SECTION 6C1-2A - DIAGNOSTIC TABLES -
V6 ENGINE
IMPORTANT:
Before performing any Service Operation or other procedure described in this Section, refer to Section
00 CAUTIONS AND NOTES in VX Service Information for correct workshop practices with regards to
safety and/or property damage.
SYSTEM COMPONENT LOCATIONS
37
35
32
16
8
7
6
5
4
30
20
24
34 36
33
13
5
9
3
25
28
27
26
21 21
22
23 18
19
10
29 15
31
17
11
14
13
12
4194
12
Figure 6C1-2A-1 V6 Engine Compartment Component Locations
1. Fuel Pump (Inside Fuel Tank) 2. Fuel Tank
3. ECC In –Car Air Temperature Sensor 4. Fuel Pressure Regulator
5. Exhaust Gas Oxygen (O2S) Sensor (Two) 6. Engine Harness (PCM) Earth (Two Terminals)
7. Idle Air Control (IAC) Valve 8. Throttle Position (TP) Sensor
9. Mass Air Flow (MAF) Sensor 10. Tachometer Lead
11. Powertrain Control Module (PCM) (Inside Vehicle) 12. Intake Air Temperature (IAT) Sensor
13. Fuel Injectors 14. Ignition Coils
15. Engine Coolant Temperature (ECT) Sensor 16. DIS Module
17. Air Cleaner 18. Crankshaft Position (CKP) Sensor
19. A/C Refrigerant Pressure Sensor 20. A/C Accumulator
21. Engine Cooling Fans (Two) 22. Oil Pressure Switch
23. Camshaft Position (CMP) Sensor 24. Battery
25. Battery Harness Fusible Link Housing 26. Engine Compartment Relay Housing
27. Engine Compartment Fusible Link Housing 28. Engine Compartment Fuse/Relay Center
29. Engine Harness (PCM) Earth (Two Terminals) 30. ABS
31. Detonation Knock Sensors (KS) (Two) 32. Brake Hydraulic Failure Switch
33. EVAP Canister Purge Solenoid 34. Diagnostic Link Connector (DLC)
35. BCM 36. Vehicle Speed Sensor (VSS)
37. Check Powertrain Malfunction Indicator Lamp(MIL)
Figure 6C1-2A-2 Engine Compartment Fuse/Relay Locations
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
Figure 6C1-2A-3 V6 Engine Component Locations
1. Idle Air Control (IAC) Valve
2. Throttle Position (TP) Sensor
3. EGR Valve
4. Injectors
5. Direct Ignition System Module
6. L.H. Knock Sensor (KS)
7. Crankshaft Position (CKP) Sensor
8. Oil Pressure Switch
9. Camshaft Position (CMP) Sensor
10. Ignition Coils (Three Places)
11. Engine Coolant Temperature (ECT) Sensor
11
10
9
8
7
6
4196
5
4
2
3
1
Figure 6C1-2A-4 V6 Engine Component Locations
1. Fuel Pressure Regulator
2. Canister Purge Solenoid
3. Injectors
4. R.H. Exhaust Gas Oxygen (O2S) Sensor
5. Transmission Pass-Through Connector
6. Vehicle Speed Sensor (VSS) (Automatic Trans)
7. PCM Connectors
8. Engine Harness Earth
7
4198
8
12
4
5
6
3
Figure 6C1-2A-5 V6 Engine Component Locations
1. Engine Harness Earth
2. Ignition Coils (Three Places)
3. Direct Ignition System Module
4. Camshaft Position (CMP) Sensor
5. Oil Pressure Switch
6. R.H. Knock Sensor (KS)
7. Vehicle Speed Sensor (VSS) Automatic Trans)
8. Injectors
7
4198
8
12
4
5
6
3
Figure 6C1-2A-6 V6 Automatic Transmission Internal Electronic Component Locations
1. Vehicle Speed Sensor
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
PCM WIRING DIAGRAMS
Figure 6C1-2A-7 V6 PCM Wiring Diagram (1 of 9) Power Circuits
New
VXPCM054C
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
BATTERY
LOC . E1
FS
(1040)
O
(740)
O
(740)
O/B (740) D12
C12
BATTERY
BATTERY
F31
D16
C14
IGNITION
IN JE C TOR VOLTAG E
MONITOR LINE
FJ
BLUE
FUSIBLE
LINK
FU
FT
R
(2H)
15a 15 50
30 ACC
IGN
START
IGNITION SWITCH
P (3) F14
P
(39)
P/B (39)
EFI RELAY
O/Y
(479)
LOC. E3 R
(481)
LG
(482)
P
(439)
P/BLU
(339)
O/BLU
(204)
12V BUS (1040)
R
(203)
O/B
(208)
B/W
(152)
F34
F35
F33
F32
TO DIS
MODULE
TO A/C
RELAY
TO MAF
SENSOR
TO CANISTER
PURGE SOLENOID
TO 3-2
SOLENOID
TO 1-2 SHIFT
SOL EN OI D A
TO 2-3 SHIFT
SOL EN OI D B
TO TCC ENABLE
SOLENOID
TO TCC PWM
SOLENOID
F28
TO
FUEL PUMP
RELAY
TO LOW SPEED
COOLING FAN
RELAY
TO HIG H SPEED
COOLING FAN
RELAY
TO
DLC
TO REMOTE
RECEIVER
MODULE
TO BODY
CONTROL
MODULE
ENGINE
COOLING
FAN 2
ENGINE
COOLING
FAN 1
TO
FUEL MODE
SWITCH
YE111
YE111
YE110
YE118
YE111
YE114
YE39
YE39
YB44
YB44
YB198
YB112
YE112
YE198
8630
85
87
Figure 6C1-2A-8 V6 PCM Wiring Diagram (2 of 9)
VXPCM051
+-
BATTERY
LOC . E 1
FS
(1040)
12V BUS (1040)
O (740)O/B (740)
D12
C12
O
(740)
O
(740)
BATTERY
BATTERY
F31
A5
F7
B5
E7
LOC. E15LOC. E5
EARTH
EARTH
EARTH
EARTH
B/R (750)
B/R (750)
PCM
D16 IGNITION
FJ
YB44
YB44
YE111
YE112
YE114
YE39
YB187
YB187
YB199
YE110
YB98
YE57
YB187
YE63
YE34
YE39
YE112 YB198
R (2H)
15a 15 50
30 OFF/ON
LOCK
ACC
IGN
START
IGNITION SWITCH
P (3)
F14 P
(39)
P/B (39)
B10
B6
B7
B9
B4
B3
CAM
SENSOR
CONNECTOR
module power supply - in
sensor power supply - out
cam signal - in
3x crank sensor - in
18x crank sensor - in
cam signal - out
tacho signal - out
crankshaft reference - out
18X cranksignal - out
bypass control
EST signal -in
P
N
M
L
K
J
H
G
F
E
D
C
B
A
DIS
MODULE
ABCD CBA
W/B (644)
GY/R (645)
B/R (453)
CRANK
SENSOR
CONN
L BLU/W
(646) BR (633)
BLU/Y (643)
BR (121)
TO INSTR UME NT CLUSTER
TERM INAL 18
(
TACHOMETER
)
B (63 0)
V (43 0)
L BLU/B (647)
T/B (4 24)
EFI REL AY
O/Y
(479) LOC. E3
LG
(482)
W (423)
CRANKSHAFT
REFERENCE LO
CAMSHAFT
POSITION
SENSOR
SIGNAL
CRANKSHAFT
REFERENCE HI
CRANKSHAFT
18X SIGNAL
BYPASS CONTROL
EST OUTPUT
IC
IC
IC
B11
B8
A
CT UA L TO RQ UE
O/W (1426)
B/W (14 27)
30
ENGINE SPEED
12V
12V
27
13
REQUESTED
TORQUE (M MR)
ACTUAL
TORQUE (M MI)
M
I
C
R
O
ABS/ETC
CONT ROL MO DUL E
DIS
CONT ROL MO DUL E
REQUESTED
TORQUE
BR/R(121)
M
I
C
R
O
P
R
O
C
E
S
S
O
R
F35
Figure 6C1-2A-9 V6 PCM Wiring Diagram (3 of 9)
VXPCM053
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
# 2
# 4 # 6
# 1 # 3 # 5
E6
F2
E2
E4
F1
E5
C14
D16
BLU (841)
V (84 3)
GY (845)
INJECTOR CONTROL
IN JECTOR VOLTAGE
MONITOR LINE
IGNITION FEED
R (481)
R (481)
P (39 )
Y (84 6)
YB199
BR/Y (844)
G (842)
D5
C9
D4
D3
GY/B (1413)
G/Y (1412)
A
B
B
A
LEFT OXYGEN SENSOR
RIGHT OXYGEN SENSOR
BLU/B (413)
V (41 2)
RIGHT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL HI
RIGHT
OXYGEN
SENSOR
SIGNAL HI
IC
IC
450 mV
450 mV
E10 FUEL PUMP RELAY
CONTROL
B/BLU
(156)
LOC. E7 LOC. E3
IN - TANK
FUEL PUMP
FUEL PUMP
RELAY
G/W (465)
12V
F28 O (240)
V (12 0)
B/W
(152)
32
51
+
-
BATTERY
LOC . E 1
FS
15a 15 50
30 OFF/ON
LOCK
ACC
IGN
START
IGNITION SWITCH
F14
87
30 86
85
F34
EFI
RELAY
(1040)
FJ
R (2H)
LOC. E4
O/Y
(479)
YB44
YB44
YB96
YB96
YE114
YB198
YR44YR44
YE97
YR44
YR32
YB198
YB198
YE110 YB199
YB198
YE39
YE39
YE114
YE111
YE97
YE22
YE22
Figure 6C1-2A-10 V6 PCM Wiring Diagram (4 of 9)
VXPCM052
PCM
IC
CIRCUIT
MASS AIR FLOW SENSOR
A7
A5
CBA
AIR FLOW
FROM
AIR FILTER
AIR FLOW
TO
THROTTLE BODY
EFI
RELAY
TO
EGR AND TFT
SENSOR
P (439)
ENGINE EARTH
MASS AIR FLOW
INPUT SIGNAL
EARTH
SENSOR EARTH
ECT SENSOR
SIGNAL
IC
B/R (750)
LOC. E5/E15
BR/W (792)
C6
D11
B
A
ENGINE COOLANT
TEMPERATURE SENSOR
Y (410)
B/Y (452)
TP SE NSOR SIGNAL
TP SE N SOR
REFERENCE
VOLTAGE
C15
C7
A
C
B
THROTTLE
POS I TI ON SENSO R
GY (416)
BLU (417)
C
B
A
A/C PRESSURE
SENSOR
D6
SENSOR
EARTH
D10
C16 A/C PRESSURE
SENSOR SIGNAL
5V REFERENCE
VOLTAGE
V/W (415)
B (469)
G/B (259)
D7
B
A
INTAKE AIR
TEMPERATURE SENSOR
IAT SENSOR SIGNAL
BR (472)
DSNEF
DSNEF
LEFT HAND KNOCK
SENSOR SIGNAL
RIGHT HAND KNOCK
SENSOR SIGNAL
C10
C11
RIGHT
HAND
KNOCK
SENSOR
LEFT
HAND
KNOCK
SENSOR
+
-
+
-
BLU (815)
LBLU (826)
OIL PRESSURE
SWITCH
F33
D1
D2
VEH IC LE SPEED
SENSOR IC
BLU/W
(831)
(AUTO)
BLU
(831)
(MAN)
T
(832)
(AUTO)
BR
(832)
(MAN)
M
I
C
R
O
P
R
O
C
E
S
S
O
R
YE111
YE33
YE3
YE23
YE113
YE30
YE106 YB198
YB187
YE100
YE3
YE199
YB195 (AUTO)
YB132 (MAN)
Figure 6C1-2A-11 V6 PCM Wiring Diagram (5 of 9)
VXPCM055
PCM
C5
C4
C3
C2
LG/W (443)
A
B
C
D
IAC VALVE
LG/B (444)
LBLU (441)
LBLU/B (442)
E12
C8
C16
D6
LG (1456)
V (435)
E
A
C
D
B
LINEAR
EXHAUST GAS
RECIRCULATION
VALVE
EGR PINTLE POSITION
EGR PWM
SIGNAL
REFERENCE
VOLTAGE
SENSOR EARTH
V/W (415)
B (469)
12V
B/R (750)
A
B
CANISTER PURGE
SOL EN OI D VA LVE
CANISTER PURGE
IGNITION
LOC. E5/E15
A/C
COMPRESSOR
A/C RELAY
A9
LG/B (366)
G (59)
A/C CLUTCH ENABLE
IAC COIL B HI
IAC COIL B LO
IAC COIL A HI
IAC COIL A LO
M
I
C
R
O
P
R
O
C
E
S
S
O
R
BATTERY
FS (1040)
FJ R (2H)
F14
LOC. E3
F33
P/B
(39)
15a 15 50
30 ACC
IGN
START
IGNITION SWITCH
P
(3)
O/Y
(479)
B/W
(152)
EFI
RELAY
LOC. E1
P (439)
YE198
YB44
YE112
YB44
YE111
YB199
YB87
YB198
YE105
YE105
YE120 YE120
YE36
YE109
YB198
YE111
YE101
YE101
YE99
YB39
YB39
Figure 6C1-2A-12 V6 PCM Wiring Diagram (6 of 9)
VXPCM057
PCM
C13 SERIAL
DATA
MAIN
5V
LOC. E3
BCM
E2/D2
E9/D3
E3/D13
M
I
C
R
O
SERIAL
DATA
MAIN
SERIAL
DATA AUX.
5V
G/W (1220)
W/G (1220)
HIGH SERIES
BCM TERMINALS
NOMINATED FIRST
DATA
LINK
CONNECTOR
1
2345678
9 10111213141516
5V
D9
DIAGNOSTIC
ENABLE
W/B (451)
B/Y (155)
B (150)
R/B (1221)
INSTRUMENTS
ABS/ETC
11
SERIAL
DATA
5V
12
17
SERIAL
DATA
5V
M
I
C
R
O
CHECK
POWERTRAIN
LAMP
OIL PRESSU RE
WARNING LAMP
POWER
ECONOMY LAMP
R
12V
P
N
D
3
1
2
SRS
ECC
9
6
M
I
C
R
O
M
I
C
R
O
SERIAL
DATA
SERIAL
DATA
5V
12V IGN
VEHICLE
SPEED
SPEEDOMETER
VEHICLE SPEED
C1
V/W (123)
M
I
C
R
O
M
I
C
R
O
P
R
O
C
E
S
S
O
R
YE114
YB175
YB164
YE111 YB198
YE112
YB190
YB87
YE98
YE110
YB66
YB128
YE114
Figure 6C1-2A-13 V6 PCM Wiring Diagram (7 of 9)
VXPCM056
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
B12 HIGH SPEED FAN
LOW SPEED FAN
M
I
C
R
O
BCM
ENGINE
COOLING
FAN 2
ENGINE
COOLING
FAN 1
O/BLU (204)
(1040)
O/B (208)
O/B (473)
ENGINE
COOLING
FAN RELAY
(LOW SPEED)
ENGINE
COOLING
FAN RELAY
(HIGH SPEED)
30
87
85
86 87A
30
87
85
86
O/B
(740)
G
Y
BLU
B
BLUE
FUSIBLE
LINK
BATTERY
FS
LOC.
E1
FU FAN 1
FT FAN 2
R
(203)
R
(001)
15a 15 50
30 ACC
IGN
START
IGNITION SWITCH
FJ
R (2H)
R (001)
B7/B7
HIGH SERIES
BCM TERMINALS
NOMINA TED FIRST
LOC. E3
B/R
(157)
LOC. E2
BL U/ W (30 4 )
C13
MAIN
SERIAL
DATA
STARTER ENABLE
5V
SERIAL
DATA
MAIN
5V
E2/D2
GY
(434) EG
NEUTRAL START
BACK-UP SW.
( MANUAL
TRANS)
A8
START
RELAY
LOC. G1
STARTER
MOTOR
M
V/W
(6)
GY/BLU (1434)
R/B (1221)
F31
YB198
YE112
YB35
YE111
YB44
YE49
YE49
YE140
YE140
YE118
YE139
YE118
YE103
YE43
YE43 YE103
YB187
YE139
YB44
YB35
YB175
YB174
YB164
YB163
TO
DLC
30 85
87 86
YE7 YE8
Figure 6C1-2A-13 V6 PCM Wiring Diagram (8 of 9)
VXPCM021
INSTRUMENT
PCM
LPG
LAMP
19
BATTERY POWE R
IGNITION
20
IGNITION SWITCH
BATTERY
FJ
FS
O/B (740) O
(740)
R
(2H)
(1040)
15a 15 50
30 ACC
IGN
START
F21
F13
F14
P (3 )
Y/G
CONTROL
SIGNAL
2-3mA
B/Y
P/G
43
30V
2A
W/G
B/R
BLU/R
2
5
6
1
LPG
TANK
SENDER
SMART UNIT
LPG
SENDER
FUEL
GAUGE
W/G
(937) A3
A5
B5
E7
F7
ENABLE
LPG
EARTH
EARTH
EARTH
EARTH
EARTH
FUEL MODE SWITCH
LPG FCV
LPG WIRING
CONFIGURATION
BATTERY
BATTERY
IGNITION
12
SERIAL
DATA
5V
G/W (1220) R/B (1221) C13 SERIAL
DATA
5V
12V
P
(39)
O/Y (1340)
Y (1030)
P/BLU (44)
M
I
C
R
O
P
R
O
C
E
S
S
O
R
M
I
C
R
O
P
R
O
C
E
S
S
O
R
F31
O
(740)
P
(39)
P
(39)
P/B
(39)
D5
C9
GY/B (1413)
G/Y (1412)
A
B
RIGHT HAND
OXYGEN SENSOR
RH O2
SIGNAL LO
RH O2
SIGNAL HI
IC
450 mV
B/R
(750)
LOC. E4
LOC. E3
LOC. E3
LOC. E5/E15
LOC.
E5 LOC.
E15
B
(155) B/Y
(155)
B/Y (155)
BCM
E2
D2
E9
D3
LOC. E1 IGNITION
YR50
YR50
YR51
YR51 YB51
YE110
YB51
YE2
YR51
YB66
YB51
YB175
YB164
YE35 YE35
YB30
YE112
YE112
YB44
YB44
YB68
YB198
YB199
YB198
YB68 YE110
YB30
YB199
YB175
YB164
YE97
YB198
YR50
YR50
YR51
YB51
YB199
YB187
YE114
YE112
Figure 6C1-2A-14 V6 PCM Wiring Diagram (9 of 9)
VXPCM050
PCM
A11
A12
A1
B1
A2
E13
E9
TCC PWM
SOLENOID
3-2 CONTROL
SOLENOID
1-2 SHIFT
SOLENOID
2-3 SHIFT
SOLENOID
PRESSURE
CONTROL
SOLENOID
LOW
PRESSURE CONTROL
SOLENOID HIGH
B
A
A
B
B
B
A
A
B
A
YB 129 TRANSMISSION
PASS-THRU CO NNECTOR
TORQUE
CONVERTER
CLUT CH (TCC)
(PWM)
SOLENOID
TORQUE
CONVERTER
CLUT CH (TCC)
ENABLE
SOLENOID
3-2 DOWNSHIFT
CONTROL
SOLENOID
1-2 SHIFT
SOLENOID A
2-3 SHIFT
SOLENOID B
PRESSURE
CONTROL
SOLENOID
C
D
B
S
A
E
T
U
P/BLU (339)
F11
F12
F13
D6
TFP SIGNAL A
TFP SIGNAL B
TFP SIGNAL C
TRANSMISSION FLUID
TEMPERATURE (TFT)
SENSOR SIGNAL
SENSOR
EARTH
N
C
R
E
DP
TRANSMISSIO N FLUID
TEMPERATURE
(TFT) SENSOR
AUTO M ATIC TRANSMI SS ION FLUID PRE SS URE
MANUAL VALVE P OSITION SWITCH (TFP)
F14 POWER/ECONOMY
SWITCH
POWER/ECONOMY
SWITCH
TCC ENABLE
SOLENOID
B
A
EFI
RELAY
F32
BR (418)
GY/R (422)
G/W (897)
LG (1222)
Y/B (1223)
GY/BLU (1229)
R (1228)
BR/Y (1224)
Y (1225)
GY (1226)
D13
A
B
L
M
B/Y (1227)
B (46 9)
12V
12V
12V
12V
12V
12V
12V
12V
12V
5V
M
I
C
R
O
P
R
O
C
E
S
S
O
R
F3
F8
A
SWITCH P
SWITCH A
SWITCH B
SWITCH C
LOC. E5/E15 LOC. E3
YB35 YB30
YB30
Ye114
YE112YB34
YB20 YB199
YB198
YB199
YB187
YB34
D
B
C
P R N D L SWITCH
F9
F6
BLU/W (771)
Y (77 2)
GY (773)
W (776)
B/R (750)
RANGE
SIGNAL P
RANGE
SIGNAL A
RANGE
SIGNAL B
RANGE
SIGNAL C
BLU (774)
B/G
YE110
TO A/C PRESSURE
SENSOR AND
IAT SENSOR
POWERTRAIN CONTROL MODULE CONNECTOR IDENTIFICATION
This powertrain control module voltage Table is for use with a digital voltmeter to further aid in diagnosis.
Connect the Black (-) probe to a good chassis earth, and back probe the powertrain control module terminal with
the Red (+) probe. These voltages were derived from a known good vehicle. The voltages you get may vary
due to low battery charge or other reasons, but they should be very close.
THE FOLLOWING CONDITIONS MUST BE MET BEFORE TESTING:
• Engine and Transmission at operating temperature
• Closed Loop
• Engine idling ( for “Engine Run” column)
• Diagnostic “Test” terminal not earthed
• Tech 2 scan tool not installed
• Accessories “OFF”
BACKPROBING VIEW OF BROWN A/B PCM CONNECTOR
Figure 6C1-2A 15 PCM Connector Terminal End View (1 of 3)
Pin
Pin Funct i on
CKT
#
Wire
Colour
Ign
"ON"
Eng
Run
Pin
Pin Funct i on
CKT
#
Wire
Colour
Ign
"ON"
Eng
Run
A1 3-2 CONTROL
SOLENOID 897 G/W 12 *
B1 1-2 SHIFT
SOLENOID
CONTROL
1222 LG 12 *
A2 2-3 SHIFT
SOLENOID
CONTROL
1223 Y/B 12 *
B2 NOT USED - - - -
A3 LPG ENABLE
OUTPUT (LPG ONLY) 937 W/G * *
B3 EST OUTPUT 423 W 0 2.0
A4 NOT USED - - - -
B4 BYPASS
CONTROL 424 T/B 0 4.7
A5 SYSTEM EARTH 750 B/R * * B5 SYSTEM EA RTH 750 B/R * *
A6 NOT USED - - - -
B6 CAMSHAFT
POSITION
SENSOR S IGNAL
630 B 4.8 4.4
A7 MAF SE N SOR
INPUT 792 BR/W 4.8 4.2
B7 CRANKSHAFT 18X
SIGNAL 647 L BLU/B 5
OR
0
2.7
TO
3.0
A8 START RELAY
CONTROL 1434 GY/BLU * * B8 TORQUE
REQUEST 1426 O/W 4-5 4-5
A9 AIR
CONDITIONING
RELAY CONT ROL
366 LG/B 12 (2)
B9 CRANKSHAFT
REFERE NCE HIGH 430 V 4.8 2.3
A10 CANISTER PURGE
SOLENOID 428 G/Y 12 13
B10 CRANKSHAFT
REFERE NCE LOW 453 B/R * *
A11 TCC SOLENOID
PWM CONTROL 418 BR 12 13
B11 TORQUE
ACHIEVED 1427 B/W .9 3-6
A12 TCC ENABLE
SOLENOID
CONTROL
422 GR/Y 12 13
B12 ENGINE COOLI NG
FAN RELA Y HIGH
SPEED CONTROL
304 BLU/W 12 (7)
(2) With air conditioning ON 0 volts, with air conditioning OFF 13 volts.
(7) With engine cooling fan "ON" 0 volts, with engine cooling fan "OFF" 13 volts.
* Less than 0.50 volts
Normal
Volta
g
es Normal
Volta
g
es
POWERTRAIN CONTROL MODULE CONNECTOR IDENTIFICATION
This powertrain control module voltage Table is for use with a digital voltmeter to further aid in diagnosis.
Connect the Black (-) probe to a good chassis earth, and back probe the powertrain control module terminal with
the Red (+) probe. These voltages were derived from a known good vehicle. The voltages you get may vary
due to low battery charge or other reasons, but they should be very close.
THE FOLLOWING CONDITIONS MUST BE MET BEFORE TESTING:
• Engine and Transmission at operating temperature
• Closed Loop
• Engine idling ( for “Engine Run” column)
• Diagnostic “Test” terminal not earthed
• Tech 2 scan tool not installed
• Accessories “OFF” BACKPROBING VIEW OF BROWN C/D PCM CONNECTOR
Figure 6C1-2A-16 PCM Connector Terminal End View (2 of 3)
Pin
Pin Funct i on
CKT
#
Wire
Colour
Ign
"ON"
Eng
Run
Pin
Pin Funct i on
CKT
#
Wire
Colour
Ign
"ON"
Eng
Run
C1 VEHICLE SPEED
OUTPUT TO
SPEEDOMETER
123 V/W 0.1
OR
12
0.1
OR
13
D1 VEHICLE SPEED
SENSOR SIGNAL
HIGH
831 BLU/W
(AUTO)
BLU
(MANUAL)
* *
C2 IAC COIL “B” LOW 444 LG/B NOT USE-
ABLE D2 VEHICLE SPEED
SENSOR SIGNAL
LOW
832 T
(AUTO)
BR
(MANUAL)
* *
C3 IAC COIL “A ” LOW 442 LBLU/B NOT USE-
ABLE D3 LH OXYGEN
SENSOR EARTH 413 BLU/B * *
C4 IAC COI L “A ” HIGH 441 LBLU NOT USE-
ABLE D4 LH OXYGEN
SENSOR SIGNAL 412 V 450
Mv (4)
C5 IAC COIL “B ” HIGH 443 LG/W NOT USE-
ABLE D5 RH OXYGEN
SENSOR EARTH 1413 GY/B * *
C6 ECT/TP SENSOR
EARTH 452 B/Y * * D6 IAT,TFT,EGR,A/C
PRESSURE
EARTH
469 B * *
C7 TP SENSOR
SIGNAL 417 BLU (5) (5) D7 INTAKE AIR
TEMPERATURE
SENSOR SIGNAL
472 BR 1.0
(3) 1.0
(3)
C8 EGR PINTLE
POSITION 1456 LG .7 .7 D8 NOT USED - - - -
C9 RH OXYGEN
SENSOR SIGNAL 1412 G/Y 450
Mv (4) D9 DIAGNOSTIC
TEST ENABLE 451 W/B 5 5
C10 LEFT HAND
KNOCK SENSOR
SIGNAL
815 BLU 1.3
Mv
A/c
1.9
Mv
A/C
D10 A/C PRESSURE
SENSOR SIGNAL 259 G/B 1-2 1-2
C11 RIGHT HAND
KNOCK SENSOR
SIGNAL
826 LBLU 1.3
Mv
A/C
1.9
Mv
A/C
D11 ENGINE COOLANT
TEMPERATURE
SENSOR SIGNAL
410 Y 1.9
(3) 1.9
(3)
C12 BATTERY
VOLTAGE FEED 740 O 12 13 D12 BATTERY
VOLTAGE FEED 740 O 12 12
C13 PRIMARY SERIAL
DATA 1221 R/B 3-5 3-5 D13 TRANS FLUID
TEMP (TFT)
SENSOR SIGNAL
1227 B/Y 1.8
(3) 1.8
(3)
C14 INJECTOR
VOLTAGE
MONITOR LINE
481 R 12 13 D14 NOT USED - - - -
C15 TP SENSOR
REFERENCE
VOLTAGE
416 GY 5 5 D15 NOT USED - - - -
C16 EGR, A/C PRESS
REFERENCE
VOLTAGE
415 V/W 5 5 D16 IGNITION FEED 39 P 12 13
(3) Varies with temperature.
(4) The voltage should vary between 100 mV - 1000 mV.
(5) 0.l25 - 1.25 volts measured between terminals "C7" and "B1" or about 4.0 volts at wide open throttle.
* Less than 0.50 volts
Normal
Volta
g
es Normal
Volta
g
es
POWERTRAIN CONTROL MODULE CONNECTOR IDENTIFICATION
This powertrain control module voltage Table is for use with a digital voltmeter to further aid in diagnosis.
Connect the Black (-) probe to a good chassis earth, and back probe the powertrain control module terminal with
the Red (+) probe. These voltages were derived from a known good vehicle. The voltages you get may vary
due to low battery charge or other reasons, but they should be very close.
THE FOLLOWING CONDITIONS MUST BE MET BEFORE TESTING:
• Engine and Transmission at operating temperature
• Closed Loop
• Engine idling ( for “Engine Run” column)
• Diagnostic “Test” terminal not earthed
• Tech 2 scan tool not installed
• Accessories “OFF” BACKPROBING VIEW OF TAN E/F PCM CONNECTOR
Figure 6C1-2A 17 PCM Connector Terminal End View (3 of 3)
Pin
Pin Funct i on
CKT
#
Wire
Colour
Ign
"ON"
Eng
Run
Pin
Pin Funct i on
CKT
#
Wire
Colour
Ign
"ON"
Eng
Run
E1 NOT USED - - - - F1 FUEL INJECTOR
# 3 CONTROL 843 V 12 13
E2 FUEL INJECTOR
#2 CONTROL 842 G 12 13 F2 FUEL INJECTOR
#4 844 BR/Y 12 13
E3 NOT USED - - - - F3 PRNDL “A” 771 BLU/W * *
E4 FUEL INJECTOR
#1 CONTROL 841 BLU 12 13 F4 FUEL MODE
SWITCH (LPG ONLY) 936 BLU/O * *
E5 FUEL INJECTOR
# 4 CONTROL 845 GY 12 13 F5 NOT USED - - - -
E6 FUEL INJECTOR
# 6 CONTROL 846 Y 12 13 F6 PRNDL “P” 776 W * *
E7 SYSTEN EARTH 750 B/R * * F7 SYSTEM EARTH 750 B/R * *
E8 NOT USED - - - - F8 PRNDL “B” 772 Y 12 13
E9 PRESSURE
CONTROL
SOLENOID HIGH
1228 R * 1.3 F9 PRNDL “C” 773 GY 12 13
E10 FUEL PUMP
RELAY CONT ROL 465 G/W (1) 13 F10 NOT USED - - - -
E11 NOT USED - - - - F11 RANGE SIGNAL
"A" 1224 BR/Y 12 13
E12 EGR CONTROL
(PWM) 435 V 0.0% 0.0% F12 RANGE SIGNAL
"B" 1225 Y 0 0
E13 PRESSURE
CONTROL
SOLENOID LOW
1229 GY/BLU * 6.8 F13 RANGE SIGNAL
"C" 1226 GY 12 13
E14 NOT USED - - - - F14
POWER/ECONOMY
SWITCH INPUT 774 BLU (6) (6)
E15 NOT USED - - - - F15 OIL PRESSURE
INPUT SIGNAL 31 DK
BLU/R * 13
E16 LPG FCV (LPG ONLY) 106
2 B/BLU (1) (1) F16
IGNITION FEED
(LPG ONLY) 39 P 12 13
(1) Battery voltage first 2 seconds
(2) With air conditioning "ON" 0 volts, with air conditioning "OFF" 13 volts.
(3) 12 volts while engine is cranking.
(6) When Power/Economy switch is depresses, voltage will momentarily change from 12 volts to 0 volts
then back to 12V.
(7) With engine cooling fan "ON" 0 volts, with engine cooling fan "OFF" 13 volts.
* Less than 0.50 volts.
Normal
Volta
g
es Normal
Volta
g
es
PCM CONNECTOR TERMINAL VOLTAGES WITH EXPLANATIONS
A1 – 3 – 2 DOWNSHIFT CONTROL SOLENOID
CONTROL
- AUTO TRANS ONLY –
The 3-2 c ontrol solenoid is a nor mally closed, pulse width m odulated solenoid used to control the 3-2 downshift.
The PCM operates the 3-2 control solenoid at
a frequency of 50 Hz (cycles per second). The solenoid is constantly fed 12 volts and PCM controls the length
of time the path to earth for the electrical circuit is closed.
A2 – 2 – 3 SHIFT SOLENOID CONTROL
- AUTO TRANS ONLY
The PCM is used to either open or pr ovide a path to earth for the 2-3 shif t solenoid. W hen the PCM provides a
path to earth, the 2-3 shift solenoid is considered “ON” and the voltage should read 0 volts.
A3 – LPG ENABLE (LPG Only)
The PCM sends a 12 volt signal out to the SMART UNIT
when LPG has been requested.
A4 – NOT USED
A5 – SYSTEM EA RTH
These terminals should have zero volts. They are connected directly to the engine earth.
A6 – NOT USED
A7 – MASS AIR-FLOW (MAF) INPUT SIGNAL
The PCM supplies a 5-volt signal voltage to the mass air flow sensor on this circuit. The mass air flow sensor
pulses the 5-volt signal to earth. These earth pulses occur at a very fast rate – from less than 500 per second
(500 Hz) with no airflow through the sensor, to upwards of m any thousands of puls es per second at high air flow
rates such as during acceleration. If measured, the voltage seen will be between 0.5 and 4.5 volts, depending
on air flow through the sensor.
