SECTION 6C3-2C - FUNCTIONAL CHECKS -

GEN III V8 ENGINE

CAUTION:

This vehicle will be equipped with a Supplemental Restraint System (SRS). A SRS will consist of either

seat belt pre-tensioners and a driver's air bag, seat belt pre-tensioners and a driver's and front

passenger's air b ags o r seat b elt p re-t ension ers, driv er’s an d f ron t p asseng er’s air bag and left and right

hand side air bags. Refer to SAFETY PRECAUTIONS, Section 12M Supplemental Restraint System of the

VT Series II Service Information before performing any service operation on, or around any SRS

components, the steering mechanism or wiring. Failure to follow the SAFETY PRECAUTIONS could

result in SRS deployment, resulting in possible personal injury or unnecessary SRS system repairs.

NOTICE:

When performing any of these Functional Checks, make certain that the drive wheels are blocked and

the parking brake is firmly set.

The following pages are to be used when ther e is a custom er com plaint and there are no diagnostic trouble c odes

set, or one or m ore of the Tech 2 Scan tool data values are not within the typical values. They are also to be used

when instruc ted from a DT C table. Befor e using these tables you should use the sym ptoms tables which m ay lead

you to using this Section.

The purpose of these tables is to diagnosis Powertrain Control Module (PCM) controlled components or

subsystems that do not have diagnostic trouble codes assigned to them. Another purpose of these tables are for

technicians who feel confident that a particular part of the subsystem is not operating properly and wants to only

check that particular item for proper operation without going through lengthy diagnostic procedures.

GEN III V8 PCM ENGINE COOLING FAN CONTROL

GEN3 0170

Re f er to Wir in g

Schematic

Part 1

Engine Cooling

Fan Relay

H igh S p ee d

P/B

Fuse

F14

Ignition

Switch

Fusible

Link FS

Fusible

Link

Fusible

Link FT O/B 208

YE118

O/BLU 204

250

O/BLU

250

YE104

12V Bus 1040

B/R 157

O/BLU

250

Engine

Earth

O/BLU 250

12V Bus 1040

BLU/W 304

YE110

B/R 157

85 87

86 30 87A

Engine Cooling

Fan Relay

Low Speed

B533

YE104 O/B 473

O/B 473

BLU/Y

533

NOTE

YB174 High Serie s

YB163 Low Seri es

Engine

Cooling

Fan Relay

Low Speed

Control

Powertrain

Control

Module

(PCM)

Engine Cooling

Fan Relay

H igh S p ee d

Control

Cooling

Fan

Cooling

Fan

Serial Data

(Class II)

Body Control Module (BCM)

Serial Data

(UART)

R/B

122 62 Serial Data

(Class II)

Serial Data

(UART) Y

104958

7J1

Power t rai n I nterf ac e Modul e (P I M)

G208

R 208

Supression

Capacitors

Circuit Description:

The GEN III V8 engine has two, two speed electric engine cooling fan m otors which provide the prim ary means of

moving air through the radiator. The cooling fans are used to cool engine coolant flowing through the radiator and

the refrigerant flowing through the A/C condenser.

The engine cooling fan high speed relay is controlled by the PCM. The PCM controls the earth path for the engine

cooling fan high speed relay.

The low s peed of the engine c ooling f an is c ontrolled by the PCM through special Data Communication to the BCM.

The BCM controls the earth path for the engine cooling fan low speed relay.

Both relays are used to control the earth paths to the electric motors that drive both fans.

Low Speed Engine Cooling Fan

The engine cooling fan low speed relay is energised by the BCM. The PCM determines when to enable the low

speed engine cooling fan based on inputs from the A/C request signal, vehicle speed and engine coolant

temperature. The engine cooling low speed fan will be turned ON when:

• A/C request indicated (YES) and

• Vehicle speed less than 30 Km/h

• Coolant temperature is gr eater than a s pec if ied value and will remain on until c oolant temperatur e reduc es to a

predetermined value.

High Speed Engine Cooling Fan

The high speed engine cooling fan is controlled by the PCM based on input from the Engine Coolant Temperature

Sensor (ECT). The PCM will only turn ON

the high s peed engine cooling f an if the low speed engine c ooling fan has been ON f or 2 sec onds and the f ollowing

conditions are satisfied.

• There is a BCM message response fault which will cause a DTC to set.

• An engine coolant temperature sensor failure is detected, such as DTC P0117, P0118, P1114, P1115.

• Coolant temperature greater than a specified value.

If the low speed fan was OFF when the criteria was met to turn the fan high speed ON, the high speed fan will

operate 5 seconds after the low speed fan. The engine cooling fan High speed relay can also be enabled by the A/C

Refriger ant Pressure T ransducer. T he A/C Refrigerant Press ure Transduc er will provide a signal to the PCM when

A/C pressure becomes to high approximately 2600 kPa.

For replacement of the cooling fan motor, refer to Section 6B3 ENGINE COOLING - of the VT Series II Service

Information.

Test Description

Numbers below refer to step numbers on the diagnostic table.

2. This entire diagnostic procedure must begin with a cold engine - at ambient air temperature. If the coolant is

hot when diagnosis is performed, replacement of good parts will result. The fans should not be running if

engine coolant temperature is less than 99°C and air conditioning is not ON.

10. On A/C equipped vehicles, the engine cooling fan High s peed relay should be energised by the PCM, as soon

as the PCM energises the A/C clutch.

GEN III V8 PCM ENGINE COOLING FAN CONTROL

STEP ACTION VALUE YES NO

1 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 2. Go to Powertrain

OBD System Check

Table in Section

6C3-2A

2 1. Ignition ON, engine stopped.

2. Engine coolant temperature below 99°C.

Are both engine cooling fan motors running ?

Go to Step 3 Go to Step 9

3 1. Ignition OFF.

2. Remove the Engine Cooling Fan High Speed Relay.

3. Ignition ON.

Do both fans continue to run ?

Go to Step 4 Go to Step 5

4 1. Ignition ON.

2. Remove Engine Cooling Fan Low Speed Relay.

Do both fans continue to run?

Go to Step 13 Go to Step 16

5 1. Ignition ON.

2. Probe Engine Cooling Fan High Speed Relay

harness connector circuit 304 with a test light to +12

volts.

Is the test light ON?

Go to Step 6 Go to Step 8

6 1. Ignition OFF.

2. Disconnect PCM RED connector.

3. Ignition ON.

4. Using test light, probe Engine Cooling Fan High

Speed Relay harness connector circuit 304 with a

test light connected to +12 volts.

Is the test light ON?

Go to Step 14 Go to Step 7

7 1. Replace PCM.

2. Refer to Section 6C3-3 Service Operations in this

Service Information CD, for PCM Reprogramming

and PCM/PIM Security Link Procedure.

Is action complete?

System OK

8 Replace Engine Cooling Fan High Speed Relay. System OK

9 1. Ignition ON.

2. Using the Tech 2 scan tool, Select HIGH FAN relay

control.

3. Turn ON HIGH FAN with scan tool.

Do both cooling fans operate in high fan mode?

Go to Step 20 Go to Step 23

10 Is the vehicle equipped with A/C? Go to Step 11 Go to Step 12

11 1. Start engine, allow to idle.

2. Turn A/C ON.

3. The fans should run when the A/C clutch engages.

Do the fans run when A/C clutch is engaged?

Go to Step 12 Go to Step 9

12 The engine cooling fan circuits are OK. System OK

13 1. Connect a test light to +12 volts.

2. Probe circuits 533 and 250 of Engine Cooling Fan

Low Speed Relay.

Is the test light ON?

Go to Step 15 Go to Step 18

14 Repair short to earth in circuit 304. System OK

15 Repair short to earth in circuit 533 and/or circuit 250. System OK

16 1. Ignition ON.

2. Probe Engine Cooling Fan Low Speed Relay

harness connector circuit 473 with a test light

connected to +12 volts.

Is the test light ON?

Go to Step 17 Go to Step 21

STEP ACTION VALUE YES NO

17 1. Ignition OFF.

2. Check for short to earth on circuit 473.

Was a short to earth found?

System OK Go to Step 18

18 Replace the BCM, refer to Section 12J-1 Low Series

Body Control Module or Section 12J-2 High Series

Body Control Module of the VT Series II Service

Information.

System OK

19 1. Reinstall Engine Cooling Fan High Speed Relay.

2. Ignition ON.

3. Using the scan tool, Select LOW FAN.

4. Turn ON LOW FAN with Scan Tool.

Does the engine cooling motor run?

Go to Step 10 Go to Step 40

20 1. Ignition ON.

2. Using the scan tool; Select HIGH FAN relay control.

3. Turn ON HIGH FAN with scan tool.

4. While fan is running, remove Engine Cooling Fan

High Speed Relay.

Did the cooling fan motor reduce to a lower running

speed ?

Go to Step 19 If engine cooling

motor turned OFF

Go to Step 40

21 Check for short to earth in circuit 250.

Was a problem found? System OK Go to Step 22

22 Replace Engine Cooling Fan Low Speed Relay.

Is action complete? System OK

23 Check fusible links FS, FT, FU, and Blue fusible link for

open.

Was a problem found?

Go to Step 29 Go to Step 24

24 1. Ignition OFF.

2. Remove Engine Cooling Fan High Speed Relay.

3. Ignition ON.

4. Probe relay socket, circuit 39 with test light

connected to earth.

Is test light ON?

Go to Step 25 Go to Step 31

25 1. Ignition ON.

2. Probe Engine Cooling Fan High Speed Relay socket

circuit 304 with a test light connected to +12 volts.

3. Using scan tool, Select HIGH FAN, enable fan ON

with up/down arrows.

Is test light ON?

Go to Step 26 Go to Step 30

26 1. Ignition ON.

2. Reinstall Engine Cooling Fan High Speed Relay.

3. Back-probe Engine Cooling Fan High Speed Relay

harness connector circuit 250 with test light

connected to +12 volts.

4. Using scan tool, Select HIGH FAN, enable fan ON.

Is test light ON?

Go to Step 27 Go to Step 32

27 1. Ignition ON.

2. Disconnect both electric cooling fan wiring harness

connectors.

3. Probe both fan harness connectors, circuits 533 and

250 with a test light to +12 volts.

4. Using scan tool, Select HIGH FAN, enable fan ON.

Is test light ON for both circuits ?

Go to Step 28 Go to Step 34

28 Probe both fan harness connector power feed circuits

with a test light connected to earth.

Is test light ON for all circuits ?

Go to Step 33 Go to Step 35

STEP ACTION VALUE YES NO

29 1. Check for short to earth that caused fusible link to

blow.

2. Check that the engine cooling fan motor is not

drawing too much current.

Is action complete ?

System OK

30 Check for open in circuit 304 from relay to PCM, or

faulty PCM connection.

Was a problem found?

System OK Go to Step 36

31 Repair open or short to earth in circuit 39.

Replace fuse if blown. System OK

32 With test light connected to +12 volts, back probe

Engine Cooling Fan High Speed Relay harness

connector circuit 157.

Does test light illuminate?

Go to Step 37 Go to Step 38

33 Check for poor connection at both fan motors. If OK,

replace the electric fan motor that did not operate. System OK

34 Check for open in circuits 533 or 250.

Was a problem found? System OK Go to Step 38

35 Repair open circuit in fan motor power circuit that did

not light test light. System OK

36 1. Replace PCM.

