembly that

do not represent an actual gear range. If either of these combinations are detected by the PCM, DTC 1810 will

set. DTC 1810 will also set if a valid gear range combination appears at the wrong time.

Figure 6C3-1-133 TFP Manual Valve Switch Assembly

VALID COMBINATION TABLE

RANGE SIGNAL A RANGE SIGNAL B RANGE SIGNAL C

PARK 12V / OPEN 0V / EARTHED 12V / OPEN

REVERSE 0V / EARTHED 0V / EARTHED 12V / OPEN

NEUTRAL 12V / OPEN 0V / EARTHED 12V / OPEN

D 12V / OPEN 0V / EARTHED 0V / EARTHED

3 12V / OPEN 12V / OPEN 0V / EARTHED

2 12V / OPEN 12V / OPEN 12V / OPEN

1 0V / EARTHED 12V / OPEN 12V / OPEN

ILLEGAL 0V / EARTHED 12V / OPEN 0V / EARTHED

ILLEGAL 0V / EARTHED 0V / EARTHED 0V / EARTHED

4353

812

DTC P1810 TFP VALVE POSITION SWITCH CIRCUIT

Conditions for running DTC P1810

• No VSS assembly DTCs P0502 or P0503.

• The system voltage is between 8.0 and 18 volts.

• The engine speed is greater than 300 RPM for 5 seconds.

• The engine is not in fuel cutoff.

• The engine torque is 54-542 N.m.

• The engine vacuum is 0-105 kPa.

Conditions for setting DTC P1810

Condition1

• The PCM detects an invalid TFP manual valve position switch state foe 60 seconds.

Condition 2

• Then engine speed is less than 80 RPM for 0.1 seconds; then the engine speed is 80-55- RPM for 0.07

seconds; then the engine speed is greater the 550 RPM.

• The vehicle speed is less than 3 km/h.

• The PCM detects a gear range of 2, D or R during an engine start.

• All conditions are met for 5 seconds.

Condition 3

• The TP angle is 8-45%.

• The PCM commands 4th gear.

• The TCC is locked ON.

• The speed ratio is 0.65-0.8 (speed ratio is engine speed divided by transmission output speed).

• The PCM detects a gear range of P or N when operating in D.

• All conditions are met for 10 seconds.

Action taken when DTC P1810 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM commands D2 line pressure.

• The PCM commands D4 shift pattern.

• The PCM freezes shift adapts from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1810

• The PCM turns the Check Powertrain Lamp OFF during the first ignition cycle that the diagnostic runs and

does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

Figure 6C3-1-134 TFP Switch Assembly Circuit

G3PCM034PT

PCM

J2-63

J1-17

J2-51

J1-53

TFP SIGNAL A

TFP SIGNAL B

TRANSMISSION FLUID

TEMPERATURE (TFT)

SENSOR SIGNAL

SENSOR EARTH

REV (N.0.)

LO (N.0.)

D3 (N.C.)

D4 (N.O.)D2 (N.C.)

TRANSMISSION FLUID

TEMPERATURE

(TF T ) SENSOR

AUTOMATIC TRANSMISSION FLUID

PRESSURE SWITCH ASSEMBLY

BR/Y (1224)YE123

YE122

YE123

YE122

YB129

Y (1225)

GY (1226)

B/Y (1227)

B/W (1230)

12V

J1-18 TFP SIGN AL C

12V

VEHICLE SPEED SENSOR

IMPORTANT:

The sensor resistance is model dependent and varies

with speed from a minimum of 0.5 volts AC at 100

RPM to more than 100 volts AC at 8000 RPM.

The Vehicle Speed Sensor (or Transmission Output

Speed Sensor) controls shift points and calculates the

TCC slip. The speed sensor contains a coil that gives

off a continuous magnetic f ield. A r otor r otates past the

sensor and the rotor teeth break the magnetic field.

Each break in the field sends a pulse to the VSSB

(Vehicle Speed Sensor Buffer). The VSSB sends two

signals to the PCM. The first is a 2002 pulse per mile

(PPM) signal that is used by the engine. The second is

the transmission/transfer case 40 pulse per revolution

(PPR) signal that is used in order to control the

transmission.

The Vehicle Speed Sensor is located on the

transmission extension housing. Trans Output Speed

= Transfer Case Speed.