A8 – START RELAY CONTROL
When the PCM receives the proper Theft Deterrent signal, the PCM will supply a earth signal to Start Relay.
This will allow the vehicle to star t. If a impr oper Theft Deter rent signal is sensed by the PCM, then the PCM will
not supply a earth signal to the Start Relay. This will prevent the starter motor from operating.
A9 – AIR CONDITIONING RELAY CONTROL
W hen the A/C is r equested, the BCM will comm unicate to the PCM via the serial data line, requesting A/C. T he
PCM supplies the earth path on this terminal to energise the A/C control relay. The voltage will be less than 1
volt when the PCM energises the relay. W hen the PCM does energise the A/C control relay, the voltage will be
more than 0.1, but less than 1 volt.
A10 – CANISTER PURGE SOLENOID CONTROL
The PCM operates a norm ally closed solenoid valve, which contr ols vacuum to pur ge the evaporative emis sions
storage canister of stored gasoline vapours. The PCM turns “ON” the pulse width modulated control of the
purge solenoid, to control purging of the stored vapours. If the PCM is not energising the purge solenoid, the
voltage measured at this terminal should equal battery voltage. If the PCM is controlling the solenoid, the
measured voltage will be between battery voltage and 0.50 volts.
A11 – TORQUE CONVERTER CLUTCH – PULSE WIDTH MODULATED APPLY SOLENOID CONTROL
- AUTO TRANS ONLY –
The PCM uses the pulse width modulated T CC apply solenoid to sm oothly engage the torque converter clutch,
after the TCC “ON-OFF” solenoid is energised. By varying the duty cycle pulse width modulation, the PCM can
slowly engage the torque converter clutch, allowing very smooth TCC engagement.
A12 – TORQUE CONVERTER CLUTCH ENABLE SOLENOID CONTROL
- AUTO TRANS ONLY
The PCM is used to either open or provide a path to earth for the torque converter solenoid. When the PCM
provides a path to earth, the T CC solenoid is cons idered ON and voltage s hould be near 0 volts. T he PCM uses
both the TCC enable solenoid and the TCC “PWM” solenoid to control the torque converter clutch.
B1 – 1 – 2 SHIFT SOLENOID CONTROL
- AUTO TRANS ONLY –
The PCM is used to either open or pr ovide a path to earth for the 1-2 shif t solenoid. W hen the PCM provides a
path to earth, the 1-2 shift solenoid is considered “ON” and the voltage should read 0 volts.
B2 – NOT USED
B3 – ELECTRONIC SPARK TIMING (EST) OUTPUT
This terminal will have very low voltage with the ignition “ ON” but engine not running. W ith the engine running at
idle, the voltage should be slightly more than 1 volt. As the engine RPM goes up, this voltage will increases.
B4 – IGNITION MODULE BYPASS CONTROL
- IGNITION SYSTEM MODE CONTROL –
With ignition “ON” and engine not running this terminal will have very low voltage. As soon as the PCM sees
engine RPM of m ore than 1600 RPM (Electronic Spark Timing “run” threshold) the PCM turns on 5 volts to the
Ignition Module Bypass Control circuit, causing the ignition module to allow the PCM to operate the ignition
system.
B5 – SYSTEM EARTH
These terminals should have zero volts. They are connected directly to the engine earth.
B6 – CAMSHAFT POSITION INPUT SIGNAL
This signal is used by the PCM to “sequence” the energis ing of the fuel inj ectors, sim ilar to the firing order of an
engine. This allows the PCM to operate the fuel injectors in a “sequential fuel injection” mode. The camshaft
position sensor is actually wired to the ignition module. The ignition module sends one pulse per every two
crankshaft revolutions to the PCM to determine actual camshaft position, and thus, engine cycle sequence.
B7 – CRANKSHAFT 18X INPUT SIGNAL
The 18X crankshaft reference input signal is used to very accurately control EST spark timing at low engine
speeds – below 1200 RPM. Below 1200 RPM, the PCM monitors the 18X signal to control spark timing. At
engine speeds above 1200 RPM, the PCM uses the 3X c rankshaf t r ef er ence input s ignal to c ontrol s park timing.
(See 3X crankshaft reference terminal D12)
B8 – TRACTION CONTROL (TORQUE REQUESTED)
The ABS/ET C m odule will send a N.m signal to the PCM when torque reduction is requested fr om the ABS/ETC
module for traction control. This N.m signal should match closely with Torque Achieved N.m signal, when
traction control is being requested.
B9 – 3X CRANKSHAFT REFERENCE INPUT SIGNA L HIGH
This terminal c ould be called the “ tac h” input. It pr ovides the PCM with RPM and crankshaf t pos ition inf or mation.
With ignition “ON” but engine not running, the voltage will be either high or low, depending on crankshaft
position. As the crankshaft turns, the voltage will be an average of the two readings. The PCM uses the 3X
signal to control fuel injection, and spark timing with engine speeds above 1200 RPM.
B10 – CRANKSHAFT REFERENCE INPUT SIGNAL LOW
This terminal should always be zero volts. It is connected through the ignition module to engine earth.
B11 – TRACTION CONTROL (TORQUE ACHIEVED)
The PCM sends a N.m signal to the ABS/ETC module on the delivered torque circuit informing the ABS/ETC
module of response made to the desired torque N.m signal. This N.m signal should match closely with the
Requested Torque N.m signal. A problem with the
delivered torque circuit should cause a ABS/ETC DTC to set, and traction control to be disabled.
B12 – ENGINE COOLING FAN – HIGH SPEED RELAY CONTROL
This terminal will have battery voltage until the PCM energises the high s peed cooling fan relay by supplying the
earth; then it will be close to zero. The input that causes the PCM to energise the high speed fan relay is the
engine coolant tem perature s ensor. T he PCM will also energis e the high speed f an relay in the Diagnos tic Mode
– i.e., ignition “ON,” engine stopped, and DLC diagnostic “test” enable terminal earthed. Refer engine fan
TABLE A-12 of the VX Series Service Information for further explanation.
(The Body Control Module operates the cooling fan low speed relay)
C1 – VEHICLE SPEED OUTPUT TO SPEEDOMETER
The PCM alternately earths this s ignal, in pulses, when it rec eives a vehicle speed signal f rom the vehicle speed
sensor in the transmission. This pulsing action takes place about 6250 times per kilometer. The speedometer
calculates vehicle speed based on the time between pulses.
C2 – IDLE AIR CONTROL (IAC)
C3 – IDLE AIR CONTROL (IAC)
C4 – IDLE AIR CONTROL (IAC)
C5 – IDLE AIR CONTROL (IAC)
These terminals connect the Idle Air Control valve, located on the throttle body, to the PCM. It is difficult to
predict what the voltage will be, and the measurement is unusable for any service procedures.
C6 – ENGINE COOLANT TEMPERA TURE and THROTTLE POSITION SENSOR EARTH
This terminal should be zero volts. It is connected through the PCM circuitry to engine earth.
C7 – THROTTLE POSITION (TP) SENSOR
The TP sensor input voltage, which follows actual throttle changes, is variable from 0 to 5 volts. Typically the
voltage is less than 1 volt at idle, and 4 to 5 volts at wide-open throttle.
C8 – LINEAR EGR VALVE PINTLE POSITION
This voltage is a indication to the PCM the position of the EGR valve pintle position. A low voltage indicates a
fully extended pintle (closed valve). A voltage near 5 volts indicates a retracted pintle (open valve).
C9 – OXYGEN SENSOR INPUT SIGNAL
- RIGHT BANK –
W ith ignition “ON” and engine not running, the voltage should be 350 – 450 m illivolts ( 0.350 – 0.450 volts). T his
is the PCM-supplied 02 c ircuit “bias” voltage. With the engine running and af ter the 02 sens or is hot, the voltage
should be rapidly changing, somewhere between 10 – 1000 millivolts (0.010 – 1.000 volt).
C10 – LEFT HAND ELECTRONIC SPARK CONTROL (ESC) “KNOCK” INPUT SIGNAL
The Electronic Spark Control “k nock” sensor detec ts when detonation is occurr ing in the combus tion cham bers.
W hen detected, the PCM will reduce the am ount of spark advance being delivered on the EST output circuit to
the ignition module.
C11 – RIGHT HAND ELECTRONIC SPARK CONTROL (ESC) “KNOCK” INPUT SIGNAL
The Electronic Spark Control “k nock” sensor detec ts when detonation is occurr ing in the combus tion cham bers.
W hen detected, the PCM will reduce the am ount of spark advance being delivered on the EST output circuit to
the ignition module.
C12 - BATTERY VOLTAGE FEED
- HOT AT ALL TIMES –
This supplies the PCM with full-time +12 volts. It stays hot even when the ignition is turned off. It receives its
voltage through the “ENGINE” fuse F31. This PCM terminal could be called the power supply and “MEMORY”
terminal.
C13 – PRIMARY SERIAL DATA
This is a dedic ated line for the T ech 2 sc an tool comm unication. T he circuit c onnects the PCM, ABS, and BCM.
The Tech 2 scan tool can “ talk” to eac h of these m odules by sending a mess age to a controller and as king only
it to respond. The communication rate is at 8192 baud. The normal voltage on this circuit is about 5 volts, but
when the Tech 2 scan tool is com municating with a controller, the voltage will vary and if read with a DVM may
read about 2.5 volts
C14 – INJECTOR CIRCUIT VOLTAGE MONITOR INPUT SIGNAL
The injector voltage monitor line is used so that the PCM will know the exact voltage the fuel injectors are
operating at. This voltage signal is used to modify the fuel injector pulse width calculation.
C15 – THROTTLE POSITION (TP) SENSOR
REFERENCE VOLTAGE
This voltage should always be 5 volts anytim e the ignition is “ ON.” It is a regulated voltage output from the PCM,
and supplies 5 volts to the TP sensor.
C16 – EGR/A/C PRESSURE SENSOR REFERENCE VOLTAGE
This voltage should always be 5 volts anytim e the ignition is “ ON.” It is a regulated voltage output from the PCM,
and supplies 5 volts to the A/C Pressure Sensor and EGR valve.
D1 – VEHICLE SPEED SENSOR – OUTPUT SHAFT SPEED INPUT SIGNAL HIGH
The transmission has an output shaft speed sensor used by the PCM to calculate vehicle speed, and to help
determ ine various autom atic trans mission shifting f unctions. It is a m agnetic inductive sens or that generates an
AC voltage signal sent to the PCM. If measured with the digital AC voltmeter, no voltage will appear until the
output shaft begins turning.
D2 – VEHICLE SPEED SENSOR – OUTPUT SHAFT SPEED INPUT SIGNA L LOW
The transmission has an output shaft speed sensor used by the PCM to calculate vehicle speed, and to help
determ ine various autom atic trans mission shifting f unctions. It is a m agnetic inductive sens or that generates an
AC voltage signal sent to the PCM. If measured with the digital AC voltmeter, no voltage will appear until the
output shaft begins turning.
D3 – OXYGEN SENSOR EARTH
- LEFT BANK –
This terminal should have zero volts. It is connected directly to the engine earth. This terminal earths the PCM
circuitry for the O2 voltage monitor inside the PCM.
D4 – OXYGEN SENSOR INPUT SIGNAL
- LEFT BANK –
W ith ignition “ON” and engine not running, the voltage should be 350 – 450 m illivolts ( 0.350 – 0.450 volts). T his
is the PCM-supplied 02 c ircuit “bias” voltage. With the engine running and af ter the 02 sens or is hot, the voltage
should be rapidly changing, somewhere between 10 – 1000 millivolts (0.010 – 1.000 volt).
D5 – OXYGEN SENSOR EARTH
- RIGHT BANK –
This terminal should have zero volts. It is connected directly to the engine earth. This terminal earths the PCM
circuitry for the O2 voltage monitor inside the PCM.
D6 – INTAKE AIR TEMPERATURE / TRANSMISSION FLUID TEMPERATURE / EGR VALVE / A/C
PRESSURE SENSOR EARTH CIRCUIT
This terminal should be zero volts. It is connected through the PCM circuitry to engine earth.
D7 – INTAKE AIR TEMPERATURE (IAT) INPUT SIGNAL
The PCM sends a 5 volt signal voltage to the IAT sensor, which is a temperature – variable-resistor called a
thermistor. The sensor is also connected to earth, and will alter the signal voltage according to incoming air
temper ature. As the air tem perature inc reases, the voltage s een on this term inal dec reases . At 0 degrees C, the
voltage will be above 4 volts. At normal operating temperature (10 degrees C to 80 degrees C) the voltage will
be less than 4 volts.
D8 – NOT USED
D9 – DIAGNOSTIC TEST ENABLE INPUT SIGNAL
This terminal is connected to the DLC diagnostic test enable terminal. W hen the diagnostic test term inal is not
earthed, this terminal will have 5 volts on it. When the DLC diagnostic test enable terminal is earthed, the
resulting zero voltage at the PCM will cause it to operate in Diagnostic Mode.
D10 – A/C REFRIGERANT PRESSURE SENSOR
INPUT SIGNAL
The signal that is sent from the pressure Sensor to the PCM indicates to the PCM what the A/C pressure is at.
Depending on the A/C pressure, this signal will indicate to the PCM if A/C pressure is to low or to high.
D11 – ENGINE COOLANT TEMPERATURE (ECT)INPUT SIGNAL
The PCM sends a 5 volt signal voltage out to the engine coolant temperature sensor, which is a temperature-
variable-resistor called therm istor. The sensor, being also connected to earth, will alter the voltage according to
engine coolant temperature. As the engine coolant temperature increases, the voltage seen on terminal B5
decreases. At 0 degrees C engine coolant temperature the voltage will be above 4 volts. At normal operating
temperature (85 degrees C to 100 degrees C) the voltage will be less than 2 volts.
D12 – BATTERY VOLTAGE FEED
- HOT AT ALL TIMES –
This supplies the PCM with full-time +12 volts. It stays hot even when the ignition is turned off. It receives its
voltage through the “ENGINE” fuse F31. This PCM terminal could be called the power supply and “MEMORY”
terminal.
D13 – TRANSMISSION FLUID TEMPERATURE (TFT) INPUT SIGNAL
- AUTO TRANS ONLY
The PCM s ends a 5 volt signal voltage out to the trans m ission f luid tem perature s ensor, which is a temperatur e-
variable-resistor called therm istor. The sensor, being also connected to earth, will alter the voltage according to
transmission fluid temperature. As the fluid temperature increases, the voltage seen on The PCM terminal will
decrease.
D14 – NOT USED
D15 – NOT USED
D16 – IGNITION SWITCH INPUT SIGNAL
This is the “ turn on” signal to the PCM f rom the ignition switch c ircuit. It is not the “power supply” to the PCM, it
only tells the PCM that the ignition s witc h is “ON.” T he voltage should equal the battery voltage when the ke y is
in either the `run’ or `crank’ position.
E1 – NOT USED
E2 – FUEL INJECTOR 2 – CONTROL
The voltage seen at these terminals actually comes through the injectors, which are connected to +12 volts.
With the engine not running, the voltage seen would be battery voltage. With the engine running at idle, the
charging system increases the voltage slightly, so this voltage will increase. With higher engine RPM or more
engine load, the resulting increase in injector pulse frequency or injector pulse width will cause this voltage to
appear slightly less.
E3 – NOT USED
E4 – FUEL INJECTOR 1 – CONTROL
The voltage seen at these terminals actually comes through the injectors, which are connected to +12 volts.
With the engine not running, the voltage seen would be battery voltage. With the engine running at idle, the
charging system increases the voltage slightly, so this voltage will increase. With higher engine RPM or more
engine load, the resulting increase in injector pulse frequency or injector pulse width will cause this voltage to
appear slightly less.
E5 – FUEL INJECTOR 4 – CONTROL
The voltage seen at these terminals actually comes through the injectors, which are connected to +12 volts.
With the engine not running, the voltage seen would be battery voltage. With the engine running at idle, the
charging system increases the voltage slightly, so this voltage will increase. With higher engine RPM or more
engine load, the resulting increase in injector pulse frequency or injector pulse width will cause this voltage to
appear slightly less.
E6 – FUEL INJECTOR 6 – CONTROL
The voltage seen at these terminals actually comes through the injectors, which are connected to +12 volts.
With the engine not running, the voltage seen would be battery voltage. With the engine running at idle, the
charging system increases the voltage slightly, so this voltage will increase. With higher engine RPM or more
engine load, the resulting increase in injector pulse frequency or injector pulse width will cause this voltage to
appear slightly less.
E7 – SYSTEM EARTH
These terminals should have zero volts. They are connected directly to the engine earth.
E8 – NOT USED
E9 – TRANSMISSION FLUID PRESSURE CONTROL
SOLENOID (TFP) – HIGH
- AUTO TRANS ONLY –
The duty cycle, and am ount of current f low to the TFP, are controlled by the PCM. T his circuit is the B+ supply
line from the PCM to the TFP. The duty cycle and amperage are controlled by the PCM.
E10 – FUEL PUMP (FP) RELAY CONTROL
Turning the ignition “ON” causes the PCM to energise (+12V) the Fuel Pump Relay. If no crankshaft reference
input pulses are received, the PCM turns “OFF” the relay. As soon as the PCM receives crankshaft reference
input pulses, the PCM will turn the Fuel Pump Relay on again.
E11 – NOT USED
E12 – EGR CONTROL
The PCM monitors EGR actual position and adjust pintle position accordingly. The PCM uses information from
several sensor s to contr ol the pintle pos ition. T he PCM provides a PWM 12 volt control signal (% Duty) for EGR
operation.
E13 – TRANSMISSION PRESSURE CONTROL
SOLENOID (PCS) – LOW
- AUTO TRANS ONLY –
The 4L60-E automatic transmission uses an electrical solenoid to control hydraulic pressure inside the
transmission. This electrical solenoid allows the PCM to control “line pressure”, similar to other automatic
transm issions that use a “throttle valve” cable or vacuum modulator. T he duty cycle, and am ount of cur rent flow
to the PCS, are both controlled by the PCM. By m onitoring this line, the PCM can determine if the comm anded
amperage has gone to the PCS and returned to the PCM.
E14 – NOT USED
E15 – NOT USED
E16 – LPG FCV (LPG Only)
This is the PCM output PWM signal to the Fuel Control Valve for LPG air/fuel ratio adjustment.
F1 – FUEL INJECTOR 2 – CONTROL
The voltage seen at these terminals actually comes through the injectors, which are connected to +12 volts.
With the engine not running, the voltage seen would be battery voltage. With the engine running at idle, the
charging system increases the voltage slightly, so this voltage will increase. With higher engine RPM or more
engine load, the resulting increase in injector pulse frequency or injector pulse width will cause this voltage to
appear slightly less.
F2 – FUEL INJECTOR 4 – CONTROL
The voltage seen at these terminals actually comes through the injectors, which are connected to +12 volts.
With the engine not running, the voltage seen would be battery voltage. With the engine running at idle, the
charging system increases the voltage slightly, so this voltage will increase. With higher engine RPM or more
engine load, the resulting increase in injector pulse frequency or injector pulse width will cause this voltage to
appear slightly less.
F3 – PRNDL A
These circuits along with PCM circuit F6 indicate to the PCM what transmission gear the driver has selected.
The PCM will then send a command via the serial data line to the instrument panel cluster (smart cluster) to
indicate to the driver what gear has been selected.
F4 – FUEL MODE SWITCH (LPG Only) This is the input signal from the LPG/Petrol switch indicating to the
PCM what mode of fueling the driver has selected.
F5 – NOT USED
F6 – PRNDL P
This circuit along with PCM circuits F3, F8, F9 indicate to the PCM what transmission gear the driver has
selected. The PCM will then send a command via the serial data line to the instrument panel cluster (smart
cluster) to indicate to the driver what gear has been selected.
F7 – SYSTEM EARTH
These terminals should have zero volts. They are connected directly to the engine earth.
F8 – PRNDL B
These circuits along with PCM circuit F6 indicate to the PCM what transmission gear the driver has selected.
The PCM will then send a command via the serial data line to the instrument panel cluster (smart cluster) to
indicate to the driver what gear has been selected.
F9 – PRNDL C
These circuits along with PCM circuit F6 indicate to the PCM what transmission gear the driver has selected.
The PCM will then send a command via the serial data line to the instrument panel cluster (smart cluster) to
indicate to the driver what gear has been selected.
F10 – NOT USED
F11 – RANGE SIGNAL A INPUT SIGNAL
- AUTO TRANS ONLY –
Range signal “A”, “B” and “C”. The PCM sends out a buffered 12 volt signal to the pressure switch assembly,
located in the automatic transmission valve body. The 12 volt signal must pass through either a normally open
or norm ally closed s witc h to reach earth. W hen the switches ) are closed, the signal should be near 0 volts. The
PCM monitors the status of these signals to determine which gear servo is actually receiving hydraulic apply
pressure.
F12 – RANGE SIGNAL B INPUT SIGNAL
- AUTO TRANS ONLY –
Range signal “A”, “B” and “C”. The PCM sends out a buffered 12 volt signal to the pressure switch assembly,
located in the automatic transmission valve body. The 12 volt signal must pass through either a normally open
or norm ally closed s witc h to reach earth. W hen the switches ) are closed, the signal should be near 0 volts. The
PCM monitors the status of these signals to determine which gear servo is actually receiving hydraulic apply
pressure.
F13 – RANGE SIGNAL C INPUT SIGNAL
- AUTO TRANS ONLY –
Range signal “A”, “B” and “C”. The PCM sends out a buffered 12 volt signal to the pressure switch assembly,
located in the automatic transmission valve body. The 12 volt signal must pass through either a normally open
or norm ally closed s witc h to reach earth. W hen the switches ) are closed, the signal should be near 0 volts. The
PCM monitors the status of these signals to determine which gear servo is actually receiving hydraulic apply
pressure.
F14 – POWER/ECONOMY INPUT SIGNAL
- AUTO TRANS ONLY –
The PCM s ends a signal of about 12 volts, and monitors the status of this circuit. In the ECON OMY pos ition the
switch is open, the PCM voltage status signal remains high – about 12 volts, and the PCM does not allow shift
point changes. When the transmission switch is pressed to the POWER position the switch is momentarily
closed and the PCM voltage status signal is momentarily pulled low. The PCM senses the momentary voltage
signal drop and enables power m ode shif ting only if other criteria are met. Thes e criteria include throttle position
and engine speed.
F15 – OIL PRESSURE SWITCH
This is a earth input to the PCM from the Oil Pressure Switch indicating proper oil pressure when the engine is
running. If oil pressure is lost while the engine is running, the oil switch will open its contacts and the earth
signal to the PCM will be rem oved. When the PCM sees this los s of ear th signal, the PCM will comm and the oil
lamp ON.
F16 – IGNITION SWITCH INPUT SIGNAL (LPG Only)
This is the “ turn on” signal to the PCM f rom the ignition switch c ircuit. It is not the “power supply” to the PCM, it
only tells the PCM that the ignition s witc h is “ON.” T he voltage should equal the battery voltage when the ke y is
in either the `run’ or `crank’ position.
PCM V6 ENGINE AND TRANSMISSION DIAGNOSTIC TROUBLE CODES (DTC)
DTC
DESCRIPTION ILLUMINATE
“CHECK
POWERTRAIN”
LAMP
P0012 No revolutions per minute signal – normal when engine is not
running No
P0101 Mass Air Flow (MAF) Sensor Out of Range Yes
P0111 Intake Air Temperature Signal Voltage Unstable No
P0112 Intake Air Temperature Signal Voltage Low No
P0113 Intake Air Temperature Signal Voltage High No
P0117 Engine Coolant Temperature Signal Voltage Low Yes
P0118 Engine Coolant Temperature Signal Voltage High Yes
P0121 Throttle Position Sensor Stuck Yes
P0122 Throttle Position Sensor Voltage Low Yes
P0123 Throttle Position Sensor Voltage High Yes
P0131 Right Hand Oxygen Sensor Signal Voltage Low Yes
P0132 Right Hand Oxygen Sensor Signal Voltage High Yes
P0134 No Right Hand Oxygen Sensor Signal Yes
P0151 Left Hand Oxygen Sensor Signal Voltage Low Yes
P0152 Left Hand Oxygen Sensor Signal Voltage High Yes
P0154 No Left Hand Oxygen Sensor Signal Yes
P0170 Long Term Fuel Trim (LTFT) Delta High No
P0173 Short Term Fuel Trim (STFT) Delta High No
P0200 Injector Voltage Monitor Fault No
P0218 Transmission Fluid Overtemperature Yes
P0325 DSNEF System Fault Yes
P0327 Left Hand Knock Sensor Circuit Fault Yes
P0332 Right Hand Knock Sensor Circuit Fault Yes
P0341 Cam/Crank Sensor Signal Intermittent No
P0342 Camshaft Position Sensor Signal Missing No
P0374 18X Reference Signal Missing No
P0400 EGR Flow Fault Indicated No
P0405 EGR Position Fault No
P0446 Canister Purge Circuit Fault No
P0502 No Vehicle Speed Signal Yes
P0503 Vehicle Speed Sensor Intermittent Signal No
P0506 Idle Speed Error No
P0507 Vacuum Leak No
P0530 A/C Refrigerant Pressure Sensor Circuit Fault No
P0560 System Voltage Too High (Long Time) Yes
P0561 System Voltage Unstable Yes
P0562 System Voltage Low Yes
P0563 System Voltage Too High Yes
P0601 Powertrain Control Module Memory Yes
PCM V6 ENGINE AND TRANSMISSION DIAGNOSTIC TROUBLE CODES (DTC) (CONTINUED)
P0712 Transmission Fluid Temperature Signal Voltage Low No
P0713 Transmission Fluid Temperature Signal Voltage High No
P0730 2-3 Shift Solenoid B Circuit Voltage High Yes
P0740 Torque Converter Clutch Enable Solenoid Circuit Fault Yes
P0741 Torque Converter Clutch System Stuck On No
P0748 Pressure Control Solenoid Current Error No
P0753 1-2 Shift Solenoid A Circuit Voltage High Yes
P0756 1-2 Shift Solenoid A Circuit Voltage Low Yes
P0757 2-3 Shift Solenoid B Circuit Voltage Low Yes
P0785 3-2 Down-Shift Control Solenoid Circuit Fault Yes
P1064 Low Speed Fan – No BCM Response No
P1116 Engine Coolant Temperature Signal Voltage Unstable No
P1255 Theft Deterrent Signal Missing Yes
P1351 Ignition Electronic Spark Timing (EST) Circuit Fault Yes
P1361 Ignition Bypass Circuit Fault Yes
P1372 No Reference Pulses While Cranking Yes
P1571 Requested Torque Out Of Range Yes
P1627 PCM - Analog to Digital (A/D) Conversion Error Yes
P1628 PCM Error – Engine Coolant Temperature Circuit No
P1642 LPG Enable Signal Out Of Range No
P1643 LPG FCV PWM Signal Out Of Range No
P1810 Transmission Fluid Pressure Manual Valve Position Switch
Assembly Circuit Malfunction Yes
P1860 Torque Converter Clutch Pulse Width Modulation Solenoid Fault No
P1870 Transmission Slipping No
4L60 E TRANSMISSION FLUID CHECKING PROCEDURE
GENERAL INFORMATION
W hen adding or changing the tr ansmiss ion fluid, use only Dexr on III. Ref er to the Series Owner's Handbook for
the recommended servicing intervals.
Because this transmission fluid changes colour and smell very easily in its life, these indicators should not
necessarily be relied upon to diagnose either transmission internal condition or fluid deterioration.
The Fluid Checking Procedure shows that a dark brown fluid colour, coupled with a delayed shift pattern, may
only indic ate that the fluid requires replacem ent and alone, is not a definite indic ation of a potential transm ission
failure.
NOTE: Do not overfill the transmission. Overfilling will cause foaming of the fluid, loss of fluid, shift complaints
and possible damage to the transmission.
TRANSMISSION FLUID COLOUR
Trans mission f luid colour when new and unused, is red. A red dye is added so that it can be distinguished from
other oils and lubricants. The red dye is not an indicator of fluid quality and is not permanent. As the vehicle is
driven, the transm ission fluid will quickly begin to look darker in colour. The colour will then appear light brown.
A DARK brown colour with a distinctively burnt odour MAY indicate fluid deterior ation and a need for the fluid to
be changed.
TRANSMISSION FLUID CHECKING PROCEDURE
1. Start the engine and drive vehicle for a maximum of 24 km, or until the transmission normal operating
temperature is reached.
NOTE: As tem peratur e greatly affec ts tr ansm iss ion fluid levels, this operation m ust only be carried out when the
transmission is at normal operating temperature (82 - 94 degrees C). If the vehicle is not at normal operating
temperature, and the proper checking procedures are not followed, the result could be a false reading of the
fluid level on the dipstick.
2. Park vehicle on level earth.
3. Move gear selector to 'PARK' position.
4. Apply park brake.
5. Let engine idle for 3 minutes with accessories turned off.
6. Locate r ed coloured dips tick in the engine com partment, lif t the lock ing lever, rem ove the dipstick and check
fluid colour, condition and level.
7. If the fluid level is low, add only enough DEXRONâ III to bring the level into the "HOT" area.
Inaccurate fluid level readings will result if checked im mediately after the vehicle has been operated under any
or all of the following conditions:
a. In high ambient temperatures above 32 degrees C.
b. At sustained high speeds.
c. In heavy city traffic during hot weather.
d. Towing
e. In commercial use (e.g. taxi).
If the vehicle has been operated under these conditions, switch the engine off and allow the vehicle to 'cool' for
approximately thirty minutes. After cool-down period, re-start the vehicle and continue from step 2.
4L60-E AUTOMATIC TRANSMISSION FLUID CHECKING PROCEDURE
STEP ACTION VALUE YES NO
1. Check the fluid colour.
Is the fluid colour red? Go to Step 2 Go to Step 11
2. Is the fluid level satisfactory? Go to Step 20 Go to Step 3
3. Check the fluid.
Is the fluid foamy? Go to Step 8 Go to Step 4
4. Check the fluid level. The proper fluid level should be In
the middle of the X-hatch.
Is the level high?
Go to Step 9 Go to Step 5
5. Fluid will be low.
Add fluid to the proper fluid level.
Is the fluid level satisfactory?
Go to Step 6 Go to Step 1
6. Check for external leaks.
Were any leaks present? Go to Step 7 Go to Step 20
7. Correct the fluid leak condition.
Is action complete? Go to Step 20
8. Is the fluid level too high? Go to Step 9 Go to Step 10
9. Remove excess fluid to adjust to the proper fluid level.
Is action complete? Go to Step 20
10. 1. Check for contaminants in the fluid.
2. Drain the fluid to determine the source of the
contamination.
Is action complete?
Go to Step 15
11. Is the fluid colour non-transparent pink? Go to Step 12 Go to Step 13
12. Replace the cooler.
Is action complete? Go to Step 15
13. The fluid colour should be light brown. Transmission fluid
may turn dark with normal use. This does not always
indicate oxidation or contamination.
Is the fluid colour light brown?
Go to Step 14 Go to Step 1
14. Drain the fluid to determine if the fluid is contaminated.
A very small amount of material in the bottom of the pan
is a normal condition, but large pieces of metal or other
material in the bottom of the pan requires a transmission
overhaul.
Was the fluid contaminated?
Go to Step 15 Go to Step 18
15. Overhaul the transmission. Refer to Section 7C5, unit
repair in VX Service Information.
Is action complete?
Go to Step 16
16. Flush the cooler.
Is action complete? Go to Step 17
17. Add new fluid.
Is action complete? Go to Step 19
18. Change the fluid and filter.
Is action complete? Go to Step 19
19. Is the fluid level satisfactory, If not, correct as necessary.
Is action complete? Go to Step 20
20. Refer to 4L60-E Transmission Functional T est Procedure,
in Section 7C3, Diagnosis, in VX Service Information.
Is action complete?
Fluid Checking
Procedure
Completed
TABLE A V6 PCM -
ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK
CIRCUIT DESCRIPTION:
The On-Board Diagnostic System Check is an organised approach in identifying a problem created by a
powertrain control system malfunction. It must be the starting point for any driveability complaint diagnosis,
because it directs the service technician to the next logic al step in diagnosing the com plaint. Understanding the
Table and using it correctly will reduce diagnostic time and prevent the unnecessary replacement of good parts.
Test Description: Number(s) below refer to step number(s) on the diagnostic Table.
1. This s tep is a c heck f or the pr oper oper ation of the "Chec k Powertrain" lamp (MIL) . T he PCM should provide
serial data communication path for the "Check Powertrain" lamp, this is a bulb check. The "Check
Powertrain" lam p should be "ON." If it can do this, it conf irm s that the PCM has power, earth and is capable
of some functions.
If the "Check Powertrain" lamp is "OFF," this indicates a problem in the "Check Powertrain" lamp fuse
circuits or the PCM earth circuits or the PCM's serial data communication circuit or a problem with the
instrument cluster. Table A-1 will check for both ignition feed and constant battery power to the PCM and
the PCM earth.
2. This check is done to see if the PCM has the capability of performing internal diagnostics. With the
diagnostic "test" term inal ear thed, the "Check Powertr ain" lamp, should f lash a DTC 0012 or flash any other
DTC(s ) stor ed in mem or y. DTC 0012 m eans there is no c rankshaf t r ef erenc e s ignal coming to the PCM, this
is normal because the engine is not running.
3. T his chec k is used to see if the PCM can supply serial data for T ech 2 sc an tool use. If a EEPRO M error is
present, the PCM may have been able to flash DTC 0012 but not enable serial data.
4. This check is to see there are any Theft Deterrent DTC stored. If Theft Deterrent system is enabled, this
may be the cause of the no crank condition.