2. Refer to Section 6C3-3 Service Operations in this

Service Information CD, for PCM Reprogramming

and PCM/PIM Security Link Procedure.

Is action complete?

System OK

37 Replace Engine Cooling Fan High Speed Relay. System OK

38 Check both relays for open in earth circuit 157.

Was a problem found? System OK Go to Step 39

39 Replace Engine Cooling Fan Low Speed Relay. System OK

40 1. Ignition OFF.

2. Remove Engine cooling Low Speed Relay.

3. Probe relay socket, circuit 250 with a test light

connected to +12 volts.

Is test light ON ?

Go to Step 45 Go to Step 41

41 1. Ignition OFF.

2. Remove Engine Cooling Fan Low Speed Relay

3. Ignition ON.

4. Probe relay socket, circuits 1040 with test light

connected to earth

Is test light ON ?

Go to Step 42 Go to Step 47

42 1. Ignition ON.

2. Probe Engine cooling Low Speed Relay socket,

circuit 473 with a test light connected to +12 volts.

3. Using scan tool, Select LOW FAN, enable fan ON.

Is test light ON?

Go to Step 43 Go to Step 46

43 1. Ignition ON.

2. Reinstall Engine Cooling Fan Low Speed Relay.

3. Back-probe low speed cooling fan relay wiring

harness connector, circuit 533 with test light

connected to +12 volts.

4. Using scan tool, Select LOW FAN, enable fan ON.

Is test light ON?

Go to Step 48 Go to Step 44

44 1. Ignition OFF.

2. Disconnect both electric cooling fan wiring harness

connectors.

3. Probe both wiring harness connector circuits 533

with test light connected to +12 volts.

4. Using scan tool, Select LOW FAN, enable fan ON.

Is test light ON?

Go to Step 52 Go to Step 50

STEP ACTION VALUE YES NO

45 Repair short to earth in circuit 250.

Is action complete? System OK

46 1. Ignition ON.

2. Using scan tool, Select LOW FAN, enable fan ON.

3. Backprobe BCM terminal 7 with a test light

connected to +12 volts.

Is test light ON?

Go to Step 51 Go to Step 53

47 Repair open in circuit which causes test light not to

come ON.

Is action complete?

System OK

48 Replace Engine Cooling Fan Low Speed Relay.

Is action complete? System OK

59 Repair short to earth System OK

50 Repair open in circuits 533 or 250.

Is action complete? System OK

51 Repair open in circuit 473 between BCM and Engine

Cooling Fan Low Speed Relay.

Is action complete?

System OK

52 Replace Engine cooling motor that did not operate.

Refer to Section 6B3 Engine Cooling - of the VT Series

II Service Information.

Is action complete?

System OK

53 Check for faulty connection at BCM, if OK replace

BCM.

Is action complete?

System OK

GEN III V8 PCM A/C REQUEST CIRCUIT DIAGNOSIS

GEN3 0175

A/C

Diode

Fuse

F33

To EFI

(Engine Cont.)

Relay

P 439

A/C

COMP

Relay

G59

LG/B 366

YE111

LG/B 366

43 18 J2

A/C

Clutch

Status

A/C Refrigerant

Pressure Sensor

Earth

A/C

Compressor

Clutch

Powertrain

Control

Module

(PCM)

Engine

Earth

B/R 750

A/C

Refrigerant

Pressure

Sensor

IAT

Sensor

G/O 469V/W 415

G/B 259

A/C Refrigerant

Pressure Sensor

5V Reference

A/C Refrigerant

Pressure Sensor

Signal

57 J2

45 J114 J258 J1

Y 1049 CB

1049 YE110

2Data Link

Connector

(DLC)

R/B

1221

YE112

DLC

BCM

DLC

G/W 1220

Cluster 12

ABS/ETC

Module

HVAC

A/C

Control

A/C

Clutch

Relay

Control

Serial Data

(Class 2)

PCM

J1 = BLU E

J2 = RE D

NOTE

"3" YB164 Low Seri es

"9" YB175 Hi gh Seri es

NOTE

YB164 Low Seri es

YB175 High Serie s

Circuit Description

The A/C clutch relay is PCM c ontrolled to delay A/C clutch engagem ent after the A/C is turned ON. This allows the

PCM to adjust engine RPM before the A/C clutch engages. The PCM will engage the A/C clutch any time A/C has

been requested unless any of the following conditions exist:

• High coolant temperature.

• Low A/C system pressure.

• High A/C system pressure.

• Wide open throttle.

• High engine RPM.

• Open A/C Pressure sensor earth circuit.

When the heater and A/C control is placed in the A/C mode, a 12 volt signal is sent to the PCM. W hen the PCM

receives this s ignal the PCM will earth the A/C clutc h relay control circ uit to energise the A/C relay. This is shown on

the scan tool as A/C request YES.

W hen a request for A/C has been detected by the PCM, the PCM will earth the A/C clutch relay control circuit, the

relay contacts will close, and current will flow through the relay to the A/C compressor clutch.

When A/C request has been detected by the PCM, the cooling fan(s ) will be turned ON when A/C pres sur e is above

a predetermined pressure.

Diagnostic Aids

• Ensure no PCM DTC(s) are stored before using this table. The PCM will not activate the A/C clutch with a

stored DTC. Also, if the A/C Refrigerant Pressure Transducer earth circuit is open, the A/C clutch will not

engage and the cooling fan will be on High speed, but no DTC will set.

Test Description

2. A/C DTCs will disable the A/C system. Repair A/C DTCs before proceeding.

3. This test determines if the A/C power fuse is open. If this fuse is open, the instrument panel, and the

blower relay will also be inoperative.

5. The request circuit is shorted to a voltage if the scan tool displays A/C request as YES.

7. This test checks to see if the A/C control unit is capable of supplying the proper voltage.

8. This test checks the continuity between the BCM and the A/C control unit.

9. If the A/C Refrigerant Pressure Transducer earth circuit is open, this will cause the A/C clutch not to engage.

GEN III V8 PCM A/C REQUEST CIRCUIT DIAGNOSIS

Step Action Value(s) Yes No

1 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 2 Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

2 Are any A/C DTCs set? Go to applicable

DTC table Go to Step 3

3 Check for blown F13 fuse.

Is fuse OK? Go to Step 5 Go to Step 4

4 Repair short to earth in F13 fuse circuit.

Replace fuse.

Is action complete?

System OK

5 1. Install the Tech 2 scan tool.

2. Idle the engine with the A/C OFF, blower switch ON.

3. Monitor A/C request on the Engine Data List using the

scan tool.

Does the scan tool indicate A/C request as ON?

Go to Step 10 Go to Step 6

6 Idle the engine with the A/C ON, blower switch ON.

Does the scan tool indicate A/C request as YES? System OK Go to Step 7

7 1. Turn OFF the ignition.

2. Disconnect the BCM connector:

- YB175 High Series

- YB164 Low Series

3. Turn ON the ignition leaving the engine off, with the

A/C ON, blower switch ON.

4. Back probe the A/C request circuit at the BCM

harness connector terminal using a DMM J 39200

connected to earth:

- ECC: Pin 9 (High series)

- Non ECC: Pin 3 (Low Series)

Does the DMM display near the specified value when A/C

is enabled?

Non-ECC

system B+

ECC System

2 to 4 Volts

Go to Step 12 Go to Step 8

8 3. Turn OFF the ignition.

4. Check the A/C request circuit for continuity between

the A/C control module and the BCM using a DMM

J 39200.

Does the DMM indicate continuity?

Go to Step 9 Go to Step 11

9 Refer to Section 2 Air conditioning of the VT Series II

Service Information for further diagnosis.

Is the action complete?

System OK

10 Inspect the A/C request circuit for an open or short to

voltage.

Did you find a problem and correct it?

System OK Go to Step 13

11 Repair the open A/C request circuit between the A/C

control unit and the BCM.

Is the action complete?

System OK

12 1. Replace PCM.

2. Refer to Section 6C3-3 in this Service Information CD

for PCM Reprogramming and PCM/PIM Security Link

Procedure.

Is action complete?

System OK

13 Inspect the A/C refrigerant pressure earth circuit for an

open.

Was a problem found?

System OK Go to Step 9

GEN III V8 PCM A/C REFRIGERANT PRESSURE TRANSDUCER CIRCUIT DIAGNOSIS

GEN3 0172

Powertrain

Control

Module

(PCM)

IAT Sensor

A/C

Refrigerant

Pressure

Sensor

PCM

J1 = BLU E

J2 = RE D

A/C Refrigerant

Pressure Sensor

Signal

A/C Refrigerant

Pressure Sensor

Signal

A/C Refrigerant

Pressure Sensor

5V Reference

A/C Refrigerant

Pressure Sensor

Earth

259G/B 415V/W 469G/O

J214 J145 J257

Circuit Description

The PCM cycles the A/C compressor clutch to optim ise the perform ance of the A/C system. The PCM determines

when to cycle the A/C compressor clutch by monitoring the A/C Refrigerant Pressure Transducer.

The A/C Ref rigerant Press ure Tr ansducer is also us ed by the PCM to enable the engine cooling fans when the A/C

compressor head pressure reaches a predetermined value.

The PCM energis es the A/C com pres sor clutch when the engine speed is less than 4800 RPM and the A/C s ystem

is requested. If you request the A/C at engine speeds greater than 4800 RPM, the PCM will not energise the A/C

compressor clutch until the engine speed decreases to less than 4000 RPM.

Any one of the following conditions disables the A/C compressor clutch.

• The Throttle is commanded to Wide Open Throttle (WOT).

• The A/C head pressure is greater than 2895 kPa (420 psi).

• The A/C head pressure is less than 176 kPa (25 psi).

• The ignition voltage is less than 10 volts.

• The engine speed is greater than 4800 rpm.

• The engine coolant temperature is greater than 125°C (257°F).

The PCM also disables the A/C compressor when certain DTCs set.

Diagnostic Aids

• Inspect the harness between the A/C clutch and PCM for intermittent connections. While the engine is

operating with the A/C enabled, move r elated electrical connec tors and harnes ses. T his may aid in locating an

intermittent fault.

• For an intermittent, refer to Section 6C3-2B SYMPTOMS in this Service Information CD.

Test Description

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

2. This step checks if the PCM can turn the A/C compressor ON.

3. This step checks for an A/C Refrigerant Pressure Transducer that is at a fixed value (stuck).

4. Inspect the A/C clutch status circuit before replacing the A/C Refrigerant Pressure Transducer. Also, a low

refrigerant charge in the A/C system can cause an A/C system performance condition.

5. Check the connections at the compressor first if the scan tool indicates that the A/C clutch is ON.

6. T he PCM’s A/C clutch status circuit may not detect voltage when the A/C is comm anded ON if the B+ supply

circuit to the A/C relay is intermittent. Inspect the relay connections and operation.

GEN III V8 PCM A/C REFRIGERANT PRESSURE TRANSDUCER CIRCUIT DIAGNOSIS

Step Action Value(s) Yes No

1 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 2 Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

2 Important: If DTCs P0530, and P1546 are set, use those

tables.