DTC P0502, P0503 and P0608 will set if a fault exists

in the vehicle speed sensor. Refer to front of this

Section for detailed information on the VSS.

DTC P1870 will set if there is a slipping condition with

the transmission.

62801

Figure 6C3-1-135 Vehicle Speed Sensor

DTC P1870 TRANSMISSION COMPONENT SLIPPING

Conditions for running DTC P1870

• No Throttle Position DTCs P0122 or P0123.

• No VSS DTCs P0502, P0503.

• No TCC solenoid valve DRTC P0740.

• No 1-2 SS valve DTC P0753.

• No 2-3 SS valve DTC P0758.

• No 3-2 SS valve assembly DTC P0785.

• No TCC PWM solenoid valve DTC P1860.

• The engine speed is greater than 300 RPM for 5 seconds.

• The engine is not in fuel cutoff.

• The vehicle speed is 56-105 km/h.

• The speed ratio is 0.67-0.90 (the speed ratio is the engine speed divided by the transmission output speed).

• The engine speed is 1200-3500 RPM.

• The engine torque is 54-542 N.m.

• The gear range is D4.

• The commanded gear is not 1st gear.

• The throttle position angle is 10-50%.

• The TFT is between 20-130°C.

• The shift solenoid performance diagnostic counters are zero.

Conditions for setting DTC P1870

DTC P1870 sets if the following conditions occur for three TCC cycles.

• The TCC is commanded ON for 5 seconds.

• The TCC is at maximum duty cycle for 1 second.

• The TCC slip speed is 80-8—RPM for 7 seconds.

IMPORTANT:

The following actions may occur before the DTC sets.

• If the TCC is commanded ON and at maximum duty cycle for 5 seconds, the Throttle Position angle is 10-40%,

and the transmission slip counter has incremented to either 1 or 2 (out of 3 to increment the fail counter for the

current ignition cycle), then the following slip conditions and actions may increment the fail counter for the

current ignition cycle:

These conditions must occur sequentially.

Condition 1

• If the TCC slip speed is 80-800 RPM for 7 seconds, then the PCM will command maximum line pressure and

freeze shift adapts from being updated.

Condition 2

• If condition 1 is met and the TCC slip speed is 80-800 RPM for 7 seconds, then the PCM will command the

TCC OFF for 1.5 seconds.

Condition 3

• If Condition 2 is met and the TCC slip speed is 80-8—RPM for 7 seconds, then the fail counter on the current

ignition cycle is incremented.

• The above slip conditions and actions may be disregarded if the TCC is commanded OFF at any time as a

result of a driving manoeuvre (sudden acceleration or deceleration).

Action taken when DTC P1870 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM inhibits TCC engagement.

• The PCM commands maximum line pressure.

• The PCM inhibits 4th gear if the transmission is in hot mode.

• The PCM freezes shift adapte from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P1870

• The PCM turns the Check Powertrain Lamp OFF during the first ignition cycle that the diagnostic runs and

does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

AUTOMATIC TRANSMISSION FLUID TEMPERA TURE SENSOR

The Automatic Transm ission Fluid Temperature (TFT)

Sensor is part of the Automatic Transmission Fluid

Pressure (TFP) manual valve position switch

assembly. This sensor helps control torque converter

clutch apply and shift quality. The TFT sensor is a

resistor, or thermistor, which changes value based on

temperature. At low temperatures the resistance is

high and at high temperatures the resistance is low.

The PCM sends a 5 volt signal to the T FT sensor and

the PCM m easures the voltage drop in the c ircuit. You

will measure a high voltage when the transmission is

cold and a low voltage when the transmission is hot.

Refer to the Temperature vs Resistance table in

Section 6C3-4 Specifications of the VX Series

Service Information.

If the TFT sensor circuit has a f ault, DTC P0711, DTC

P0712 or P0713 is set. A DT C P0712 indic ates a shor t

circuit c ondition, while a DTC P0713 indicates an open

circuit condition. DTC P0218 is set if the transmission

is operating at a high temperature for a period of time.

DTC P0218 TRANSMISSION FLUID OVERTEMPERATURE

Conditions for running DTC P0218

• No TFT sensor DTCs P0711, P0712, P0713.

• The ignition switch is in the RUN position for 5 seconds.

Conditions for setting DTC P0218

• The TFT is greater than 130°C for 10 minutes (600 seconds).

Action taken when DTC P0218 Sets

• The PCM illuminates the Check Powertrain Lamp when the diagnostic runs and fails.