5. This test determines if the vehicle is able to crank. If the vehicle will not crank, refer to Table A-4.0 to
diagnosis starter cranking circuit.
7. T his test is us ed to determ ine the caus e of a "Crank s But Will Not Run," although the PCM is powered up, a
"Cranks But Will Not Run" symptom could exist because of a PCM problem or the vehicle electrical system.
8. Look at all the param eters to determ ine if one is not in a normal s tate with just the ignition "ON" and engine
stopped. Look at the ECT value to see if the value is shifted above or below where it should be. If so, refer
"Diagnostic Aid Table" on DTC P0118.
9. Look at all the parameters to determine that all values are within typical ranges for normal operating
temperatures at idle. Keep in mind that a basic engine problem may alter sensor value.
DIAGNOSTIC AIDS:
If the Serial Data circuit is shorted to voltage or earth or open, the vehicle will not crank. Check Serial Data
circuit from PCM to BCM, and from BCM to all other controllers.
M
I
C
R
O
VXPCM30
INSTRUMENTPCM
12 SERIAL
DATA
5V
G/W (1220)
LOC. E3
R/B (1221)
CHECK
POWERTRAIN
LAMP
12V
5V
5V
D9
C13
SERIAL
DATA
DIAGNOSTIC
ENABLE
W/B (451)
BCM
E2
D2 E9
D3
DATA LINK
CONNECTOR
1546
1613129
B (150)
B/Y (155 )
M
I
C
R
O
YE111
YE112
YB198
YE111
YE114
YB66
YB164
YB175
YB164
YB175
YB128
DATA LINK CO NNECTO R
YB128
(863)
O/B BLU/B R/B
(1221)
(740)
16 9
(1220)
(155)
B/Y G/W
W/B
(451)
B
(150)
Y
(1049)
1
8
YB66
INSTRUMENTS
T
BLU/B
BR/W
(234)
(25)
(14)
(10)
(875)
(155)
(1340)
G/W
(44)
(121)
(8)
(30)
BLU/Y
G
O/Y
P/BLU
BR/R
V/W
(33)
(946)
(1220)
(88)
(15)
(123)
(85)
(19)
GY
W
V/R
BR
BR/O
Y/R
B/Y
LBLU
BLU
TABLE A V6 PCM - ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK
STEP ACTION VALUE YES NO
1.
1. Ignition "ON" engine "STOPPED".
2. Observe the "CHECK POWERTRAIN" lamp (MIL).
Is the "CHECK POWERTRAIN" lamp (MIL) "ON" steady?
Go to Step 2 If
No, "CHECK
POWERTRAIN"
lamp, Go to
Table A-1 in this
Section
----------------------
If "CHECK
POWERTRAIN"
lamp is flashing
DTC 0012, or
any other DTC
Go to Step 10
2. Jumper Data Link Connector (DLC) terminal "6" To "5".
Does "CHECK POWERTRAIN" lamp flash DTC 0012, or
any other DTC?
Go to Step 3 Go to Table A-1
in this Section
3. 1. Disconnect Data Link Connector jumper.
2. Install scan tool to Data Link Connector.
Does scan tool display PCM serial data.?
Go to Step 4 Go to Table A-2
in this Section
4. 1. Ignition "ON".
2. Using Tech 2 scan tool, check for DTC P1255.
Is DTC P1255 set?
Go to DTC
P1255 Table Go to Step 5
5. Does engine crank? Go to Step 6 Go to
Table A-4.0
6. 1. With Tech 2 scan tool, display DTC(s).
Are any Diagnostic Trouble Codes displayed?
NOTE: Check both Current and History codes.
Refer To
Applicable DTC
Table.
Start with lowest
DTC
Go to Step 7
7. Does engine start? Go to Step 8 Go to
Table A-3.1
8. 1. Ignition "ON", engine "STOPPED".
2. Compare Tech 2 scan tool data with typical values
shown on scan data page.
Are values normal or within typical ranges?
Go to Step 9 Refer to
indicated
"Component(s)-
System" checks
in this Section.
TABLE A V6 PCM - ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK
STEP ACTION VALUE YES NO
9. 1. Run engine until normal operating temperature is
reached.
2. Run engine at 1500 revolutions per minute for 2
minutes, then idle engine.
3. Compare Tech 2 scan data with typical values
shown on "scan data" page in this Section.
Are values normal or within typical ranges?
Refer to
"Symptom"
Diagnosis
Tables" in
Section 6C1-2B
of the VX Series
Service
Information
Refer to
indicated
"Component(s)-
System "checks
in this Section
10. Check for earthed diagnostic "TEST" terminal circuit.
Was a problem found? Verify Repair Go to Step 11
11. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
TABLE A-1 V6 PCM -
NO "CHECK POWERTRAIN" MALFUNCTION INDICATOR LAMP (MIL)
CIRCUIT DESCRIPTION:
There should always be a steady "Check Powertrain" (MIL) lamp with the ignition "ON" and engine stopped.
Battery voltage is supplied directly to the "Check Powertrain" (MIL) lamp bulb through a fused circuit. The
Powertrain Control Module (PCM) will control the lamp via serial data communication to the Body Control
Module (BCM) on the ser ial data circuit. When the PCM determ ines that the "Chec k Powertrain" lam p should be
"ON", the PCM will send a message on the serial data circuit to the BCM requesting the (MIL) "ON". The BCM
will then send a serial data communication message to the instrument panel (IP) Cluster. The IP Cluster will
then determine what message the BCM is sending, and will then turn "ON" the "Check Powertrain" lamp.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. Fuse F13 supplies power to the instrument panel cluster. If this fuse is blown, the cluster lamps will not light.
5. If the T ech 2 sc an tool will not comm unicate with the vehicle, there m ay be a problem in the serial data line.
Table A-2 will check this serial data line.
6. If the Tech 2 scan tool is capable of commanding the MIL "ON" and "OFF", the PCM may be at fault.
7. This step checks for proper serial data voltage to the instrument panel (IP) cluster.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
P.C.M CONNECTOR 3
YB1 99
E1
F1
G
(842)
BLU
(841)
GY
(845)
Y
(846)
B/R
(750)
R
(1228)
G/W
(465)
V
(435)
GY/BLU
(1229)
(843)
V
(844)
BR/Y
(771)
BLU/W
(766)
W
(750)
B/R
Y
(772)
GY
(773)
BR/Y
(1224)
Y
(1225)
GY
(1226)
BLU
(774)
BLU/R
(31)
E16
F16
P
(39))
B/BLU
(1062)
(936)
BLU/O
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
DATA LINK CO NNECTO R
YB128
(863)
O/B BLU/B R/B
(1221)
(740)
16 9
(1220)
(155)
B/Y G/W
W/B
(451)
B
(150)
Y
(1049)
1
8
YB66
INSTRUMENTS
T
BLU/B
BR/W
(234)
(25)
(14)
(10)
(875)
(155)
(1340)
G/W
(44)
(121)
(8)
(30)
BLU/Y
G
O/Y
P/BLU
BR/R
V/W
(33)
(946)
(1220)
(88)
(15)
(123)
(85)
(19)
GY
W
V/R
BR
BR/O
Y/R
B/Y
LBLU
BLU
M
I
C
R
O
VXPCM30
INSTRUMENTPCM
12 SERIAL
DATA
5V
G/W (1220)
LOC. E3
R/B (1221)
CHECK
POWERTRAIN
LAMP
12V
5V
5V
D9
C13
SERIAL
DATA
DIAGNOSTIC
ENABLE
W/B (451)
BCM
E2
D2 E9
D3
DATA LINK
CONNECTOR
1546
1613129
B (150)
B/Y (155 )
M
I
C
R
O
YE111
YE112
YB198
YE111
YE114
YB66
YB164
YB175
YB164
YB175
YB128
TABLE A-1 V6 PCM - NO "CHECK POWERTRAIN" MALFUNCTION INDICATOR LAMP (MIL)
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section
2. Check IP cluster fuse F13.
Is fuse OK? Go to Step 3 Go to Step 9
3. 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. Ignition "ON".
4. Probe PCM battery feed circuits and ignition feed
circuit with a test light connected to earth.
Is the test light "ON" for all circuits?
Go to Step 4 Go to Step 15
4. 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. Probe PCM earth circuits with a test light connected
to B+.
Is the test light "ON" for both circuits?
Go to Step 5 Go to Step 16
5. 1. Ignition "OFF".
2. Reconnect PCM connectors.
3. Connect Tech 2 scan tool to DLC.
4. Ignition "ON", engine stopped.
Does Tech 2 scan tool display PCM serial data?
Go to Step 6 Go to Table A-2
6. With scan tool still connected to DLC, command the MIL
"ON" using the scan tool.
Does the MIL turn "ON" when commanded "ON" using
the scan tool?
Go to Step 14 Go to Step 7
7. 1. Ignition "OFF".
2. Remove IP Cluster from dash panel.
3. Ignition "ON".
4. Using DVM, probe IP Cluster connector terminal
12 with the DVM connected to earth.
Does the DVM display a varying voltage between the
specified value?
3-5 volts Go to Step 8 Go to Step 10
8. Check for poor connection between the IP Cluster and
cluster connector.
Was a problem found?
Verify Repair Go to Step 11
9. Repair short to earth in IP cluster fuse circuit.
Is action complete ? Verify Repair
10. Repair open in the serial data circuit from the BCM to
IP Cluster.
Is action complete?
Verify Repair
11. Check "Check Powertrain " (MIL) bulb for open.
Was a problem found? Go to Step 12 Go to Step 13
12. Replace "Check Powertrain " (MIL) bulb.
Is action complete? Verify Repair
13. Replace IP cluster.
Is action complete? Verify Repair
TABLE A-1 V6 PCM - NO "CHECK POWERTRAIN" MALFUNCTION INDICATOR LAMP (MIL) (CONT)
STEP ACTION VALUE YES NO
14. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Security Link
procedure.
Is action complete?
Verify Repair
15. Check for short to earth, and repair open in power circuit
that did not light test light.
Is action complete?
Verify Repair
16. Repair open in earth circuit that did not light test light.
Is action complete?
TABLE A-2 V6 PCM -
NO SERIAL DATA, WILL NOT FLASH DTC P0012, MALFUNCTION INDICATOR LAMP
(MIL) "CHECK POW ERTRAIN" LAMP "ON" STEADY
CIRCUIT DESCRIPTION:
There s hould always be a steady (MIL) "Check Powertrain" lamp when the ignition is "O N" and engine stopped.
Battery voltage is supplied directly to the (MIL) "Check Powertrain" lamp bulb. The Powertrain Control Module
(PCM) will control the "Check Powertrain" lamp and turn it "ON" via the serial data communication circuit..
With the ignition "ON", engine stopped and diagnostic "test" terminal earthed, the "Check Powertrain" lamp
should flash a DTC 0012, followed by any diagnostic trouble code(s) stored in memory.
A steady lamp suggests a fault in the IP cluster.
With the Tech 2 scan tool connected to the DLC and the ignition switch on, the scan tool should display serial
data communication. If the scan tool does not display serial data, the serial data circuit may be open or shorted.
There are several other control modules that are connected to the serial data line (PCM, BCM, ABS/ETC
module, ECC module, SRS module and IP cluster). Any one of these controllers could cause a fault on the
serial data line. This fault could result in the scan tool not being able to display serial data.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. This step checks to see if the PCM will flash DTC 0012 or any other DTC.
3. This step checks to see if the Tech 2 scan tool will
communicate with the PCM.
4. Using a Digital Volt\Ohm meter (DVM), there should be 3 to 5 volts at the DLC terminal 9. If the voltage is
higher or lower, serial communication will be effected. This serial data circuit is also connected to several
other controllers. A problem with any one of these other controllers, may cause serial data communication
malfunction.
13. T his step c hec ks to see if the Serial Data circ uit is shor ted to voltage or earth. Chec k Serial Data circ uit fr om
PCM, to BCM, and from BCM to all other controllers.
DIAGNOSTIC AIDS:
If there is a fault with the serial data circuit, it could be caused by one or more of the several controllers
connected to this serial data circuit. Isolate the fault by disconnection one at a time each controller until the
serial data communication is restored.
M
I
C
R
O
VXPCM30
INSTRUMENTPCM
12 SERIAL
DATA
5V
G/W (1220)
LOC. E3
R/B (1221)
CHECK
POWERTRAIN
LAMP
12V
5V
5V
D9
C13
SERIAL
DATA
DIAGNOSTIC
ENABLE
W/B (451)
BCM
E2
D2 E9
D3
DATA LINK
CONNECTOR
1546
1613129
B (150)
B/Y (155 )
M
I
C
R
O
YE111
YE112
YB198
YE111
YE114
YB66
YB164
YB175
YB164
YB175
YB128
P.C.M CONNECTOR 3
YB1 99
E1
F1
G
(842)
BLU
(841)
GY
(845)
Y
(846)
B/R
(750)
R
(1228)
G/W
(465)
V
(435)
GY/BLU
(1229)
(843)
V
(844)
BR/Y
(771)
BLU/W
(766)
W
(750)
B/R
Y
(772)
GY
(773)
BR/Y
(1224)
Y
(1225)
GY
(1226)
BLU
(774)
BLU/R
(31)
E16
F16
P
(39))
B/BLU
(1062)
(936)
BLU/O
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
DATA LINK CO NNECTO R
YB128
(863)
O/B BLU/B R/B
(1221)
(740)
16 9
(1220)
(155)
B/Y G/W
W/B
(451)
B
(150)
Y
(1049)
1
8
TABLE A-2 V6 PCM - NO SERIAL DATA OR WILL NOT FLASH DTC P0012,
MALFUNCTION INDICATOR LAMP (MIL) "CHECK POWERTRAIN" LAMP "ON" STEADY
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section.
2. 1. Ignition" ON" engine stopped.
2. Earth diagnostic "TEST" terminal No. 6.
Does "CHECK POWERTRAIN" lamp flash DTC 0012 or
any other DTC?
Go to Step 3 Go to Step 6
3. 1. Connect Tech 2 scan tool to DLC.
2. Ignition "ON", engine stopped.
Does Tech 2 scan tool display PCM serial data?
No trouble found Go to Step 4
4. 1. Ignition "ON" engine stopped.
2. Using DVM, probe DLC terminal 9 with DVM
connected to earth.
Does DVM display voltage varying between the specified
value?
3-5 volts Go to Step 5 Go to Step 8
5. Check connections between the DLC and the PCM. If not
OK repair, if connection are OK, Replace PCM,
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information for PCM Programming and
Security link procedure.
Is action complete?
Verify Repair
6. 1. Ignition "ON" engine stopped.
2. Using DVM, probe DLC terminal 6 with DVM
connected to earth.
Does DVM display voltage at specified value?
5 volts Go to Step 13 Go to Step 12
TABLE A-2 V6 PCM - NO SERIAL DATA OR WILL NOT FLASH DTC P0012,
MALFUNCTION INDICATOR LAMP (MIL) "CHECK POWERTRAIN" LAMP "ON" STEADY (CONTINUED)
STEP ACTION VALUE YES NO
7. Replace IP cluster.
Is action complete? Verify Repair
8. Is voltage steady at or above the specified value? 5 volts Go to Step 11 Go to Step 9
9. 1. Connect Tech 2 scan tool to DLC.
2. Ignition "ON", engine stopped.
Does Tech 2 scan tool display BCM serial data?
Go to Step 10 Go to Step 13
10. Repair open or short to earth in the serial data circuit
between the PCM and the DLC.
Is action complete?
Verify Repair
11. Repair short to voltage on the serial data circuit.
NOTE: Insure that none of the other controllers on the
serial data circuit are causing this voltage
problem. Unplug each controller one at a time
to isolate short to voltage.
Is action complete?
Verify Repair
12. Check for an open in the Diagnostic Test circuit from the
PCM to the DLC.
Was a problem found?
Verify Repair Go to Step 5
13. Check for short to earth or short to voltage or open in the
serial data line.
Refer to Diagnostic Aids.
Was a problem found?
Verify Repair Go to Step 7
TABLE A-3.1 V6 PCM -
ENGINE CRANKS BUT WILL NOT RUN
CIRCUIT DESCRIPTION:
This is the first of several diagnostic T ables that must be followed in an orderly, progressive fashion in order to
find the cause of a no-start. These Tables assume an adequate supply of good quality fuel is in the fuel tank,
that the cranking motor circuit is in good working order, and that the engine will crank with adequate RPM.
Thes e Tables also assum e that no Diagnostic T rouble Code (DT C) P1255 or P1372 is set in the PCM m emory,
as determined by the On-Board Diagnostic Circuit Check. The On-Board Diagnostic System Check is always
the beginning point for all diagnostic procedures.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
1. The PCM must be operable. The On-Board Diagnostic System Check will prove that. There are few
chances that the PCM itself would cause a no-start, but the On-Board Diagnostic System Check will
uncover any problems in the PCM power and earth circuitry.
4. NOTE: If the vehicle is fitted with LPG, and If the vehicle will not start in the LPG mode only, and no DTC
P1642 is set, PCM term inal A3 circuit 937 may be shorted to voltage. Refer to Section 8A2 LPG SYSTEM
in VX Service Information for further diagnosis of the LPG system.
This checks for a short to earth on the injector control circuit. If this were to occur, the engine would be
extremely flooded, since the injectors would be "ON" continuously, and would inject fuel any time there is
fuel pressure.
5. Any time the PCM has been "OFF" for at least 10 seconds, it should energise the Fuel Pump Relay for 2
seconds after the ignition is tur ned "ON." If the engine is not crank ed, the PCM should turn the relay "OFF"
after 2 seconds. Proper operation of the Fuel Pump electrical circuit would be noted here by the test light
being "ON" for 2 seconds after the ignition switch is turned to the "ON" position. After 2 seconds, the test
light should go "OFF."
6. Note that this check is for sufficient voltage at the spark plug wire. If, for some reason, the spark plug
electrodes were wet with fuel (engine f looded), this could c ause a no-start. However, a "flooded" engine is a
symptom of some other problem. There is no normal condition that should ever be able to "flood" the
engine.
7. This is a quick check of the fuel system. The easiest place to install the pressure gauge is where the fuel
pipes come up into the engine compartment. There are 2 hoses, and the gauge must be connected to the
hose or pipe leading directly to the fuel rail. This connection is on the left (passenger) side of the fuel rail
(refer Service Operation 3.10 FUEL CONTROL SYSTEM; Fuel System Pressure Test of the VX Series
Service Information). The other hose or pipe leads to the pressure regulator, and no pressure testing is
done there. If the pressure is not as specified, or continues to drop after the pump stops running, the Fuel
System Diagnostic Table A-4.3 in this Section must be used.
VXPCM017
# 2 # 4 # 6
# 1 # 3 # 5
PCM
C12
D12
E6
F2
E2
E4
F1
E5
C14
D16
BATTERY FEED
BATTERY FEED
O (740)
O (740)
BLU (841)
V (84 3)
GY (845)
INJECTOR CONTROL
IN JECTOR VOLTAGE
MONITOR LINE
IGNITION FEED
O/Y (479)
EFI RELAY
B/W (152)
P (3)
O/B (740)
IGN SW
M
I
C
R
O
R (481)
P (39 )
P/B
(39)
Y (84 6)
BR/Y (844)
G (842)
F31
F14
F34
+-
BATTERY
FS
FJ
R (2H)
(1040)
YE112
YB198
YB198YE112
YE39
YE114
YE39 YB199
YE22
YE22
NOTE: Use ST 125 spark checker or equivalent. An ST 125 requires about 25,000 volts (25 k ilovolts, or 25 k V)
to "spar k ". Do not us e a s par k plug in open air ear thed to the engine as an indic ation of s uf f ic ient "spar k". Only a
few kilovolts are required to jump the gap of a spark plug outside of the engine, and that would be an
inadequate test of the ignition coil output ability.
INJECTORS
GY
(1)
(842)
(481)
Y
V
BLU
(6)
(4)
(2)
(846)
(843)
G
R
(845)
(841)
(5)
(844)
BR/Y
(3)
FUEL PUMP RELAY
YE 96
(465)
G/W
(152)
B/W V
(120)
O
(240)
TABLE A-3.1 V6 PCM - ENGINE CRANKS BUT WILL NOT RUN
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Is DTC P1255 present ? Go to DTC
P1255 Table in
this Section
Go to Step 3
3. Is DTC P1372 present ? Go to DTC
P1372 Table in
this Section
Go to Step 4
4. NOTE: If this vehicle is fitted with LPG and the engine will
not start in the LPG mode only, and DTC P1642 is not
set, check the LPG Enable circuit 937 at PCM terminal
A3 for a short to voltage.
1. Check fuel tank quantity .
2. Disconnect ALL injector electrical connectors.
3. Connect test light between the terminals of each
injector harness connector.
• Be very careful to NOT short across the terminals,
or to engine earth.
4. Ignition "ON", note test light.
Is light "OFF" ?
Go to Step 5 Go to Step 8
5. 1. Probe Fuel Pump Relay "5" circuit with a test light
connected to earth.
2. Ignition "ON".
3. Using TECH 2 scan tool, Select Fuel Pump.
4. Activate Fuel Pump.
Is test light "ON"?
Go to Step 6 Go to
Table A-4.1
in this Section
6. 1. Ignition "OFF".
2. Remove the spark plug leads from 2 spark plugs.
3. Connect ST 125 spark checker (refer note above) to
each individually, and check for spark while cranking
the engine.
4. Check both wires. A few sparks and then nothing
is considered no spark.
Was there spark on both wires ?
Go to Step 7 Go to
Table A-8.1 in
this Section
TABLE A-3.1 V6 PCM - ENGINE CRANKS BUT WILL NOT RUN
STEP ACTION VALUE YES NO
7. 1. Ignition "OFF".
2. Reconnect both spark plug leads to spark plugs.
3. Reconnect all injector electrical connectors.
4. Remove Fuel Pump Relay from engine compartment
"FUSE AND RELAY CENTRE," and crank engine
for 15 seconds to relieve any residual fuel pressure.
5. Ignition "OFF," connect Fuel Pressure Gauge
• (Gauge to be installed in the pressure line,
between the fuel feed hose and the fuel inlet
line to the fuel rail, at left rear of fuel rail.)
6. Reinstall Fuel Pump Relay
7. Observe fuel pressure when ignition is turned
"ON."
8. Pressure should be within the value, and not
continue to drop after pump stops running.
Is fuel pressure at or between the value ?
270 to 350
kPa Go to
Table A-3.2 in
this Section
Go to
Table A-4.3 in
this Section
8. Repair short to earth on Injector Circuit.
Was Injector Circuit shorted to earth ? Verify Repair Go to Step 9
9. Replace PCM.
Refer to Section 6C1-3 Service Operations, for PCM
Programming and Security Link procedure.
Is action complete?
Verify Repair
TABLE A-3.2 V6 PCM -
ENGINE CRANKS BUT WILL NOT RUN
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
6. "STEADY LIGHT " indicates the PCM is continuously supplying the ear th path on the injector circuit. It is not
a harness problem at this point; That would have been in TABLE A-3.1. This may destroy an injector, as
they are designed to be energised in short pulses and may not withstand 100% "ON" time. If any injector
check s les s than 11.4 ohm s, it c ould be the cause of the def ective PCM. T he PCM can be dam aged when it
attempts to energise the injector circuit with a very-low-resistance load. Normal injector resistance is
approximately 12.2 ohms at 20 degrees C per individual injector.
INJECTORS
GY
(1)
(842)
(481)
Y
V
BLU
(6)
(4)
(2)
(846)
(843)
G
R
(845)
(841)
(5)
(844)
BR/Y
(3)
VXPCM017
# 2 # 4 # 6
# 1 # 3 # 5
PCM
C12
D12
E6
F2
E2
E4
F1
E5
C14
D16
BATTERY FEED
BATTERY FEED
O (740)
O (740)
BLU (841)
V (84 3)
GY (845)
INJECTOR CONTROL
IN JECTOR VOLTAGE
MONITOR LINE
IGNITION FEED
O/Y (479)
EFI RELAY
B/W (152)
P (3)
O/B (740)
IGN SW
M
I
C
R
O
R (481)
P (39 )
P/B
(39)
Y (84 6)
BR/Y (844)
G (842)
F31
F14
F34
+-
BATTERY
FS
FJ
R (2H)
(1040)
YE112
YB198
YB198YE112
YE39
YE114
YE39 YB199
YE22
YE22
TABLE A-3.2 V6 PCM - ENGINE CRANKS BUT WILL NOT RUN
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. • From Table A-3.1.
1. Ignition "OFF".
2. With all injectors disconnected, connect test light
across both harness terminals of one injector
connector.
• Be very careful to not short across the terminals, or
to engine earth.
3. Have a helper crank the engine while you closely
observe the test light.
4. Test light should blink while cranking, indicating
electrical injector pulses are present, do this test for
all injectors
Did test light blink while cranking ?
Go to Step 3 If
there was no
blinking light, Go
to Table 3.3 in
this Section
----------------------
If
the test light was
on steady (no
blinking light) Go
to Step 6
3. Check the remaining 5 injector connectors for
blinking test light, as described in step 2.
Did all the remaining injector connectors blink the
test light ?
Go to Step 4 Go to Step 5
4. • At this point, the fuel control system, fuel delivery
system, and ignition system are OK.
Check For:
• Fouled spark plugs.
• Proper MAF sensor operation. If engine
will start with MAF sensor electrical
connector disconnected, refer Table
A-6.1 in this Section.
• Proper TP sensor circuit operation. Use
Tech 2 scan tool to monitor TP sensor
signal. If voltage is over 1.25 volts with
throttle closed, refer Table A-6.2 in this
Section.
• Restricted exhaust system. Loosen
front pipe from exhaust manifold(s). If
the engine will start, refer Table A-13 in
this Section.
• Improper engine coolant temperature
(ECT) sensor resistance. Refer DTC
P0118 Diagnostic Aids in this Section to
check resistance of ECT sensor.
• Water or foreign material in fuel, or
incorrect fuel.
• Spark plug wires crossed.
• Camshaft timing chain.
• Inadequate engine compression.
Is action complete?
Verify Repair
5. Repair open in injector power circuit and injector circuit to
connector that did not blink the test light.
Is action complete ?
Verify Repair
6. Check for a short to earth in injector circuit that caused
test light to stay "ON" steady.
Was a problem found?
Verify Repair Go to Step 7
TABLE A-3.2 V6 PCM - ENGINE CRANKS BUT WILL NOT RUN (CONTINUED)
STEP ACTION VALUE YES NO
7. Check resistance across each injector. Each injector
should be between the specified value.
Is each injector at the value ?
11.4 - 12.6
ohms Go to step 8 Go to step 9
8. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
9. 1. Replace any injector that did not measure within
the specified value.
2. Retest beginning at Step 2.
Is action complete?
11.4 - 12.6
ohms Verify Repair
TABLE A-3.3 V6 PCM -
ENGINE CRANKS BUT WILL NOT RUN
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2 "NO LIGHT" indicates no PCM control of the injector. Fuse F34 supplies +12 volts to the injectors. Probe
both terminals of one injector connector with a test light to earth. There should be a light on only one
terminal, confirming ignition voltage to one terminal, but not both.
3. The PCM inj ec tor control c irc uit may be open. Rec onnec t the injec tor s. Us ing a tes t light c onnected to ear th,
check for a light at the PCM connector terminals. A light at this point indicates that injector control circuit is
not "open." The voltage to light that test light comes from circuit 481, through the injector windings, and
continues through the injector control circuit to PCM connector terminals.
7. There is no terminal identification on the relay connector socket, but the relay itself has terminal numbers.
Make certain the correct relay connector socket terminal (NOT the relay) is being probed.
VXPCM017
# 2 # 4 # 6
# 1 # 3 # 5
PCM
C12
D12
E6
F2
E2
E4
F1
E5
C14
D16
BATTERY FEED
BATTERY FEED
O (740)
O (740)
BLU (841)
V (84 3)
GY (845)
INJECTOR CONTROL
IN JECTOR VOLTAGE
MONITOR LINE
IGNITION FEED
O/Y (479)
EFI RELAY
B/W (152)
P (3)
O/B (740)
IGN SW
M
I
C
R
O
R (481)
P (39 )
P/B
(39)
Y (84 6)
BR/Y (844)
G (842)
F31
F14
F34
+-
BATTERY
FS
FJ
R (2H)
(1040)
YE112
YB198
YB198YE112
YE39
YE114
YE39 YB199
YE22
YE22
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
P.C.M CONNECTOR 3
YB1 99
E1
F1
G
(842)
BLU
(841)
GY
(845)
Y
(846)
B/R
(750)
R
(1228)
G/W
(465)
V
(435)
GY/BLU
(1229)
(843)
V
(844)
BR/Y
(771)
BLU/W
(766)
W
(750)
B/R
Y
(772)
GY
(773)
BR/Y
(1224)
Y
(1225)
GY
(1226)
BLU
(774)
BLU/R
(31)
E16
F16
P
(39))
B/BLU
(1062)
(936)
BLU/O
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
E.F.I RELAY
YE 39
B/W
P/B
O/Y
(152)
(39)
(479)
(1040)
ENGINE 12V BUS
INJECTORS
GY
(1)
(842)
(481)
Y
V
BLU
(6)
(4)
(2)
(846)
(843)
G
R
(845)
(841)
(5)
(844)
BR/Y
(3)
TABLE A-3.3 V6 PCM - ENGINE CRANKS BUT WILL NOT RUN
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Ignition "OFF"
2. Disconnect injector connectors. From Table A-3.2
No Light
3. Ignition "ON," engine stopped.
4. Probe each terminal of each injector harness
connector with a test light to earth.
Is the test light "ON" at each terminal?
Go to Step 3 If
the test light was"
ON" at both
terminals, repair
short to voltage
on injector circuit.
----------------------
If
there was no
light "ON", Go to
Step 7
3. 1. Ignition "OFF".
2. Reconnect injectors.
3. Ignition "ON".
4. Backprobe PCM injector control terminals with a
test light connected to earth.
Is test light "ON" at each terminal?
Go to Step 4 Go to Step 12
4. 1. Ignition "ON".
2. With a Tech 2 scan tool, monitor TP sensor
signal voltage.
Is voltage less than value?
1.25 volts Go to Step 5 Go to
Table A-6.2
in this Section
5. Check for faulty crankshaft reference High signal input to
PCM connector terminal.
Was a problem found?
Verify Repair Go to Step 6
TABLE A-3.3 V6 PCM - ENGINE CRANKS BUT WILL NOT RUN (CONTINUED)
STEP ACTION VALUE YES NO
6. Replace PCM.
Refer to Section 6C1-3 SERVICE OPERATIONS of the
VX Series Service Information, for PCM Programming
and Security Link procedure.
Is action complete?
Verify Repair
7. 1. Ignition "OFF".
2. Disconnect EFI relay.
3. Ignition "ON".
4. Probe EFI relay harness connector terminal "30" and
terminal "85" with a test light connected to earth.
Is the test light "ON" at both circuits?
Go to Step 8 Go to Step 13
8. 1. Ignition "OFF".
2. Disconnect EFI relay.
3. With test light connected to 12 volts, probe relay
harness terminal earth circuit of EFI relay.
Is test light "ON", is it?
Go to Step 9 Go to Step 14
9. Check injector fuse F34 for an open.
Was a problem found? Go to step 15 Go to Step 10
10. Check for an open in injector power circuit from fuse F34
to injector splice.
Was a problem found?
Verify Repair Go to Step 11
11. Replace EFI relay.
Is action complete? Verify Repair
12. Repair open injector control circuit that did not light test
light.
Is action complete?
Verify Repair
13. Check fuses and repair circuit that did not turn
"ON" test light.
Is action complete?
Verify Repair
14. Repair earth circuit to EFI relay.
Is action complete? Verify Repair
15. Repair short to earth in fuse circuit.
Replace fuse.
Is action complete?
Verify Repair
TABLE A- 4.0 V6 PCM -
STARTER CRANKING CIRCUIT
CIRCUIT DESCRIPTION:
W hen the ignition is turned to the "ON" position, battery power is supplied from a fusible link to the Start Relay
terminal "30". As the ignition switch is turned to the START position, power is supplied to the Start Relay
terminal 85. The PCM supplies the earth signal needed to energise the Start Relay and allows power to the
starter motor.
When the ignition is turned “ON”, the PCM will then look for the proper Theft Deterrent signal sent from the
BCM. If the PCM has determined that the proper Theft Deterrent signal is present, the PCM will allow the
vehicle to crank. If the PCM determines that a improper Theft Deterrent signal was sent from the BCM, or no
Thef t Deter rent s ignal was s ent, the PCM will not supply a earth signal from the PCM ter m inal to the Start Relay
terminal "86". When the Start Relay receives this earth signal from the PCM, the relay will be energised,
allowing the starter motor to operate. This removed earth signal to the Start Relay will cause the vehicle not to
crank.
If there is a problem with the Theft Deterrent signal from the BCM to the PCM, DTC P1255 will set.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. This step checks to see if DTC P1255 is set. This DTC could prevent the vehicle from cranking. This step
also verifies that if a PCM was replaced, that the Security Link procedure was performed.
3. This step checks to see if power is being applied to the starter motor. If test light lights, the problem is with
the starter motor.
12. This step checks the adjustment of the Neutral start switch.
VXPCM033
PCM
BCM
A13
SERIAL
DATA
STARTER
ENABLE
5V
SERIAL
DATA
MAIN
5V
BATTERY
FS
F31
A5/A6O/B (740)
(1040)
BATTERY M AIN POWER
FJ
R (2H)
F14
E20/D6P/B (39) IGNITION ON
15a 15 50
30 ACC
IGN
START
IGNITION SWI TCH
P (3)
B/Y
(155)
B
(150)
LOC. E3
LOC. G1 451691
DATA LINK
CONNECTOR
B/Y (155) ELECTRONIC EARTH
HIGH CURRENT
EARTH
A1/A5
LOC. E3
B/G (151) B10/B11
LOC. E3
E2/D2
E9/D3
E3/D13 SERIAL
DATA AUX.