1. Idle the engine.

2. Turn ON the A/C.

Does the A/C clutch engage?

Go to Step 3 Go to Step 5

3 1. Observe the A/C High Side pressure display on the

Engine Data List using the scan tool.

2. Turn OFF the A/C for 10 seconds.

3. Turn ON the A/C for 10 seconds.

Did the A/C High Side pressure increase more than the

specified value when the A/C controls were turned ON?

27 kPa

(4 psi) Refer to

Diagnostic Aids Go to Step 4

4 Does the scan tool indicate the A/C clutch ON? Go to Step 7 Go to Step 6

5 Repair the intermittent A/C clutch circuit from the A/C

relay to the splice.

Is the action complete?

System OK Go to Step 11

6 1. Turn OFF the ignition.

2. Disconnect the A/C compressor clutch harness

connector.

3. Probe the A/C compressor clutch B+ supply circuit to

the battery earth using a test lamp J 34142-B.

4. Idle the engine.

5. Turn ON the A/C.

Does the test lamp illuminate?

Go to Step 8 Go to Step 12

7 Probe the A/C compressor clutch B+ supply circuit to the

A/C compressor clutch earth circuit using a test lamp

Does the test lamp illuminate?

Go to Step 9 Go to Step 11

8 Repair the faulty A/C clutch connection or the open A/C

clutch coil.

Is the action complete?

System OK

9 Repair the open or the shorted A/C clutch B+ supply

circuit.

Is the action complete?

System OK

10 Repair the open A/C clutch earth circuit.

Is the action complete? System OK

11 Inspect the A/C refrigerant pressure earth circuit for an

open.

Was a problem found?

System OK Go to Step 10

GEN III V8 PCM FUEL INJECTOR BALANCE TEST

GEN3 01 01

FUEL INJECTOR

TESTER

LOW VEHICLE BATTERY

READY TO TEST

TEST IN PROGRE SS

AMPERAGE SUPPLY S ELEC TOR SWIT CH

PUSH TO START TEST

Coil Test

4 amp

2.5 amp

0.5 amp

Balance Test

4 amp

0.5-2.5

amp

1. First Reading

2. Second Reading

Test Description

Caution: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and

personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel

pressure gauge. Place the towel in an approved container w hen the connection of the fuel pressure gauge

is complete.

4. The engine coolant temperature must be below the operating temperature in order to avoid irregular fuel

pressure readings due to Hot Soak fuel boiling.

5. The fuel press ure should be within the spec ified range. If the f uel press ure is not within the specif ied range, go

to Fuel System Diagnosis in Section 6C3-2A DIAGNOSTIC CHARTS - GEN III V8 Engine.

6. T he fuel pressure should reach a steady value. If the fuel pressure does not reach a steady value, go to Fuel

System Diagnosis.

7. If the pressure drop value for each fuel injector is within 10 kPa (1.5 psi) of the average pressure drop value,

the fuel injectors are flowing properly. Calculate the pressure drop value for each fuel injector by subtracting

the second pressure reading from the first pressure reading. Refer to the illustration above.

GEN III V8 PCM FUEL INJECTOR BALANCE TEST

Step Action Value(s) Yes No

1 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 2 Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

2 Did you perform the Fuel Injector Coil Test Procedure? Go to Step 3 Go to Fuel Inj.

Coil Test - ECT

Between

10-35°C in this

Section

3 Is the engine coolant temperature above the specified

value? 94°C (201°F) Go to Step 4 Go to Step 5

4 Allow the engine to cool below the specified value.

Is the engine coolant temperature below the specified

value?

94°C (201°F) Go to Step 5

5 Caution: Wrap a shop towel around the fuel pressure

connection in order to reduce the risk of fire and

personal injury. The towel will absorb any fuel

leakage that occurs during the connection of the fuel

pressure gauge. Place the towel in an approved

container when the connection of the fuel pressure

gauge is complete.

1. Connect the J 34730-A fuel pressure gauge to the fuel

pressure test port.

2. Energise the fuel pump using the scan tool.

3. Place the bleed hose of the fuel pressure gauge into

an approved petrol container.

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

5. Observe the reading on the fuel pressure gauge.

Is the fuel pressure within the specified limits?

380-440 kPa

(55-62 psi) Go to Step 6 Go to

Fuel System

Diagnosis in

Section 6C3-2B

6 Turn the fuel pump OFF.

Does the fuel pump remain constant? Go to Step 7 Go to

Fuel System

Diagnosis in

Section 6C3-2B

7 1. Connect the J 39021 fuel injector tester to a fuel

injector.

2. Set the amperage supply selector switch on the fuel

injector tester to the Balance Test 0.5-2.5 amp

position.

3. Turn the fuel pump ON then OFF in order to

pressurise the fuel system.

4. Record the fuel pressure indicated by the fuel

pressure gauge after the fuel pressure stabilises. This

is the 1st pressure reading (refer to (1) in the

illustration).

5. Energise the fuel injector by depressing the Push to

Start Test button on the fuel injector tester.

6. Record the fuel pressure indicated by the fuel

pressure gauge after the fuel pressure gauge needle

has stopped moving. This is the 2nd pressure reading

(refer to (2) in the illustration).

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

8. Subtract the 2nd pressure reading from the 1st

pressure reading for one fuel injector. The result is the

pressure drop value.

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

10. Add all of the individual pressure drop values. This is

the total pressure drop.

11. Divide the total pressure drop by the number of fuel

injectors. This is the average pressure drop.

Does any fuel injector have a pressure drop value that is

either higher than the average pressure drop or lower

than the average pressure drop by the specified value?

10 kPa

(1.5 psi) Go to Step 8 Go to Symptoms

Step Action Value(s) Yes No

8 NOTE: Do not repeat any portion of this test before

running the engine in order to prevent the engine from

flooding.

Re-test any fuel injector that does not meet the

specification. Refer to procedure in Step 7.

Does any fuel injector still have a pressure drop value

that is either higher than the average pressure drop or

lower than the average pressure drop by the specified

value?

10 kPa

(1.5 psi) Go to Step 9 Go to Symptoms

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

Replacement in Section 6C3-3.

Is the replacement complete?

System OK

GEN III V8 PCM FUEL INJECTOR COIL TEST - ECT BETWEEN 10 - 35°C

GEN3 0102

FUEL INJECTOR

TESTER

AMPERAG E SUPPLY SELECTOR SWITCH

PUS H TO STAR T TES T

LOW VEHICLE BATTERY

READY TO TEST

TES T IN PROGRESS

J 39021

B+

J 39 2 00 D M M

V-DC mA

V-AC A

OFF µ A

Coil Test

4 amp

2.5 amp

0.5 amp

Balance Test

4 amp

0.5-2.5

amp

Test Description

Caution: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and

personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel

pressure gauge. Place the towel in an approved container w hen the connection of the fuel pressure gauge

is complete.

2. The engine c oolant tem peratur e aff ects the ability of the fuel inj ector tes ter to detect a f aulty fuel injector. If the

engine coolant temperature is NOT between 10°C and 35°C (50°F and 95°F), go to Fuel Inj. Coil Test - ECT

Outside 10-35°C in this Section.

3. The first second of the voltage displayed by the DMM may be inaccurate due to the initial current surge.

Therefore, record the lowest voltage displayed by the DMM after the first second of the test. The voltage

displayed by the DMM should be within the specified range (refer to the example). The voltage displayed by the

DMM may increase throughout the tes t as a fuel inject or windings warm and the resistance of the fuel injector

windings changes. An erratic voltage reading (large fluctuations in voltage that do not stabilise) indicates an

intermittent connection within the fuel injector.

Examples

Resistance

Ohms Voltage Specification at

10°C-35°C (50°F-95°F)

11.4 - 12.6 5.5 - 6.6 V

Fuel Injector

Number Voltage

Reading

Pass/Fail

1 6.3 P

2 5.9 P

3 6.2 P

4 6.1 P

5 4.8 F

6 6.0 P

7 5.0 F

8 5.3 F

GEN III V8 PCM FUEL INJECTOR COIL TEST - ECT BETWEEN 10 - 35°C

Step Action Value(s) Yes No

1 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 2 Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

2 1. Connect the Tech 2 scan tool.

2. Check the engine coolant temperature.

Is the engine coolant temperature within the specified

value?

10°C - 35°C

(50°F - 95°F) Go to Step 3 Go to Fuel Inj.

Coil Test - ECT

Outside 10-35°C

in this Section

3 1. Turn the ignition ON

Note: In order to prevent flooding of a single cylinder and

possible engine damage, relieve the fuel pressure before

performing the fuel injector coil test procedure.

2. Relieve the fuel pressure. Refer to the Fuel Pressure

Relief Procedure.

3. Access the fuel injector electrical connectors as

required.

4. Connect the J 39201 fuel injector tester to B+ and

earth.

5. Set the amperage supply selector switch on the fuel

injector tester to the Coil Test 0.5 amp position.

6. Connect the leads from the J 39200 Digital Multi-

Meter (DMM J 39200) to the fuel injector tester. Refer

to the illustration associated with the test description.

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

8. Connect the fuel injector tester to a fuel injector.

Important: Check the engine coolant temperature again

in order to ensure that the correct chart is being used.

9. Press the Push to Start Test button on the fuel

injector tester.

10. Observe the voltage reading on the DMM.

Important: The voltage reading may rise during the test.

11. Record the lowest voltage observed after the first

second of the test.

12. Repeat Steps 8 through 11 for each fuel injector.

Did any fuel injector have an erratic voltage reading

(large fluctuations in voltage that do not stabilise) or

voltage readings outside of the specified value?

5.5-6.6 V Go to Step 4 Go to Fuel

Injector Balance

Test in this

Section

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

Replacement in Section 6C3-3 in this Service Information

CD.

Is the replacement complete?

Go to

Fuel

Injector Balance

Test in this

Section

GEN III V8 PCM FUEL INJECTOR COIL TEST - ECT OUTSIDE 10 - 35°C

GEN3 0102

FUEL INJECTOR

TESTER

AMPERAGE SUPP LY SELECT OR SWITC H

PUS H TO STAR T TES T

LOW VEHICLE BATTERY

READY TO TEST

TES T IN PROGRESS

J 39021

B+

J 39 2 00 D M M

V-DC mA

V-AC A

OFF µ A

Coil Test

4 amp

2.5 amp

0.5 amp

Balance Test

4 amp

0.5-2.5

amp

Test Description

Caution: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and

personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel

pressure gauge. Place the towel in an approved container w hen the connection of the fuel pressure gauge

is complete.

2. The engine c oolant tem peratur e aff ects the ability of the fuel inj ector tes ter to detect a f aulty fuel injector. If the

engine coolant temperature is NOT outside 10°C and 35°C (50°F and 95°F), go to Fuel Inj Coil Test - ECT

Between 10-35°C in this Section.

3. The first second of the voltage displayed by the DMM may be inaccurate due to the initial current surge.

Therefore, record the lowest voltage displayed by the DMM after the first second of the test. The voltage

displayed by the DMM m ay increas e throughout the test as the fuel injector windings warm and the resistance

of the fuel injector windings changes. An erratic voltage reading (large fluctuations in voltage that do not

stabilise) indicates an intermittent connection within the fuel injector.