• The PCM freezes shift adapte from being updated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

Conditions for clearing the Check Powertrain Lamp and DTC P0218

• The PCM turns the Check Powertrain Lamp OFF during the first ignition cycle that the diagnostic runs and

does not fail.

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

DTC P0711 TFT SENSOR CIRCUIT RANGE/PERFORMANCE

Conditions for running DTC P0711

• No VSS assembly DTCs P0502, P0503.

• No transmission component slipping DTC P1870.

• The system voltage is between 8.0 volts and 18 volts.

• The engine is run-in g for 409 seconded (6.8 minutes).

• The vehicle speed is greater than 8 km/h for 409 seconds cumulative during the current ignition cycle.

• The TCC slip speed is greater than 120 RPM for 409 seconds cumulative during the current ignition cycle.

• The TFT at startup is between –40 and +21°C.

• The TFT is between –38 and +15°C.

• The engine coolant temperature (ECT) is greater than 70°C and has changed by 50°C since startup.

Conditions for setting DTC P0711

• The TFT does not change more than 1.50°C for 409 seconds since startup.

• The TFT changes more than 20°C in 200 milliseconds, 14 times within 7 seconds.

Action taken when DTC P0711 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

IMPORTANT:

The actions listed below are in order of highest to lowest priority.

• The PCM determines a default TFT using the following matrix:

1 If any ECT DTCs P0117 or P0118 are set, then the default TFT is equal to 135°C.

2 If the ECT is 125°C or more, then the default TFT is equal to 135°C.

3 If the engine run time is less than 300 seconds and:

- No intak e air tem per ature (IAT ) DT Cs P0112 or P0113 are set and IAT is available, then the default T FT is

equal to IAT.

- Any IAT DTCs P0112 or P0113 are set or IAT is NOT available, then the default TFT is equal to 90°C.

4 If the engine run time is greater than 300 seconds and no IAT DTCs P0112 or P0113 are set and IAT is

available and ECT is between 40 and 125°C and:

- IAT at startup is less than 15°C, then the default TFT is equal to the ECT plus 5°C.

- IAT at startup is greater than 35°C, then the default TFT is equal to the ECT plus 10°C.

- IAT at startup is between 15 and 35°C, then the default TFT is equal to the ECT.

5 If the engine run tim e is greater than 300 s econds and any IAT DTCs P0112 or P0113 are set or IAT is NOT

available, then the default TFT is equal to the ECT.

6 If the engine run time is gr eater than 300 s ec onds and ECT is les s than 40°C or more, then the default T FT is

equal to 60°C.

• The PCM freezes shift adapts from being updated.

• The PCM stores DTC P0711 in PCM memory

Conditions for clearing the Check Powertrain Lamp and DTC P0711

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

DTC P0712 TFT SENSOR CIRCUIT LOW INPUT

Conditions for running DTC P0712

• The system voltage is between 8.0 volts and 18 volts.

• The ignition switch is in the RUN position.

Conditions for setting DTC P0712

• The TFT sensor indicates a signal voltage less than 0.2 volts for 10 seconds.

Action taken when DTC P0712 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

IMPORTANT:

The actions listed below are in order of highest to lowest priority.

• The PCM determines a default TFT using the following matrix:

1. If any ECT DTCs P0117 or P0118 are set, then the default TFT is equal to 135°C.

2. If the ECT is 125°C or more, then the default TFT is equal to 135°C.

3. If the engine run time is less than 300 seconds and:

- No intak e air tem per ature (IAT ) DT Cs P0112 or P0113 are set and IAT is available, then the default T FT is

equal to IAT.

- Any IAT DTCs P0112 or P0113 are set or IAT is NOT available, then the default TFT is equal to 90°C.

4. If the engine run time is greater than 300 seconds and no IAT DTCs P0112 or P0113 are set and IAT is

available and ECT is between 40 and 125°C and:

- IAT at startup is less than 15°C, then the default TFT is equal to the ECT plus 5°C.

- IAT at startup is greater than 35°C, then the default TFT is equal to the ECT plus 10°C.

- IAT at startup is between 15 and 35°C, then the default TFT is equal to the ECT.

5. If the engine run tim e is greater than 300 seconds and any IAT DTCs P0112 or P0113 are set or IAT is NOT

available, then the default TFT is equal to the ECT.