R/B (1221)
GY/BLU
(1434)
GY
(434)
G/W (1220)
G/W (1220)
NEUTRAL START
BACK-UP SW.
( MANUAL
TRANS)
STARTER
MOTOR
M
START
RELAY
TO SRS
CONTROL
MODULE
TO INSTRUMENTS
ECC AND ABS/ETC
CONTROL MODULES
V (5)
A8
R (001 )
V (6 )
YB176
YB175
YB175
YB174
YB175
YB176
YB165
YB164
YB164
YB165
YB164
YB165
YB128
YB44
YE112
YB35
YB35
YE49
YE49
YB187
YB44
87 86
30 85
STARTER MOTOR SOLENOID
V
(6)
IGNITION SWITCH
YB 44
BR
(4)
V
(5)
(2)
R
(3)
P
Y E 49
START RELAY
V
(5)
(2)
GY
V/W
R
(434)
(6)
NEUTRAL START & BACK-UP SWITCH
(1434)
GY/BLU
(24)
LG GY
(434)
(750)
B/R
(42)
BR/BLU
TABLE A-4.0 V6 PCM - STARTER CRANKING CIRCUIT
STEP ACTION VALUE YES NO
1 Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2 1. Install a Tech 2 scan tool.
2. Using the scan tool, check for a DTC P1255.
Is DTC P1255 set?
Go to the
appropriate DTC
Table
Go to Step 3
3 1. Ignition OFF.
2. Using a test light, probe the starter solenoid terminal
"S" with test light connected to earth.
3. Have a helper turn the ignition switch to the START
position, note the test light.
Does the test light illuminate when the ignition switch is
turned to the START position?
Refer to
Section 6D1-2
Starting System -
V6 Engine of the
VX Series
Service
Information
Go to Step 4
4 1. Remove the start relay.
2. With a test light connected to earth probe the start
relay harness terminal 30.
3. Turn the ignition ON.
Does the test light illuminate?
Go to Step 5 Go to Step 15
5 1. With the start relay still removed and the test light
connected to earth probe the start relay harness
terminal 85.
2. Turn the ignition to the start position.
Did the test light illuminate?
Go to Step 7 Go to Step 14
6 Check for an open circuit between the starter solenoid
and the Start Relay.
Was a problem found?
Verify Repair Go to Step 8
7 1. Ignition OFF.
2. Remove the Start Relay.
3. Connect a test light between the relay harness
terminal 85 and terminal 86.
4. Turn the ignition switch to the START position.
Does the test light illuminate when the ignition switch is
turned to the START position?
Go to Step 6 Go to Step 9
8 Replace the Start Relay.
Is the action complete? Verify Repair
TABLE A-4.0 V6 PCM - STARTER CRANKING CIRCUIT (CONTINUED)
STEP ACTION VALUE YES NO
9 Is the vehicle equipped with a manual transmission? Go to Step 10 Go to Step 12
10 1. Ignition ON engine OFF.
2. With a test light connected to B+, probe both of the
circuits at the neutral start switch.
Did the test light illuminate at both terminals?
Go to Step 16 Go to Step 11
11 Check the adjustment of the neutral start switch. If the
Adjustment is OK, replace the neutral start switch.
Is the action complete?
Verify Repair
12 Check for open circuit from the neutral start switch to the
Start Relay.
Was a problem found?
Verify Repair Go to Step 17
13 Repair the short to earth in the faulty circuit.
Replace the fusible link or the fuse as necessary.
Is the action complete?
Verify Repair
14 Repair the open in the ignition circuit.
Is the action complete? Verify Repair
15 Check for an open circuit 2 including the fusible link.
Is the action complete? Verify Repair
16 Repair the open in circuit 434.
Is the action complete? Verify Repair
17 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
TABLE A-4.1 V6 PCM -
FUEL PUMP ELECTRICAL CIRCUIT
Circuit Description:
When the ignition switch is turned "ON," the Power Control Module (PCM) energises its Fuel Pump Relay
control output. It will provide +12 volts to the Fuel Pump Relay, as long as the engine is cranking or running, and
the PCM is receiving crankshaft reference input signal pulses.
If there are no ignition reference pulses (ignition "ON ," engine stopped - or - engine stalled), the PCM will shut
"OFF" the Fuel Pump Relay within 2 seconds.
Improper electrical control of the pump will result in one or more of the following symptoms:
• Cranks, but won't run.
• Hard start.
• Cuts out, may feel like ignition problem.
• Excessive cranking time.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. If the fuse is blown, this test will check f or short to earth on Fuel Pum p power feed circuit. To preve nt mis-
diagnosis, be sure Fuel Pump is disconnected and ignition is "OFF" before performing this test.
4. This checks to see if the cause of the blown fuse is a short to earth in the Fuel Pump Relay power feed
circuit..
8. Determ ines if the PCM and Fuel Pum p Rela y circuit ar e operatin g correct ly. The PCM sh ould turn "ON" the
Fuel Pum p Rela y.
- If test light stays "OFF," go to Table A-4.2
- If test light stays "ON," disconnect the Fuel Pump Relay. If the test light now stays "ON," repair short to
voltage on Fuel Pum p power feed circuit, but if the light goes out, check f or short to voltage on Fuel Pump
Relay control circuit. If no voltage on Fuel Pump Relay control circuit, replace relay.
9. This should turn "ON" the Fuel Pump if Fuel Pump power feed circuit wiring is OK. If the Fuel Pump runs
(Pump Runs? YES), the Fuel Pump electrical circuit is OK. Continue to Table A-4.3 in this Section to
complete the testing of the fuel delivery system.
14. The fuel pump is serviceable separate from the Modular Sender Assembly. Refer to
Section 6C1-3 Service Op erat ion s of the VX Series Serice Information for replacement procedures.
FUEL TANK
(156)
(155)
B/BLU
B/Y
(30)
(120)
T
V
FUEL PUMP RELAY
YE 96
(465)
G/W
(152)
B/W V
(120)
O
(240)
TABLE A-4.1 V6 PCM - FUEL PUMP ELECTRICAL CIRCUIT
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Check Fuel Pump fuse. ("F/PMP" fuse F28 in
engine compartment fuse and relay centre)
Is the Fuel Pump fuse blown ?
Go to step 3 Go to step 8
3. 1. Ignition "OFF".
2. Disconnect Fuel Pump electrical connector to pump.
3. Backprobe Fuel Pump Relay harness connector for
Fuel Pump power feed circuit.
with a test light connected to + battery terminal.
Is the test light "ON" ?
Go to Step 15 Go to step 4
4. 1. Ignition "OFF".
2. Reconnect Fuel Pump electrical connector.
3. Replace Fuel Pump fuse F28 ("F/PMP").
4. Ignition "ON".
5. Recheck fuse.
Is Fuel Pump fuse OK ?
Problem was an
intermittent short
to earth.
Go to step 5
5. Check for short to earth in Fuel Pump power feed circuit.
Was a problem found? Verify Repair Go to step 6
6. Check for shorted to earth Fuel Pump .
Was Fuel Pump shorted to earth ? Verify Repair Go to step 7
7. Replace Fuel Pump Relay.
Is action complete? Verify Repair
8. 1. Ignition "OFF" for 10 seconds:
2. Disconnect Fuel Pump Relay connector from relay
housing bracket.
3. With Fuel Pump Relay connected, probe relay
connector terminal "5" with test light connected to
earth.
4. Using TECH 2 scan tool, Select FUEL PUMP .
5 Turn Fuel Pump "ON" and "OFF"
Is test light "ON" and "OFF" when Fuel Pump is
"ON" and "OFF" ?
Go to Step 9 If Test
Light stays
"OFF", Go to
Chart A-4.2 in
this Section
-----------------------
-
If Test Light stays
"ON", Go to
Step 16
9. 1. Ignition "OFF".
2. Disconnect Fuel Pump Relay.
3. Apply +12 volts to Fuel Pump Relay terminal "5".
4. Check that the Fuel Pump is running, check by
listening for Fuel Pump operation in fuel tank.
Is Fuel Pump running ?
Go to Step 10 Go to Step 11
STEP ACTION VALUE YES NO
10. 1. Fuel Pump electric al circuits are OK.
2. Reconnect Fuel Pump Relay.
To complete testing of the fuel delivery pressure
system, continue to Chart A-4.3
Go to Chart
A-4.3 in this
Section
11. Check for faulty connection at Fuel Pump and relay.
Is connection faulty? Verify Repair Go to Step 12
12 Check for open in Fuel Pump power feed circuit.
Was a problem found? Verify Repair Go to Step 13
13. Check for open in Fuel Pump .
Is Fuel Pump open? Verify Repair Go to Step 14
14. If both circuits check OK, replace Fuel Pump .
Is action complete? Verify Repair
15. Check for and repair short to earth in Fuel Pump power
feed circuit.
Is repair complete?
Verify Repair
16. 1. Ignition "OFF".
2. Disconnect Fuel Pump Relay.
Is the test light "OFF"?
Go to Step 17 Go to Step 18
17. Repair short to voltage in circuit 465.
Is action complete ?
Verify Repair
18. Repair short to voltage in circuit 120.
Is action complete ? Verify Repair
TABLE A-4.2 V6 PCM -
FUEL PUMP ELECTRICAL CIRCUIT
Circuit Description:
Relay connector has no terminal identification. See diagram above for terminal identification.
There are 3 basic circuits to any relay. They are:
• LOAD - This is the device controlled by the relay. In this case, it is the Fuel Pumps power feed circuit.
• LINE - This is the vol tage supp ly that will po wer the load whenever th e rela y s witch c ontacts are clos ed. In
this case, it is the fused power circuit.
• CONTRO L - This is the cir cuitr y that en ergis es the sm all e lec tromagnet windi ngs in the r el a y, which c aus es
the-switching contacts to change position. In this case, one side of the relay windings is simply earthed.
The other control circuit is the +12 volts supplied by the PCM whenever it wants the relay to be energised.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. This checks the earth circuit) to the relay windings, part of the relay's control circuitry. (CONTROL)
3. This checks Fuel Pump +12 volt power supply circuit to the relay switching contacts. (LINE)
4. T his c hecks for the relay contr ol vo lta ge s up pl ied b y th e PC M to t he r e lay. (CONTROL) It is th e P CM's on ly
output that switches +12 volts to control a circuit. All other PCM outputs switch the earth circuit.
5. At th is point, the 3 other cir cuits to the re lay are OK. This check is to determ ine if the co ntacts in the r elay
will close, allowing the "line" voltage to pass through the switching contacts to the "load" terminal of the
relay, which goes to the fuel pump motor.
7. If the light stays "OFF," these checks will detect the fault in the Fuel Pump Relay control circuit.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
P.C.M CONNECTOR 3
YB1 99
E1
F1
G
(842)
BLU
(841)
GY
(845)
Y
(846)
B/R
(750)
R
(1228)
G/W
(465)
V
(435)
GY/BLU
(1229)
(843)
V
(844)
BR/Y
(771)
BLU/W
(766)
W
(750)
B/R
Y
(772)
GY
(773)
BR/Y
(1224)
Y
(1225)
GY
(1226)
BLU
(774)
BLU/R
(31)
E16
F16
P
(39))
B/BLU
(1062)
(936)
BLU/O
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
FUEL TANK
(156)
(155)
B/BLU
B/Y
(30)
(120)
T
V
FUEL PUMP RELAY
YE 96
(465)
G/W
(152)
B/W V
(120)
O
(240)
TABLE A-4.2 V6 PCM - FUEL PUMP ELECTRICAL CIRCUIT
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check.
2. • Test light stay's "OFF" on previous page.
1. Ignition "ON", engine stopped.
2. Disconnect Fuel Pump Relay connector from relay
housing bracket.
3. With Fuel Pump Relay connected, probe relay
connector earth circuit with a test light connected to
+12 volts.
Is test light "ON"?
Go to Step 3 Go to step 12
3. Probe relay connector power feed circuit with test light
connected to earth.
Is test light "ON" ?
Go to Step 4 Go to step 13
STEP ACTION VALUE YES NO
4. 1. Probe relay connector Fuel Pump Relay control
circuit with test light to earth.
2. Using TECH 2 scan tool, Select FUEL PUMP.
3. Turn Fuel Pump "ON" and "OFF".
Is test light "ON" and "OFF", when Fuel Pump is turned
"ON" and "OFF"?
Go to Step 5 For vehicles
without
Telematics Go to
Step 9.
For vehicles
withTelematics
Go to Step 7.
5. 1. Using TECH 2 scan tool, Select FUEL PUMP .
2. Turn Fuel Pump "ON" and "OFF".
3. Probe Fuel Pump Relay connector Fuel Pump power
feed circuit with test light to earth.
Is test light "ON" and "OFF", when Fuel Pump is
Turned "ON" and "OFF"?
Go to Step 6 Go to Step 9
6. Fuel Pump Relay is operating correctly.
Repair open in power feed circuit from Fuel Pump Relay
to Fuel Pump.
Is action complete?
Verify Repair
7 1. Probe the telematics connector YR55 terminal 12
fuel pump relay drive circuit circuit with test light to
earth.
2. Using TECH 2 scan tool, Select FUEL PUMP.
3. Turn Fuel Pump "ON" and "OFF".
Is test light "ON" and "OFF", when Fuel Pump is
turned "ON" and "OFF"?
Go to Step 8 Go to Step 14.
8. 1. Probe the telematics connector YR55 terminal 25
fuel pump relay drive circuit circuit with test light to
earth.
2. Using TECH 2 scan tool, Select FUEL PUMP.
3. Turn Fuel Pump "ON" and "OFF".
Is test light "ON" and "OFF", when Fuel Pump is
turned "ON" and "OFF"?
Go to step 9 Replace
Telematics
Module.
Refer Section
12Q Telematics
in this Service
Information.
9 1. Ignition "OFF"
2. Replace Fuel Pump Relay.
Will engine start ?
Verify Repair Go to OBD
System Check
(Table A)
10. Check for short to earth in Fuel Pump Relay control
circuit.
Was a problem found ?
Verify Repair. Go to step 11
11. Replace PCM.
Refer to Section 6C1-3 SERVICE OPERATIONS in this
Volume, for PCM Programming and Security Link
procedure.
Is action complete?
Verify Repair
12. Repair open in relay earth circuit .
Is action complete? Verify Repair
13. Repair open in Fuel Pump power feed circuit .
Is action complete? Verify Repair
14. Repair open in Fuel Pump Relay Control circuit .
Is action complete? Verify Repair
9
8
7
2
3
5
6
4
1
4280
10
1. Fuel Pressure Too LOW or Too HIGH or Pressure
That Continues to Drop After The Ignition is Turned
OFF Can Cause The Following Driveability
Complaints:
• Poor Idle Quality
• Excessive Exhaust Odor
• Poor Fuel Economy
• Excessive Cranking Time
• Detonation
• Loss of Power
• DTC P0132 or P0152
• DTC P0131 or P0151
2. Fuel Rail
3. Fuel Injectors
4. Vacuum Hose Fitting
5. Fuel Pressure Regulator
6. Fuel Return Line
7. Fuel Pressure Gauge Connects Into This Line For
Testing
8. Fuel Feed (Pressure) Line
9. Fuel Filter
10. Fuel Tank
TABLE A-4.3 V6 PCM -
FUEL DELIVERY SYSTEM
CIRCUIT DESCRIPTION:
Fuel is drawn from the tank by the electric fuel pump and is fed under pressure through a fuel filter and
continues on into the fuel rail and then is injected into the ports through the fuel injectors.
Fuel press ure in the system is governed by the fuel press ure regulator, in suc h a manner that a certain pressure
difference between fuel pressure and inlet manifold pressure is maintained. Excess fuel above the regulated
pressure is returned to the fuel tank by the pressure regulator and the fuel return line.
The fuel pump has a check valve to maintain pressure at the fuel rail after the pump stops running. The check
valve plays an im por tant part in the fuel delivery sys tem : to k eep the fuel r ail "charged" with fuel af ter the pum ps
shuts off. When the engine begins cranking to start, there is no delay before fuel injection begins, and quick
starting is ensured. The check valve is inside the fuel pump, and is not serviceable.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. These are electrical system checks, which must both be OK before any further fuel delivery system checks
can be made. If either do not "pass," refer Table A-4.1, Fuel Pump Electrical Circuit in this Section.
3. T his has eleven sequenc ed s egm ents to f ollow in or der. "1" and "2" is to reduce the r esidual pres sure in the
lines before opening the lines. "6" is to purge any air from the lines after installing the gauge. It also serves
to cool the fuel r ail for m ore accurate pres sure testing if the engine is hot. "8" is to allow the PCM to "power
down," so the next tim e the ignition is turned "ON," the PCM will energise its Fuel Pum p Relay c ontrol for 2
seconds . "9" and "10" indicate what the pressure should do when the ignition is turned "O N". There are two
things to note: (A) - pressure reading, and (B) - that the pressure does not continue to drop after the pump
stops running.
4. At this point, the r egulated pr ess ur e should be within specific ation, and the pr ess ur e does not drop when the
pump s tops running. This check is to see if the press ure regulator will modulate the regulated f uel pres sure
when the vacuum s ignal to it changes. During norm al engine operation, the regulated pr essure can c hange,
based on inlet manifold pressure. W hen the manifold pressure is at its lowest (engine idling), fuel pressure
will be at its lowest regulated pressure. When inlet manifold pressure is at its highest (wide open throttle),
regulated fuel pressure will be at its highest regulated pressure.
FUEL PUMP RELAY
YE 96
(465)
G/W
(152)
B/W V
(120)
O
(240)
TABLE A-4.3 V6 PCM - FUEL DELIVERY SYSTEM
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Ignition "ON".
2. Using TECH 2 scan tool, Select FUEL PUMP .
3. Turn Fuel Pump "On" and "OFF"
4. Listen for Fuel Pump in fuel tank.
Does fuel pump run when turned "ON" with TECH
2 scan tool?
Go to Step 3 Go to
Table A-4.1
in this Section
3. 1. Disable output test for Fuel Pump .
2. Turn ignition "OFF".
3. Remove Fuel Pump Relay from engine compartment
fuse and relay centre, then crank engine for 15
seconds to relieve any residual fuel pressure.
4. Connect Fuel Pressure Gauge, then reinstall fuel
pump relay.
5. Remove vacuum hose from fuel pressure
regulator.
6. Ignition "ON",
7. Enable output test with Tech 2 scan tool for Fuel
Pump and allow pump to run for 15 seconds. This is
to purge the lines of any air before pressure testing.
8. Disable output test for Fuel Pump .
9. Ignition "OFF" for 10 seconds.
10. Observe fuel pressure when ignition is turned "ON".
11. Pressure should be within specified value and not
continue to drop (after a small amount) after pump
stops running.
Is fuel pressure at or between the specified value and
holding?
270 to 350
kPa
Go to Step 4 Go to
Table A-4.4
in this Section
TABLE A-4.3 V6 PCM - FUEL DELIVERY SYSTEM (CONTINUED)
STEP ACTION VALUE YES NO
4. 1. Ignition "ON".
2. Enable output test with Tech 2 scan tool for fuel
pump and note fuel pressure.
3. Connect a hand vacuum pump to the fuel pressure
regulator vacuum fitting, and apply 38 cm Hg
of vacuum to the fuel pressure regulator.
4. Note fuel pressure with vacuum applied to
regulator.
When vacuum is applied, is fuel pressure at least specified
value difference then when no vacuum applied?
15 kPa Fuel supply
system OK.
Refit regulator
vacuum hose.
Go to Step 5
5. Replace fuel pressure regulator
Is repair complete ? Verify Repair
9
8
7
2
3
5
6
4
1
4280
10
1. Fuel Pressure Too LOW or Too HIGH or Pressure
That Continues to Drop After The Ignition is Turned
OFF Can Cause The Following Driveability
Complaints:
• Poor Idle Quality
• Excessive Exhaust Odor
• Poor Fuel Economy
• Excessive Cranking Time
• Detonation
• Loss of Power
• DTC P0132 or P0152
• DTC P0131 or P0151
2. Fuel Rail
3. Fuel Injectors
4. Vacuum Hose Fitting
5. Fuel Pressure Regulator
6. Fuel Return Line
7. Fuel Pressure Gauge Connects Into This Line For
Testing
8. Fuel Feed (Pressure) Line
9. Fuel Filter
10. Fuel Tank
TABLE A-4.4 V6 PCM -
FUEL DELIVERY SYSTEM
CIRCUIT DESCRIPTION:
Fuel is drawn from the tank by the electric fuel pump and is fed under pressure through a fuel filter and
continues on into the fuel rail and then is injected into the ports through the fuel injectors.
Fuel press ure in the system is governed by the fuel press ure regulator, in suc h a manner that a certain pressure
difference between fuel pressure and inlet manifold pressure is maintained. Excess fuel above the regulated
pressure is returned to the fuel tank by the pressure regulator and the fuel return line.
The fuel pump has a check valve to maintain pressure at the fuel rail after the pump stops running. The check
valve plays an important part in the fuel delivery system: to keep the fuel rail "charged" with fuel after the pumps
shuts off. When the engine begins cranking to start, there is no delay before fuel injection begins, and quick
starting is ensured. The check valve is inside the fuel pump, and is not serviceable.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. If the pr ess ur e continues to dr op af ter the pump st ops r unning, there is a leak somewhere. Either the Fuel Pump
check valve is leaking fuel back into the tank, the regulator has an internal leak allowing fuel to leak from the
pressure to the return side, or an injector is leaking (dripping).
TABLE A-4.4 V6 PCM - FUEL DELIVERY SYSTEM
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. • From Table A-4.3
• Fuel pressure not OK.
Does fuel pressure continue to drop after pump stops?
Go to Step 3 Go to Step 10
3. 1. Ignition "OFF" for 10 seconds.
2. While you observe the pressure gauge, have an
assistant turn the ignition "ON".
3. When the pump stops running, pinch shut the
rubber section of the pressure (supply) hose.
connection.
Fuel pressure should now hold, does it?
Go to Step 4 Go to step 7
4. Check for leaks in the "pressure-side" of the fuel
System.
Were any leaks found ?
Verify Repair Go to step 5
5. Replace fuel pump.
Is action complete? Verify Repair
6. Check For:
• Fuel pressure line restricted between pump and
fuel rail.
• Fuel supply line between tank and pump either
restricted or leaking.
• Restricted fuel filter.
• Restricted in-tank fuel strainer.
• Defective Fuel Pump .
Was a problem found?
Verify Repair Go to Service
Operation 3.10
FUEL
CONTROL
SYSTEM of the
VX Series
Service
Information for
Fuel Pump
pressure test
procedures
7. 1. Ignition "OFF" for 10 seconds.
2. Release pinched off pressure (supply) hose.
3. While you observe the pressure gauge, have an
assistant turn the ignition "ON".
4. When the pump stops running, pinch shut the
rubber section of the fuel return hose.
DO NOT PINCH OFF THE FUEL RETURN HOSE AT
THE FUEL PRESSURE REGULATOR.
Fuel pressure should now hold, does it?
Go to Step 8 Go to Step 9
8. Replace fuel pressure regulator.
Is action complete ? Verify Repair
9. Locate and replace leaking injectors.
Is action complete ? Go to Step 11
10. Is there fuel pressure? Go to Step 11 Go to Step 6
11. Is Pressure between specified values? 270 to 350
kPa
Fuel Delivery
System OK Go to
Table A-4.5
in this Section
9
8
7
2
3
5
6
4
1
4280
10
1. Fuel Pressure Too LOW or Too HIGH or Pressure That
Continues to Drop After The Ignition is Turned OFF Can
Cause The Following Driveability Complaints:
• Poor Idle Quality
• Excessive Exhaust Odor
• Poor Fuel Economy
• Excessive Cranking Time
• Detonation
• Loss of Power
• DTC P0132 or P0152
• DTC P0131 or P0151
2. Fuel Rail
3. Fuel Injectors
4. Vacuum Hose Fitting
5. Fuel Pressure Regulator
6. Fuel Return Line
7. Fuel Pressure Gauge Connects Into This Line For
Testing
8. Fuel Feed (Pressure) Line
9. Fuel Filter
10. Fuel Tank
TABLE A-4.5 V6 PCM
FUEL DELIVERY SYSTEM
CIRCUIT DESCRIPTION:
Fuel is drawn from the tank by the electric fuel pump and is fed under pressure through a fuel filter and
continues on into the fuel rail and then is injected into the ports through the fuel injectors.
Fuel press ure in the system is governed by the fuel press ure regulator, in suc h a manner that a certain pressure
difference between fuel pressure and inlet manifold pressure is maintained. Excess fuel above the regulated
pressure is returned to the fuel tank by the pressure regulator and the fuel return line.
The ex ternal fuel pum p has a chec k valve to m aintain pr essur e at the fuel rail after the pum p stops running. The
check valve plays an im portant part in the fuel deliver y system: to k eep the fuel rail "char ged" with f uel after the
pumps shuts off. W hen the engine begins cranking to start, there is no delay before fuel injection begins, and
quick starting is ensured. The check valve is inside the fuel pump , and is not serviceable.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. If any fuel lines, fittings, filter, or components are restricted, correct pressure cannot be attained.
6. W hen the fuel return hose is pinched shut, there is no pressure regulator control to lim it the pressure. The
pressure reading will be whatever the Fuel Pump is capable of producing. This is the same as attaching a
pressure gauge directly to the output of the Fuel Pump . The pressure reading would be a "maximum
pressure - no flow" reading, and should be well over 320 kPa. Do not allow the pressure to exceed 414 kPa.
10. At this point, the pressure checks are OK, but a complete test has not been performed. Return to
Table A-4.3 in this Section to complete the testing.
11. This is to determ ine if the cause of the high pressure is a restricted fuel return line, or a defective pressure
regulator. If the pressure is normal when the regulator outlet (hose or fuel pipe attached to regulator) is
connected only to an open hose, then the problem is a restricted return line between the regulator and the
tank.
12. The fuel pressure regulator on the Non-Supercharged Engine application is serviceable separate from the
fuel rail. The pressure regulator on the Supercharged Engine application is part of the fuel rail, and the
complete fuel rail must be replaced. Refer to section “3" in this service information for fuel pressure
regulator replacement service procedures.
TABLE A-4.5 V6 PCM - FUEL DELIVERY SYSTEM
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Is fuel pressure less than values? Go to Step 3 Go to Step 11
3. • There is low fuel pressure
1. Make close inspection of all fuel lines between fuel
tank and fuel rail for restrictions.
• This includes these lines:
- Tank to filter.
- Filter to fuel rail.
Were any restrictions found ?
Go to Step 4 Go to Step 5
4. Repair any restrictions, then recheck pressure.
Is action complete ? Verify Repair
5. Replace fuel filter, then recheck fuel pressure.
Is fuel pressure still less then value ? Less then 270
kPa Go to Step 6 Go to Step 10
6. 1. Ignition "OFF".
2. Pinch shut the fuel return hose at the
fuel gauge sender unit (this fuel return hose is the
lower hose). DO NOT PINCH OFF THE FUEL
RETURN HOSE AT THE FUEL PRESSURE
REGULATOR.
3. Ignition "ON"
4. Enable output test with Tech 2 scan tool for fuel
pump.
Is fuel pressure at or above the specified value?
350 kPa Go to Step 7 Go to Step 9
7. Replace pressure regulator and recheck pressure.
Is pressure now between value ? 270 to 350
kPa Verify Repair Go to Step 8
8. Replace in-tank fuel strainer.
Is action complete ? Verify Repair
9. • Pressure less than 320 kPa
Replace fuel pump
Is action complete ?
Verify Repair
10. Is pressure between value, and does not continue
dropping when pump stops ? 270 to 350
kPa Verify Repair Go to Table
A-4.1
11. 1. Disconnect fuel return line flexible hose from fuel
pipe that leads to the pressure regulator.
2. Attach a long length of hose to the fuel pipe leading
to the pressure regulator.
3. Insert other end of hose into an approved fuel
container.
4. Enable output test with Tech 2 scan tool for fuel
pump.
Is fuel pressure still more than value ?
350 kPa Go to Step 12 Go to Step 13
TABLE A-4.5 V6 PCM - FUEL DELIVERY SYSTEM (CONTINUED)
STEP ACTION VALUE YES NO
12. Replace pressure regulator
Is action complete ? Verify Repair
13. Locate and correct restricted fuel return line to
tank, or blocked return line screen filter in fuel tank
return connector, or screen in fuel pressure
regulator.
Is action complete ?
Verify Repair
TABLE A-6.1 V6 PCM -
MAF SENS OR OUTPUT CHECK
CIRCUIT DESCRIPTION:
The signal that is sent from the Mass Air Flow (MAF) sensor is sent in the form of a frequency output. A large
quantity of air passing through the MAF sensor will be indicated as a high frequency output (such as when
under acceleration). A small quantity of air passing through the sensor will be indicated as a low frequency
output (such as when decelerating or at idle). T he Tech 2 scan tool displays this inform ation both as air flow in
grams per second, grams per cylinder and frequency. A "normal" reading is approximately 4-9 grams per
second at idle and increases with RPM.
TEST DESCRIPTION: Number(s) below refer to Step number(s) on the diagnostic Table.
3. This step checks for the proper Mass Air Flow grams per second at idle.
4. This step checks for the proper Mass Air Flow grams per second at 2500 RPM.
5. This s tep c hecks the Mas s Air F low sensor for a steady decrease in gr ams per s ec ond as the RPM c hanges
from 2500 to idle.
DIAGNOSTIC AIDS:
Check air filter for being plugged
Check for air intake ducts for restrictions
Check air intake ducts for leaks after the MAF sensor
Check for partly restricted exhaust system
Check for any other source that would allow air into the engine after the MAF sensor.
This would include:
• inlet manifold gasket
• inlet manifold
• throttle body and or gasket
• PCV system, this includes the oil dipstick for proper seating
• injector o-rings
TABLE A-6.1 V6 PCM - MAF SENSOR OUTPUT CHECK
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Is DTC P0101 present? Go to DTC
P0101 Go to Step 3
3. 1. Ignition "ON", engine running at normal operating
temperature.
2. Using Tech 2 scan tool; select Data List, then select
"Mass Air Flow G/S".
3. With engine at idle, the Tech 2 scan tool should
indicate a MAF sensor reading between the
specified value.
Is the reading between the specified value ?
4-9 Grams
Per Second
(G/S)
at Idle
Go to Step 4 Go to Step 6
V6PCM006
IC
CIRCUIT
MASS AIR FLOW SENSOR
A7
A5
PCM
CBA
AIR FLOW
FROM
AIR FILTER
AIR FLOW
TO
THROTTLE BODY
EFI
RELAY
F33 P (43 9)
ENGINE EARTH
BR/W (792)
MASS AIR FLOW
INP U T SIG NAL
EARTH
5 V
M
I
C
R
O
IC
BR (750)
YE100
YE111 YB187
LOC. E5/E15
TABLE A-6.1 V6 PCM - MA F SENSOR OUTPUT CHECK (CONTINUED)
STEP ACTION VALUE YES NO
4. Increase engine RPM to 2500 and hold steady. The Tech
2 should now indicate a MAF sensor reading at the
specified value.
Is the reading at the specified value ?
17-20 Grams
Per Second
(G/S)
at
2500 RPM
Go to Step 5 Go to Step 6
5. Release the throttle, and watch the MAF sensor readings
on the Tech 2. The Mass Air Flow G/S should decrease
at a steady rate down to the reading determined at idle,
did it ?
No trouble found
with Mass Air
Flow sensor
Go to Step 6
6. Check for restrictions in the Mass Air Flow induction
system. Also check for air leaks after the MAF sensor or
a possible restricted exhaust system.
Refer to Diagnostic Aids above.
If all checks OK, replace the Mass Air Flow sensor.
Is action complete ?
Verify Repair
TABLE A-6.2 V6 PCM
TP SENSOR OUTP UT CHECK
CIRCUIT DESCRIPTION:
The Throttle Position (TP) sensor is attached to the throttle body, and is internally rotated by the throttle body
shaft. It is a potentiometer with one end connected to 5 volts f rom the PCM and the other to PCM earth. A thir d
wire is connected to the PCM, allowing it to measure the variable output voltage from the TP sensor.
As the throttle valve angle is changed ( accelerator pedal m oved), the T P Sensor output voltage also changes in
proportion. At a closed throttle position, the output voltage is usually below 1.0 volt. As the throttle valve opens,
the output increases so that, at wide-open throttle, the output should be above 4.0 volts. By monitoring the
output voltage from the TP sensor, the PCM can determine fuel needs based on throttle opening (driver
demand).
A brok en or loose TP Sensor, or one that has an unstable output, c an c ause inter mittent bursts of fuel because
the PCM thinks the throttle is moving. Results could include engine surge or poor idle quality. If the PCM
interprets a high voltage when engine RPM is less than 400, har d st arting c ould be the res ult ( clear - f lood mode).
A problem in any of the TP sensor circ uits will set either a DT C P0122 or DTC P0123 after the engine is started.
Once a Diagnostic Trouble Code is set, the PCM will use an artificial default value for TP sensor based on
engine RPM to enable the vehicle to be driven, although performance could be less than normal.