From the voltages r ec orded, identif y the highest voltage, excluding any voltages above 9.5 volts. Subtract eac h

voltage that is not above 9.5 volts from the highest voltage. Record each subtracted value (refer to the

Example). The subtracted value for any fuel injector with a subtracted value that is greater than 0.6 volt is

faulty. Replace the fuel injector. A fuel injector with a recorded voltage above 9.5 volts is also faulty. Replace

the fuel injector.

Examples

Highest Voltage

Reading Acceptable Subtracted Value

Above/Below

10°C-35°C (50°F-95°F)

7.1 V 0.6 V

Injector

Number

Voltage Subtracted

Value

Pass/Fail

1 9.8 -- F

2 6.6 0.5 P

3 6.9 0.2 P

4 5.8 1.3 F

5 7.0 0.1 P

6 7.1 0.0 P

7 9.6 -- F

8 6.0 1.1 F

GEN III V8 PCM FUEL INJECTOR COIL TEST - ECT OUTSIDE 10 - 35°C

Step Action Value(s) Yes No

1 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 2 Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

2 1. Connect the Tech 2 scan tool.

2. Check the engine coolant temperature.

Is the engine coolant temperature outside the specified

value?

10°C - 35°C

(50°F - 95°F) Go to Step 3 Go to Fuel Inj

Coil Test - ECT

Between

10-35°C in this

Section

3 1. Turn the ignition off.

Note: In order to prevent flooding of a single cylinder and

possible engine damage, relieve the fuel pressure before

performing the fuel injector coil test procedure.

2. Relieve the fuel pressure. Refer to the Fuel Pressure

Relief Procedure in Section 6C3-3 in this Service

Information CD.

3. Access the fuel injector electrical connectors as

required.

4. Connect the J 39201 fuel injector tester to B+ and

earth.

5. Set the amperage supply selector switch on the fuel

injector tester to the Coil Test 0.5 amp position.

6. Connect the leads from the J 39200 Digital Multi-

Meter (DMM J 39200) to the fuel injector tester. Refer

to the illustration associated with the test description.

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

8. Connect the fuel injector tester to a fuel injector.

Important: Check the engine coolant temperature again

in order to ensure that the correct chart is being used.

9. Press the Push to Start Test button on the fuel

injector tester.

10. Observe the voltage reading on the DMM.

Important: The voltage reading may rise during the test.

11. Record the lowest voltage observed after the first

second of the test.

12. Repeat Steps 8 through 11 for each fuel injector.

13. Identify the highest voltage reading recorded from the

highest voltage reading recorded.

14. Subtract any other voltage reading recorded from the

highest voltage reading recorded.

15. Repeat Step 14 for all the remaining fuel injectors.

Is any value that resulted from subtracting greater than

the specified value?

0.6 V Go to Step 4 Go to Fuel

Injector Balance

Test in this

Section

4 Replace any fuel injector that had any of the following:

• A subtracted value exceeding 0.6 volts.

• An initial reading above 9.5 volts.

• An erratic reading.

Refer to Fuel Injector Replacement in Section 6C3-3 in

this Service Information CD.

Is the replacement complete?

Go to Fuel

Injector Balance

Test in this

Section

GEN III V8 PCM FUEL INJECTOR CIRCUIT DIAGNOSIS

GEN3 0178

To EFI

(Engine Cont.)

Relay

To EFI

(Engine Cont.)

Relay

Fuse

F34

YE111

R 481

To Ig nitio n

Coils

2, 4, 6, 8

481

Fuse

F35

YE111

LG 482

To Ig nitio n

Coils

1, 3, 5, 7

R 481

Fuel

Injector

G 842

Fuel

Inject or 2

Driver

R 481

Fuel

Injector

BR/Y 844

Fuel

Inject or 4

Driver

R 481

Fuel

Injector

Y 846

Fuel

Inject or 6

Driver

R 481

Fuel

Injector

LG 848

Fuel

Inject or 8

Driver

LG 482

Fuel

Injector

BLU 841

Fuel

Inject or 1

Driver

LG 482

Fuel

Injector

V 843

Fuel

Inject or 3

Driver

LG 482

Fuel

Injector

GY 845

Fuel

Inject or 5

Driver

LG 482

Fuel

Injector

P/B 847

Fuel

Inject or 7

Driver

PCM

J1 = BLU E

J2 = RE D

Powertrain

Control

Module

(PCM)

Circuit Description

The PCM will enable an injector on the intake stroke of each cylinder. Individual cylinder fuel control is referred to as

Sequential Multiport Fuel Injector (SFI).

Ignition voltage is supplied directly to the fuel injectors. The PCM controls each injector by earthing the control

circuit via an internal switch called a driver. The primary function of the driver is to supply the earth for the

component being controlled.

Diagnostic Aids

• If an injector is disconnected while the engine is operating the injector driver will be disabled for the entire

ignition cycle.

• When the injector driver is disabled, an engine misfire will be apparent.

• For an intermittent condition, refer to Section 6C3-2B SYMPTOMS in this Service Information CD.

Test Description

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

2. This step determines if a malfunction is present. For any test that requires probing the PCM or a component

harness connector, use the Connector Test Adapter Kit J 35616-A. Using this kit prevents damage to the

harness connector terminals.

5. There are two ways to isolate a malfunctioning injector circuit.

6. Check injector connections before replacing the injector. A faulty connection causes an inoperative injector.

9. Check for an ignition feed circuit that is shorted to earth.

10. Disconnecting the PCM allows using the DMM J39200 to check continuity of the circuits. This will aid in

locating an open or shorted circuit.

GEN III V8 PCM FUEL INJECTOR CIRCUIT DIAGNOSIS

Step Action Value(s) Yes No

1 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 2 Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

2 Important: This table assumes that there are no Ignition

Coil/Module circuit malfunctions or mechanical, and

DTCs P0351, P0352, P0353, P0354, P0355, P0356,

P0357, P0358 are not set.

1. Install the Tech 2 scan tool.

2. Start and idle the engine.

3. Monitor all the Ignition Coils on the Engine Data List

(there are a total of 8) using a scan tool.

Are any of the Ignition Coil indicating FAULT?

Go to Step 3 Refer to

Diagnostic Aids

3 Are the injector fuses OK? Go to Step 4 Go to Step 7

4 1. Turn OFF the ignition.

2. Disconnect the injector(s) harness that the Ignition

Coil FAULT was indicating.

3. Turn ON the ignition leaving the engine OFF.

4. Using a test lamp J 34142-B connected to earth,

probe the injector harness ignition feed circuit.

Does the test lamp illuminate?

Go to Step 5 Go to Step 9

5 1. Turn OFF the ignition.

2. Connect the injector test lamp (J 34730-2C) to isolate

the injector harness.

3. Start the engine and idle.

Does the test lamp flash?

Go to Step 6 Go to Step 10

6 1. Inspect the injector harness terminals for correct

terminal tension.

2. Replace terminal as necessary.

Does the terminal need replacing?

System OK Go to Step 14

7 1. Turn OFF the ignition.

2. Disconnect the injector harness connectors related to

the fuse that was open.

3. Using a test lamp J 34142-B connected to B+, probe

the injector harness ignition feed circuit.

Does the test lamp illuminate?

Go to Step 12 Go to Step 8

8 Measure the resistance of each injector that is powered

by the fuse that is open using a DMM J 39200.

Does any injector measure less than the specified value?

11.4Ω Go to Step 14 Go to Step 13

9 Repair the injector ignition feed circuit to isolated injector.

Is the action complete? System OK

10 1. Turn OFF the ignition.

2. Disconnect the BLUE PCM connector.

3. Check the injector driver circuit for an open or short to

earth.

Is the injector driver circuit open or shorted to earth?

Go to Step 11 Go to Step 15

11 Repair injector driver circuit for an open or short to earth.

Is the action complete? System OK

12 Repair the earthed ignition feed circuit to the injectors.

Is the action complete? System OK

13 Repair intermittent short to earth in the injector ignition

feed circuit.

Is the action complete?

System OK

14 Replace the faulty injector(s) that was isolated. Refer to

Fuel Injector Replacement.

Is the action complete?

System OK

15 1. Replace PCM.

2. Refer to Section 6C3-3 in this Service Information CD

for PCM Reprogramming and PCM/PIM Security Link

Procedure.

Is action complete?

System OK

16 Inspect the appropriate injector circuit for the following:

• Poor connections at the injector and the PCM

terminal

• Intermittent short to earth

• Intermittent opens

If a problem is found, repair the circuit as necessary.

Did you find and correct the condition?

System OK Intermittent

condition. Go to

Section 6C3-2B

Symptoms in this

Service

Information CD

GEN III V8 PCM ELECTRONIC IGNITION SYSTEM DIAGNOSIS

GEN 3 0160

Powertrain

Control

Module

(PCM)

Tachometer

Input

Instrument

Cluster

BR/R 121

Tach

Input 30 YE112

ABS/ETC

Module

BR 121

10 J2

CKP Sensor

Si gnal I nput Reference

Low

12 21 02 J1

12VIgnition

Feed

61 73 39 J2

12V

Ignition

Feed

CMP Se n s or

Si gnal I nput

Reference

Low

Hall Sensor

Trigger Circuit

Ampl ifier an d

V oltage R eg.

Electronics

Camshaft

Position

(CMP)

Sensor

47g

4700pf

Power

Gnd

BAC

R/W 632 W/B 631

BR 633

ABC

BLU 643 LBLU/W 646

LBLU/B 647

Magnetic

Pickup Crankshaft

Position

(CKP)

Sensor

Pulse Shaper

And Voltage

Reg. Electronics

Output Power

Gnd

Tachometer

Output

PCM

J1 = BLU E

J2 = RED

Circuit Description

A Crankshaft Position (CKP) sensor determines the engine crankshaft position. The sensor is mounted and

protrudes into the r ear of the engine bloc k. T he s ens or is near a slotted wheel on the cranks haf t. T he r otation of the

slotted wheel causes a magnetic flux change in the sensor. This produces a voltage signal from the electronic

Ignition Control Module (ICM). The signal creates the reference pulses needed by the Powertrain Control Module

(PCM). These signals trigger the correct ignition coil to fire, at the correct time.

The ignition system on this engine uses an individual ignition coil/module for each cylinder. The PCM controls the

ignition system operation. There are eight Ignition Control ( IC) circuits, one per c ylinder , that connect the PCM and

the ignition coil/modules. Each ignition coil/module has a power feed, a chassis earth circuit, and a reference low

circuit. T he PCM causes a spar k to occur by earthing the IC circuit, which s ignals the ignition module to trigger the

ignition coil and fire the spark plug. The PCM controls the sequencing and timing.

Diagnostic Aids

The following may cause an intermittent:

• Check for poor connections. Check for adequate terminal tension.

• Corrosion

• Incorrectly routed harness

• Rubbed through wire insulation

• Broken wire inside the insulation

• Using Freeze Fram e/Failure Rec ords data m ay aid in locating an interm ittent condition. If you cannot duplicate

the DT C, the inf orm ation included in the F reeze Frame /Failur e Records data can help deter mine the dist ance

traveled since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition

cycles the diagnostic reported a pass and/or fail. Operate vehicle within the same freeze frame condition

(RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed.