6. If the engine run tim e is greater than 300 s econds and ECT is less than 40°C or m ore, then the def ault TFT

is equal to 60°C.

• The PCM freezes shift adapts from being updated.

• The PCM stores DTC P0712 in PCM history.

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

IMPORTANT:

The actions listed below are in order of highest to lowest priority.

• The PCM determines a default TFT using the following matrix:

4. If any ECT DTCs P0117 or P0118 are set, then the default TFT is equal to 135°C.

5. If the ECT is 125°C or more, then the default TFT is equal to 135°C.

6. If the engine run time is less than 300 seconds and:

- No intak e air tem per ature (IAT ) DT Cs P0112 or P0113 are set and IAT is available, then the default T FT is

equal to IAT.

- Any IAT DTCs P0112 or P0113 are set or IAT is NOT available, then the default TFT is equal to 90°C.

5. If the engine run time is greater than 300 seconds and no IAT DTCs P0112 or P0113 are set and IAT is

available and ECT is between 40 and 125°C and:

- IAT at startup is less than 15°C, then the default TFT is equal to the ECT plus 5°C.

- IAT at startup is greater than 35°C, then the default TFT is equal to the ECT plus 10°C.

- IAT at startup is between 15 and 35°C, then the default TFT is equal to the ECT.

7. If the engine run tim e is greater than 300 seconds and any IAT DTCs P0112 or P0113 are set or IAT is NOT

available, then the default TFT is equal to the ECT.

8. If the engine run tim e is greater than 300 s econds and ECT is less than 40°C or m ore, then the def ault TFT

is equal to 60°C.

• The PCM freezes shift adapts from being updated.

• The PCM stores DTC P0712 in PCM memory

Conditions for clearing the Check Powertrain Lamp and DTC P0712

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

DTC P0713 TFT SENSOR CIRCUIT HIGH INPUT

Conditions for running DTC P0713

• The system voltage is between 8.0 volts and 18 volts.

• The ignition switch is in the RUN position.

Conditions for setting DTC P0713

• The TFT sensor indicates a signal voltage greater than 4.92 volts for 10 seconds.

Action taken when DTC P0713 Sets

• The PCM stores the DTC information into memory when the diagnostic runs and fails.

• The Check Powertrain Lamp will not be illuminated.

• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in

the Freeze Frame/Failure Records.

IMPORTANT:

The actions listed below are in order of highest to lowest priority.

• The PCM determines a default TFT using the following matrix:

1. If any ECT DTCs P0117 or P0118 are set, then the default TFT is equal to 135°C.

2. If the ECT is 125°C or more, then the default TFT is equal to 135°C.

3. If the engine run time is less than 300 seconds and:

- No intak e air temperature ( IAT ) DTCs P0112 or P0113 ar e se t and IAT is available, then the def ault TFT is

equal to IAT.

- Any IAT DTCs P0112 or P0113 are set or IAT is NOT available, then the default TFT is equal to 90°C.

4. If the engine run time is greater than 300 seconds and no IAT DTCs P0112 or P0113 are set and IAT is

available and ECT is between 40 and 125°C and:

- IAT at startup is less than 15°C, then the default TFT is equal to the ECT plus 5°C.

- IAT at startup is greater than 35°C, then the default TFT is equal to the ECT plus 10°C.

- IAT at startup is between 15 and 35°C, then the default TFT is equal to the ECT.

5. If the engine run tim e is greater than 300 seconds and any IAT DTCs P0112 or P0113 are set or IAT is NOT

available, then the default TFT is equal to the ECT.

6. If the engine run tim e is greater than 300 s econds and ECT is less than 40°C or m ore, then the def ault TFT

is equal to 60°C.

• The PCM freezes shift adapts from being updated.

• The PCM stores DTC P0712 in PCM memory

Conditions for clearing the Check Powertrain Lamp and DTC P0713

• A last test failed (current DTC) clears when the diagnostic runs and does not fail.

• The PCM cancels the DT C default actions when the fault no longer exists and the ignition switch is OFF long

enough in order to power down the PCM.

Figure 6C3-1-136 TFT Circuit

G3PCM034PT

PCM

J2-63

J1-17

J2-51

J1-53

TFP SIGNAL A

TFP SIGNAL B

TRANSMISSION FLUID

TEMPERATURE (TFT)

SENSOR SIGNAL

SENSOR EARTH

REV (N.0.)