The TP sensor is not adjustable. The PCM uses the reading at idle as "0% throttle," so no adjustment is
necessary.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table. If a DTC P0122 or
DTC P0123 is present, follow that Table first,
2. This is a check of the voltage at the idle position. It is usually less than 1.0 volt.
3. The voltage should increase at the same steady rate at which the throttle is opened with the throttle valve.
6. With the throttle valve wide open, the TP sensor output needs to be above 4 volts, allowing the PCM to
interpret a wide open throttle position.
7. If the throttle s top screw has been inadvertently reset, the T P sensor output at idle c ould be out of allowable
limits.
9. If the closed-throttle voltage is over 2.5 volts, hard starting may be encountered (worse cold) due to "clear-
flood" mode. This mode occurs when engine RPM is less than 400, and TP sensor input indicates the
throttle is more than 80% open. Poss ible causes: short to voltage on input signal c ircuit, open earth circuit ,
or a faulty sensor.
DATA LINK CONNECTO R
YB128
(863)
O/B BLU/B R/B
(1221)
(740)
16 9
(1220)
(155)
B/Y G/W
W/B
(451)
B
(150)
Y
(1049)
1
8
THROTTLE POSITION SENS OR
YE 30
(452) (416)
(417)
GY
B/Y
BLU
VXPCM005
SENSOR EARTH
TP SENSOR SIGNAL
TP SEN SOR
REFERENCE
VOLTAGE
PCM
5V
M
I
C
R
O
C15
C7
C6
A
C
B
THROTTLE
POSITION SENSOR
GY (416)
BLU (417)
B/Y (452)
TO
ECT
SENSOR
YB198YE30
TABLE A-6.2 V6 PCM - TP SENSOR OUTPUT CHECK
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Ignition "ON", engine stopped, throttle plate closed.
2. Tech 2 scan tool set to TP sensor voltage.
Is voltage on Tech 2 scan tool within value shown?
0.25 to 1.25
volts Go to Step 3 Go to Step 4
3. 1. Ignition "ON".
2. With Tech 2 scan tool still connected, monitor the
voltage as the throttle is slowly and steadily
opened to a wide-open-position.
3. Voltage should increase at a steady rate, with no
sudden changes.
Did voltage increase at a steady rate with throttle
movement ?
Go to Step 6 Go to Step 8
4. 1. Ignition "ON", engine stopped.
2. Tech 2 'Scan" tool set to TP sensor voltage.
Is voltage on Tech 2 scan tool within value shown?
1.26 to 2.5
volts Go to Step 7 Go to Step 5
5. 1. Ignition "ON", engine stopped.
2. Tech 2 scan tool set to TP sensor voltage.
Is voltage on Tech 2 scan tool over value shown?
2.5 volts Go to Step 9 Go to Step 12
6. 1. Ignition "ON".
2. With the Tech 2 scan tool still connected, monitor
the voltage as the throttle valve is opened to the
wide open position.
• Have a helper ensure that the throttle valve is fully
open when accelerator pedal is fully depressed.
• If throttle valve does not fully open when pedal is
depressed, check for extra floor mats or carpet under
accelerator pedal. Then refer to SERVICE
OPERATIONS, 3.10 FUEL CONTROL SYSTEM –
Throttle Cable - "Adjust" in this Section.
Is the TPS voltage above the specified value?
4 volts TP sensor is
working properly
Go to OBD
System Check in
this Section
Go to Step 6
7. 1. Check throttle stop screw. refer to SERVICE
OPERATIONS, 3.10 FUEL CONTROL SYSTEM -
Throttle Stop Screw - "Reset Procedure" in this
Section.
Reset only if incorrect.
2. Ignition "ON".
3. Tech 2 scan tool connected to data link connector.
4. Recheck TPS voltage.
Is voltage now within the specified value ?
0.25 to 1.25
volts Go to Step 6 Go to Step 8
8. Replace TP sensor.
Is action complete ? Verify Repair
9. 1. Ignition "OFF".
2. Disconnect TPS.
3. Connect Tech 2 scan tool to data link connector,
set to TPS voltage.
4. Ignition "ON"
Is voltage on Tech 2 scan tool at or below specified
value?
1.25 volt Go to Step 10 Go to Step 11
10. Check for open in TP sensor earth circuit..
Was a problem found? Verify Repair Go to Step 8
11. Repair short to voltage on TP sensor signal circuit.
Is action complete ? Verify Repair
12. Repair short to earth on TP sensor signal circuit.
Is repair complete ? Verify Repair
TABLE A-6.3 V6 PCM -
OXYGEN SENSO R CHECK
CIRCUIT DESCRIPTION:
The oxygen s ensors are m ounted in the exhaus t pipes near the cylinders. At operating tem perature, the oxygen
sensors are required to respond quickly to changes to oxygen content in the exhaust. If the oxygen sensors
become contaminated or faulty, a sluggish driveability or a complaint of poor idle condition may exist. A proper
oxygen sensor response should be almost instantaneous to the fuelling mode command.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. Never perform this test on a cold engine. The oxygen sensor must be near nor mal operating temper ature for
this T able to work. It is im portant to see a low voltage and a high voltage res ponse very quic kly because this
means the oxygen sensor is not contaminated or faulty.
TABLE A-6.3 V6 PCM - OXYGEN SENSOR CHECK
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Ignition "ON", engine Running.
2. Run engine at 1600 to 1800 RPM for 2 minutes, or
until engine temperature is above 85 degrees C,
then let engine idle.
3. Using Tech 2 scan tool, select Misc. Test, then
A/F Ratio, then display "RH O2 Sensor and LH
O2 Sensor.
4. With engine idling, Press the Down select button on
Tech 2 scan tool until 11.7 A/F Ratio is displayed,
at the same time note the response of both O2
Sensors.
5. Both O2 Sensors should display above specified
value.
6. Then press the Up select button on Tech 2 scan
tool until 17.7 A/F Ratio is displayed, at the same
time note the response of both O2 Sensors.
7. Both O2 Sensors should display below specified
value.
Did both O2 Sensors display above and below the
specified value ?
Above 700
mV
Or
Below 100
mV
No trouble
found Go to Step 3
3. Replace the O2 Sensor that did not perform as specified
in Step 2.
Is action complete ?
Verify Repair
VXPCM003
PCM
D5
C9
D4
D3
GY/B (1413)
G/Y (1412)
LEFT OXYGEN SENSOR
RIGHT OXYGEN SENSOR
VB (413)
V (41 2)
RIGHT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL HI
RIGHT
OXYGEN
SENSOR
SIGNAL HI
IC
IC
M
I
C
R
O
450 mV
450 mV
YB198YE97
YE97
TABLE A-6.4 V6 PCM -
CANISTER PURGE SOLENOID CHECK
CIRCUIT DESCRIPTION:
The canister purge is controlled by a solenoid that allows manifold vacuum to purge the fuel vapour canister
when energised. The PCM supplies a earth to energise the solenoid (purge "ON").
If the following conditions are met with the engine running, the canister purge solenoid is energised.
• Engine run time after start more than 3 minutes and 15 seconds if coolant is less than 80 degrees C or
• Engine run time after start is more than 15 seconds if coolant is above 80 degrees C.
• Coolant temperature above 60 degrees C
• Engine not in Decel fuel cutoff mode.
• Throttle is less than 92%.
• Engine is in closed loop fuel mode or open loop fuel mode.
TEST DESCRIPTION: Number(s) below refer to Step number(s) on the diagnostic Table.
2. Checks to see if the solenoid is opened or closed. The solenoid is normally energised in this step, so it
should be open.
3. This checks to see if the Canister Purge Solenoid mechanical function is functioning properly by earthing
Canister Purge Solenoid several times with the Tech 2 scan tool.
4. This checks to see if +B volts is supplied to the Canister Purge Solenoid.
5. This checks to see if the PCM is supplying the earth signal for the Canister Purge Solenoid.
DIAGNOSTIC AIDS:
Normal operation of the Canister Purge Solenoid is described as follows:
W ith the ignition "ON", engine "OFF", diagnostic "Test" terminal unearthed, the Canister Purge Solenoid will be
de-energised.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
CANNISTER P URGE
(439) (428)
PG/Y
B
A
A
B
CANISTER PURGE
SOLENOID V ALVE
PCM
CANISTER PURGE
VXPCM027
A10
G/Y (428)
MANIFOLD
VACUUM
TO CARBON
CANISTER
B/W
(152)
LOC. E3
M
I
C
R
O
YE39YE39
YE99
YE111
YB187
F14
IGN SW
EFI
RELAY
+
-
BATTERY
FS
FJ
P (3) P/B
(39)
(1040) O/Y (479)
R (2H)
TABLE A-6.4 V6 PCM - CANISTER PURGE SOLENOID CHECK
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Note: This Table only covers the solenoid portion of the
Canister Purge system.
1. Ignition OFF.
2. Disconnect purge vacuum hose from top of canister,
and place a vacuum gauge in hose.
3. Ignition "ON", engine Running.
4. With Tech 2 scan tool enable Canister Purge
Solenoid "ON" with Up and Down buttons on Tech 2
scan tool.
Does vacuum gauge read manifold vacuum with canister
purge solenoid display "ON"?
No trouble found.
Canister Purge
Solenoid is OK.
Go to Step 3
3. 1. Ignition "ON", engine "OFF".
2. Place index finger on top of Canister Purge
Solenoid.
3. Enable Canister Purge Solenoid "ON" and "OFF"
several times with the Tech 2 scan tool.
Does the solenoid click while enabling and disabling ?
Canister Purge
Solenoid
electrical is OK.
Go to Step 10 for
vacuum check
Go to Step 4
4. 1. Ignition "ON", engine "OFF".
2. Disconnect Canister Purge Solenoid electrical
connector.
3. With a test light connected to earth, probe Canister
Purge Solenoid electrical connector power feed
circuit.
Is test light "ON" ?
Go to Step 5 Go to Step 6
5. 1. Ignition "ON", engine "OFF".
2. Disconnect Canister Purge Solenoid electrical
connector.
3. With a test light connected to +B volts, probe
Canister purge Solenoid electrical connector Purge
Solenoid control circuit.
4. With Tech 2" Scan" tool, enable Canister Purge
Solenoid "ON" with up and down buttons on the
Tech 2 scan tool.
Is test light "ON" when Canister Purge Solenoid is
commanded "ON" ?
Go to Step 7 Go to Step 8
6. Check for open in power feed circuit.
Is action complete ? Verify Repair
7. Replace Canister Purge Solenoid.
Is action complete ? Verify Repair
8. Check for open in Purge Solenoid control circuit from
PCM to Canister Purge Solenoid.
Was a open found ?
Verify Repair Go to Step 9
9. Check for poor connection at PCM. If connection is
OK, replace PCM. Refer to Section 6C1-3 Service
Operations of the VX Series Service Information, for the
Programming and Security Link procedure.
Is the action complete?
Verify Repair
10. Check manifold vacuum hose from manifold to Canister
Purge Solenoid for kinks, pinched, cracked, or plugged.
Repair as necessary.
Is action complete?
Verify Repair
TABLE A-6.5 V6 PCM -
EFI RELAY DIAGNOSIS
CIRCUIT DESCRIPTION
The EFI relay protects the battery from a parasitic draw. The following components are powered by the EFI
relay:
• Injectors
• DIS Module
• Transmission
• A/C System
• EVAP Solenoid
• MAF Sensor
• Oxygen Sensors
DIAGNOSTIC AIDS
• The following may cause an intermittent:
- Poor connections. Check for adequate terminal tension.
- Corrosion.
- Incorrectly routed harness.
- Rubbed through wire insulation.
- Broken wire inside the insulation.
4350
+
-
BATTERY
LOC . E 1
FS
(1040) O (7 40 )O/B (740)
D12
C12
BATTERY
BATTERY
F31
PCM
D16
(39)
(P)
(740)
(O)
(740)
(O)
IGNITION
FJ
R (2H)
15a 15 50
30 OFF/ON
LOCK
ACC
IGN
START
IGNITION SWITCH
P (3)
F14 P/ B (39)
EFI RELAY
O/Y
(479) LOC. E3
LG
(482)
M
I
C
R
O
P
R
O
C
E
S
S
O
R
F35
C14 IN JECTOR VOLTAGE
MONITOR LINE
F34
R
(481)
TO
INJECTORS
F35
LG
(482)
TO DIS
MODULE
F32
P/BLU
(339)
TO 3-2
SOLENOID
TO 1-2 SHIFT
SOLENOID A
TO 2-3 SHIFT
SOLENOID B
TO TCC ENABLE
SOLENOID
TO TCC PWM
SOLENOID
TO MAF
SENSOR
P
(439)
TO CANISTER
PURGE SOLENOID
TO A/C
RELAY
TO DIS
MODULE
YB44 YE112 YB198
YB198
YE111
YE111
YE111
YE111
YE111
YE110
YE39
YE39
YE114
YB44
12V BUS (1040)
86
30
8587
TEST DESCRIPTION: The numbers below refer to the step numbers on the diagnostic table.
NOTE: For any test that requires probing the PCM or a com ponent harness c onnector, use the Connector T est
Adapter Kit J35616-A. Using this kit prevents damage to the harness connector terminals.
2. This test checks the fusible link FS power feed to the EFI relay.
3. This test checks the fused power feed ignition circuit.
4. This test is checking the earth circuit of the EFI relay.
5. This step isolates the circuit from the EFI relay. All of the circuits at the relay are good if the test lamp
illuminates.
E.F.I RELAY
YE 39
B/W
P/B
O/Y
(152)
(39)
(479)
(1040)
ENGINE 12V BUS
TABLE A-6.5 V6 PCM - EFI RELAY 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
2 1. Turn OFF the ignition.
2. Remove the engine compartment Fuse/Relay panel
cover.
3. Remove the EFI relay.
4. Probe the fusible link FS power feed circuit to the EFI
relay harness terminal 87 with a test lamp J34142-B
connected to earth.
Does the test lamp illuminate?
Go to Step 3 Go to Step 8
3 1. Turn ON the ignition leaving the engine OFF.
2. Probe the fused ignition feed circuit to the EFI relay
harness terminal 85 with the test lamp J34142-B
connected to a earth.
Does the test lamp illuminate?
Go to Step 4 Go to Step 9
4 1. Turn OFF the ignition.
2. Probe the earth circuit to the EFI relay harness
terminal 86 with the test lamp J34142-B connected to
B+.
Does the test lamp illuminate?
Go to Step 5 Go to Step 10
5 1. Turn OFF the ignition
2. Jump the EFI relay B+ feed circuit terminal 87 and the
EFI relay load circuit terminal 30 together using a
fused jumper wire.
3. Probe the following fuses with a test lamp J34142-B
connected to earth:
- F32
- F33
- F34
- F35
Does the test lamp illuminate for all fuses?
Go to Step 6 Go to Step 11
6 Check for poor terminal contact at the EFI relay harness
connector.
Did you find and correct the condition?
System OK Go to Step 7
7 Replace the EFI relay.
Is the action complete? System OK
TABLE A-6.5 V6 PCM - EFI RELAY DIAGNOSIS
Step Action Value(s) Yes No
8 Repair the open in fusible link FS circuit to the EFI relay.
Is the action complete? System OK
9 Repair the fused ignition feed circuit to the EFI relay.
Replace fuse if open.
Is the action complete?
System OK
10 Repair the open in the earth circuit for the EFI relay.
Is the action complete? System OK
11 Repair open in the EFI relay load circuit, or open in
fuse(s) circuit that did not illuminate the test light.
Is the action complete?
TABLE A-7.1 V6 PCM -
IDLE AIR CONTROL (IAC) SYSTEM
CIRCUIT DESCRIPTION:
The PCM controls engine idle speed by moving the IAC valve to control closed-throttle air flow around the
throttle plate. It does this by sending voltage pulses (called "counts" or "steps") to the IAC motor windings. The
motor shaft and conical valve move a given distance for each pulse received.
• TO INCREASE IDLE SPEED: The PCM sends enough puls es to retrac t the IAC valve and allow m ore air to
bypass the throttle plate through the idle air passage, until idle speed reaches the PCM-desired idle RPM.
• TO DECREASE IDLE SPEED: The PCM sends enough pulses to extend the IAC valve and reduce the
airflow bypassing the throttle plate through the idle air passage, until idle speed reaches the PCM-desired
RPM.
The PCM desired idle RPM, and the commanded IAC position, is based on:
• Engine Coolant Temperature
• Actual engine RPM (crankshaft reference input)
• Engine load (A/C request input, engine fan command)
• Battery voltage
• Vehicle speed (VSS)
• Throttle position (TP)
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. This tests the PCM's ability to control IAC valve.
DIAGNOSTIC AIDS:
Remove IAC and check for frozen or sticking IAC. Check that TP sensor is within acceptable range.
VXPCM025
PCM
C5
C4
C3
C2
LG/W (443)
A
B
C
D
IAC VALVE
IAC
COIL B LO
IAC
COIL A LO
IAC
COIL B HI
IAC
COIL A HI
12V
12V
12V
12V
M
I
C
R
O
LG/B (444)
LBLU (441)
LBLU/B (442)
YB198
YE36
TABLE A-7.1 V6 PCM - IDLE AIR CONTROL (IAC) SYSTEM
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check
in this Section.
2. 1. Using TECH 2 scan tool, Select RPM CONTROL.
2. With the up/down arrows, vary RPM from 600 to 1675
RPMs.
Does engine speed rise and fall?
Go to Step 3 Go to
Table A-7.2
in this Section
3. No trouble found with IAC system.
Check For:
• Vacuum leaks (Causes Fast Idle Speeds).
• Sticking or binding throttle shaft, cables, or linkages.
• Engine Coolant Temperature sensor resistance.
Refer DTC P0118 in this Sectin.
• TP Sensor Operation. Refer Table A-6.2 in this Section
• Dirty or loose battery cables or earth straps.
• System earth circuit terminals at the engine for being
clean and tight.
• Inspect all accessory drive pulleys. They should all spin
freely.
• Spark plugs that are excessively worn, mis-gapped or
cracked.
• For high or low fuel pressure, or leaking injectors - refer
Table A-4.3 in this Section
• A/C Clutch Control circuit failure.
Refer Table A 11.1 or Table A 11.3 in this Section.
• Generator Output - if under 9 volts or over 16 volts,
PCM will not command the IAC to move.
• Throttle Body - remove IAC and inspect bore for foreign
material or evidence of IAC valve "Dragging" in the bore.
• Throttle Stop Screw, refer SERVICE
OPERATIONS, 3.10 FUEL CONTROL SYSTEM -
Throttle Stop Screw - Reset Procedure of the VX Series
Service Information
Refer To "Rough, Unstable, Or Incorrect Idle" In Section
6C1-2B SYMPTOMS of the VX Series Service
Information.
Verify Repair
TABLE A-7.2 V6 PCM
IDLE AIR CONTROL (IAC) SYSTEM
CIRCUIT DESCRIPTION:
The PCM controls engine idle speed by moving the IAC valve to control closed-throttle air flow around the
throttle plate. It does this by sending voltage pulses (called "counts" or "steps") to the IAC motor windings. The
motor shaft and conical valve move a given distance for each pulse received.
• TO INCREASE IDLE SPEED: The PCM sends enough puls es to retrac t the IAC valve and allow m ore air to
bypass the throttle plate through the idle air passage, until idle speed reaches the PCM - desired idle RPM.
• TO DECREASE IDLE SPEED: The PCM sends enough pulses to extend the IAC valve and reduce the air
flow bypassing the throttle plate through the idle air passage, until idle speed reaches the PCM-desired
RPM.
The PCM desired idle RPM, and the commanded IAC position, is based on:
• Engine Coolant Temperature (ECT)
• Actual engine RPM (crankshaft reference input)
• Engine load (A/C request input, engine fan command)
• Battery voltage
• Vehicle Speed (VSS)
• Throttle Position (TPS)
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. With the ignition "ON," engine stopped, and Tech 2: IAC reset, the PCM should issue electrical
"extend/retrac t" pulses to the IAC valve. With the IAC disc onnected, each connec tor term inal should have a
"pulsing" voltage, noted by a flashing or flickering test light. The rate of flashing or flickering is not important.
8. There are 2 separate windings in the IAC motor. Each winding (A - to - B, and C - to- D) should have
between 40 and 80 ohms resistance. Also, there should be no continuity between the two windings.
VXPCM025
PCM
C5
C4
C3
C2
LG/W (443)
A
B
C
D
IAC VALVE
IAC
COIL B LO
IAC
COIL A LO
IAC
COIL B HI
IAC
COIL A HI
12V
12V
12V
12V
M
I
C
R
O
LG/B (444)
LBLU (441)
LBLU/B (442)
YB198
YE36
+
BATTERY
-
DC Amps
Test Light
NOTE: When performing this test, ensure that a standard low power test light is used.
Do not use a "High-W attage" test light, as the PCM could be dam aged. A high wattage test light will either give
inaccurate test results, or damage the PCM, or both.
• A low-power test light must be used for any circuit testing. While a particular brand of test light is not
suggested, a simple test on any test light will ensure it to be OK for PCM circuit testing. Connect an
accurate ammeter (such as the digital multimeter) in series with the test light being tested, and power the
test light-amm eter circuit with the vehicle battery (See above). If the am meter indicates less than 3/10 am p
current flow (0.3 A or 300 ma), the test light is OK to use. If more than 0.3A (300 ma), do not use !
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
IDLE AIR CO NTROL VALVE
(442)
(441) (444)
(443)
LBLU/B
LBLU LG/B
LG/W
TABLE A-7.2 V6 PCM - IDLE AIR CONTROL (IAC) SYSTEM
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. • From Table A-7.1
1. Disconnect IAC valve electrical connector.
2. Ignition "ON", engine stopped. Using TECH 2 scan
tool, select RE SET IAC.
3. Probe each IAC harness connector terminal for 5
seconds with test light connected to earth, while
using Tech 2.
• See note above for proper test light usage.
Does test light flash at all terminals while IAC is being
reset ?
Go to Step 3 If No light
one or more
terminals,
Go to Step 6
----------------------
If steady light
one or more
terminals,
Go to Step 13
3. Check for faulty IAC terminals.
Were any faulty terminals found ? Go to Step 4 Go to Step 5
4. Repair faulty terminals
Is action complete? Verify Repair
5. Replace IAC valve.
Is action complete ? Verify Repair
6. Check for open or short to earth in circuit(s) that did not
light the test light.
Were any opens or short's found ?
Go to Step 7 Go to Step 8
7. Repair any opens or short found.
Is action complete? Verify Repair
8. 1. Check resistance across IAC coils.
2. Check all IAC terminals opposite harness
connectors terminals "A" to "B" and "C" to "D".
Are the IAC coils within specified value ?
40 to 80
ohms Go to Step 9 Go to Step 5
TABLE A-7.2 V6 PCM - IDLE AIR CONTROL (IAC) SYSTEM (CONTINUED)
STEP ACTION VALUE YES NO
9. Check for short between windings by measuring for
continuity between IAC terminals "A" to "D".
Ohmmeter should indicate an open circuit, does it?
Go to Step 10 Go to Step 5
10. Check for faulty PCM terminals .
Were any faulty terminals found ? Go to Step 17 Go to Step 11
11. Check for faulty IAC terminals.
Were any faulty terminals found ? Go to Step 14 Go to Step 12
12. Replace PCM.
Refer to Section 6C1-3 Service Operations, for PCM
Programming and Security Link procedure.
Is action complete?
Verify Repair
13. 1. Ignition "OFF".
2. Disconnect PCM.
3. Ignition "ON".
4. Check for short to voltage on circuits that steady
light was "ON".
Was a short to voltage found ?
Go to Step 15 Go to Step 14
14. Check for faulty IAC connections.
Were faulty connections found ? Go to Step 16 Go to Step 5
15. Repair short to voltage.
Is action complete? Verify Repair
16. Repair faulty IAC connections.
Is action complete? Verify Repair
17. Repair faulty PCM terminals.
Is action complete? Verify Repair
TABLE A-8.1 V6 PCM -
DIRECT IGNITION SYSTEM (DIS) CHECK
CIRCUIT DESCRIPTION:
The DIS ignition system uses a waste spark method of spark distribution. In this type of ignition system the
ignition m odule triggers the correct ignition coil, based on signals from the crankshaft sensor. Each ignition coil
provides the high secondar y voltage required to fire two spar k plugs at the sam e tim e on "c om panion" cylinders,
i.e. cylinders with pistons at the top of the their s trok e (T DC) at the sam e tim e. O ne of thes e pistons would be at
the top of its compression stroke, the other piston would be at the top of its exhaust stroke.
For additional information about the DIS system, refer to Section 6C1-1 GENERAL DESCRIPTION of the VX
Series Service Information.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
5. Terminal "P" to the DIS module is the +12 volt supply to the DIS system.
7. This procedure will check the crankshaft sensor output, through the harness to the DIS module harness
connector. DIS m odule harness connector term inals "N" and "P" are jumper ed together to provide power to
the sensor Hall circuits. Terminal "M" is earthed to provide an earth path for the Hall circuits. As the
crankshaft balancer interrupter rings are related, the test light should blink "ON" and "OFF" as the blades
pass the cr ank shaf t sensor air gap. T he test light should be "O N" when the blade is in the crankshaf t sensor
air gap, indicating the Hall circuits are providing the earth path for the test light connected to +12 volts.
Terminal "H", the 3X signal terminals, should blink "ON" and "OFF" three times per crankshaft revolution.
NOTE: Use ST -125 spark check er or equivalent to chec k f or adequate spark . An ST-125 requires about 25,000
volts (25 kilovolts, or 25 kV) to "Spark". Do not use a spark plug in open air earthed to the engine as an
indication of sufficient "Spark". Only a few kilovolts are required to jump the gap of a spark plug outside of the
engine, and that would be an inadequate test of the ignition system.
DIRECT IGNITION M ODULE
YE 57
(647)
LBLU/B
W/B
(644)
B/R
(453)
LBLU/W
(646)
BLU/Y
(643)
V
(430)
T/B
(424)
(633)
BR
(645)
GY/R
LG
(482)
B
(630)
BR
(121)
W
(423)
PNMLKJHGFED
CBA
M
I
C
R
O
A
FUSE
FUSE
F35
85 30
8786
F14
IGNITION
SWITCH
TO
FUSIBLE
LINK
FJ
TO
INJECTORS
4281
CRANK
SENSOR
CONNECTOR
CAM
SENSOR
CONNECTOR
TO
FUSIBLE
LINK
FS
EFI
RELAY
BLU
152
PRIMARY
WINDINGS
SECO NDARY
WINDINGS
12V
POWER
SUPPLY
TO COILS
TOP OF MODULE
6 – 3
2 – 5
4 – 1
COIL PACK
A
B
C
D
EBR
(121)
B7
B4
B3
PCM
EST OUTPUT
BYPASS CONTROL
CRANKSHAFT
18X SIGNAL
CRANKSHAFT
REFERENCE LO
IC
IC
IC
CAMSHAFT
POSITION
SENSOR
SIGNAL
CRANKSHAFT
REFERENCE HI
B9
B6
B10
BLU/ Y (643)
W (423)
T/B (4 24)
LBLU/B (647)
V (430)
B (630)
YB187
YE57
YB187
YE63
YE34
YE39
YE39
YE114
LBLU/W
(646)
BR
(633)
B/R (453)
GY/R (645)
W/B (644)
LG (482)
P/B (39)
F
G
18X CRANK SENSOR – IN
18X CRANK SENSOR – OUT
ES T SIG NAL – IN
BYPASS CO NT R OL
CRANKSHAFT REFERENCE – OUT
TACHO SIGNAL – OUT
SENSO R POW ER SUPP LY – OUT
MODULE POWER SUPPLY – IN
CAM SIG NAL OUT
CAM SIG NAL IN
DIS
MODULE
3X CRANK SENSOR – IN
H
J
K
L
N
P
3
6
2
5
1
4
M
BCD CBA
YE111
TABLE A-8.1 V6 PCM - DIRECT IGNITION SYSTEM (DIS) CHECK
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Remove one spark plug lead.
2. Connect ST-125 spark checker (see note above) to
lead and check for spark while cranking the engine.
3. Check 3 wires on the same side of the engine this
way. A few sparks and then nothing is considered
No Spark.
Is spark present on all spark plug leads ?
Go to Step 3 If Spark on only
1 or 2 leads,
Go to Step 4
_____________
If No Spark,
Go to Step 5
3. No trouble found with ignition system
Is action complete ? Verify Repair
4. Refer to DIS module and coil checking procedure, Table
A-8.2 Step 5 in this Section.
Is action complete ?
Verify Repair
5. 1. Disconnect 14-pin connector from DIS module.
2. Ignition "ON", probe harness connector terminal "P"
with a test light connected to earth.
Is test light "ON" ?
Go to Step 9 Go to Step 6
6. Check ignition module fuse F35.
Is fuse open? Go to Step 7 Go to Step 8
7. Repair short to earth in fuse circuit.
Replace fuse.
Is action complete?
Verify Repair
8. Check for open in power circuit to DIS ignition module
harness connector terminal "P".
Was a problem found ?
Verify Repair Go to
Table A-6.5
9. 1. Ignition "OFF".
2. Get three paper clips, and re-form until straight.
3. Bend one of the straightened paper clips into a very
narrow "U", and use it to jumper DIS module
harness connector terminals "N" and "P".
4. Insert a straightened paper clip into terminal "M".
Connect a jumper lead from this paper clip to earth.
• Ensure that the Two paper clips and/or jumper
leads Do Not Touch.
5. Insert a straightened paper clip into harness
connector terminal "H", and connect a test light
between this terminal and +12 volts.
6. Ignition "ON".
7. Using a 28 mm socket and hand tools, slowly rotate
the crankshaft balancer one revolution, while
observing the test light.
The test light should go "ON" and "OFF" as the 3X
interrupter blades pass through the sensor air gap,
does it ?
Go to Table 8.2,
Step 8 in this
Section
Go to Step 10
10. Check for good continuity, and for no Shorts or Opens on
the 4 circuits between the crank sensor and DIS module.
If all are OK, replace crank sensor. Refer DIS SERVICE
OPERATIONS in Section 6C1-3 of the VX Series Service
Information for proper procedure.
It must be followed.
Is action complete ?
Verify Repair
TABLE A-8.2 V6 PCM -
DIRECT IGNITION SYSTEM (DIS) CHECK
CIRCUIT DESCRIPTION:
The DIS ignition system uses a waste spark method of spark distribution. In this type of ignition system the
ignition m odule triggers the correct ignition coil, based on signals from the crankshaft sensor. Each ignition coil
provides the high secondar y voltage required to fire two spar k plugs at the sam e tim e on "c om panion" cylinders,
i.e. cylinders with pistons at the top of the their s trok e (T DC) at the sam e tim e. O ne of thes e pistons would be at
the top of its compression stroke, the other piston would be at the top of its exhaust stroke.
For additional information about the DIS system refer to Section 6C1-1 GENERAL DESCRIPTION of the VX
Series Service Information.
TEST DESCRIPTION: Number(s) below refer to Step number(s) on the Diagnostic Table.
3. Terminal "G", the 18x signal terminal, should blink ON" and "OFF" eighteen times per crankshaft revolution.
5. This procedure will check the modules ability to control the ignition coil primary system.
7. These checks are for the primary and secondary windings of each of the three ignition coils. The resistance
of each of the six checks (3 primary and 3 secondary windings) must be within the specified ranges.
DIRECT IGNITION M ODULE
YE 57
(647)
LBLU/B
W/B
(644)
B/R
(453)
LBLU/W
(646)
BLU/Y
(643)
V
(430)
T/B
(424)
(633)
BR
(645)
GY/R
LG
(482)
B
(630)
BR
(121)
W
(423)
PNMLKJHGFED
CBA
M
I
C
R
O
A
FUSE
FUSE
F35
85 30
8786
F14
IGNITION
SWITCH
TO
FUSIBLE
LINK
FJ
TO
INJECTORS
4281
CRANK
SENSOR
CONNECTOR
CAM
SENSOR
CONNECTOR
TO
FUSIBLE
LINK
FS
EFI
RELAY
BLU
152
PRIMARY
WINDINGS
SECO NDARY
WINDINGS
12V
POWER
SUPPLY
TO COILS
TOP OF MODULE
6 – 3
2 – 5
4 – 1
COIL PACK
A
B
C
D
EBR
(121)
B7
B4
B3
PCM
EST OUTPUT
BYPASS CONTROL
CRANKSHAFT
18X SIGNAL
CRANKSHAFT
REFERENCE LO
IC
IC
IC
CAMSHAFT
POSITION
SENSOR
SIGNAL
CRANKSHAFT
REFERENCE HI
B9
B6
B10
BLU/ Y (643)
W (423)
T/B (4 24)
LBLU/B (647)
V (430)
B (630)
YB187
YE57
YB187
YE63
YE34
YE39
YE39
YE114
LBLU/W
(646)
BR
(633)
B/R (453)
GY/R (645)
W/B (644)
LG (482)
P/B (39)
F
G
18X CRANK SENSOR – IN
18X CRANK SENSOR – OUT
ES T SIG NAL – IN
BYPASS CO NT R OL
CRANKSHAFT REFERENCE – OUT
TACHO SIGNAL – OUT
SENSO R POW ER SUPP LY – OUT
MODULE POWER SUPPLY – IN
CAM SIG NAL OUT
CAM SIG NAL IN
DIS
MODULE
3X CRANK SENSOR – IN
H
J
K
L
N
P
3
6
2
5
1
4
M
BCD CBA
YE111
TABLE A-8.2 V6 PCM - DIRECT IGNITION SYSTEM (DIS) CHECK
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Ignition "OFF".
2. Remove the paper clip from terminal "H" and insert
it into terminal "G".