• For an intermittent condition, refer to Section 6C3-2B SYMPTOMS in this Service Information CD.

Test Description

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

3. Monitoring the Engine Data List Ignition Coil determines if a fault is present.

4. A good indic ation that the fuse is open is all the Ignition Coils are indic ating FAULT on one side of the engine.

Inspect the ignition feed circuit for a earthed circuit.

8. If the fuse is open and no problem can be found with the ignition coil/module circuits, inspect the injector

circuits for being earthed. Fuse F34 and fuse F35 feeds the ignition coil/module circuits and injector circuits.

GEN III V8 PCM ELECTRONIC IGNITION SYSTEM DIAGNOSIS

Step Action Value(s) Yes No

1 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 2 Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

2 Are DTCs P0335, P0336, P0351-P0358 set? Go to Applicable

DTC table Go to Step 3

3 Important: This table assumes that there are no Ignition

Coil/Module circuit malfunctions or mechanical, and

DTCs P0351, P0352, P0353, P0354, P0355, P0356,

P0357, P0358 are not set.

1. Install the scan tool.

2. Start and idle the engine.

3. Monitor all the Ignition Coils on the Engine Data List

(There are a total of 8). using a scan tool.

Are any of the Ignition Coils indicating FAULT?

Go to Step 4 Intermittent

Condition. Go to

Diagnostic Aids

4 1. Turn ON the ignition leaving the engine OFF

2. Using a test light connected to earth, probe both sides

of both Ignition/Injector fuses.

Does test light illuminate at both terminals of both fuses?

Go to Step 5 Go to Step 8

5 1. Turn OFF the ignition.

2. Disconnect the ignition coil 8-way harness connector

for the Ignition Coil module that is indicating FAULT.

3. Turn ON the ignition leaving the engine OFF.

4. Probe the ignition feed circuit at the 8-way harness

connector using a test lamp J 34142-B connected

battery to earth.

Does the test lamp illuminate?

Go to Step 6 Go to Step 10

6 Using a test lamp J 34142-B probe the ignition feed

circuit at the 8-way connector to the ignition coil/module

earth circuit.

Does the test lamp illuminate?

Go to Step 7 Go to Step 13

7 Using a test lamp J 34142-B probe the ignition feed

circuit at the ignition coil/module electrical 8-way

connector to the ignition coil/module reference low circuit.

Does the test lamp illuminate?

Go to Step 21 Go to Step 17

8 1. Inspect for an open ignition coil/module fuse.

2. Locate and repair the ignition feed circuit for a earthed

circuit if the fuse is open.

3. Replace the fuse.

Did you find and correct the problem?

System OK Go to Step 9

9 Repair open in the ignition feed circuit between the EFI

relay and the splice.

Is the action complete?

System OK

10 1. Disconnect the ignition 8-way coil/module harness

connector for the Ignition Coil that is indicating

FAULT.

2. Probe the ignition feed circuit at the ignition

coil/module main 8-way connector using a test lamp

J 34142-B connected to battery earth.

Does the test lamp illuminate?

Go to Step 11 Go to Step 12

11 Repair the open circuit between the splice and the

ignition coil/module connector.

Is the action complete?

System OK

12 Repair the open ignition feed circuit between the fuse

block (open fuse) and splice.

Is the action complete?

System OK

13 1. Disconnect the ignition 8-way coil/module harness

connector for the Ignition Coil that is indicating

FAULT.

2. Using a test light J3414-B probe the ignition feed

circuit at the ignition coil/module 8-way connector to

the ignition coil/module earth circuit.

Does the test lamp illuminate?

Go to Step 14 Go to Step 16

14 1. Check for a poor connection at the ignition

coil/module electrical 8-way connector.

2. Repair poor connections as necessary.

Did you find and correct the problem?

System OK Go to Step 15

Step Action Value(s) Yes No

15 Repair the open earth circuit between the main 8-way

connector and the ignition coil/module connector.

Is the action complete?

System OK

16 Repair the open earth circuit between the earth and the

main 8-way connector.

Is the action complete?

System OK

17 1. Disconnect the ignition 8-way coil/module harness

connector for the Ignition Coil that is indicating

FAULT.

2. Probe the ignition feed circuit at the ignition

coil/module 8-way connector using a test lamp

J 34142-B connected to battery earth.

Does the test lamp illuminate?

Go to Step 18 Go to Step 20

18 1. Check for a poor connection at the 8-way ignition

coil/module electrical connector.

2. If a poor connection is found, repair as necessary.

Did you find and correct a problem?

System OK Go to Step 19

19 Repair the open reference low circuit between the main

8-way connector and the ignition coil/module connector.

Is the action complete?

System OK

20 Repair the open reference low circuit between the PCM

and the splice.

Is the action complete?

System OK

21 1. Check for poor connections at the ignition coil/

module 8-way harness connector, ignition coil/

module harness connector, and splices.

2. Repair poor connections as necessary.

Did you find and correct the problem?

System OK Go to Step 22

22 Replace ignition coil/module.

Is the action complete? System OK

GEN III V8 PCM AUTOMATIC TRANSMISSION ECONOMY/POWER SWITCH

GEN3 0177

Fuse

F13

P/BLU 44

Power

Economy

Lamp

SDI

Instrument Panel Cluster 12

ABS/ETC

Module

ECC

Module

G/W 1220

Serial Data

(UART)

Serial Data

(UART)

Body

Control

Module

(BCM)

NOTE

BCM Terminal

9 YB175 High Series

3 YB164 Low Series

NOTE

YB175 High Serie s

YB164 Low Seri es

R/B 1221

Serial Data

(UART)

Serial Data

(Class II)

Powertrain

Interface

Module

(PIM)

Y 1049 2DLC

Serial Data

(Class II) Powertrain

Control

Module

(PCM)

Economy/Power

Swit ch I nput

Signal

J171

YE112

YB30

YE112

YB30

Engine Earth

151

B/G 774

BLU

Economy/Power

Switch

PCM

J1 = BLU E

J2 = RE D

DLC

Circuit Description:

The driver can select three transmission shift modes, ECONOMY or POWER or CRUISE using a dash or centre

console mounted switch for Economy/Power, and a cruise switch located on the steering column. The

Economy/Power switch is wired to the PCM and allows the driver to choose the Economy mode, for the best fuel

econom y in all driving c onditions through the inc reased us e of T CC. Power m ode provides later upshif ts and higher

line pressure in the transmission.

The PCM s ends out a buf fered voltage s ignal, about 12 volts, and monitor s the s tatus of this c irc uit. Onc e the dr iver

selects Power, the switch momentarily pulls low the buffered 12 volts, and the PCM will interpret this as a Power

selection and adjust the transmission shift pattern accordingly, and instructs the instrument panel to turn ON the

Power lamp. If while driving, the driver selects the Economy position, again the buffered 12 volts is momentarily

pulled low, and the PCM will adjust the tr ansmiss ion shift pattern and instruc t the instrum ent panel to turn OFF the

Power lamp.

When the key is turned ON, the PCM shift mode is set to the last mode that was previously selected

(Economy/Pow er). The cruise control is set to OFF at every key ON cycle.

In cruise mode operation, when the driver activates the cruise control, the Power lamp and power mode will turn

OFF (if vehicle was in power mode) and the transmission shift pattern will switch to cruise shift pattern. When in

cruise mode the PCM will modify the transmission calibration so that earlier downshift and later upshift points are

provided.

For replacem ent of the Econom y/Power switch, refer to Section 7C4 AUTOMATIC TRANSMISSION - On Vehicle

Servicing of the VT Series II Service Information.

Test Description:

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

2. This step tests for proper operation of the transmission POWER switch, the wiring and the PCM.

3. This step tests for proper POWER lamp illumination.

5. This step determines if the switch is faulty.

8. Some interior parts must be removed to disconnect and replace the transmission switch, Refer to

Section 1A3 - INSTRUMENT PANEL AND CONSOLE, of the VT Series I Service Information.

GEN III V8 PCM AUTOMATIC TRANSMISSION ECONOMY/POWER SWITCH

STEP ACTION VALUE YES NO

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

performed? Go to Step 2 Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

2 1. With the engine OFF, turn the ignition switch to the

RUN position.

2. Connect the Tech 2 scan tool.

3. Place the transmission power switch in the Power

position and observe the scan tool display.

Does the scan tool display POWER?

Go to Step 3 Go to Step 10

3 Is the power lamp ON, when the scan tool displays

POWER? Go to Step 4 Go to Step 5

4 Place the transmission power switch in the Economy

position and observe the scan tool display.

Does the scan tool display ECONOMY?

Go to Step 6 Go to Step 7

5 Check for an open in the power lamp bulb, or the bulb

power feed circuit.

Did you find and correct the open condition?

Verify the Repair Go to Step 17

6 Does the power lamp go off, when the scan tool

displays ECONOMY? No Trouble

Found.

Economy/ Power

switch OK.

Refer to Section

6C3-2B

Symp toms -

Intermittents in

this Service

Information CD.

Go to Step 8

7 Disconnect the power switch from the wiring harness

connector.

Does the scan tool display ECONOMY?

Go to Step 12 Go to Step 9

8 Check for a short to earth on the power lamp circuit in

the instrument panel cluster.

Did you find and correct the short to earth condition?

Verify the Repair

9 Check for a short to earth in circuit 774.

Did you find and correct the short to earth condition? Verify the Repair Go to Step 16

10 1. Disconnect the power switch from the wiring

harness connector.

2. Using a fused jumper wire, momentarily connect the

two terminals of the economy/power switch wiring

harness connector together.

Does the scan tool display POWER?

Go to Step 12 Go to Step 11

11 Using a fused jumper wire, momentarily connect the

economy/power switch signal circuit to earth.

Does the scan tool display Power?

Go to Step 15 Go to Step 14

12 Check the Power switch connector for a shorted or

loose terminal connection.

Did you find and correct the faulty condition?

Verify the Repair Go to Step 13

13 Replace the faulty economy/power switch.

Refer to Section 7C4 Automatic Transmission -

on Vehicle Service of the VT Series I Service

Information.

Is the action complete?

Verify the Repair

14 Check for an open economy/power switch signal circuit

or a faulty PCM connection.

Did you find and correct the open circuit?

Verify the Repair Go to Step 16

15 Check for an open in the earth circuit.

Did you find and correct the open circuit? Verify the Repair

16 1. Replace PCM.

2. Refer to Section 6C3-3 Service Operations in this

Service Information CD, for PCM Reprogramming

and PCM/PIM Security Link Procedure.

Is action complete?