LO (N.0.)

D3 (N.C.)

D4 (N.O.)D2 (N.C.)

TRANSMISSION FLUID

TEMPERATURE

(TF T ) SENSOR

AUTOMATIC TRANSMISSION FLUID

PRESSURE SWITCH ASSEMBLY

BR/Y (1224)YE123

YE122

YE123

YE122

YB129

Y (1225)

GY (1226)

B/Y (1227)

B/W (1230)

12V

J1-18 TFP SIGN AL C

12V

ELECTRICAL CONNECTOR

The transmission electrical connector is an important

part of the transmission operating system. Any

interference with the electrical connection can cause

the transmission to set Diagnostic Trouble Codes

(DTCs) or affect proper operation.

The following items can affect the electrical

connection:

• Bent pins in the connector from rough handling

during connection and disconnection.

• Wires backing away from the pins or coming

uncrimped (in either the internal or the external

wiring harness).

• Dirt contamination entering the connector when

disconnected.

• Pins in the internal wiring connector bac king out of

the connector or pushed out of the connector

during reconnection.

• Excessive transmission fluid leaking into the

connector, wicking up into the external wiring

harness and degrading the wire insulation.

• Moisture intrusion in the connector.

• Low pin retention in the external connector from

excessive connection and disconnection of the

wiring connector assembly.

• Pin corrosion from contamination.

• Damaged connector assembly.

13265

Figure 6C3-1-137

Remember the following points:

• In order to r emove the connector , squeeze the two

tabs toward each other and pull s traight up without

pulling by the wires.

• Limit twisting or wiggling the connector during

removal. Bent pins can occur.

• Do not pry the connector off with a screwdriver or

other tool.

• Visually inspect the seals to ensure that they are

not damaged during handling.

• In order to reinstall the external wiring connector,

first align the pins by lining up the arrows on each

half of the connector. Push the connector straight

down into the transmission without twisting or

angling the mating parts.

• The connector should click into place with a

positive feel and/or noise.

IMPORTANT:

Whenever the transmission external wiring connector

is disconnected from the internal harness and the

engine is operating, DTCs will set. Clear these DTCs

after reconnecting the external connector.

1.14 ABBREVIATIONS AND GLOSSARY OF TERMS

Abbreviations used in this Service Information CD are listed below in alphabetical order with an explanation of the

abbreviation.

POWERTRAIN MANAGEMENT

AC - ALTERNATING CURRENT - A current whose polarity is constantly changing between positive and negative.

A/C - AIR CONDITIONING

A/F - AIR/FUEL (A/F RATIO)

ANALOG SIGNAL - An electrical signal that varies in voltage within a given parameter.

BAROMETRIC PRESSURE - Atmospheric pressure. May be called BARO, or barometric absolute pressure.

BATTERY - Stores chemical energy and converts the chemical energy into electrical energy. This provides DC

current for the vehicle’s electrical systems.

CAT. CONV - CATALYTIC CONVERTER - A muffler-shaped device fitted in the exhaust system between the

engine and the m uffler. T he purpose of the catalytic converter is to chem ically convert engine producing gas es into

environmentally safe gases. HC, CO, and NOx emitted by the engine, are converted to water vapour, carbon

dioxide, and nitrogen.

CHECK POWERTRAIN LAM P (CPL) - A W arning indicator located on the instrument panel, and controlled by the

PCM. The lamp is illuminated by the PCM when it detects a fault in the engine management system, or when the

ignition is ON with the engine not running (bulb check).

CKT - CIRCUIT

CLOSED LOOP - A fuel control m ode of operation that us es the signal f rom the exhaus t oxygen sensor, in order to

control the air/fuel ratio precisely at a 14.7 to 1 ratio. This allows maximum efficiency of the catalytic converter.

CO - CARBON MONOXIDE - One of the pollutants found in the engine exhaust.

DIAGNOST IC TROUBLE CODE - The PCM c an detect faults in the engine m anagement system . If a fault occur s,

the PCM may turn on the Check Powertrain Lamp (CPL) and a two digit c ode number will set. A diagnostic trouble

code c an be read f rom the PCM thr ough the Check Powertrain Lam p (CPL) or with the Tech 2 s can tool. T his DT C

will indicate the area of the fault.

DIAGNOSTIC TEST ENABLE TERMINAL - A terminal in the Data Link Connector(DLC) that is earthed to get a

Diagnostic Trouble Code.