3. Ignition "ON".
Slowly rotate the crankshaft balancer one revolution and
note test light. It should go "ON" and "OFF" as the 18X
interrupter blades pass through the sensor air gap,
does it ?
Go to Step 4 Go to Step 3
3. Check for good continuity, and for no Shorts or Opens on
the 4 circuits between the crank sensor and DIS module.
If all are OK, replace crank sensor. See DIS Service
Operations in Section 6C1-3 of the VX Series Service
Information for proper procedure. It must be followed.
Is action complete ?
Verify Repair
4. 1. Remove test light and all leads from harness
connector terminals. Reconnect 14-pin connector to
DIS module. Torque retaining bolt to specification
value.
2. Disconnect all spark plug leads from the DIS coils.
3. Remove 6 screws that retain the coils to the module.
4. Remove all three coils.
5. Connect the test light clip lead to one of the two coil
terminals on the module.
6. Connect the test light probe to the other coil
terminal on the module.
7. While the engine is cranking, observe test light.
The test light should blink.
8. This test should be performed for each pair of
module terminals that connect to the three (3)
ignition coils.
Is the test light blinking for all three coil pairs ?
0.6 to 1.2
N.m Go to Step 6 Go to Step 5
5. If no blink, or blinks on less than all 3 pairs, replace DIS
module.
Is action complete ?
Verify Repair
6. 1. Ignition "OFF".
2. Using a digital ohmmeter, check resistance across
the ignition coil primary winding (underside)
terminals
3. Correct resistance of the ignition coils primary
winding must be within the specified value.
Are all three coils (6-3, 2-5, 4-1) within this range ?
0.3 ohms
to
1.5 ohms
Go to Step 8 Go to Step 7
7. Replace coil(s) that had the incorrect ohms reading.
Is action complete ? Verify Repair
8. 1. Check resistance across the ignition coil secondary
tower terminals. Each tower is marked.
2. Correct resistance of the ignition coil secondary
windings must be within the specified value.
Are all three coils (6-3, 2-5, 4-1) within this range ?
5000
(5K ohms)
to
7000
(7K ohms)
Go to Step 10 Go to Step 9
TABLE A-8.2 V6 PCM - DIRECT IGNITION SYSTEM (DIS) CHECK (CONTINUED)
STEP ACTION VALUE YES NO
9. Replace coil(s) that had the incorrect ohms reading.
Is action complete ? Verify Repair
10. At this point, all DIS components test indicate the DIS
system should produce spark. If a No Spark condition still
exists, very closely check the metal terminals in the
plastic connectors at the DIS module and crank sensor.
Also check the resistance of the spark plug leads,
ensuring that none are "Open"
Is action complete ?.
Verify Repair
Refer to PCM wiring Mech. for further deta ils of A/C wiring
TABLE A-11.1 V6 PCM
A/C CLUTCH CONTROL ( NON ECC S YSTEM )
CIRCUIT DESCRIPTION:
W ith the blower fan s witc hed "ON", and the air conditioning switched "ON," s witc hed ignition voltage is supplied
from fuse F13 through the A/C master switch, and then to the BCM. The BCM will then supply a serial data
signal to the PCM requesting A/C. If the BCM does not receive a earth signal from the blower switch to BCM,
the BCM will not supply the serial data request for A/C to the PCM. Once the PCM receives this serial data
signal, the PCM will energise the A/C compressor relay by supplying a earth signal (A/C Relay Control ) from
the PCM. The BCM also supplies a earth signal from BCM terminal "7" to the low speed cooling fan relay.
This serial data signal to the PCM is also us ed to adjust the idle speed bef ore turning "ON" the A/C com press or
relay. If this signal is not available to the PCM, the A/C compressor will be inoperative.
This system also incorporates a A/C Refrigerant Pressure Sensor. The A/C Refrigerant Pressure Sensor signal
indicates Low / High pressure on the A/C high side refrigerant pressure line 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.
The purpose of this A/C Refrigerant Pressure Sensor is to protect the system from danger because of either
refrigerant pressure too low (which could damage the compressor due to insufficient lubrication), or too high
(which could result in a leak in the sealed refrigerant R134a system).
The PCM will NOT energise the A/C control relay if any of the following conditions are present:
• DTC P0530 is set.
• RPM more than 4,800. If de-energised because of RPM, it can re-energised when RPM falls below 4,000
for at least 10 seconds.
• Throttle is more than 90% open.
• A/C Refrigerant Pressure Sensor voltage is to Low or to High.
FS (1040)
R (2)
O/Y (479)
FJ 30
15a 15 50
Off/On
Lock
Acc
Ign
Start
M
I
C
R
O
P
R
O
C
E
S
S
O
R
M
I
C
R
O
F31
F33
Loc. E5/E15
A/C
Compressor
A/C Relay
EFI
Relay
F14
4282
P (3) P/B (39)
O/B ( 740)
YB176
YB165
YB175
YB164
YB175
YB164
YB174
YB163
YE120
YE105
YE111
YB44
YB44
YE101YE101
YB198
YB187
YE105
YE120
YB176
YB165
A5/A6
E2/D2
B/G (1 51)
Loc. E3
Loc. E3
B/Y (155)
A1/A5
B10/B11
E20/D6
Battery
Serial
Data
C13
A9 LG/B (366)
R/B (1221)
A/C
Enable
5V
5V
Ignition Switc h
Battery Main Power
Ignition On
El ect roni c Eart h
Serial
Data
Main
Hi gh C ur r ent
Earth
BCM
PCM
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
1. The PCM's diagnostic circuits must be proven before any further testing is performed.
2. The PCM does not normally energise the A/C control relay unless the engine is running.
4. This checks for operation of the condenser fan.
20, 21, 22, 23, 24, 26, 28 There are no terminal identification on the relay connector (although the relay itself
has terminal numbers). Make certain the correct relay connector terminal (not the relay) is being probed.
39. The most likely cause of an automotive air conditioner not working is a discharged refrigerant R134a
system, due to a refrigerant leak.
Check For: If fuse F13 is blown, check for short to earth on all circuit associated with this fuse.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
A/C COM PRESSOR
(59)
G
(750)
B/R
A
1
2
G
(59)
B/R
(750)
A/C RELAY
Y E 101
(366)
(439)
LG/B
P
G
P
(59)
(439)
YB 5 4
(291)
(248)
(44)
O
R/W
P/BLU
R/BR
GY
BR/W
B/R
(962)
(8)
(19)
(292)
TABLE A-11.1 V6 PCM - A/C CLUTCH CONTROL ( NON-ECC SYSTEM )
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Ignition "ON", engine stopped.
2. Disconnect the A/C compressor clutch electrical
connector and reconnect, and note compressor
clutch.
Did compressor clutch cycle "OFF" then "ON" with
electrical connector disconnected and reconnected?
If A/C clutch
cycled
"OFF" then "ON"
or will not
disengage
Go to Step 6
Go to Step 3
3. 1. Ignition "ON", engine idling.
2. Blower Switch turned "ON".
3. Cycle the A/C switch "ON" and "OFF", waiting a
few seconds between positions.
Listen for A/C compressor clutch. Does it cycle "ON" and
"OFF?
Go to Step 4 Go to Step 14
4. 1. Ignition "ON", engine idling.
2. A/C switch in the "ON" position.
Does the A/C condenser fan operate when the A/C
Switch is turned "ON" ?
Go to Step 5 Go to
Table A-12
in this Section
5. 1. A/C clutch control circuits OK.
2. If complaint is insufficient cooling, review
symptoms.
Is action complete ?
Verify Repair
6. 1. Ignition "OFF".
2. Disconnect A/C compressor electrical connector.
2. Observe A/C clutch.
Is A/C clutch staying engaged to compressor?
Go to Step 7 Go to Step 8
TABLE A-11.1 V6 PCM - A/C CLUTCH CONTROL ( NON-ECC SYSTEM ) (CONTINUED)
STEP ACTION VALUE YES NO
7. Replace A/C compressor clutch. Refer to Section 2B in
Section 1 of this Service Information for details.
Is action complete?
Verify Repair
8. 1. Ignition "ON", engine "OFF".
2. Using test light connected to B+, backprobe PCM
terminal for A/C Relay Control.
Does test light illuminate?
Go to Step 9 Go to Step 11
9. Check for a short to earth in circuit for A/C Relay Control
from the PCM to A/C Compressor Relay.
Was a problem found?
Verify Repair Go to Step 10
10. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
11. 1. Ignition "ON".
2. Disconnect A/C compressor electrical connector.
3. Using test light connected to earth, probe A/C
compressor electrical connector power circuit.
4. With test light "ON", remove A/C Compressor Relay
and note test light.
Did test light turn "OFF"?
Go to Step 12 Go to Step 13
12. Replace A/C Compressor Relay.
Is action complete? Verify Repair
13. Repair short to voltage on A/C compressor power feed
circuit from A/C Compressor Relay to A/C compressor.
Is action complete?
Verify Repair
14. 1. Ignition "ON", engine idling.
2. Install scan tool.
3. Observe A/C Refrigerant Pressure Sensor voltage
display on the scan tool.
Is indicated A/C Refrigerant Pressure Sensor voltage at
or between the specified value?
0.35V - 4.2V Go to Step 15 Go to Step 39
15. Check power supply fuse to A/C master switch.
Is fuse open? Go to Step 16 Go to Step 17
16. Repair short to earth in fuse circuit, and replace fuse.
Is action complete? Verify Repair
17. 1. Ignition "ON", engine "OFF".
2. Turn A/C Master Switch to "ON" position.
2. Using test light connected to earth, backprobe BCM
terminal for A/C Select Input circuit.
Dose test light illuminate?
Go to Step 20 Go to Step 18
18. Check for open or poor connection in circuit from A/C
Master Switch to BCM A/C Select Input, or open in power
feed circuit to A/C Master Switch.
Was a problem found?
Verify Repair Go to Step 19
19. Replace A/C Master Switch.
Is action complete? Verify Repair
20. 1. Ignition "ON", engine idling.
2. Remove Blower Inhibit Relay from Relay center,
leave harness connector connected to relay.
3. Using test light connected to B+, backprobe relay
harness connector terminal 30.
4. Turn A/C Master Switch to "ON" position.
Does test light illuminate?
Go to Step 21 Go to Step 26
TABLE A-11.1 V6 PCM - A/C CLUTCH CONTROL ( NON-ECC SYSTEM ) (CONTINUED)
STEP ACTION VALUE YES NO
21. 1. Ignition "ON", engine idling.
2. Using test light connected to B+, backprobe BCM
terminal for Blower Switch Input Signal.
3. Turn A/C Master Switch to "ON" position.
4. Turn Blower Switch to "ON" position.
Does test light illuminate?
Go to Step 22 Go to Step 33
22. 1. Ignition "OFF".
2. Remove A/C Compressor Relay from Relay center.
3. Ignition "ON", engine idling.
4. Turn A/C Master Switch to "ON" position.
5. Turn Blower Switch to "ON" position.
6. Using test light connected to B+, probe terminal "2"
of A/C Compressor Relay harness connector.
Does test light illuminate?
Go to Step 23 Go to Step 35
23. 1. Ignition "ON", engine "OFF".
2. Using test light connected to earth, probe A/C
Compressor Relay harness terminals 1 and 3.
Does test light illuminate on both circuits?
Go to Step 24 Go to Step 36
24. 1. Ignition "OFF".
2. Reinstall Blower Inhibit Relay and A/C Compressor
Relay.
3. Disconnect electrical connector at A/C compressor.
4. Ignition "ON", engine idling.
5. Turn A/C Master Switch to the "ON" position.
6. Turn Blower Switch to the "ON" position.
7. Using test light connected to earth, probe A/C
compressor harness power feed circuit from A/C
Compressor Relay to compressor.
Dose test light illuminate?
Go to Step 25 Go to Step 37
25. Check A/C compressor earth circuit for an open, if open
repair. If earth circuit is OK, Replace A/C compressor.
Refer to Section 2C of the VX Series Service Information.
Is action complete?
Verify Repair
26. 1. Ignition "ON", engine idling.
2. Using test light connected to B+, backprobe Blower
Inhibit Relay terminal 85 for Blower Inhibit Relay
Earth Output Signal from BCM.
3. Turn A/C master switch "ON".
Dose test light illuminate?
Go to Step 28 Go to Step 27
27. Check for open in circuit from BCM to Blower Inhibit
Relay or poor connection at BCM. If OK, replace BCM.
Is action complete?
Verify Repair
28. 1. Ignition "ON", engine "OFF".
2. Disconnect Blower Inhibit Relay from harness
connector.
3. Using test light connected to earth, probe relay
harness terminal 86.
Does test light illuminate?
Go to Step 30 Go to Step 29
29. Repair open in circuit from Blower Inhibit Relay terminal
86 to Ignition Switch.
Is action complete?
Verify Repair
TABLE A-11.1 V6 PCM - A/C CLUTCH CONTROL ( NON-ECC SYSTEM ) (CONTINUED)
STEP ACTION VALUE YES NO
30. 1. Ignition "ON", engine "OFF".
2. With Blower Inhibit Relay still disconnected, probe
relay harness terminal 87 with a test light connected
to B+.
Does test light illuminate?
Go to Step 31 Go to Step 32
31. Replace Blower Inhibit Relay.
Is action complete? Verify Repair
32. Repair open in earth circuit to Blower Inhibit Relay.
Is action complete? Verify Repair
33. Check for open circuit from Blower Switch to BCM Blower
Switch Input terminal.
Was a problem found?
Verify Repair Go to Step 34
34. Check for open in circuit from Blower Inhibit Relay
terminal 30 to Blower Switch.
Was a problem found?
Verify Repair Go to Step 38
35. Check for open in circuit from A/C Compressor Relay to
PCM terminal for A/C Relay Control.
Was a problem found?
Verify Repair Go to Step 10
36. Repair open in circuit that did not light.
Is action complete? Verify Repair
37. Check for open in circuit from A/C Compressor to A/C
Compressor Relay.
Was a problem found?
Verify Repair Go to Step 12
38. Replace Blower Switch.
Is action complete? Verify Repair
39. Check A/C Pressure Sensor signal circuit for short to
earth.
Was a problem found?
Verify Repair Go to Step 40
40. Check A/C refrigerant (R-134a) system for being
undercharged, or overcharged.
Is action complete.
Verify Repair
Refer to PCM wiring Mech. for further details on A/C wiring
TABLE A-11.3 V6 PCM -
A/C CLUTCH CONTROL WI TH ELECTRONIC CLIMATE CONTROL (ECC)
CIRCUIT DESCRIPTION:
When the A/C is reques ted, the Elec tronic Climate Control Module will supply a signal to the BCM. The BCM will
then send a s erial data request to the PCM. When the PCM rec eives the ser ial data request on PCM ser ial data
circuit, 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
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 not operative.
The BCM also supplies the earth signal from BCM 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 indica tes low and high side r ef riger ant pres s ures to the PCM. The PCM uses this inf or mation to adjus t the
idle air c ontrol valve to compensate f or the higher engine loads pr es ent with high A/C refr igerant pr es s ures ., and
not allow A/C operation if pressure is to low 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:
• DTC P0530 is set.
• RPM more than 4,800. If de-energised because of RPM, it can re-energised when RPM falls below 4,000
for at least 10 seconds.
• Throttle is more than 90% open.
• A/C Refrigerant Pressure Sensor voltage is to Low or to High.
FS (1040)
R (2)
O/Y (479)
FJ 30
15a 15 50
Off/On
Lock
Acc
Ign
Start
M
I
C
R
O
P
R
O
C
E
S
S
O
R
M
I
C
R
O
F31
F33
Loc. E5/E15
A/C
Compressor
A/C Relay
EFI
Relay
F14
4282
P (3) P/B (39)
O/B ( 740)
YB176
YB165
YB175
YB164
YB175
YB164
YB174
YB163
YE120
YE105
YE111
YB44
YB44
YE101YE101
YB198
YB187
YE105
YE120
YB176
YB165
A5/A6
E2/D2
B/G (1 51)
Loc. E3
Loc. E3
B/Y (155)
A1/A5
B10/B11
E20/D6
Battery
Serial
Data
C13
A9 LG/B (366)
R/B (1221)
A/C
Enable
5V
5V
Ignition Switc h
Battery Main Power
Ignition On
El ect roni c Eart h
Serial
Data
Main
Hi gh C ur r ent
Earth
BCM
PCM
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
1. The PCM's diagnostic circuits must be proven before any further testing is performed.
3. The PCM does not normally energise the A/C control relay unless the engine is running.
4. W hen the T ech 2 sc an tool is installed, and the A/C switch is turned "ON", the s can tool should dis play "A/C
Requested".
6. This checks for operation of the condenser fan.
7. The most likely cause of an automotive air conditioner not cooling properly is a discharged or overcharged
refrigerant R134a system.
18, 19, 20 There are no terminal identification on the relay connector (although the relay itself has terminal
numbers). Make certain the correct relay connector terminal (not the relay) is being probed.
Check For: If fuse F13 is blown, check for short to earth on all circuit associated with this fuse.
YB 175
B.C.M CO NNECTOR 3
BERLINA & CALAIS
LBLU
Y/R
O/BLU
B
BLU/W
W/BLU
(43)
(39)
(97)
(83)
(94)
O/W
Y/B
B/R
(161)
(143)
(640)
(1150)
(260)
(1144)
(840)
Y
P/B
GY
LBLU
(494)
W
(160)
V/R
R/B
W/G
B/Y
GY/B
(229)
(1221)
(1220)
(556)
(96)
(261)
G/W
Y
Y/B
W
W/R
(266)
(1220)
(272)
(717)
(308)
BR/G
(271)
R/W
GY/R
(1391)
B.C.M CONNECTOR 3
EXECUTIVE
YB164
(83)
(97)
W/G
(229)
B/G
W/BLU
(266)
(1144)
P/BLU
G/W
BLU/W
(1220)
(494)
BR/G
GY
(1220)
B
GY
(1391)
LBLU
(151)
(271)
R/B
R/W
(1150)
(291)
V/R
(8)
O
P/B
B/R
Y
GY/R
(1221)
(94)
(39) (44)
(248)
10
20 1
11
B.C.M CONNECTOR 4
YB1 76
GY
B/Y
O/B
LBLU
(155)
(8)
(740)
(263)
(1128)
(28)
B/Y
B/W
GY/BLU
(492)
W
(1138)
YB 165
B.C.M CONNECTOR 4
(492)
GY/BLU
(173)
Y
B/R
BR
(292)
(90)
(263)
LBLU B/Y
O/B
(155)
(740)
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
A/C CONTR OL (E.C.C)
YB 87
(1220)
(52)
(44)
(735)
(734) (19)
(64)
(51)
(292)
(155)
(8)
P/BLU
Y/B
G/W
LG/B
BLU/B
GY
B/Y
B/R
Y
B/R
BR/W
G
(342)
LIGHT S W ITCH
YB 33
(151)
B/G
GY
(8)
(717)
WW/R
(308)
BR/BLU
(42)
(49)
BLU
W/B
(147)
B
(1150)
OR EXECUTIVE
A/C COM PRESSOR
(59)
G
(750)
B/R
A
1
2
G
(59)
B/R
(750)
A/C RELAY
Y E 101
(366)
(439)
LG/B
P
G
P
(59)
(439)
TABLE A-11.3 V6 PCM - A/C CLUTCH CONTROL WITH ELECTRONIC CLIMATE CONTROL (ECC)
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section.
2. Check fuse for Electronic Climate Control module.
Is fuse OK ? Go to Step 3 Go to Step 16
3. 1. Ignition "ON", engine stopped.
2. Cycle A/C master switch "ON" and "OFF", waiting a
few seconds between positions.
3. Observe the A/C compressor clutch.
4. It should not cycle "ON" and "OFF",
Did the compressor clutch not cycle "ON" and "OFF" ?
Go to Step 4 If either engages
or will not
disengage
Go to Step 13
4. 1. Ignition "ON".
2. Install Tech 2 scan tool.
3. Turn A/C switch "On"
Does Tech 2 scan tool display "A/C Requested" ?
Go to Step 5 Go to Step 8
5. 1. Ignition "ON", engine idling.
2. Cycle the A/C switch "ON" and "OFF", waiting a
few seconds between positions.
3. Listen for A/C compressor clutch.
Does A/C compressor clutch cycle "ON" and "OFF"?
Go to Step 6 Go to Step 17
6. Ignition "ON", engine idling.
Does the A/C condenser fan operate when the A/C is
turned "ON"?
Go to Step 7 Go to
Table A-12
in this Section
7. A/C clutch control circuits OK. If complaint is Insufficient
A/C cooling, review symptoms.
Is action complete ?
Verify Repair
8. Check for poor connection or an open circuit between
BCM and Electronic Climate Control Module.
Was a problem found ?
Verify Repair Go to Step 9
9. 1. Ignition "OFF".
2. Disconnect BCM connectors.
3. Ignition "ON", engine "OFF".
4. Using DVM connected to earth, probe BCM harness
connector terminal for A/C Select Input from
Electronic Climate Control module.
5. Turn "ON" A/C switch.
Does DVM indicate voltage between the specified value?
2 - 4
volts Go to Step 11 Go to Step 10
10. Check for a open or short to earth in A/C Select circuit
between BCM and Electronic Climate Control module.
Was a problem found?
Verify Repair Go to Step 12
11. Replace BCM.
Is action complete ? Verify Repair
12. Check for poor connection at Electronic Climate Control
module, if connection OK, replace faulty Electronic
Climate Control Module.
Is action complete ?
Verify Repair
13. Check for short to earth from PCM circuit A/C Relay
Control to A/C Co mpresso r Relay.
Was a problem found?
Verify Repair Go to Step 14
14. Check for short to voltage on power feed circuit to A/C
compressor.
Was a problem found?
Verify Repair Go to Step 15
TABLE A-11.3 V6 PCM - A/C CLUTCH CONTROL WITH ELECTRONIC CLIMATE CONTROL (ECC) (CONT)
STEP ACTION VALUE YES NO
15. Replace defective A/C compressor relay.
NOTE: If compressor clutch still will not disengage,
replace A/C compressor clutch. Refer to Section 2B of the
VX Series Service Information for details.
Is action complete ?
Verify Repair
16. Repair short to earth in fuse circuit.
Replace fuse.
Is action complete?
Verify Repair
17. 1. Ignition "ON", engine idling.
2. Install scan tool.
3. Observe A/C Refrigerant Pressure Sensor voltage
display on the scan tool.
Is indicated A/C Refrigerant Pressure Sensor voltage at
or between the specified value?
0.35V - 4.2V Go to Step 18 Go to Step 29
18. 1. Ignition "ON", engine idling.
2. Disconnect A/C compressor relay.
3. Probe both relay terminals "3" and "1" of harness
connector, with a test light connected to earth.
Is test light "ON" at both terminals ?
Go to Step 19 Go to Step 25
19. 1. Ignition "ON", engine idling.
2. Probe A/C compressor relay connector circuit for
A/C Relay Control with a test light connected to B+.
3. Turn A/C switch "ON".
Is test light "ON" when the A/C switch is "ON" ?
Go to Step 20 Go to Step 23
20. 1. Ignition "ON", engine idling.
2. Reconnect A/C compressor relay.
3. Backprobe relay harness terminal "5" with a test light
connected to earth.
4. Turn A/C switch "ON".
Is test light "ON" when A/C switch is turned "ON"?
Go to Step 21 Go to Step 15
21. 1. Ignition "OFF".
2. Disconnect A/C compressor electrical connector.
3. Ignition "ON", engine idling.
4. Probe compressor harness connector terminal
power feed circuit with a test light connected to
earth.
5. Turn A/C switch "ON".
Is test light "ON" when the A/C switch is turned "ON"?
Go to Step 22 Go to Step 28
22. Check for a poor earth circuit to A/C compressor.
Was a problem found? Verify Repair Go to Step 27
23. Check for a faulty connection for A/C compressor relay.
Was a problem found ? Verify Repair Go to Step 24
24. Check for a open in the PCM A/C Relay Control circuit,
from the PCM to the A/C compressor relay.
Was a problem found ?
Verify Repair Go to Step 26
25. Repair open in circuit that did not light test light.
Is action complete ? Verify Repair
26. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
TABLE A-11.3 V6 PCM - A/C CLUTCH CONTROL WITH ELECTRONIC CLIMATE CONTROL (ECC) (CONT)
STEP ACTION VALUE YES NO
27. Replace A/C compressor.
Is repair complete ? Verify Repair
28. Repair open in circuit 59 to A/C compressor clutch.
Is repair complete ? Verify Repair
29. Check A/C Pressure Sensor signal circuit for short to
earth.
Was a problem found?
Verify Repair Go to Step 30
30. Check A/C refrigerant (R-134a) system for being
undercharged, or overcharged.
Is action complete.
Verify Repair
TABLE A-12.1 V6 PCM -
ELECTRIC FAN CONTROL
CIRCUIT DESCRIPTION:
On this V6 engine, there are two single speed electric engine cooling fan motor assemblies. One fan motor
provides high speed cooling operation, and the other fan motor provides low speed cooling operation. Both of
these fan motors provide the primary means of moving air through the engine radiator. These electric cooling
fan motors are used to cool engine coolant flowing through the radiator. These electric cooling fan motors are
also used to cool the refrigerant flowing through the A/C condenser (if fitted).
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 engine Cooling Fan Low Speed Relay is controlled by the PCM through Serial Data Communication to the
BCM. The BCM controls the earth path for the engine Cooling Fan Low Speed Relay.
ENGINE COOLING FAN LOW SPEED.
The engine cooling fan low speed relay is energised by the BCM. The PCM determines when to enable the
engine cooling fan low speed 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)
• Vehicle speed less than 54 Km/h
or
• Coolant temper ature is greater than 104 degrees C and will rem ain on until coolant tem perature goes down
below 99 degrees C
or
• A/C pressure >1500kPa
or
• DTC Set
Battery
FS
FU Fa n 1 O/B LU ( 204)
O/B ( 208)
FT Fan 2
RR
(001) (203)
O/B
(740) O
(740) A5/A6
F31
G
Y
O/Y
(250)
BLU/Y
(533)
B
BLU
(1040) Battery Ma in Power
Hi gh Series BC M Term inals Nominat ed Fi rst
Low
Sp ee d Fan
B7/B7
E2/D2
B10/B11
A1/A5
Serial Data
High
Current Earth
El ectroni c Earth
BLU/W (304)
Ser ia l Data
High
Speed
Fan
85 85
B12
C13
87 30
O/B (473)
R/B (1221)
B/P (157)
B/G
(151)
B/Y (155)
Loc. E3
4270-B
Loc. E2
86
87
87A
86 30
Blue
Fusible
Link
Loc.
E1
Engine
Cooling
Fan Rela y
(High Speed)
Engine Cooling
Fan Rela y
(Low Speed)
Engine
Cooling
Fans
M
I
C
R
O
P
R
O
C
E
S
S
O
R
M
I
C
R
O
BCM
PCM
YB176
YB165
YB174
YB163
YB174
YB163
YB175
YE112
YB198
YB187
YB164
YB176
YB165
YE139
YE139
YE140
YE140
YE43 YE103
YE103
YE43
ENGINE COOLING FAN HIGH SPEED
The engine cooling fan high speed is controlled by the PCM based on input from the Engine Coolant
Tem per ature Sensor ( ECT) . T he PCM will only turn "O N" the engine cooling fan high speed if the engine cooling
low speed fan has been "ON" for 2 seconds and the following conditions are satisfied.
• There is a BCM message response fault which will cause a DTC P1064.
• An engine coolant temperature sensor failure is detected, such as DTC P0116, P0117, P0118 or P1628.
• Coolant temperature greater than 107 degrees C.
• If the fan low speed was "OFF" when the criteria was met to turn the fan high speed "ON", the fan high
speed will come "ON" 5 seconds after the fan low speed is turned "ON".
• The engine cooling fan High speed relay can also be enable by the A/C Refrigerant Pressure Sensor. The
A/C Refrigerant Pressure Sensor will provide a signal to the PCM when A/C pressure becomes to high
approximately 2000 kPa.
Test Description: Number(s) below refer to step number(s) on the diagnostic Table.
2. This entire diagnostic procedure m ust begin with a "cold" engine - at ambient air temper ature. If the coolant
is hot when diagnosis is performed, replacement of good parts will result. Fan should not be running if
engine coolant temperature is less than 99 degrees C and air conditioning is not "ON".
7. Using the Tech 2 scan tool will allow operation of the High Speed Relay. If the fan operates with the scan
tool, the High Speed Cooling Fan is operating properly.
.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
BERLINA & CALAIS
B.C.M CONNE CTOR 2
V
LBLU
(14)
(140)
O/R Y
(173)
(782)
BR
(90)
O/B
(151)
(440)
(15)
BLU
O/V
B/G Y
(196) (473)
EXECUTIVE
B.C.M CONNE CTOR 2
Y B 163
DG/YBLU
(140)
(15)
O/R
(674)
G/W
(359)
W
(1138)
(440)
(151)
(14)
O/V
B/G
LBLU
O/B
R/BR
Y
(473)
(962)
(196)
YE 43
B/R
(157)
BLU/W
(304)
O/B
(740)
O/Y
(250)
YE 103
(1040)
O/Y
(250)
ENGINE 12V BUS
BLU/Y
(533)
O/B
(473)
B/R
(157)
B
(250) (208)
G
TABLE A-12.1 V6 PCM - ELECTRIC FAN CONTROL
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check
2. 1. Ignition "ON", engine stopped.
2. Engine coolant temperature below 99
degrees C.
Is the High Speed Cooling Fan running?
Go to Step 3 Go to Step 6
3. 1. Ignition “ON”, engine stopped.
2. Remove the High Speed Cooling Fan Relay.
Does the High Speed Cooling Fan stop running?
Go to Step 4 Go to Step 9
4. 1. Ignition "OFF".
2. Disconnect the PCM connectors.
3. Using the test light connected to B+, probe PCM
harness connector terminal for High Speed Cooling
Fan Relay control circuit.
Does test light illuminate?
Go to Step 5 Go to Step 10
5. Check for open or short to earth in High Speed Cooling
Fan Relay control circuit.
Was a problem found?
Verify Repair Go to Step 21
TABLE A-12.1 V6 PCM - ELECTRIC FAN CONTROL (CONTINUED)
STEP ACTION VALUE YES NO
6. Is Low Speed Cooling Fan Running? Go to
Table A-12.2
in the Section
Go to Step 7
7. 1. Ignition “ON”, engine stopped.
2. Using Tech 2 scan tool: Select High Fan Relay
Control.
3. Turn “ON” High Fan with scan tool.
Does High Speed Cooling Fan operate?
Go to Step 8 Go to Step 12
8. The High Speed Cooling Fan is OK.
Verify Low Speed Fan operation. Refer to Table A-12.2.
Is action complete?
System OK
9. Repair short to earth in High Speed Cooling Fan earth
circuit between fan motor and High Speed Relay.
Is action complete?
Verify Repair
10. 1. Ignition “OFF”.
2. Reconnect the PCM connectors.
3. Ignition “ON”.
4. Using test light connected to B+, probe High Speed
Cooling Fan Relay control circuit at relay harness
connector.
Does test light illuminate?
Go to Step 11 Go to Step 16
11. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 12 Go to Step 9
12. Check for open or short to earth in power supply fuse and
circuit to High Speed Cooling Fan Relay. Replace fuse if
open.
Was a problem found?
Verify Repair Go to Step 13
13. 1. Ignition “ON”, engine stopped.
2. Remove High Speed Cooling Fan Relay.
3. Using test light connected to B+, probe relay harness
connector terminal 86.
4. Using Tech 2 scan tool, command “ON” and “OFF”
High Speed Cooling Fan.
Does test light turn “ON” and “OFF” with scan tool
commands?
Go to Step 14 Go to Step 5
14. 1. Ignition “OFF”.
2. Disconnect High Speed Cooling Fan motor electrical
connector.
3. Using test light connected to earth, probe power feed
circuit to fan motor.
Does test light illuminate?
Go to Step 17 Go to Step 15
15. Repair open or short to earth in power feed circuit to High
Speed Cooling Fan motor. Repair fusible link if open.
Is action complete?
Verify Repair
16. Replace High Speed Cooling Fan Relay.
Is action complete? Verify Repair Go to Step 21
17. 1. Ignition “ON”, engine stopped.
2. Remove High Speed Cooling Fan Relay.
3. Using fused jumper lead connected to earth, probe
High Speed Cooling Fan Relay harness connector
terminal 87.
Does High Speed Cooling Fan motor operate?
Go to Step 18 Go to Step 20
TABLE A-12.1 V6 PCM - ELECTRIC FAN CONTROL (CONTINUED)
STEP ACTION VALUE YES NO
18. Using test light connected to B+, probe High Speed
Cooling Fan Relay harness connector terminal 30.
Does test light illuminate?
Go to Step 16 Go to Step 19
19. Repair open in earth circuit to High Speed Cooling Fan
Relay terminal 30.
Is action complete?
Verify Repair
20. Check for open in earth circuit from High Speed
CoolingFan Relay to High Speed Cooling Fan motor.
Was a problem found?
Verify Repair Go to Step 22
21. Check for poor connection at PCM.
Was a problem found? Verify Repair Go to Step 11
22. Replace High Speed Cooling Fan motor.
Is action complete? Verify Repair
TABLE A-12.2 V6 PCM -
ELECTRIC FAN CONTROL
CIRCUIT DESCRIPTION:
On this V6 engine, there are two single speed electric engine cooling fan motor assemblies. One fan motor
provides high speed cooling operation, and the other fan motor provides low speed cooling operation. Both of
these fan motors provide the primary means of moving air through the engine radiator. These electric cooling
fan motors are used to cool engine coolant flowing through the radiator. These electric cooling fan motors are
also used to cool the refrigerant flowing through the A/C condenser (if fitted).