Verify the Repair

17 Replace Instrument Panel (IP) cluster.

Is action complete? Verify Repair

GEN III V8 PCMINSTRUMENT PANEL GEAR INDICATOR CHECK

GEN3 0179

Fuse

F13

Instrument Panel

Gear Indicator Lamps

PRND 3 2 1

SDI

P/BLU

1220G/W

1220

G/W

ABS/ETC

Module

ECC

Module

9Body

Control

Module

(BCM)

Serial Data

(UART)

Serial Data

(UART)

NOTE

BCM Terminal

9 YB175 High Series

3 YB164 Low Series

NOTE

YB175 High Serie s

YB164 Low Seri es 1221

R/B

Serial Data

(UART)

Serial Data

(Class II)

9DLC

Powertrain

Interface

Module

(PIM)

1049Y2DLC

58 J1

Serial Data

(Class II)

771

BLU/W

PRNDL

772

72 J1

PRNDL

773

62 J2

PRNDL

776

34 J1

PRNDL

PPowertrain

Control

Module

(PCM)

Engine Earth

750B/R

ADBC

SW A SW B SW C SW P

PRNDL

Switch

Circuit Description

The transmission PRNDL switch is a multi-signal switch assembly that signals the PCM the gear selected. The

PCM will then determine the signal f rom the PRNDL s witch and send a com m and via serial data com munic ation to

the instrument panel cluster to illuminate the correct gear indicator lamp.

The PRNDL switch uses four discrete circuits to pull four PCM voltages low in various combinations to indicate each

gear r ange. The voltage level of the c ircuits is r epresented as Clos ed = earthed, and Open = open circ uit. The four

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

The scan tool will display all four circuits (P, A, B, C) and the appropriate Open and Closed to represent the gear

selected. If the gear selected does not match the Open/Closed chart as displayed below on the Scan Tool, or the

instrument panel cluster 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.

Diagnostic Aids

• Monitor the Scan Tool while moving related connectors and wiring harness. If a failure is indicated, the scan

data will change states from either Closed to Open or Open to Closed. Moving the gear selector slowly through

each gear while monitoring the scan tool may also help isolate the problem.

• Any circuitry that is suspected as causing the intermittent complaint, should be thoroughly checked for backed

out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring

connection or physical damage to the wiring harness.

• When a fault has occurred, the PCM defaults to 3rd gear until a correct combination is received by the PCM.

Therefore, some selected gear positions may not be possible until the fault is repaired.

Description

Numbers below refer to step numbers on the diagnostic chart.

4. Any c ircuitry that is suspected as caus ing the interm ittent com plaint, should be thoroughly checked f or back ed

out term inals , im pr oper m ating, br ok en lock s, im pr operly form ed or dam aged term inals , poor term inal to wiring

connection or physical damage to the wiring harness.

5. An invalid circ uit will cause the PRNDL display to go out. Jum pering each c ircuit to earth sim ulates the PRNDL

switch operation and checks the circuitry and PCM. While the PRNDL switch is disconnected and the circuits

are not jum pered to earth, the s can tool should indicate a Open value. A value that is indicated as Closed with

no jumper to earth indicates a earthed circuit or faulty PCM.

TRANSMISSION RANGE / PRNDL SWITCH VALID INPUT COMBINATIONS

GEAR

POSITION

SELECTED

SCAN TOOL PRNDL DISPLAY

(P, A, B, C)

P A B C

PARK (P) LOW

(0) LOW

(0) HIGH

(12) HIGH

(12)

REVERSE (R) HIGH

(12) LOW

(0) LOW

(0) HIGH

(12)

NEUTRAL (N) LOW

(0) HIGH

(12) LOW

(0) HIGH

(12)

DRIVE 4 (D) HIGH

(12) HIGH

(12) LOW

(0) LOW

(0)

DRIVE (3) LOW

(0) LOW

(0)

DRIVE 2 (2) HIGH

(12) LOW

(0) HIGH

(12) LOW

(0)

DRIVE 1 (1) LOW

(0) HIGH

(12) HIGH

(12) LOW

(0)

GEN III V8 PCMINSTRUMENT PANEL GEAR INDICATOR CHECK

STEP ACTION VALUE YES NO

1 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 2. Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

2 1. Ignition ON, engine OFF.

2. Install a scan tool.

3. Move the gear selector through all its ranges.

Does the scan tool indicate an INVALID in any of the

ranges?

Go to Step 3 Go to Step 10

3 Compare the scan tool values with the Transmission

Range Switch Valid Input Combinations table.

Are all the circuit indicated as Open?

Go to Step 4 Go to Step 5

4 Check the transmission PRNDL switch earth

circuit for an open or poor connection and repair if

necessary.

Was a problem found?

Verify Repair Go to Step 5

5 1. Moving the gear selector through all its ranges and

note which circuit did not correspond with the

Transmission Range Switch Valid Input

Combination table.

2. Disconnect the PRNDL switch electrical connector.

3. Jumper the circuit with the incorrect value to earth.

Does the jumpered circuit go from a OPEN value to a

CLOSED value?

Go to Step 8 Go to Step 6

6 Check the affected circuit for an open or short to earth

and repair as necessary.

Was a problem found?

Verify Repair Go to Step 7

7 Check for a poor connection at the PCM connector

and

repair as necessary.

Was a problem found?

Verify Repair Go to Step 9

8 Replace the PRNDL switch.

Is action complete? Verify Repair

9 Replace the PCM.

Is action complete? Verify Repair

10 Does the scan tool indicate the same gear as the

instrument cluster? System OK,

refer to Diagnostic

Aids

Go to step 11

11 Remove the instrument cluster and inspect indicator

lamp for being burnt.

Was a problem found?

Verify Repair Go to Step 12

12 Replace the instrument cluster.

Is action complete? Verify Repair

GEN III V8 PCMENGINE COOLANT LEVEL SWITCH DIAGNOSIS

GEN3 0156

PCM

J1 = BLU E

J2 = RED

Powertrain

Control

Module

(PCM)

Powertrain

Control

Module

(PCM)

5V 5V

ECT

Sensor

Signal

TP Senso r

Reference

Throttle

Relaxer

Control

Module

Engine Coolant

Temperature

(ECT)

Sensor

Throttle

Position

(TP)

Sensor Coolant

Level

Switch

Engine

Earth

Sensor

Signal Sensor

Earth ECT

Sensor

Earth

Coolant

Level

Switch

Input

08 74 C1

Y410

B/R 750

G69

30 J1

GY/B 455

80 J1

B/Y 452

BLU 417

24 J2

B/Y 452

BLU 417

GY 416

416

Throttle

Relaxer

Control

Module

Circuit Description

The engine coolant level switch is loc ated in the coolant surge tank and is a f loat type sensor. T he PCM supplies a

voltage to the engine coolant level switch which is a normally open switch.

When the coolant level is within an acceptable range the switch is closed. The switch opens when the engine

coolant level drops below an predetermined amount. W hen the PCM does not detect a earth signal (switch open)

from the engine coolant level switch, the PCM will send a serial data m essage to the instrum ent cluster. which will

turn ON the Low Coolant lamp.

Diagnostic Aids

• The following may cause an intermittent:

- Poor connection: Check for adequate terminal tension.

- Corrosion

- Incorrectly routed harness

- Broken wire inside the insulation.

• For an intermittent, refer to Section 6C3-2B SYMPTOMS in this Service Information CD.

• If the Low Coolant lamp does not illuminate, and the engine coolant level switch diagnosis table does not find a

problem with the switch, either the Low Coolant bulb is open or there is a problem with the instrument cluster.

Test Description

Numbers below refer to step numbers on the diagnostic chart.

4. This step checks the engine coolant level switch signal between the PCM and the Switch.

6. This step checks the engine coolant level switch earth circuit between the PCM and the Switch.

9. This step checks the engine coolant level switch signal for a short to earth.

10. This step checks for an open in the engine coolant level switch signal circuit between the PCM and the switch.

GEN III V8 PCM ENGINE COOLANT LEVEL SWITCH DIAGNOSIS

STEP ACTION VALUE YES NO

1 1. Check for poor float movement in the Coolant Surge

Tank.

2. If you find poor float movement, replace the Coolant

Surge Tank. Refer to Section 6B3 Coolant Surge

Tank Replacement in VT Series II Commodore,

Calais Service Information.

Was a problem found?

System OK Go to Step 2

2 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 3. Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

3 Important: This table assumes the coolant level is at the

correct level or the coolant level is low and the Low

Coolant Lamp did not illuminate. If the coolant level is low

refer to Section 6B3 Engine Cooling in VT Series II

Commodore, Calais Service Information, for further

diagnosis of the cooling system.

Turn ON the ignition leaving the engine OFF.

Do the instrument panel warning indicator lamps

illuminate?

Go to Step 4 Go to Section

12C Instrument

Panel Cluster

diagnosis.

4 Is the customer concerned that the Low Coolant lamp is

on at all times? Go to Step 5 Go to Step 8

5 1. Disconnect the Engine Coolant Level Switch.

2. Measure the voltage of the Engine Coolant Level

Switch signal circuit using a DMM connected to

battery earth.

Does the DMM display near the specified value?

B+ Go to Step 6 Go to Step 11

6 1. Jumper the engine coolant level switch signal circuit

to earth using a fused jumper wire.

2. Monitor the Low Coolant level state using the scan

tool.

Does the scan tool display Low Coolant Level as OFF?

Go to Step 7 Go to Step 18

7 Jumper the engine coolant level switch signal circuit to

the Engine Coolant Level Switch earth circuit using a

fused jumper wire.

Does the scan tool display Low Coolant Level as OFF?

Go to Step 12 Go to Step 16

8 1. Disconnect the Engine Coolant Level Switch.

2. Measure the voltage of the Engine Coolant Level

Switch signal circuit using a DMM connected to earth.

Does the DMM display near the specified value?

B+ Go to Step 9 Go to Step 10

9 1. Jumper the Engine Coolant Level Switch signal circuit

to earth using a fused jumper wire.

2. Monitor the Low Coolant level state using the scan

tool.

Does the scan tool display Low Coolant Level as YES?

Go to Step 18 Go to Step 13

10 1. Turn OFF the ignition.

2. Disconnect the BLUE PCM connector.

3. Check continuity of the Engine Coolant Level Switch

signal circuit using a DMM connected to earth.

Does the DMM display continuity?

Go to Step 14 Go to Step 18

11 1. Turn OFF the ignition.

2. Disconnect the BLUE PCM connector.

3. Check continuity of the Engine Coolant Level Switch

signal circuit using a DMM connected to earth.

Does the DMM display continuity?

Go to Step 17 Go to Step 15

12 1. Check for poor connection at the Engine Coolant

Level Switch harness connector.

2. If you find a poor connection, repair as necessary.

Was a problem found?

System OK Go to Step 13

GEN III V8 PCM - ENGINE COOLANT LEVEL SWITCH DIAGNOSIS (CONTINUED)

STEP ACTION VALUE YES NO

13 Replace the Engine Coolant Level Switch. Refer to

Section 6B3, 2.11 Engine Coolant Level Switch in VT

Series II Commodore, Calais Service Information.

Is action complete?

System OK

14 Check for short to earth in the Engine Coolant Level

Switch signal circuit.

Was a problem found?

System OK Go to Step 18

15 Repair the engine coolant level switch circuit for an open.

Is action complete? System OK

16 Repair the engine coolant level switch earth circuit for an

open.

Is action complete?

System OK

17 1. Check for poor connection at PCM connector.

2. If you find a poor connection, repair as necessary.

Was a problem found?

System OK Go to Step 18

18 1. Replace PCM.

2. Refer to Section 6C3-3 in VT Series II Commodore,

Calais Service Information, for PCM reprogramming

and PCM/PIM Security Link Procedure.

Is action complete?