DIGITAL SIGNAL - An electrical signal that is either ON or OFF.

DLC - DATA LINK CONNECTOR - Used at the assembly plant to evaluate the engine management system. For

service to flash the Check Powertrain Lamp (CPL), use of Tech 2 scan tool and performing other system checks.

DLC DATA STREAM - An output from the PCM, initiated by the Tech 2 scan tool. This output is a digital signal,

used by assembly plant test equipment and the Tech 2 scan tool. This signal is transmitted from the PCM to the

Data Link Connector(DLC).

DMM (10 Meg.) - MULTIMETER - A multipurpose meter that has capability of measuring Voltage, Amps, and

Ohms.

DRIVER - An electronic device, usually a power transistor, that operates like an electrical switch turning a circuit

ON and OFF.

DUTY CYCLE - The time, in percentage, that a circuit is ON versus OFF .

FIELD SERVICE MODE - A PCM m ode of operation that is used during service. It is operational when the engine

is running and the DLC diagnostic test enable terminal is earthed.

ENGINE COOL AN T TEM PERATURE (ECT ) SENSOR - A s ensor that senses the engine coolant tem perature and

sends that information to the powertrain control module.

EECS - EVAPORATIVE EMISSIONS CONTROL SYSTEM - Used to prevent petrol vapours from the fuel tank

from entering into the atmosphere. The vapours are stored in a canister located under the vehicle. The canister

contains an activated charcoal element. The petrol vapours are purged from the canister into the manifold to be

burned in the engine.

EMI O R ELECT RICAL NOISE - An unwanted signal interfering with another needed s ignal. Comm on ex amples ar e

an electric razor's effect on a television or AM radio reception while driving under high voltage power lines.

EPROM - ERASABLE PROGRAMMABLE READ ONLY MEMORY - Type of Read Only Memory (ROM) that can

be erased with ultraviolet light and reprogrammed.

ESD - ELECTROSTATIC DISCHARGE - The discharge of static electricity, which has built up on an insulated

material.

EEPROM - ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY - Type of read only

mem ory (ROM) that can be electr ically pr ogramm ed, eras ed and reprogram m ed using a scan tool. Also r eferred to

as Flash Memory.

FIELD SERVICE MODE - A PCM mode of operation that is used during service. The field service mode is

operational when the engine is running and the DLC diagnostic test enable terminal is earthed.

FUSE - A thin metal strip which melts through when excessive current flows through it, creating an open circuit,

protecting a circuit from damage.

HC - HYDROCARBONS (HC) - Any unburned fuel leaving the engine from incomplete combustion.

IAC VALVE - IDLE AIR CONTROL VALVE - Installed on the throttle body unit and controlled by the PCM to

regulate idle air flow and thus idle RPM.

IAT SENSOR - INTAKE AIR TEMPERATURE SENSOR - A sensor that enses intake manifold incoming air

temperature and sends the information to the PCM.

IDEAL M IXTURE - T he air/fuel ratio which provides the best perf ormanc e, while m aintaining ma ximum conversion

of exhaust emissions, typically 14.7 to 1 on petrol engines.

IGN - IGNITION

INPUTS - Information from sensors (MAF, TPS, etc.) and switches (A/C request, etc.) used by the PCM to

determine how to control its outputs.

INTERMITTENT - An electrical signal that occurs now and then; not continuously. In electrical circuits, refers to

occasional open, short, or earth in a circuit.

IPC - INSTRUMENT PANEL CLUSTER

LOW - A voltage less than a spec ific threshold. O perates the s am e as an earth and m ay, or may not, be connected

to chassis earth.

MAF - M ASS AIR FLOW SENSO R - A devic e that monitors the amount of air f low coming in the engine intak e. T he

MAF sensor sends a signal to the PCM.

N.C. - NORMALLY CLOSED - Switch contacts that are closed when they are in the normal operating position.

N.O. - NORMALLY OPEN - Switch contacts that are normally open when in the normal operating position.

NOx - NITROGEN OXIDE - One of the pollutants found in spark ignition engine exhaust. They are formed from

normal combustion and increase in severity with combustion temperatures.

OXYGEN SENSO R - The exhaust gas oxygen sensor is loc ated in the exhaust m anif old. T he O2 sens or m easur es

the oxygen in the exhaust m anifo ld af ter the com bus tion proces s. T he O2 s ensor produc es a small elec trical s ignal

based on the amount of oxygen in the exhaust gas.