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 engine Cooling Fan Low Speed Relay is controlled by the PCM through Serial Data Communication to the
BCM. The BCM controls the earth path for the engine Cooling Fan Low Speed Relay.
ENGINE COOLING FAN LOW SPEED.
The engine cooling fan low speed relay is energised by the BCM. The PCM determines when to enable the
engine cooling fan low speed 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)
• Vehicle speed less than 54 Km/h
or
• Coolant temper ature is greater than 104 degrees C and will rem ain on until coolant tem perature goes down
below 99 degrees C
or
• A/C pressure >1500kPa
or
• DTC Set
Battery
FS
FU Fa n 1 O/B LU ( 204)
O/B ( 208)
FT Fan 2
RR
(001) (203)
O/B
(740) O
(740) A5/A6
F31
G
Y
O/Y
(250)
BLU/Y
(533)
B
BLU
(1040) Battery Ma in Power
Hi gh Series BC M Term inals Nominat ed Fi rst
Low
Sp ee d Fan
B7/B7
E2/D2
B10/B11
A1/A5
Serial Data
High
Current Earth
El ectroni c Earth
BLU/W (304)
Ser ia l Data
High
Speed
Fan
85 85
B12
C13
87 30
O/B (473)
R/B (1221)
B/P (157)
B/G
(151)
B/Y (155)
Loc. E3
4270-B
Loc. E2
86
87
87A
86 30
Blue
Fusible
Link
Loc.
E1
Engine
Cooling
Fan Rela y
(High Speed)
Engine Cooling
Fan Rela y
(Low Speed)
Engine
Cooling
Fans
M
I
C
R
O
P
R
O
C
E
S
S
O
R
M
I
C
R
O
BCM
PCM
YB176
YB165
YB174
YB163
YB174
YB163
YB175
YE112
YB198
YB187
YB164
YB176
YB165
YE139
YE139
YE140
YE140
YE43 YE103
YE103
YE43
ENGINE COOLING FAN HIGH SPEED
The engine cooling fan high speed is controlled by the PCM based on input from the Engine Coolant
Tem per ature Sensor ( ECT) . T he PCM will only turn "O N" the engine cooling fan high speed if the engine cooling
low speed fan has been "ON" for 2 seconds and the following conditions are satisfied.
• There is a BCM message response fault, which will cause a DTC P1064.
• An engine coolant temperature sensor failure is detected, such as DTC P0116, P0117, P0118 or P1628.
• Coolant temperature greater than 107 degrees C.
• If the fan low speed was "OFF" when the criteria was met to turn the fan high speed "ON", the fan high
speed will come "ON" 5 seconds after the fan low speed is turned "ON".
• The engine c ooling fan High speed relay can also be enabled by the A/C Ref rigerant Pressure Sensor . T he
A/C Refrigerant Pressure Sensor will provide a signal to the PCM when A/C pressure becomes to high
approximately 2000 kPa.
TEST DESCRIPTION: Number(s) below refer to step number(s) 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 may result. Fan should not be
running if engine coolant temperature is less than 99 degrees and air conditioning is not “ON”.
6. Us ing the T ech 2 sc an tool will allow operation of the Low Speed Cooling Fan Relay. If the fan operates with
the scan tool, the Low Speed Cooling Fan is operating properly.
7. This test verifies that the Low Speed Cooling Fan will operate when the A/C system is turned “ON”.
TABLE A-12.2 V6 PCM - ELECTRIC FAN CONTROL
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check.
2. 1. Ignition “ON”, engine stopped.
2. Engine coolant temperature below 99 degrees C.
3. Turn “OFF” A/C (if fitted).
Is Low Speed Cooling Fan running?
Go to Step 3 Go to Step 6
3. 1. Ignition “ON”, engine stopped.
2. Remove the Low Speed Cooling Fan Relay.
Does the Low Speed Cooling Fan stop running?
Go to Step 4 Go to Step 10
4. 1. Ignition “OFF”.
2. Disconnect the BCM connectors.
3. Using test light connected to B+, probe BCM harness
connector terminal for Low Speed Cooling Fan Relay
control circuit.
Does test light illuminate?
Go to Step 5 Go to Step 11
5. Check for open or short to earth in Low Speed Cooling
Fan Relay control circuit.
Was a problem found?
Verify Repair
Go to Step 22
6. 1. Ignition “ON”, engine stopped.
2. Using Tech 2 scan tool: Select Low Fan Relay
Control.
3. Turn “ON” Low Fan with scan tool.
Does Low Speed Cooling Fan operate?
Go to Step 7 Go to Step 13
7. Notice: If vehicle is not equipped with A/C, proceed to
Step 8.
1. Ignition “ON”, engine stopped.
2. Turn “ON” A/C system and blower motor switch.
Does Low Speed Cooling Fan Operate?
Go to Step 8 Go to Step 9
8. The Low Speed Cooling Fan circuit is OK.
Is action complete? Verify Repair
9. Refer to Table A-11.1 A/C Clutch Control, for Non ECC
system, or Table A-11.3 A/C Clutch Control with ECC.
Is action complete?
Verify Repair
TABLE A-12.2 V6 PCM - ELECTRIC FAN CONTROL (CONTINUED)
STEP ACTION VALUE YES NO
10. Repair short to earth in Low Speed Cooling Fan earth
circuit between fan motor and Low Speed Relay.
Is action complete?
Verify Repair
11. 1. Ignition “OFF”.
2. Reconnect BCM connectors.
3. Ignition “ON”, engine stopped.
4. Using test light connected to B+, probe Low Speed
Cooling Fan Relay control circuit at relay harness
connector.
Does test light illuminate?
Go to Step 12 Go to Step 17
12. Verify the A/C system (if fitted) is working properly. If OK,
replace BCM.
Is action complete?
Verify Repair
13. Check for open or short to earth in fusible link power
supply to Low Speed Cooling Fan Relay. Repair fusible
link if open.
Was a problem found?
Verify Repair Go to Step 14
14. 1. Ignition “ON”, engine stopped.
2. Remove Low Speed Cooling Fan Relay.
3. Using test light connected to B+, probe relay harness
connector terminal 86.
4. Using Tech 2 scan tool, command “ON” and “OFF”
Low Speed Cooling Fan.
Does test light turn “ON” and “OFF” with scan tool
commands?
Go to Step 15 Go to Step 5
15. 1. Ignition “OFF”.
2. Disconnect Low Speed Cooling Fan motor electrical
connector.
3. Using test light connected to earth, probe power feed
circuit to fan motor.
Does test light illuminate?
Go to Step 18 Go to Step 16
16. Repair open or short to earth in power feed circuit to Low
Speed Cooling Fan motor. Repair fusible link if open.
Is action complete?
Verify Repair
17. Replace Low Speed Cooling Fan Relay.
Is action complete? Verify Repair
18. 1. Ignition “ON”, engine stopped.
2. Remove Low Speed Cooling Fan Relay.
3. Using a fused jumper lead connected to earth, probe
Low Speed Cooling Fan Relay harness connector
terminal 30.
Does Low Speed Cooling Fan motor operate?
Go to Step 19 Go to Step 21
19. Using test light connected to B+, probe Low Speed
Cooling Fan Relay harness connector terminal 87.
Does test light illuminate?
Go to Step 17 Go to Step 20
20. Repair open in earth circuit to Low Speed Cooling Fan
Relay terminal 87.
Is Action complete?
Verify Repair
21. Check for open in earth circuit from Low Speed Cooling
Fan Relay to Low Speed Cooling Fan motor.
Was a problem found?
Verify Repair Go to Step 23
22. Check for poor connection at BCM.
Was a problem found? Verify Repair Go to Step 12
23. Replace Low Speed Cooling Fan motor.
Is action complete? Verify Repair
1. Back Pressure Gauge Assembly.
2. Exhaust Gas Heated Oxygen (HO2S) Sensor
3. L.H. Engine Exhaust Pipe.
TABLE A-13 V6 PCM -
RESTRICTED EXHAUST CHECK
There are tim es when a restricted exhaust can cause a variety of owner complaints. Below is a list of some of
these owner complaints.
• No power, sluggish
• Hesitation on acceleration
• Surges while driving
• Poor fuel economy
• Stalling
• Hard starting
Things that could cause a restricted exhaust:
A. Collapsed exhaust pipe.
B. Muffler. Loose baffles may cause internal restriction
C. Catalytic converter. Things that can cause a catalytic converter to become restricted: (1) The use of
LEADED FUEL (2) A ver y ric h-running engine. T his rich-r unning condition could be caused by fuel pres sure
too high, or by a malfunction in the engine control system (3) Engine in a bad state of tune. Worn parts in
the ignition system can cause an engine misfire, which sends unburned fuel into the exhaust system. The
catalytic converter "sees" this unburned fuel as a rich-running condition. (4) Push-starting the engine. This
can send a tremendous amount of unburned fuel into the exhaust system.
4283
1
2
3
TABLE A-13 V6 PCM - RESTRICTED EXHAUST CHECK
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Carefully remove O2 sensor.
Did O2 sensor remove from exhaust system ? Go to Step 3 Go to Step 6
3. 1. Install exhaust back pressure gauge in place of
removed O2 sensor.
2. Ignition "ON", engine started.
3. Observe the exhaust system back pressure reading
on the gauge.
Is the reading below the specified value ?
8.6 kPa Go to Step 4 Go to Step 7
4. Accelerate engine to 2000 RPM and observe reading on
gauge.
Is reading on gauge below the specified value ?
20.7 kPa Go to Step 5 Go to Step 7
5. No problem with exhaust system.
NOTE: Make sure to coat threads of O2 sensor with a
specified anti-seize compound prior to
installation.
Is action complete ?
Go to OBD
System Check
in this Section
6. If the O2 sensor will not remove from the exhaust
System, make sure that the exhaust system is Above 60
C. Excessive force may damage threads. If the O2
sensor cannot be removed , the exhaust pipe and O2
sensor may need to be replaced.
Was removal of O2 sensor successful ?
Go to Step 3 Verify Repair
7. NOTE: If there are no obvious reasons for the
excessive back pressure, a restricted catalytic
converter should be suspected and replaced
using current recommended procedures. Refer
above. Things that could cause a
restricted exhaust: for possible causes.
NOTE: Make sure to coat threads of O2 sensor with a
specified anti-seize compound prior to
installation.
Is action complete ?
Verify Repair and
Go to OBD
System Check
in this Section
DTC P0101 V6 PCM
MASS AIR FLOW (MAF) SENSOR OUT OF RANGE
CIRCUIT DESCRIPTION:
The Mass Air Flow (MAF) sensor measures the flow of air which passes through it in a given time. The PCM
uses this information to monitor the operating condition of the engine for fuel delivery calculations. A large
quantity of air movement indicates acceleration, while a small quantity indicates deceleration or idle.
The MAF sensor produces a frequency signal which cannot be easily measured.
The MAF sensor can be diagnosed using the procedures on this Table.
W ith DTC P0101 set, the PCM will use a default value for air flow based on throttle position, and engine speed
and some vehicle performance will return. When DTC P0101 is set the MIL "Check Powertrain Lamp" will be
illuminated.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
CONDITIONS FOR SETTING THE DTC
• No MAF signal for over 2 seconds.
• Above conditions present for at least 10 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• The PCM will substitute a MAF sensor value based on RPM, throttle angle and IAC position.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
An intermittent may be caused by a poor connection, mis-routed harness, rubbed through wire insulation, or a
wire broken inside the insulation.
Check for:
• Poor Connection at PCM Pin - Inspect harness connectors for backed out terminals, improper mating,
broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
• Mis-Routed Harness - Inspect MAF sensor harness to ensure that it is not too close to high voltage wires,
such as spark plug leads.
• Damaged Harness - Inspect harness for damage. If harness appears OK, observe Tech 2 scan tool while
moving related connectors and wiring harness. A change in display would indicate the intermittent fault
location.
V6PCM006
IC
CIRCUIT
MASS AIR FLOW SENSOR
A7
A5
PCM
CBA
AIR FLOW
FROM
AIR FILTER
AIR FLOW
TO
THROTTLE BODY
EFI
RELAY
F33 P (43 9)
ENGINE EARTH
BR/W (792)
MASS AIR FLOW
INP U T SIG NAL
EARTH
5 V
M
I
C
R
O
IC
BR (750)
YE100
YE111 YB187
LOC. E5/E15
• Plugged Air Filter - A wide open throttle ac c elera tion f rom a s top should c aus e the MAF r eading on the T e ch
2 sc an tool to range from about 4-7 g/s at idle to 100 or greater at the time of the 1-2 shift on an autom atic
transmission. If not, check for restriction.
TEST DESCRIPTION: Number(s) below refer to step(s) on the diagnostic Table.
5. Verifies that both ignition feed voltage and a good earth circuit are available.
6. This step checks to see if PCM recognises a problem.
7. A voltage r eading at s ensor har ness c onnector ter minal "A" of les s than 4 or over 6 volts indic ates a fault in
circuit 792 or poor connection.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
M.A.F SENSOR
YE 100
(439)
(750)
(792)
B/R
PBR/W
DTC P0101 V6 PCM - MASS AIR FLOW (MAF) SENSOR OUT OF RANGE
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Ignition "ON".
2. Using Tech 2 scan tool, select MAF frequency.
Is "MAF frequency" reading at the specified value ?
0 Hz Go to Step 4 Go to Step 3
3. Replace MAF sensor.
Is action complete ? Verify Repair
4. 1. Ignition "OFF".
2. Disconnect MAF sensor.
3. Ignition "ON".
4. Connect a test light to earth, and probe MAF sensor
harness connector terminal "C".
Is test light "ON" ?
Go to Step 5 Go to Step 11
5. 1. Ignition "OFF".
2. Disconnect MAF sensor.
3. Ignition "ON".
4. Measure voltage between MAF sensor harness
connector terminals "B" and "C" .
Is voltage greater then specified value ?
10 volts Go to Step 7 Go to Step 10
6. 1. Ignition "OFF".
2. Reconnect MAF sensor.
3. Ignition "ON" engine idling.
Is MAF sensor "MASS AIR FLOW" reading between
Specified value ?
4 - 9
grams/sec DTC P0101 is
intermittent. If no
additional DTC's
were stored, refer
to "Diagnostic
Aids" above.
Go to Step 3
7. 1. Ignition "OFF".
2. Disconnect wiring harness connector from MAF
sensor.
3. Ignition "ON".
4. Measure voltage at MAF sensor harness connector
terminal "A" with a voltmeter to earth.
Is the measured voltage between the specified values ?
4 - 6 volts Go to Step 6 Go to Step 8
8. Is voltage on MAF sensor harness connector
Terminal "A" less than specified value ? 4 volts Go to Step 9 Go to Step 12
DTC P0101 V6 PCM - MASS AIR FLOW (MAF) SENSOR OUT OF RANGE (CONTINUED)
STEP ACTION VALUE YES NO
9. Check for an open or short to earth on circuit 792.
Is a fault found ? Verify Repair Go to Step 13
10. Repair open in circuit 750.
Is action complete ? Verify Repair
11. Repair open or short to earth in circuit 439 .
Replace fuse F33 if blown.
Is action complete ?
Verify Repair
12. Repair short to voltage on circuit 792.
Is action complete ? Verify Repair
13. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0111 V6 PCM -
INTAKE AIR TEMPERATURE (IAT) SIGNAL VOLTAGE UNSTABLE
CIRCUIT DESCRIPTION:
The Intake Air Temperature (IAT) sensor uses a thermistor to control the signal voltage to the PCM. The PCM
applies a voltage ( about 5 volts ) on c irc uit 472 to the s ens or. When manifold intake air is c old (s uc h as when the
engine is first s tarted on a cold day), the sens or (therm istor) resistanc e is high, therefore, the PCM will sens e a
high signal voltage. If the manifold intake air is warm, the sensor (thermistor) resistance is low, therefore, the
PCM will sense a low signal voltage.
CONDITIONS FOR RUNNING THE DTC
• The engine has been operating for more than 10 seconds.
CONDITIONS FOR SETTING THE DTC
• IAT sensor reading changes more than 7°C (140 millivolts) in 100 milliseconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P0111 is set, the PCM will default to a 25°C IAT for engine operation.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
W hen attem pting to diagnose an inter mittent problem , use the s napshot mode of the Tec h 2 scan tool to r eview
diagnostic information.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
VXPCM002
D6
D7
B
A
INTAKE AIR
TEMPERATURE SENSOR
SENSOR EARTH
IAT SENSOR SIGNAL
PCM
5V
BR (472)
B (46 9)
M
I
C
R
O
YE198YE22
TO
A/C PRSSURE
SENSOR AND
TFT SENSOR
IAT SENSOR TABLE RESISTANCE-TEMPERATURE CHARACTERISTICS
Temp
(C) No Load
Ω
ΩΩ
Ω Temp
(C) No Load
Ω
ΩΩ
Ω
-40 102,129 60 679
-35 73,345 65 566
-30 53,253 70 475
-25 39,066 75 400
-20 28,940 80 338
-15 21,638 85 287
-10 16,321 90 245
-5 12,414 95 210
0 9,517 100 180
5 7,355 105 156
10 5,729 110 135
15 4,497 115 117
20 3,555 120 102
25 2,830 125 89
30 2,268 130 79
35 1,829 135 69
40 1,483 140 61
45 1,210 145 54
50 993 150 48
55 819
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
AIR TEMP SENS OR
YE 23
B
(469)
BR
(472)
DTC P0111 V6 PCM - INTAKE AIR TEMPERATURE (IAT) SIGNAL VOLTAGE UNSTABLE
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Install Tech 2 scan tool and set up snapshot
mode to trigger on DTC P0111.
2. Watch the Tech 2 scan tool while wiggling
the IAT sensor connector.
Does the "IAT" reading change sharply?
Go to Step 8 Go to Step 3
3. Wiggle and tug the IAT sensor harness.
Does the "IAT" reading change sharply? Go to Step 9 Go to Step 4
4. Wiggle and tug the harness at the PCM.
Does the "IAT" reading change sharply? Go to Step 10 Go to Step 5
5. Lightly tap on the PCM.
Does the "IAT" reading change sharply? Go to Step 6 DTC P0111 is
intermittent, refer
to Diagnostic
Aids above.
DTC P0111 V6 PCM - INTAKE AIR TEMPERATURE (IAT) SIGNAL VOLTAGE UNSTABLE (CONTINUED)
STEP ACTION VALUE YES NO
6. Make sure PCM is mounted securely to vehicle.
Was a problem found? Verify Repair Go to Step 7
7. Replace PCM.
Refer to Section 6C1-3 SERVICE OPERATIONS of the
VX Series Service Information, for PCM Programming
and Security Link procedure.
Is action complete?
Verify Repair
8. 1. Check IAT sensor connector.
2. Check the tightness of the female terminal grip
with a spare male terminal.
3. Inspect connectors for corrosion. If
connectors are corroded, try cleaning with
electronic part cleaner and retest.
4. If these repairs do not resolve the problem,
replace terminals.
Is action complete?
Verify Repairs
9. 1. Check for an open in the IAT harness.
2. Check for broken strands of wire in IAT sensor
harness.
3. Check for cuts or pinches in IAT sensor harness.
4. Make repairs as necessary.
Is action complete?
Verify Repairs
10. 1. Check the IAT sensor connection at the PCM.
2. Check tightness of the female terminal grip with a
spare male terminal.
3. Inspect connectors for corrosion. If connectors
are corroded, try cleaning with electronic parts
cleaner and retest.
4. Remove connector strain relief and remove
terminal from connector to check for broken
locking tang.
Is action complete?
Verify Repairs
DTC P0112 V6 PCM -
INTAKE AIR TEMPERATURE (IAT) SIGNAL VOLTAGE LOW
CIRCUIT DESCRIPTION:
The Intake Air Temperature (IAT) sensor uses a thermistor to control the signal voltage to the PCM. The PCM
applies a voltage (about 5 volts) on circ uit 472 to the sensor . When the intake air is cold, the sens or (ther m istor)
resistance is high, therefore, the PCM will sensor a high signal voltage. If the intake air is warm, the sensor
(thermistor) resistance is low, therefore, the PCM will sense a low signal voltage.
CONDITIONS FOR RUNNING THE DTC
• The engine has been operating for more than 10 seconds.
CONDITIONS FOR SETTING THE DTC
• IAT Sens or signal voltage is at or les s than 0.3 volts, indicating an intake air temper ature at or above 135°C
for more than one second.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P0112 is set, the PCM will default to a 25°C IAT for engine operation.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Intake Air Temper ature (IAT) on a T ech 2 scan tool indicates the temperature of the air in the air cleaner. If the
engine has been allowed to sit overnight, the IAT sensor and engine coolant temperature values should be
within a f ew degrees of each other. Af ter the engine is s tarted, the IAT will increas e due to engine com partment
temperatures, however, IAT will rarely exceed 80 degrees C.
When the PCM detects a fault in the IAT circuit, a default value of 25 degrees C will be used.
Check harness routing for possible short to earth in circuit 469.
Refer to "Intermittents" in Section 6C1-2B SYMPTOMS of the VX Series Service Information.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
VXPCM002
D6
D7
B
A
INTAKE AIR
TEMPERATURE SENSOR
SENSOR EARTH
IAT SENSOR SIGNAL
PCM
5V
BR (472)
B (46 9)
M
I
C
R
O
YE198YE22
TO
A/C PRSSURE
SENSOR AND
TFT SENSOR
IAT SENSOR TABLE RESISTANCE-TEMPERATURE CHARACTERISTICS
Temp
(C) No Load
Ω
ΩΩ
Ω Temp
(C) No Load
Ω
ΩΩ
Ω
-40 102,129 60 679
-35 73,345 65 566
-30 53,253 70 475
-25 39,066 75 400
-20 28,940 80 338
-15 21,638 85 287
-10 16,321 90 245
-5 12,414 95 210
0 9,517 100 180
5 7,355 105 156
10 5,729 110 135
15 4,497 115 117
20 3,555 120 102
25 2,830 125 89
30 2,268 130 79
35 1,829 135 69
40 1,483 140 61
45 1,210 145 54
50 993 150 48
55 819
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
AIR TEMP SENS OR
YE 23
B
(469)
BR
(472)
DTC P0112 V6 PCM - INTAKE AIR TEMPERATURE (IAT) SIGNAL VOLTAGE LOW
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Ignition off.
2. Install Tech 2 scan tool.
3. Ignition on, then off, then back on.
4. Does Tech 2 scan tool momentarily display "IAT"
equal or greater than specified value?
135 degrees
C Go to Step 3 DTC P0112 is
intermittent, if no
additional DTCs
were stored, refer
to "Diagnostic
Aids" above.
3. 1. Disconnect IAT sensor wiring harness.
2. Ignition off.
3. Install Tech 2 scan tool.
4. Ignition on, then off, then back on.
Does Tech 2 scan tool momentarily display "IAT" below
specified value?
-30 degrees
C Go to Step 4 Go to Step 6
4. Measure resistance across IAT sensor.
Does value correspond to specified value? Refer to IAT
table above. Go to Step 5 Go to Step 7
DTC P0112 V6 PCM - INTAKE AIR TEMPERATURE (IAT) SIGNAL VOLTAGE LOW
STEP ACTION VALUE YES NO
5. Check for intermittent or loose terminals in harness
connector, or terminals shorted together.
Was a problem found?
Verify Repair. Go to Step 8
6. Check for a short in circuit 472 to earth or to IAT sensor
earth.
Was a problem found?
Verify Repair. Go to Step 8
7. Replace IAT sensor.
Is action complete? Verify Repair.
8. Replace PCM.
Refer to Section 6C1-3, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair.
DTC P0113 V6 PCM -
INTAKE AIR TEMPERATURE (IAT) SIGNAL VOLTAGE HIGH
CIRCUIT DESCRIPTION:
The Intake Air Temperature (IAT) sensor uses a thermistor to control the signal voltage to the PCM. The PCM
applies a voltage (about 5 volts) on circ uit 472 to the sensor . When the intake air is cold, the sens or (ther m istor)
resistance is high, therefore, the PCM will sensor a high signal voltage. If the intake air is warm, the sensor
(thermistor) resistance is low, therefore, the PCM will sense a low signal voltage.
CONDITIONS FOR RUNNING THE DTC
• The engine has been operating for more than 10 seconds.
CONDITIONS FOR SETTING THE DTC
• IAT sensor signal voltage is more than 4.9 volts indicating an intake air temperature is at or below -30°C for
one second.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P0113 is set, the PCM will default to a 25°C IAT for engine operation.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
A Tech 2 scan tool indicates the temperature of the air in the intake. W hen the PCM detects a fault in the IAT
sensor circuit, a default value of 25 degrees C will be used by the PCM.
Carefully check harness and connections for possible open circuit 472 or circuit 469.
An open circuit 469 will set DTC P0112 and DTC P0713, if the engine has been allowed to sit overnight, then
the intak e air tem peratur e and engine c oolant tem peratur e values should be within a few degrees of eac h other.
After the engine is started, the IAT sensor will increase due to engine compartment temperatures.
Refer to "Intermittents" in Section 6C1-2B SYMPTOMS of the VX Series Service Information.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. A Diagnostic Trouble Code P0113 will set, due to an open sensor, wire or connection. This test will
determine if the wiring and PCM are OK.
6. This will determine if the IAT sensor signal (circuit 472) or the IAT sensor earth (circuit 469) is open.
VXPCM002
D6
D7
B
A
INTAKE AIR
TEMPERATURE SENSOR
SENSOR EARTH
IAT SENSOR SIGNAL
PCM
5V
BR (472)
B (46 9)
M
I
C
R
O
YE198YE22
TO
A/C PRSSURE
SENSOR AND
TFT SENSOR
IAT SENSOR TABLE RESISTANCE-TEMPERATURE CHARACTERISTICS
Temp
(C) No Load
Ω
ΩΩ
Ω Temp
(C) No Load
Ω
ΩΩ
Ω
-40 102,129 60 679
-35 73,345 65 566
-30 53,253 70 475
-25 39,066 75 400
-20 28,940 80 338
-15 21,638 85 287
-10 16,321 90 245
-5 12,414 95 210
0 9,517 100 180
5 7,355 105 156
10 5,729 110 135
15 4,497 115 117
20 3,555 120 102
25 2,830 125 89
30 2,268 130 79
35 1,829 135 69
40 1,483 140 61
45 1,210 145 54
50 993 150 48
55 819
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
AIR TEMP SENS OR
YE 23
B
(469)
BR
(472)
DTC P0113 V6 PCM - INTAKE AIR TEMPERATURE (IAT) SIGNAL VOLTAGE HIGH
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Ignition off.
2. Install Tech 2 scan tool.
3. Ignition on, then off, then back on.
Does Tech 2 scan tool momentarily display "IAT" at or
between the specified value?
-30 to -40
degrees C Go to Step 3 DTC P0113
intermittent. If no
additional DTCs
were stored, refer
to "Intermittents"
in Section 6C1-
2B S YMPT OMS
of the VX Series
Service
Information.
3. 1. Ignition off.
2. Install Tech 2 scan tool.
3. Ignition on, then off, then back on.
Does Tech 2 scan tool momentarily display "IAT" at the
Specified Value or higher?
130 °
degrees C Go to Step 4 Go to Step 6
DTC P0113 V6 PCM - INTAKE AIR TEMPERATURE (IAT) SIGNAL VOLTA GE HIGH (CONTINUED)
STEP ACTION VALUE YES NO
4. Check resistance across "IAT" sensor terminals.
Is value OK? See IAT
table above. Go to Step 5 Go to Step 12
5. Is there an intermittent or loose terminal in sensor
harness connector? Verify Repair Go to Step 11
6. 1. Ignition off.
2. Install Tech 2 scan tool.
3. Jumper circuit 472 to earth.
4. Ignition on, then off, then back on.
5. Does Tech 2 scan tool momentarily display "IAT" at
specified Value or higher?
130 °
degrees C Go to Step 7 Go to Step 8
7. Check for an open sensor earth circuit or faulty
Connection.
Was an open or faulty connection found?
Verify Repair Go to Step 10
8. Check for an open circuit 472 or faulty connection.
Was an open or faulty connection found? Verify Repair Go to Step 10
9. Replace intake air temperature sensor. Verify Repair
10 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
11. 1. Ignition "OFF"
2. Disconnect PCM connectors.
3. Remove jumper from IAT sensor harness.
4. Ignition "ON".
5. Check for short to voltage in circuit 472.
Was a short to voltage found?
Verify Repair Go to Step 10
12 Replace IAT sensor.
Is action complete ? Verify Repair
DTC P0117 V6 PCM
ENGINE COOLANT TEMPERATURE (ECT) SIGNAL VOLTAGE LOW
CIRCUIT DESCRIPTION:
The Engine Coolant T emperature ( ECT) sensor uses a therm istor to control the signal voltage to the PCM. The
PCM applies about 5 volts on c ircuit 410 to the sens or. When the engine coolant is c old, the sensor (therm ist or)
resistance is high, therefore the PCM will see high signal voltage about 4.0 - 4.5 volts.
As the engine coolant warm s, the s ensor r esistanc e becom es les s, and the PCM s ees a lower s ignal voltage. At
norm al engine oper ating temperatur e (85 degrees C to 95 degrees C), the voltage should m easure about 2.2 to
1.8 volts.
CONDITIONS FOR RUNNING THE DTC
• Time since engine started is greater than 20 seconds
CONDITIONS FOR SETTING THE DTC
• ECT s ensor s ignal voltage is less than 0.3 volts , indic ating an engine c oolant temperature at or above 140 C
for one second.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• The PCM will substitute a coolant temperature default value. The PCM arrives at this default, or substitute
value, by switching to a starting point, then counting upwards to 95°C at a rate of 11 degrees per minute.
• When Diagnostic Trouble Code P0117 is set, the TCC will be applied with a cold engine and the engine
cooling fan will be turned "ON".
• A DTC P0117 may enable TCC operation when cold.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Check harness routing for a potential short to earth in circuit 410.
Check terminals at ECT sensor for a good connector.
The Tech 2 scan tool reads engine coolant temperature in degrees Celsius. After engine is started, the
temperature should rise steadily to about 90 C then stabilise when thermostat opens.
The "Temperature to Resistance Value" scale may be used to test the engine coolant temperature sensor at
various tem perature levels to evaluate the poss ibility of a "shif ted" (mis -scaled) s ensor. A "shifted" sensor could
result in poor driveability complaints.
Refer to "Intermittents" in Section 6C1-2B SYMPTOMS of the VX Series Service Information.
VXPCM004
C6
D11
B
A
ENGINE COOLANT
TEMPERATURE SENSOR
SENSOR EARTH
ETC SENSOR SIGNAL
5V
4k
348
Ω
Ω
Y (41 0)
B/Y (452)
M
I
C
R
O
YE106
TO
THROTTLE POSITION
SENSOR
YB198
ECT SENSOR TABLE TEMP. TO RESISTANCE VALUES (APPROXIMATE)
C OHMS
110 134
100 180
90 244
70 474
40 1,483
30 2,268
20 3,555
0 9,517
-10 16,320
-20 28,939
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. This test will determine if circuit 410 is shorted to earth which will cause the conditions for DTC P0118.
4. If checking resistance at the engine coolant temperature sensor is difficult because of sensor location,
disconnect the PCM connectors and check resistance between engine coolant temperature signal and
sensor earth terminals.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
COOLANT TEM P SENSO R
YE106
Y
(410)
B/Y
(452)
DTC P0117 V6 PCM - ENGINE COOLANT TEMPERATURE (ECT) SIGNAL VOLTAGE LOW
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Using Tech 2 scan tool, select "Eng. Coolant Temp" on
the data display.
Is the "Eng. Coolant Temp" display value at or above the
specified value?
140 degrees
C Go to Step 3 If no additional
DTCs were
stored, refer to
"Intermittents" in
Section 6C1-2B
SYMPTOMS of
the VX Series
Service
Information.
3. 1. Ignition "Off".
2. Disconnect engine coolant temperature sensor
wiring harness.
3. Ignition "On".
Does Tech 2 scan tool display "Eng. Coolant Temp"
below specified value?
-30 degrees
C Go to Step 4 Go to Step 7
DTC P0117 V6 PCM - ENGINE COOLANT TEMPERATURE (ECT) SIGNAL VOLTAGE LOW (CONTINUED)
STEP ACTION VALUE YES NO
4. Check resistance across engine coolant temperature
sensor terminals.
Does DVM ohms reading match the specified values for
temperature to sensor resistance?
See table
above.
Go to Step 5 Go to Step 8
5 Check for intermittent or loose terminals in sensor
harness connector, or for the 2 terminals shorting
together when connected to the sensor.
Was a faulty connection found?
Verify Repair Go to Step 6
6 Replace PCM.
Refer to Section 6C1-3 SERVICE OPERATIONS of the
VX Series Service Information, for PCM Programming
and Security Link procedure.
Is action complete?
Verify Repair
7 Check circuit 410 for short to earth or to sensor earth.
Was a short found? Verify Repair Go to Step 6
8 Replace ECT sensor.
Is replacement complete? Verify Repair
DTC P0118 V6 PCM
ENGINE COOLANT TEMPERATURE (ECT) SIGNAL VOLTAGE HIGH
CIRCUIT DESCRIPTION:
The Engine Coolant T emperature ( ECT) sensor uses a therm istor to control the signal voltage to the PCM. The
PCM applies about 5 volts on c ircuit 410 to the sens or. When the engine coolant is c old, the sensor (therm ist or)
resistance is high, therefore the PCM will see high signal voltage, about 4 - 4.5 volts.