System OK

GEN III V8 PCM

MANUAL TRANSMISSION REVERSE LOCKOUT SOLENOID DIAGNOSIS

CIRCUIT DESCRIPTION

GEN3 0180

Y838

44 42 02 J2 79 J1 47 48 J2

Powertrain

Control

Module (PCM)

TCC SOL

Valve

Control

TC C PWM SOL

Valve

Control

3-2 SS

V a lve Assembly

Control

2-3 SS

Valve

Control

1-2 SS

Valve

Control

Reverse

Lockout

Control

TU S B A

GY/R 422

BR 418

G/W 897

Y/B 1223

B422 T418 W897 Y1223 LG 1222

R 339

Torque

Converter

Clutch

Solenoid

(TCC SOL)

Valve

Torque

Converter

Clutch Pulse

Width

Modulation

Solenoid

(TCC PWM SOL)

Valve

3-2 Shift

Solenoid

(3-2 SS)

Valve

Assembly

2-3 Shift

Solenoid

(2-3 SS)

Valve

1-2 Shift

Solenoid

(1-2 SS)

Valve

Automatic

Transmission

P/BLU 339

YE110

P/BLU

339

Manual Transmission

Reverse Lockout Solenoid

To EFI

(Engine Cont.)

Relay Fuse

F32

1222

PCM

J1 = BLU E

J2 = RE D

The EFI (Engine Cont.) relay supplies an ignition voltage through fuse F32 to the reverse lockout solenoid. The

PCM controls the solenoid by earthing the control circuit via an internal switch called a driver. The driver supplies

the earth for the component being contr olled. Each driver has a fault line which the PCM m onitors. W hen the PCM

commands a component ON, the voltage of the control circuit should be low (near 0 volts). When the PCM

commands the control circuit to a component OFF, the voltage potential of the circuit should be high (near battery

voltage).

When the reverse lockout solenoid is energised, the operator can shift the transmission into reverse. The PCM

enables the revers e lockout solenoid whenever vehic le speed is below 3 km /h. W hen the vehicle speed is above 5

km/h, the PCM de-energises the solenoid, which prevents the operator from shifting the transmission into reverse.

Diagnostic Aids

• Monitor a Tech 2 scan tool while moving related connectors and wiring harness. If a failure is indicated, the

scan data will change states from either Low to High, or from High to Low. Moving the gear selector slowly

through each gear while monitoring the scan tool may also help isolate the problem.

• Any c ircuitry that is suspected as caus ing the interm ittent com plaint, should be thoroughly checked f or back ed

out term inals , im pr oper m ating, br ok en lock s, im pr operly form ed or dam aged term inals , poor term inal to wiring

connection or physical damage to the wiring harness.

• If the Revers e Lockout Solenoid electr ically is working pr operly, but the transm ission will not shift into reverse,

the problem m ay be inside the transmis sion. Refer to Manual T ransm iss ion for f urther diagnosis of the reverse

lockout operation.

Test Description

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

2. This step checks to see if the transmission can be shifted into reverse while the speedometer is indicating

vehicle speed.

3. This step indicates if the Tech 2 scan tool will indicate the ON and OFF state of the reverse lock-out solenoid.

GEN III V8 PCMMANUAL TRANSMISSION REVERSE LOCKOUT SOLENOID DIAGNOSIS

Step Action Value(s) Yes No

1 Did you perform the Powertrain On-Board Diagnostic

(OBD) System Check? Go to Step 2 Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

1. Raise drive wheels off ground and support vehicle.

2. Install Tech 2 scan tool and select Engine Data.

3. Ignition ON, engine running.

4. Shift the transmission into first gear and slowly

release the clutch to allow the drive wheels to rotate

to 5 - 15 km/h.

5. While speedometer is reading 5 - 15 km/h, depress

clutch and try to shift into reverse gear.

Were you unable to shift into reverse gear?

Go to Step 3 Go to Step 4

3 While the speedometer is reading 5 - 15 km/h, the Tech

2 scan tool should indicate Reverse Lock-out as OFF,

and when the speedometer is reduced to 3 km/h or lower

the Tech 2 scan tool should indicate ON.

Did the Tech 2 reading show as indicated?

Go to Step 4 Go to Step 6

4 1. Turn OFF the ignition.

2. Disconnect the RED PCM connector.

3. Turn ON the ignition.

4. Measure the current from the solenoid control circuit

in the PCM harness connector to earth for 2 minutes

using a DMM J 39200 on 10 amp scale.

Does the current-draw measure less than the value

shown (but not 0)?

1.5A No trouble found.

Go to Diagnostic

Aids

Go to Step 5

5 1. Turn OFF the ignition.

2. Disconnect the solenoid.

3. Measure the resistance from the solenoid control

circuit in the PCM harness connector to earth using a

DMM J 39200.

Does the DMM display infinite resistance?

Go to Step 13 Go to Step 11

6 1. Turn OFF the ignition.

2. Disconnect the reverse lock-out solenoid.

3. Connect a test lamp J 34142-B between the terminals

in the solenoid harness connector.

4. Ignition ON engine running.

5. Rotate drive wheels to 5 - 15 km/h and then below 3

km/h.

Does the test lamp turn ON and OFF?

Go to Step 9 Go to Step 7

7 Probe the ignition feed circuit in the solenoid harness

connector with the test lamp connected to earth.

Does the test lamp illuminate?

Go to Step 8 Go to Step 12

8 1. Turn OFF the ignition.

2. Reconnect the solenoid.

3. Disconnect the RED PCM connector.

4. Turn ON the ignition.

5. Probe the solenoid control circuit in the PCM harness

connector with a fused jumper wire connector to

earth.

Does the solenoid operate?

Go to Step 10 Go to Step 11

9 Check the connections at the solenoid.

Did you find and correct the condition? Verify Repair Go to Step 13

10 Check the connection at the PCM.

Was a problem found? Verify Repair Go to Step 14

11 Repair open or short to earth or short to voltage in the

solenoid control circuit.

Is the repair complete?

Verify Repair

12 Repair the faulty solenoid ignition feed circuit.

Is the repair complete? Verify Repair

Step Action Value(s) Yes No

13 Replace the solenoid.

Is action complete? Verify Repair

14 1. Replace PCM.

2. Refer to Section 6C3-3 in this Service Information CD

for PCM reprogramming and PCM/PIM Security Link

Procedure.

Is action complete?

Verify Repair

GEN III V8 PCM - AUTOMATIC TRANSMISSION WIRING HARNESS CHECK

Step Action Value(s) Yes No

Important: This procedure cannot be used for checking the automatic transmission fluid pressure (TFP) manual valve

position switch circuit, or the automatic transmission fluid temperature (TFT) sensor circuit. Refer to the TFP Manual Valve

Position Switch Resistance Check in this Section, for those circuits.

1 1. Install the J 39775 jumper harness on the

transmission side of the 20-way connector.

2. Using a J 39200 digital multimeter (DMM) and a

J 35616 connector test adapter kit, measure the

resistance between terminals A and E (1-2 shift

solenoid (A) valve).

Is the resistance within the specified range?

19-24 ohm

@ 20°C

(68 °F)

24-31 ohm

@ 100°C

(212°F)

Go to Step 3

Go to Step 2

2 1. Disconnect the 1-2 shift solenoid (SS) valve from the

automatic transmission wiring harness assembly.

2. Using the J 39200 DMM, measure the resistance of

the 1-2 SS valve.

Is the resistance within the specified range?

19-24 ohm

@ 20°C

(68 °F)

24-31 ohm

@ 100 °C

(212°F)

Go to Step 14

Go to Step 16

3 Measure the resistance between terminals B and E (2-3

shift solenoid (B) valve).

Is the resistance within the specified range?

19-24 ohm

@ 20°C

(68°F)

24-31 ohm

@ 100°C

(212°F)

Go to Step 5

Go to Step 4

4 1. Disconnect the 2-3 shift solenoid (SS) valve from the

A/T wiring harness assembly.

2. Using the J 39200 DMM, measure the resistance of

the 2-3 SS valve.

Is the resistance within the specified range?

19-24 ohm

@ 20°C

(68°F)

24-31 ohm

@ 100°C

(212°F)

Go to Step 14

Go to Step 16

5 Measure the resistance between terminals T and E

(torque converter clutch solenoid valve).

Is the resistance within the specified range?

21-26 ohm

@ 20°C

(68°F)

26-33 ohm

@ 100°C

(212°F)

Go to Step 6

Go to Step 14

6 Measure the resistance between terminals U and E

(torque converter clutch pulse width modulation solenoid

valve).

Is the resistance within the specified range?

10-11 ohm

@ 20°C

(68°F)

13-15 ohm

@ 100°C

(212°F)

Go to Step 8

Go to Step 7

7 1. Disconnect the TCC PWM solenoid valve from the A/T

wiring harness assembly.

2. Using the J 39200 DMM, measure the resistance of

the TCC PWM solenoid valve.

Is the resistance within the specified range?

10-11 ohm

@ 20°C

(68°F)

13-15 ohm

@ 100°C

(212°F)

Go to Step 14

Go to Step 16

8 Measure the resistance between terminals S and E (3-2

shift solenoid valve assembly).

Is the resistance within the specified range?

20-24 ohm

@ 20°C

(68°F)

29-32 ohm

@ 100°C

(212°F)

Go to Step 10

Go to Step 9

9 1. Disconnect the 3-2 shift solenoid (SS) valve assembly

from the A/T wiring harness assembly.

2. Using the J 39200 DMM, measure the resistance of

the 3-2 SS valve assembly.

Is the resistance within the specified range?

20-24 ohm

@ 20°C

(68°F)

29-32 ohm

@ 100°C

(212°F)

Go to Step 14

Go to Step 16

Step Action Value(s) Yes No

10 Measure the resistance between terminals C and D

(pressure control solenoid valve).

Is the resistance within the specified range?

3-5 ohm @

20°C (68°F)

4-7 ohm @

100°C

(212°F)

Go to Step 12

Go to Step 11

11 1. Disconnect the pressure control (PC) solenoid valve

from the A/T wiring harness assembly.

2. Using the J 39200 DMM, measure the resistance of

the PC solenoid valve.

Is the resistance within the specified range?

3-5 ohm @

20°C (68°F)

4-7 ohm @

100°C

(212°F)

Go to Step 14

Go to Step 16

12 Using the J 39200 DMM and the J 35616 connector test

adapter kit, measure the resistance from terminals A, B,

C, D, E, S, T and U of the A/T wiring harness assembly at

the transmission 20-way connector to the transmission

case.

Is the resistance more than the specified value?

250 K ohm

System OK

Go to Step 13

13 1. Disconnect the A/T wiring harness assembly from all

the components.

2. Measure the resistance from all the component

terminals to the transmission case.

Is the resistance more than the specified value?

250 K ohm

Go to Step 14

Go to Step 16

14 Inspect for high resistance or a short.

• Inspect the A/T wiring harness assembly at the

transmission 20-way connector, and the component

connectors for the following conditions:

- Insufficient electrical connections

- Backed out, or damaged terminals

- A damaged terminal

- Reduced terminal tension

- A chafed wire that could short to bare metal or

other wiring

- A broken wire inside the insulation

- Moisture intrusion

- Corrosion

• If diagnosing for a possible intermittent condition,

move or massage the A/T wiring harness assembly

while observing the test equipment for a change.