OPEN LOOP - The PCM control of the fuel control system without the use of the oxygen sensor information.

OUTPUT – Functions that typically include solenoids and relays that are controlled by the PCM.

PIM - POW ERTRAIN INT ERFACE M ODULE - The PIM acts as a com munic ation translator between the PCM and

other onboard contr ollers that us e a diff erent s erial data pr otocol. T he GEN III V8 PCM uses the new Class II ser ial

data to c ommunicate, while other c ontroller s on the vehicle ar e designed to tr ans mit serial data via the c onventional

Universal Asynchronous Receive Transmit (UART) protocol. Since these two types of serial data are not

compatible, a translator or PIM is required to transmit data in either direction between the PCM and other controller.

PCM - POWERTRAIN CONTROL MODULE - A metal cased box, containing electronic circuitry, which electrically

monitors and controls the transmission system and emission systems on the engine management system. It also

turns ON the Check Powertrain Lamp (CPL) when a malfunction occurs in the system.

PCV - POSITIVE CRANKCASE VENT ILAT ION - Method of rebur ning crankc ase fum es, rather than passing them

directly into the atmosphere.

PROM - PROGRAMMABLE READ ONLY MEMORY - An electronic term used to describe the engine calibration

unit. A plug-in memory unit that instructs the PCM how to operate for a particular vehicle.

PULSE WIDTH MODULATED (PWM) - A digital signal turned ON and OFF for a percentage of available on-plus-

off cycle time. A signal that is 30% ON and 70% OFF would be called a 30% ON PWM signal.

QUAD DRIVER - A transistor, in the PCM, capable of operating four separate outputs. Outputs can be either ON-

OFF or pulse width modulated.

RAM - RANDOM ACCESS MEMORY - Is the micropr ocessors "sc ratch pad". The proc essor can write into or read

from this mem ory as needed. T his mem ory is volatile and needs a constant supply of voltage to be retained. If the

voltage is lost or removed, this memory is lost.

SERIAL DATA - Serial data is a series of rapidly changing voltage signals pulsed from high to low. These signals

are typically 5 volts (UART), 7 volts (Class II), and 12 or 0 volts (high or low) and are transmitted through a wire

often referred to as the Serial Data Circuit.

SFI - SEQUENTIAL FUEL INJECTION - Method of injecting fuel into the engine. A fuel injector is placed at each

inlet port of a cylinder head, directly in front of the intake valve, mounted in the intake manifold.

SOLENOID - An electromagnetic coil, which creates a magnetic field, when current flows through it and causes a

plunger or ball to move.

SWITCH - Opens and closes circuits, thereby controlling current flow.

TCC - TORQUE CONVERTER CLUTCH - A PCM contr olled s olenoid in an automatic tr ansmiss ion which pos itively

couples the transmission input shaft to the engine.

TECH 2 SCAN TOOL - The T ech 2 scan tool is a hand held c omputer designed tool to aid in diagnos is and repair

of autom otive sys tems with electronic c ontrols/interfac es. The T ech 2 scan tool connects to the vehicle’s Data Link

Connector (DLC).

TP SENSOR - THROTTLE POSITION - A sensor that sends a signal to the PCM. The PCM can determine, from

this signal, the current throttle position and the rate of throttle opening / closing.

VACUUM, MANIFOLD - A vacuum source from below the throttle plate.

VACUUM, PORTED - Vacuum source from a small port in the throttle body. With the throttle closed, there is no

vacuum bec ause the port is on the air cleaner s ide of the thr ottle blade and is expos ed to engine vacuum only after

the throttle is open.

VSS - VEHICLE SPEED SENSOR - A permanent magnet type sensor, which produces an AC voltage, which is

sent to the PCM to determine vehicle speed.

UART - UNIVERSAL ASYNCHRONOUS RECEIVE AND TRANSMIT - A method of communicating between

electronic devices.WOT - WIDE OPEN THROTTLE - A throttle position opening greater than 80%.

AUTOMATIC TRANSMISSION

AT - Automatic Transmission

BUMP - A sudden and forceful apply of a clutch or a band.

CHUGGLE - A bucking or jerk ing. This condition m ay be most noticeable when the converter clutch is engaged. It

is similar to the feel of towing a trailer.

DC - Direct Current

DELAYED - A c ondition where a shif t is ex pected but does not occ ur for a period of time. Th is could be described

as a clutch or band engagement that does not occur as quickly as expected during a part throttle or wide open

throttle application of the accelerator, or during m anual downshifting to a lower range. T his term is also defined as

LATE or EXTENDED.

DOUBLE BUMP (DOUBLE FEEL) - Two sudden and forceful applications of a clutch or a band downshifting

during a zero throttle coastdown.

DRIVE LINK NOISE - A whine or growl that increases or fades with vehicle speed and is most noticeable under a

light throttle acceleration. It may also be noticeable in PARK or NEUTRAL operating ranges with the vehicle

stationary.

EARLY - A condition where the shift occurs before the vehicle has reached proper speed. This condition tends to

labour the engine after the upshift.

END BUMP - A firmer feel at the end of a shift than at the start of the shift. This is also defined as END FEEL or

SLIP BUMP.

ENGINE BRAKING - A condition where the engine is used to slow the vehicle on closed throttle or low gear.

ETC - Electronic Traction Control

FINAL DRIVE NOISE - A hum related to vehicle speed which is most noticeable under a light throttle acceleration.

FIRM - A noticeably quick applic ation of a clutc h or band that is c onsidered nor m al with a medium to heavy throttle.

This apply should not be confused with HARSH or ROUGH.

FLARE - A quick increase in engine RPM along with a momentary loss of torque. This most generally occurs

during a shift. This condition is also defined as SLIPPING.

FULL THROTTLE DETENT DOWNSHIFT - A quick application of the accelerator pedal to its full travel, forcing a

downshift.

HARSH (ROUGH) - A more noticeable application of a clutch or band than FIRM. This condition is considered

undesirable at any throttle position.

HEAVY THROTTLE - Approximately 3/4 of accelerator pedal travel (75% throttle position).

HUNTING - A quick repeating series of upshifts and downshifts that causes a noticeable change in engine RPM,

such as a 4-3-4 shift pattern. This condition is also defined as BUSYNESS.

INITIAL FEEL - A distinctly firmer feel at the start of a shift than at the finish of the shift.

LATE - A shift that occurs when the engine RPM is higher than normal for a given amount of throttle.

LIGHT THROTTLE - Approximately 1/4 of accelerator pedal travel (25% throttle position).

MEDIUM THROTTLE - Approximately 1/2 of accelerator pedal travel (50% throttle position).

MINIMUM THROTTLE - The least amount of throttle opening required for an upshift.

OBD - On Board Diagnostic

OSS - Output (Shaft) Speed Sensor

PC - Pressure Control

PLAN ETARY GEAR NOISE - A whine related to vehic le speed, which is m ost noticeable in FIRST gear, SECOND

gear, FOURTH gear or REVERSE. The condition may become less noticeable, or go away , after an upshift.

PM - Permanent Magnet

PUMP NOISE - A high pitched whine that increases in intensity with engine RPM. This condition may also be

noticeable in all operating ranges with the vehicle stationary or moving.

RPM - Revolutions Per Minute

SHIFT CONDITION DEFINITIONS

SHUDDER - A repeating jerk ing condition similar to CHUGGLE but more severe and rapid. This condition m ay be

most noticeable during certain ranges of vehicle speed.

SLIPPING - A notic eable increase in engine RPM without a vehicle speed increas e. A slip usually oc curs during or

after initial clutch or band apply.

SOFT - A slow, almost unnoticeable clutch or band apply with very little shift feel.

SS - Shift Solenoid

SURGE - A repeating engine related condition of acceleration and deceleration that is less intense than

CHUGGLE.

TAP - Transmission Adaptive Pressure

TFP - Transmission Fluid Pressure

TFT - Transmission Fluid Temperature

TIE-UP - A condition where two opposing c lutch and/or bands ar e attem pting to apply at the same tim e caus ing the

engine to labour with a noticeable loss of engine RPM.

TORQUE CONVERTER NOISE - A whine usually noticed when a vehicle is stopped and the transmission is in

DRIVE or REVERSE. The noise will increase with engine RPM.

TV - Throttle Valve

WIDE OPEN THROTTLE (WOT) - Full travel of the accelerator pedal (100% throttle position).

ZERO THROTTLE COASTDOWN - A full release of the accelerator pedal while the vehicle is in motion and in

drive range.