Did you find high resistance or a short?

Go to Step 1

Go to Step 15

15 Replace the A/T wiring harness assembly.

Is the replacement complete?

Go to Step 1

16 Replace the faulty component.

Is the replacement complete?

Go to Step 1

GEN III V8 PCM

AUTOMATIC TRANSMISSION FLUID PRESSURE (TFP) VALVE POSITION SWITCH RESISTANCE CHECK

Step Action Value(s) Yes No

Important:

Whenever the transmission 20-way connector is disconnected and the engine is running, multiple DTCs will set. Be sure to

clear these codes when you are finished with this procedure.

This procedure tests the automatic Transmission Fluid Pressure (TFP) manual valve position switch circuits and the

automatic Transmission Fluid Temperature (TFT) sensor circuit. Do not use this procedure to test other automatic

transmission circuits. Refer to the Automatic Transmission Wi ring Harness Check in this Section.

1 1. Install the J 39775 jumper harness on the

transmission side of the 20-way connector.

2. Using the J 39200 digital multimeter (DMM) and the

J 35616 connector test adapter kit, measure the

resistance from terminal N to the transmission case.

Is the resistance greater than the specified value?

50 K ohm Go to Step 3 Go to Step 2

2 1. Disconnect the TFP manual valve position switch from

the A/T wiring harness assembly.

2. Measure the resistance from terminal C of the TFP

manual valve position switch to the switch housing.

Is the resistance greater than the specified value?

50 K ohm

Go to Step 16 Go to Step 19

3 Measure the resistance from terminal R to the

transmission case.

Is the resistance less than the specified value?

200 ohm

Go to Step 5 Go to Step 4

4 1. Disconnect the TFP manual valve position switch from

the A/T wiring harness assembly.

2. Measure the resistance from terminal E of the TFP

manual valve position switch to the switch housing.

Is the resistance less than the specified value?

200 ohm

Go to Step 16 Go to Step 19

5 Measure the resistance from terminal P to the

transmission case.

Is the resistance greater than the specified value?

50 K ohm

Go to Step 7 Go to Step 6

6 1. Disconnect the TFP manual valve position switch from

the A/T wiring harness assembly.

2. Measure the resistance from terminal D of the TFP

manual valve position switch to the switch housing.

Is the resistance greater than the specified value?

50 K ohm

Go to Step 16 Go to Step 19

7 1. Start the engine.

2. Allow the engine to idle.

3. Set the parking brake.

4. Place the gear selector in R (reverse).

5. Measure the resistance from terminal N to the

transmission case.

Is the resistance less than the specified value?

200 ohm

Go to Step 8 Go to Step 16

8 1. Place the gear selector in 1 (first).

2. Measure the resistance from terminal N to the

transmission case.

Is the resistance less than the specified value?

200 ohm

Go to Step 9 Go to Step 16

9 1. Place the gear selector in 3 (third).

2. Measure the resistance from terminal R to the

transmission case.

Is the resistance greater than the specified value?

50 K ohm Go to Step 10 Go to Step 16

10 1. Place the gear selector in D (drive).

2. Measure the resistance from terminal P to the

transmission case.

Is the resistance less than the specified value?

200 ohm Go to Step 11 Go to Step 16

11 1. Place the gear selector in 2 (second).

2. Measure the resistance from terminal P to the

transmission case.

Is the resistance greater than the specified value?

50 K ohm Go to Step 12 Go to Step 16

Step Action Value(s) Yes No

12 1. Turn the ignition OFF.

Important: The resistance of the TFT sensor is

temperature dependent, and therefore varies far more

than any other device. Refer to Transmission Fluid

Temperature Sensor in this Section.

2. Measure the resistance from terminal L to terminal M

(TFT sensor) of the J 39775 jumper harness.

Is the resistance within the specified range?

3088-3942

ohm @ 20°C

(68°F)

159-198 ohm

@ 100°C

(212°F)

Go to Step 13 Go to Step 14

13 1. Measure the resistance from terminal L to the

transmission case.

2. Measure the resistance from terminal M to the

transmission case.

Are both resistances greater than the specified value?

10 M ohm System OK Go to Step 14

14 1. Disconnect the TFP manual valve position switch from

the A/T wiring harness assembly.

Important: The resistance of the TFT sensor is

temperature dependent, and therefore varies far more

than any other device. Refer to Transmission Fluid

Temperature Sensor in this Section.

2. Using the J 39200 DMM, measure the resistance

between terminal A and terminal B of the TFP manual

valve position switch (TFT sensor).

Is the resistance within the specified range?

3088-3942

ohm @ 20°C

(68°F)

159-198 ohm

@ 100°C

(212°F)

Go to Step 15 Go to Step 19

15 1. Measure the resistance from TFP manual valve

position switch terminal A to the transmission case.

2. Measure the resistance from TFP manual valve

position switch terminal B to the transmission case.

Are both resistances greater than the specified value?

10 M ohm Go to Step 16 Go to Step 19

16 1. Inspect for high resistance or a short:

Inspect the A/T wiring harness assembly for poor

electrical connections at the automatic transmission

20-way connector, and at the TFP manual valve

position switch. Look for the following conditions:

- A backed out terminal

- A damaged terminal

- Reduced terminal tension

- Moisture intrusion

- Corrosion

2. If diagnosing for an intermittent condition, massage

the wiring harness while watching the test equipment

for a change.

Did you find high resistance or a short?

Go to Step 1 Go to Step 17

17 1. Disconnect the TFP manual valve position switch from

the A/T wiring harness assembly.

2. Inspect the following circuits for an open or short:

- Circuit 1224

- Circuit 1225

- Circuit 1226

- Circuit 1227

Did you find an open or shorted condition?

Go to Step 18 Go to Step 19

18 1. Replace the A/T wiring harness assembly.

2. Refer to Section 7C4 Control Valve Body and Wiring

Harness Replacement of the VT Series II Service

Information.

Is the replacement complete?

Go to Step 1

19 1. Replace the TFP manual valve position switch.

2. Refer to Section 7C4 Valve Body and Pressure Switch

Replacement of the VT Series II Service Information.

Is the replacement complete?

Go to Step 1

GEN III V8 PCM - AUTOMATIC TRANSMISSION FUNCTIONAL CHECK PROCEDURE

Step Action Value(s) Yes No

The Functional Test Procedure is the first step in diagnosing mechanical or hydraulic transmission conditions and provides

procedures and references to the Symptom Diagnosis tables in this Section for specific diagnostic information.

1 Important: Engine performance can greatly affect

transmission performance. Ensure that the complaint is

not the result of poor engine performance before

continuing.

Verify the customer complaint.

Has the customer complaint been verified?

Go to Step 2

2 Important: Many transmissions have default actions that

take place once a DTC fault is detected. These actions

may be interpreted as being a transmission concern.

Has the Powertrain On Board Diagnostic (OBD) System

Check been performed?

Go to Step 3 Go to Powertrain

OBD System

Check Table in

Section 6C3-2A

3 1. Perform a visual inspection. Look for the following

conditions:

- Vehicle damage

- Transmission oil pan damage. Refer to Section 7C4

On-Vehicle Servicing, of the VT Series II Service

Information.

- Worn or damaged suspension parts. Refer to

Section 3 Front Suspension, of the VT Series I

Service Information.

- Worn or damaged steering parts. Refer to Section

9A Steering, of the VT Series I Service Information.

- Transmission range selector linkage damaged or

out of adjustment. Refer to Section 7C4 Shift Cable

Adjustment of the VT Series I Service Information.

- Loose, worn, damaged or missing:

- mounts or struts

- brackets

- mounting hardware

Refer to Section 7C4 Transmission Assembly

Removal of the VT Series I Service Information.

2. Transmission cooler or cooler line restrictions. Refer

to Transmission Cooler Reverse Flush and Flow Rate

Check, Section 7C4 of the VT Series II Service

Information.

3. Fluid leaks. Refer to Fluid Leak Checking Procedure,

Section 7C4 of the VT Series II Service Information.

Was an item identified that needs service?

Go to the

Appropriate

Repair or

Diagnosis

Section

Go to Step 4

4 Perform the Transmission Fluid Checking Procedure,

Section 7C3 of the VT Series II Service Information.

Is the procedure complete?

Go to Step 5 Go to

Transmission

Fluid Checking

Procedure in

Section 7C3 of

the VT Series II

Service

Information

5 Perform the Road Test Procedure. Refer to Section 7C3

of the VT Series II Service Information.

Did the vehicle exhibit any objectionable condition?

Go to Step 6 System OK

6 Did the vehicle exhibit objectionable torque converter

operation? Go to Step 15 Go to Step 7

7 Did the vehicle exhibit a noise condition? Go to Symptom

Diagnosis Table

(Noise and

Vibration

Diagnosis) in

Section 7C3 of

the VT Series II

Service

Information

Go to Step 8

Step Action Value(s) Yes No

8 Did the vehicle exhibit a vibration condition? Go to Step 9 Go to Step 10

9 Did the vibration occur only during TCC apply or release? Go to Step 15 Go to Symptom

Diagnosis Table

(Noise and

Vibration

Diagnosis) in

Section 7C3 of

the VT Series II

Service

Information

10 Did the vehicle exhibit a shift speed condition such as

low or high shift speeds? Go to Symptom

Diagnosis Table

(Shift Speed

Diagnosis) in

Section 7C3 of

the VT Series II

Service

Information

Go to Step 11

11 Did the vehicle exhibit any of the following shift quality

(feel) conditions?

• Harsh, soft, delayed or no engagement

• Harsh, soft or delayed shifts

• Shift shudder, flare or tie-up

Go to Step 12 Go to Step 13

12 Perform the Line Pressure Check Procedure . Refer to

Section 7C3 of the VT Series II Service Information.

Is the line pressure within specification?

Go to Symptom

Diagnosis Table

(Shift Quality

(Feel) Diagnosis)

in Section 7C3 of

the VT Series II

Service

Information

Go to Symptom

Diagnosis Table

(Fluid Diagnosis)

in Section 7C3 of

the VT Series II

Service

Information

13 Did the vehicle exhibit any of the following shift pattern

conditions?

• No upshift or downshift

• Only one or two forward gears

• No First, Second, Third or Fourth gear

• Slipping

• Non-first gear start

Go to Symptom

Diagnosis

(Shift Pattern

Diagnosis) in

Section 7C3 of

the VT Series II

Service

Information

Go to Step 14

14 Did the vehicle exhibit any of the following range

performance conditions?

• No Park, Reverse or Dri ve

• No engine braking

• No gear selection

• Incorrect gear selection

Go to Symptom

Diagnosis Table

(Range

Performance

Diagnosis) in

Section 7C3 of

the VT Series II

Service

Information

System OK

15 1. Refer to Torque Converter Diagnosis Procedure.

2. Did the vehicle exhibit any of the following TCC

conditions?

- Stuck on or off

- Early or late engagement

- Incorrect apply or release

- Soft or harsh apply

- Clunk or shudder

- No torque multiplication

- Excessive slip

- Poor acceleration

- Engine stalls

Go to Symptom

Diagnosis Table

(Torque

Converter

Diagnosis) in

Section 7C3 of

the VT Series II

Service

Information

System OK