As the engine coolant warms, the sensor (thermistor) resistance becomes less, and the PCM sees a lower
signal voltage. At normal engine operating temperature (85 degrees C to 95 degrees C), the voltage will
measure about 2.2 to 1.8 volts.
A Diagnostic Trouble Code P0118 may enable TCC operation when cold.
CONDITIONS FOR RUNNING THE DTC
• Time since engine started is greater than 10 seconds.
CONDITIONS FOR SETTING THE DTC
• ECT input signal voltage is greater than 4.64 volts, indicating an engine coolant temperature at or lower
than -30 degrees C for one second.
• Above conditions present for at least 1 second.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• The PCM will substitute a coolant temperature default value. The PCM arrives at this default, or substitute
value, by switching to a starting point, then counting upwards to 95°C at a rate of 11 degrees per minute.
• W hen the Diagnostic Tr ouble Code P0117 is set, the T CC will be applied with a c old engine and the engine
cooling fan will be forced "ON".
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
VXPCM004
C6
D11
B
A
ENGINE COOLANT
TEMPERATURE SENSOR
SENSOR EARTH
ETC SENSOR SIGNAL
5V
4k
348
Ω
Ω
Y (41 0)
B/Y (452)
M
I
C
R
O
YE106
TO
THROTTLE POSITION
SENSOR
YB198
DIAGNOSTIC AIDS:
A Tech 2 scan tool reads engine coolant temperature in degrees Celsius. After engine is started, the
temperature should rise steadily to about 90 C then stabilise when thermostat opens.
A faulty connection, or an open in circuit 410 or circuit 452 will result in a Diagnostic Trouble Code (DTC)
P0118.
If DT C P0123 is als o set, c hec k circ uit 452 f or f aulty wiring or connections. Check terminals at s ens or f or a good
connection. The "Temperature to Resistance Value" scale may be used to test the engine coolant temperature
sensor at various temperature levels to evaluate the possibility of a "shifted" (mis-scaled) sensor. A "shifted"
sensor could result in poor driveability complaints.
Refer to "Intermittents" in Section 6C1-2B SYMPTOMS of the VX Series Service Information.
ECT SENSOR TABLE TEMP. TO RESISTANCE VALUES (APPROXIMATE)
C OHMS
110 134
100 180
90 244
70 474
40 1,483
30 2,268
20 3,555
0 9,517
-10 16,320
-20 28,939
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. This test simulates a Diagnostic Trouble Code 15. If the PCM recognises the low signal voltage, (high
temperature) and the Tech 2 scan tool reads 130 C or above, the PCM and wiring are OK.
4. This test will determine if circuit 410 is open. There should be an open circuit voltage of 5 volts present at
Engine Coolant Tem perature ( ECT) sens or harness c onnector if m easur ed with a DVM. By jum pering this 5
volt signal to earth, the PCM should recognise this change.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
COOLANT TEM P SENSO R
YE106
Y
(410)
B/Y
(452)
DTC P0118 V6 PCM - ENGINE COOLANT TEMPERA TURE (ECT) SIGNAL VOLTAGE HIGH
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Using Tech 2 scan tool, select "Eng. Coolant
Temp" on the data display.
Is the "Eng. Coolant Temp" display value at or between
the specified value ?
-30 to -40
degrees C Go to Step 3 If no additional
DTCs were
stored, refer to
"Intermittents" in
Section 6C1-2B
SYMPTOMS of
the VX Series
Service
Information.
3. 1. Ignition "OFF".
2. Disconnect engine coolant temperature sensor
powertrain wiring harness.
3. Jumper harness terminals together.
4. Ignition "ON".
Does Tech 2 scan tool display "Eng. Coolant Temp" at or
above specified value?
130 degrees
C Go to Step 10 Go to Step 4
4. Jumper circuit 410 to earth.
Does Tech 2 scan tool display "Eng. Coolant Temp" at
or above specified value?
130 degrees
C Go to Step 5 Go to Step 8
5. Check resistance across engine coolant temperature
sensor terminals.
Does DVM reading match the specified values for
temperatures to sensor resistance?
See table
above
Go to Step 6 Go to Step 9
6. Check for intermittent or loose terminals in sensor
harness connector. Terminals may not be contacting
the sensor when connected.
Was a problem found?
Verify Repair Go to Step 7
7. Replace PCM.
Refer to Section 6C1-3 SERVICE OPERATIONS of the
VX Series Service Information, for PCM Programming
and Security Link procedure.
Is action complete?
Verify Repair
8. Check circuit 410 for an open, short to voltage or faulty
connection at PCM.
Was a problem found?
Verify Repair Go to Step 7
9. Replace ECT sensor.
Is action complete? Verify Repair
10. Check for faulty connection.
Was a problem found? Verify Repair Go to Step 9
DTC P0121 V6 PCM -
THROTTLE POSITION (TP) SENSOR STUCK
CIRCUIT DESCRIPTION:
The Throttle Position (TP) sensor provides a voltage signal that changes relative to the throttle blade angle.
Signal voltage will vary from about 0.25 to 1.25 volts at idle to about 4 volts at Wide Open Throttle (WOT).
The TP sensor signal is one of the most important inputs used by the PCM for transient fuelling and
transmission control and for most of the PCM control outputs.
Diagnostic Trouble Code (DTC) P0121 is used to detect a stuck open or TP sensor. DTC P0121 detects if the
TP sensor does not return with the throttle blade when decelerating.
CONDITIONS FOR RUNNING THE DTC
• Time since engine started is greater than 20 seconds
CONDITIONS FOR SETTING THE DTC
• The Throttle Position (TP) sensor percentage of opening angle indicated is greater than the RPM that can
be reached with a Mass Air Flow reading of less than 301 mg/cyl for 20 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• W hen DTC P0121 is set, the PCM will calculate throttle position bas ed off of IACV and MAF for engine and
transmission operation.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
A T ech 2 scan tool reads thr ottle position in volts. W ith ignition "ON'' or at idle, T P sensor s ignal voltage should
read about 0.25 to 1.25 volts with the throttle closed and increase at a steady rate as throttle is moved toward
Wide Open Throttle (WOT).
The Tech 2 scan tool will read throttle angle. 0%=closed throttle; 100%=WOT.
If voltage is steady above DTC P0122 voltage criteria and below DTC P0123 voltage criteria, check for a short
to voltage on the TP Sensor signal circuit.
Refer to "Intermittents" in Section 6C1-2B SYMPTOMS of the VX Series Service Information.
VXPCM005
SENSOR EARTH
TP SENSOR SIGNAL
TP SEN SOR
REFERENCE
VOLTAGE
PCM
5V
M
I
C
R
O
C15
C7
C6
A
C
B
THROTTLE
POSITION SENSOR
GY (416)
BLU (417)
B/Y (452)
TO
ECT
SENSOR
YB198YE30
DTC P0121 CRITERIA TABLE MAF LESS THAN 301 MG/CYL. (APPROXIMATE)
TPS%
V6 RPM
20 800
22 1,200
27 1,600
29 2,000
33 2,400
37 2,800
39 3,200
40 3,600
41 4,000
44 4,400
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. This step checks to verify the throttle linkage is moving freely.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
THROTTLE POSITION SENS OR
YE 30
(452) (416)
(417)
GY
B/Y
BLU
DTC P0121 V6 PCM - THROTTLE POSITION (TP) SENSOR STUCK
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Inspect throttle cable, linkage, and blade movement.
Are components binding or sticking? Verify Repair Go to Step 3
3 Using Tech 2 scan tool to monitor TP sensor voltage,
inspect TP sensor for binding or sticking during its
movement from closed throttle to wide open throttle and
back to closed throttle position.
Was fault found ?
Go to Step 4 DTC P0121
intermittent. If no
additional DTC's
were stored, refer
to Diagnostic
Aids above.
4. Replace binding Throttle Position (TP) sensor.
Is action complete? Verify Repair
DTC P0122 V6 PCM -
THROTTLE POSITION (TP) SENSOR VOLTAGE LOW
CIRCUIT DESCRIPTION:
The Throttle Position (TP) sensor provides a voltage signal that changes relative to the throttle blade. Signal
voltage will vary from about 0.25 to 1.25 volts at idle to about 4 volts at Wide Open Throttle (WOT).
The TP sensor signal is one of the most important inputs used by the PCM for transient fuelling and
transmission control and for most of the PCM control. Outputs.
CONDITIONS FOR RUNNING THE DTC
• Time since engine started is greater than 20 seconds
CONDITIONS FOR SETTING THE DTC
• The TP Sensor voltage between the PCM TP Sensor signal terminal and the TP Sensor earth terminal is
less than 0.2 volts for more than two seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• W hen a DTC P0122 is set, the PCM does not receive the proper signal from the TP sensor, but it can still
determ ine the TP sens or value with a default value based on RPM, Idle Air Control Valve position and Mas s
Air Flow.
• If DTC P0122 is set, the transmission will have no TCC.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
A T ech 2 scan tool reads thr ottle position in volts. W ith ignition "ON'' or at idle, T P sensor s ignal voltage should
read about 0.25 to 1.25 volts with the throttle closed and increase at a steady rate as throttle is moved toward
Wide Open Throttle (WOT).
The Tech 2 scan tool will read throttle angle. 0%=closed throttle; 100%=WOT.
An open or short to earth in circuit 416 or circuit 417 will result in a DTC P0122.
Refer to "Intermittents" in Section 6C1-2B SYMPTOMS of the VX Series Service Information.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. This test sim ulates a Diagnostic Trouble Code P0123: (high voltage) If the PCM recognises the high signal
voltage and the Tech 2 scan tool reads over 4 volts or above, the PCM and wiring are OK.
4. This simulates a high signal voltage to check for an open in circuit 417. The Tech 2 scan tool will not read
up to 12 volts, but what is important is that the PCM recognises the signal on circuit 417.
VXPCM005
SENSOR EARTH
TP SENSOR SIGNAL
TP SEN SOR
REFERENCE
VOLTAGE
PCM
5V
M
I
C
R
O
C15
C7
C6
A
C
B
THROTTLE
POSITION SENSOR
GY (416)
BLU (417)
B/Y (452)
TO
ECT
SENSOR
YB198YE30
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
THROTTLE POSITION SENS OR
YE 30
(452) (416)
(417)
GY
B/Y
BLU
DTC P0122 V6 PCM - THROTTLE POSITION (TP) SENSOR VOLTAGE LOW
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Throttle closed
Is Tech 2 scan tool display "TPS Voltage" at or below
specified value?
0.2 Volt
(200 mV) Go to Step 3 DTC P0122 is
intermittent, if no
additional DTCs
were stored, refer
to "Intermittents"
in Section 6C1-
2B S YMPT OMS
of the VX Series
Service
Information.
3. 1. Disconnect TPS wiring harness.
2. Jumper circuits 416 & 417 together.
Does Tech 2 scan tool display "TPS Voltage" above
Specified value?
4.0 Volts
(400 mV) Go to Step 6 Go to Step 4
4. Probe circuit 417 with test light connected to 12 volts.
Does Tech 2 scan tool display "TPS Voltage" above
specified value?
4.0 Volts
(400 mV) Go to Step 5 Go to Step 7
5. Check for open or short on circuit 416 or faulty
connection.
Was a short, open or faulty connection found?
Verify Repair Go to Step 8
6. Replace Throttle Position (TP) Sensor.
Is action complete? Verify Repair
7. Check for open or short on circuit 417 or faulty
connection.
Was a short, open or faulty connection found?
Verify Repair Go to Step 8
8. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0123 V6 PCM -
THROTTLE POSITION (TP) SENSOR VOLTAGE HIGH
CIRCUIT DESCRIPTION:
The Throttle Position (TP) sensor provides a voltage signal that changes relative to the throttle blade. Signal
voltage will vary from about 0.25 to 1.25 volts at idle to about 4 volts at Wide Open Throttle (WOT).
The TP sensor signal is one of the most important inputs used by the PCM for transient fuelling and
transmission control and for most of the PCM control. Outputs.
CONDITIONS FOR RUNNING THE DTC
• Time since engine started is greater than 20 seconds
CONDITIONS FOR SETTING THE DTC
• The TP Sensor voltage between the PCM TP Sensor signal terminal and the TP Sensor earth terminal is
greater than 4.9 volts (97%) for more than two seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• W hen a DTC P0123 is set, the PCM does not receive the proper signal from the TP sensor, but it can still
determ ine the TP sens or value with a default value based on RPM, Idle Air Control Valve position and Mas s
Air Flow.
• If DTC P0123 is set, the transmission will have no TCC.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
A T ech 2 scan tool reads thr ottle position in volts. W ith ignition "ON'' or at idle, T P sensor s ignal voltage should
read about 0.25 to 1.25 volts with the throttle closed and increase at a steady rate as throttle is moved toward
Wide Open Throttle (WOT).
The Tech 2 scan tool will read throttle angle. 0%=closed throttle; 100%=W OT. An open in circuit 452 will result
in a DTC P0123.
Refer to "Intermittents" in Section 6C1-2B SYMPTOMS of the VX Series Service Information.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. With the TP sensor disconnected, the TP sensor signal voltage should go low if the PCM and wiring are OK.
4. Probing circuit 452 with a test light connected to 12 volts checks the sensor earth circuit. A faulty sensor
earth will cause a DTC P0123.
VXPCM005
SENSOR EARTH
TP SENSOR SIGNAL
TP SEN SOR
REFERENCE
VOLTAGE
PCM
5V
M
I
C
R
O
C15
C7
C6
A
C
B
THROTTLE
POSITION SENSOR
GY (416)
BLU (417)
B/Y (452)
TO
ECT
SENSOR
YB198YE30
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
THROTTLE POSITION SENS OR
YE 30
(452) (416)
(417)
GY
B/Y
BLU
DTC P0123 V6 PCM - THROTTLE POSITION (TP) SENSOR VOLTA GE HIGH
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Throttle closed.
Is Tech 2 scan tool display "TPS Voltage" over specified
value?
2.5 volts Go to Step 3 If no additional
DTCs were
stored, refer to
"Intermittents" in
Section 6C1-2B
SYMPTOMS of
the VX Series
Service
Information.
3. Disconnect TPS wiring harness.
Does Tech 2 scan tool display "TPS Voltage" below
specified value?
0.2 volts
(200 mV) Go to Step 4 Go to Step 7
4. Probe TP sensor earth circuit with test light connected to
battery voltage.
Is test light "ON"?
Go to Step 5 Go to Step 8
5. Check for a faulty connection.
Was faulty connection found?
Verify Repair Go to Step 6
6. Replace Throttle Position Sensor (TPS). Verify Repair
7. Is the TP sensor signal circuit shorted to voltage? Verify Repair Go to Step 9
8. Is the TP sensor earth circuit open? Verify Repair Go to Step 9
9. Replace PCM.
Refer to section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0131 V6 PCM -
RIGHT HAND OXYGEN SENSOR (O2S) SIGNAL VOLTAGE LOW
CIRCUIT DESCRIPTION:
The PCM supplies a voltage of about 450 millivolts between terminal "C9" and "D5". The Oxygen (O2) sensor
varies the voltage within a range of about 1 volt if the exhaust is rich, down through about 100 millivolts, if
exhaust is lean.
The sensor is like an open circuit and produces no voltage when it is below about 360 degrees C. An open
sensor circuit or cold sensor causes "Open Loop" operation.
CONDITIONS FOR RUNNING THE DTC
• No IAT Sensor DTC’s are set.
• IAT Sensor is below 75°C.
• The system is in "Closed Loop”.
• Throttle angle is between 9% and 30%.
CONDITIONS FOR SETTING THE DTC
• The RH 02S signal voltage remains below 200 millivolts for 46 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• Once a 02S DTC is set, and current, the PCM will operate the fuel system in the “Open Loop” mode.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Using the T ech 2 scan tool, obser ve the Long Term Fuel Trim values at diff erent RPMs and air flow conditions.
The Tech 2 scan tool also displays the Long Term Fuel Trim cells, so the Long Term Fuel Trim values can be
checked in each of the cells to determine when the DTC P0131 or DTC P0151 may have been set. If the
conditions for DTC P0131 or DTC P0151 exists, the Long Term Fuel Trim values will be around +25%.
VXPCM003
PCM
D5
C9
D4
D3
GY/B (1413)
G/Y (1412)
LEFT OXYGEN SENS OR
RIGHT OXYGEN SENSOR
VB (413)
V (41 2)
RIGHT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL HI
RIGHT
OXYGEN
SENSOR
SIGNAL HI
IC
IC
M
I
C
R
O
450 mV
450 mV
YB198YE97
YE97
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
4. The DTC P0131 or lean exhaust is most likely caused by one of the following:
• O2 Sensor Wire - Sensor pigtail may be mispositioned and contacting the exhaust manifold.
• Check for intermittent earth in wire between connector and sensor.
• MAF Sensor - A shifted MAF sensor could cause the fuel system to go lean. Refer to TABLE A-6.1 of the
VX Series Service Information.
• Lean Injector(s) - Perform power balance test using the Tech 2 scan tool.
• Fuel Contamination - Water, even in small amounts, near the in-tank Fuel Pump inlet can be delivered to
the injectors. The water causes a lean exhaust and can set a DTC P0131 and/or DTC P0151.
• Fuel Pressure - System will go lean if pressure is too low. It may be necessary to monitor fuel pressure
while driving the vehicle at various road speeds and/or loads to confirm. Refer to TABLE A-4.1 of the VX
Series Service Information.
• Exhaust Leaks - If there is an exhaust leak, the engine can cause outside air to be pulled into the exhaust
and past the sensor. Vacuum or crankcase leaks can cause a lean condition.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
EXHAUST GAS SENSOR
YE 97
BA
(1412)
(412) (413)
(1413)
GY/BGY
V BLU/B L.H
R.H
OR OR
DTC P0131 V6 PCM - RIGHT HAND OXYGEN SENSOR (02S) SIGNAL VOLTAGE LOW
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. 1. Start engine.
2. Run engine until it reaches normal operating
temperature (Above 80 degrees C).
3. Continue to run at 1600 to 1800 RPM for two
minutes.
Does Tech 2 scan tool indicate O2 sensor voltage fixed
below specified value?
200 mV Go to Step 3
DTC P0131 is
intermittent, If no
additional DTCs
were stored, refer
to "Intermittents"
in Section 6C1-
2B S YMPT OMS
of the VX Series
Service
Information.
3. Disconnect O2 sensor connector.
With engine idling, does Tech 2 scan tool display O2
sensor voltage between the specified values?
Between
350 mV and
550 mV
Go to Step 4 Go to Step 6
4. 1. Refer to step 4 Test above description first.
2. Perform the checks on the items as noted.
• MAF sensor operation
• Low fuel pressure
• Contaminated fuel ex haust manifold leaks ahead of O 2
sensor
• Lean injector (possibly restricted)
• O2 sensor earth circuit
Are all items checked found to be OK?
Go to Step 5 Verify Repair
DTC P0131 V6 PCM - RIGHT HAND OXYGEN SENSOR (02S) SIGNAL VOLTAGE LOW (CONTINUED)
STEP ACTION VALUE YES NO
5. Replace Oxygen sensor.
Is action complete?
Verify repair
6. 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. With O2 sensor still disconnected, check O2 signal
circuit 1412 for a short to earth.
Is a short to earth detected?
Go to Step 7 Go to Step 8
7. Repair circuit 1412.
Is action complete? Verify Repair
8. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0132 V6 PCM -
RIGHT HAND OXYGEN SENSOR (O2S) SIGNAL VOLTAGE HIGH
CIRCUIT DESCRIPTION:
The PCM supplies a voltage of about 450 millivolts between terminal "C9" and "D5". The Oxygen (O2) sensor
varies the voltage within a range of about 1 volt, if the exhaust is rich and down through about 100 millivolts if
exhaust is lean.
The sensor produces no voltage when it is below about 360 degrees C. An open sensor circuit or cold sensor
causes "Open Loop" operation.
CONDITIONS FOR RUNNING THE DTC
• No TP Sensor DTC’s are set.
• The system is in "Closed Loop”.
• Throttle angle is between 9% and 30%.
CONDITIONS FOR SETTING THE DTC
• The RH 02S signal voltage remains above 780 millivolts for 40 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• Once a 02S DTC is set, and current, the PCM will operate the fuel system in the “Open Loop” mode.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Using the Tech 2 scan tool, observe the Long Term Fuel Trim values at different RPM and air flow conditions.
The Tech 2 scan tool also displays the Long Term Fuel Trim cells, so the Long Term Fuel Trim values can be
checked in each of the cells to determine when the DTC P0132 may have been set. If the conditions for DTC
P0132 exists, the Long Term Fuel Trim values will be around - 22%.
VXPCM003
PCM
D5
C9
D4
D3
GY/B (1413)
G/Y (1412)
LEFT OXYGEN S ENSOR
RIGHT OXYGEN SENSOR
VB (413)
V (41 2)
RIGHT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL HI
RIGHT
OXYGEN
SENSOR
SIGNAL HI
IC
IC
M
I
C
R
O
450 mV
450 mV
YB198YE97
YE97
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. The O2 sensor MUST be at operating temperature before checking operation.
3. This step checks for a short to voltage on the O2 signal line.
7. Earthing circuit 1412 causes a low O2 signal voltage. If the PCM and wiring are OK, the PCM should
recognise the low voltage and confirm the lean signal.
8. A DTC P0132 will most likely NOT be caused by a faulty O2 sensor. DTC P0132 indicates a rich exhaust
and diagnosis should begin with the items listed:
• Fuel pressure. System will go rich, if pressure is too high. The PCM can compensate for some increase.
However, if it gets too high, a DTC P0132 or DTC P0152 may be set. Refer to fuel system diagnosis
TABLE A-4.3 of the VX Series Service Information.
• Rich injector.
• Leaking injector. Refer to TABLE A-4.3 of the VX Series Service Information.
• Check for fuel contaminated oil.
• Short to voltage on circuit 1412.
• HEI shielding. An open earth circuit 453 (ignition system) may result in EMI, or induced electrical "noise."
The PCM looks at this "noise" as reference pulses. The additional pulses result in a higher than actual
engine speed signal. The PCM then delivers too much fuel, causing system to go rich. Engine tachometer
will also show higher than actual engine speed, which can help in diagnosing this problem.
• Canister purge. Check for fuel saturation. If full of fuel, check canister control and hoses.
• MAF sensor. A shifted MAF sensor could cause the fuel system to go rich.
• Check for leaking fuel pressure regulator diaphragm by checking vacuum line to regulator for fuel.
• TP Sensor . An interm ittent T P sensor output will cause the system to go rich, due to a f alse indication of the
engine accelerating.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
EXHAUST GAS SENSOR
YE 97
BA
(1412)
(412) (413)
(1413)
GY/BGY
V BLU/B L.H
R.H
OR OR
DTC P0132 V6 PCM - RIGHT HAND OXYGEN SENSOR (O2S) SIGNAL VOLTAGE HIGH
NOTE: Oxygen Sensor Contamination - If fuel containing lead or silicone is used, or engine repairs using
unapproved RTV gasket sealer are performed, the sensor may be contaminated. it may send a "false" rich
exhaust indication to the PCM, and the PCM will attempt to drive the fuel system lean to compensate. Poor
driveability or a Diagnostic Trouble Code P0131 could result. if this happens, the sensor will need to be
replaced, but every attempt to locate the source of contamination should be pursued.
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2. 1. Engine at normal operating temperature
(above 80 degrees C).
2. Run engine at approximately 1600 RPM to 1800
RPM for two minutes.
Is Tech 2 scan tool voltage above specified value?
750 mV Go to Step 3 DTC P0132 is
intermittent,
If no additional
DTC(s) were
stored, refer to
"Intermittents" in
Section 6C1-2B
SYMPTOMS of
the VX Series
Service
Information.
3. 1. Ignition "OFF".
2. Disconnect O2 sensor wiring harness.
3. With ohmmeter connected to earth, probe circuit
1412 at O2 sensor wiring harness connector.
4. Ignition "ON".
Is voltmeter indicating less then specified value?
350 mV Got to Step 7 Go to Step 4
4. 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. Probe circuit 1412 at O2 sensor wiring harness
connector.
5. Ignition "ON".
Is voltmeter indicating voltage below specified value ?
350 mV Go to Step 6 Go to Step 5
5. Repair circuit 1412, shorted to voltage.
Is action complete? Verify Repair
6. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
7. 1. Disconnect O2 sensor wiring harness connector.
2. Jumper harness connector circuit 1412 to earth.
With engine running, does Tech 2 scan tool display O2
voltage below specified value?
350 mV Go to Step 8 Go to Step 9
8. See to step 8 above, to perform additional checks for:
• High Fuel Pressure
• Map Sensor Operation
• Leaking Injectors
• Ignition Earth Circuit
• Canister Purge
• Engine Coolant Temperature Sensor Circuit
• Intake Air Temperature Sensor Circuit
• Throttle Position Sensor Operation
Do all additional checks from step 8 test above OK.?
Go to Step 8
above Verify Repair
9. 1. Ignition "OFF"
2. Disconnect PCM connectors.
3. Check O2 sensor earth circuit 750 for good
continuity between PCM connector terminal "D5"
and engine earth.
Is an "OPEN" circuit indicated?
Verify Repair Go to Step 10
10. Check PCM earth wire connection at engine. Must be a
clean and tight connection to the engine.
Is connection good?
Go to Step 6 Verify Repair
DTC P0134 V6 PCM -
NO RIGHT HAND OXYGEN SE NSOR (O2S) SIGNAL
CIRCUIT DESCRIPTION:
The ex haust oxygen sens or is mounted in the ex haust pipe with the sensing portion exposed to exhaust gases.
After the sensor is hot (360 degrees C), it becomes a voltage generator, producing a "changing" voltage. This
voltage ranges from approximately 100 millivolts with a "lean" exhaust, to 900 millivolts with a "rich" exhaust.
When the sens or is c old (below 360 degrees C) it acts lik e an open c ircuit and produc es alm ost no voltage. T he
PCM supplies a very small "bias" voltage between terminals C9 and D5, normally about 450 millivolts. If
measured with the 10 megaohm digital voltmeter, it may measure as low as 350 millivolts. W hen the sensor is
hot, it's output overshadows this PCM supplied voltage.
When the fuel system is correctly operating in the closed-loop mode, the sensor output is changing several
times per second, going above and below a mid-point range of 490-500 millivolts at a hot idle. The PCM
compares the voltage between the sensor signal and sensor earth terminals and decides the needed fuel
mixture correction. The PCM also monitors the changing voltage, watching for transitions above and below the
mid- point range, to decide when to operate in the closed-loop m ode. An open circ uit, defective, or contaminated
sensor could caus e the voltage to stay within a 410- 477 m illivolt band too long, k eeping the system in open-loop
and setting a DTC P0134.
CONDITIONS FOR RUNNING THE DTC
• Engine run time is longer than 4 minutes.
• No TP Sensor DTC’s are set.
• The ECT sensor is more than 85°C.
• Throttle angle is more than 15%.
CONDITIONS FOR SETTING THE DTC
• The RH 02S voltage stays between 410-477 millivolts.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• Once a 02S DTC is set, and current, the PCM will operate the fuel system in the “Open Loop” mode.
VXPCM003
PCM
D5
C9
D4
D3
GY/B (1413)
G/Y (1412)
LEFT OXYGEN SENS OR
RIGHT OXYGEN SENSOR
VB (413)
V (41 2)
RIGHT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL HI
RIGHT
OXYGEN
SENSOR
SIGNAL HI
IC
IC
M
I
C
R
O
450 mV
450 mV
YB198YE97
YE97
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Norm al Tech 2 scan tool voltage varies between 100 mV to 999 m V while in "Clos ed Loop". DTC P0134 sets if
voltage remains between 410 and 477 millivolts, but the system will go "Open Loop" before the "Check
Powertrain" lamp is turned "ON".
Refer to "Interm ittents" in Section 6C1-2B SYM PTOMS of the VX Series Service Inform ation. To diagnose the
oxygen sensor, refer TABLE A-6.3. of the VX Series Service Information
NOTE: Oxygen Sensor Contamination - If fuel containing lead or silicone is used, or engine repairs using
unapproved RTV gasket sealer are performed, the sensor may be contaminated. It may send a "False" rich
exhaust indication to the PCM, and the PCM will attempt to drive the fuel system lean to compensate. Poor
driveability or a Diagnostic Trouble Code P0134 could result. If this happens, the sensor will need to be
replaced, but every attempt to locate the source of contamination should be pursued.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. The Tech 2 scan tool allows you to read the same oxygen sensor voltage the PCM is using for its
calculations.
3. This step simulates a lean exhaust indication to the PCM. If the PCM and wiring are OK, the PCM will see
the lean indication and the Tech 2 scan tool should display O2 voltage below 200 mV.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
EXHAUST GAS SENSOR
YE 97
BA
(1412)
(412) (413)
(1413)
GY/BGY
V BLU/B L.H
R.H
OR OR
DTC P0134 V6 PCM - NO RIGHT HAND OXYGEN SENSOR (O2S) SIGNAL
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Engine at normal operating temperature
(above 85 degrees C).
2. Run engine at approximately 600 to 1800 RPM for
two minutes.
Is Tech 2 scan tool oxygen sensor voltage between
specified values?
410-477 mV
Go to Step 3 If no additional
DTCs were
stored, refer to
“Intermittents” in
Section 6C1-2B
SYMPTOMS.
3. 1. Ignition ON, engine stopped.
2. Disconnect O2 and jumper the O2 signal and low
circuits (PCM side) to earth.
3. Using Tech 2 scan tool, monitor O2 voltage.
Is the O2 voltage less than the specified value?
0.2 Volt
(200 mV) Go to Step 7 Go to Step 4
DTC P0134 V6 PCM - NO RIGHT HAND OXYGEN SENSOR (O2S) SIGNAL (CONTINUED)
STEP ACTION VALUE YES NO
4. 1. Remove the jumper wire from the O2 signal circuit
(leaving the O2 low circuit jumpered to earth).
2. Using a DVM, measure voltage between the O2
signal circuit (PCM side) and earth.
Does the O2 signal voltage measure near the specified
value?
410-477 mV
Go to Step 5 Go to Step 6
5. 1. Ignition OFF.
2. Disconnect the PCM.
3. Check continuity of the O2 low circuit between the
PCM harness connector and the O2 harness
connector.
4. If the O2 low circuit measures over 5 ohms, repair
open or poor connection as necessary.
Was a problem found?
Verify Repair Go to Step 8
6. 1. Ignition OFF.
2. Disconnect the PCM.
3. Check continuity of the following circuits:
• The O2 signal circuit between the PCM harness
connector and the O2 harness connector.
• The O2 low circuit between the PCM harness
connector and the O2 harness connector.
4. If either circuit measures over 5 ohms, repair open
or poor connection as necessary.
Was a problem found?
Verify Repair Go to Step 9
7. 1. Check the following circuits for a poor terminal
connection at the O2 harness connector.
• O2 signal circuit.
• O2 low circuit.
2. If a problem is found, repair as necessary.
Was a problem found?
Verify Repair Go to Step 10
8. 1. Check for poor O2 low circuit terminal connection at
PCM.
2. If a problem is found, repair as necessary.
Was a problem found?
Verify Repair Go to Step 11
9. 1. Check the O2 signal circuit and the O2 low circuit for
a poor terminal connection at the PCM.
2. If a problem is found, repair as necessary.
Was a problem found?
Verify Repair Go to Step 11
10. Replace the O2 sensor.
Is action complete? Verify Repair
11. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
DTC P0151 V6 PCM -
LEFT HAND OXYGEN SENSOR (O2S) SIGNAL VOLTAGE LOW
CIRCUIT DESCRIPTION:
The PCM supplies a voltage of about 450 millivolts between terminal "D4" and "D3". The Oxygen (O2) sensor
varies the voltage within a range of about 1 volt if the exhaust is rich, down through about 100 millivolts, if
exhaust is lean.
The sensor is like an open circuit and produces no voltage when it is below about 360 degrees C. An open
sensor circuit or cold sensor causes "Open Loop" operation.
CONDITIONS FOR RUNNING THE DTC
• No IAT Sensor DTC’s are set.
• IAT Sensor is below 75°C.
• The system is in "Closed Loop”.
• Throttle angle is between 9% and 30%.
CONDITIONS FOR SETTING THE DTC
• The LH 02S signal voltage remains below 200 millivolts for 46 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• Once a 02S DTC is set, and current, the PCM will operate the fuel system in the “Open Loop” mode.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Using the T ech 2 scan tool, obser ve the Long Term Fuel Trim values at diff erent RPMs and air flow conditions.
The Tech 2 scan tool also displays the Long Term Fuel Trim cells, so the Long Term Fuel Trim values can be
checked in each of the cells to determine when the DTC P0151 or DTC P0131 may have been set. If the
conditions for DTC P0151 or DTC P0131 exists, the Long Term Fuel Trim values will be around +25%.
VXPCM003
PCM
D5
C9
D4
D3
GY/B (1413)
G/Y (1412)
LEFT OXYGEN SENS OR
RIGHT OXYGEN SENSOR
VB (413)
V (41 2)
RIGHT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL HI
RIGHT
OXYGEN
SENSOR
SIGNAL HI
IC
IC
M
I
C
R
O
450 mV
450 mV
YB198YE97
YE97
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
4. The DTC P0151 or lean exhaust is most likely caused by one of the following:
• O2 Sensor Wire - Sensor pigtail may be mispositioned and contacting the exhaust manifold.
• Check for intermittent earth in wire between connector and sensor.
• MAF Sensor - A shifted MAF sensor could cause the fuel system to go lean. Refer to TABLE A-6.1 of the
VX Series Service Information.
• Lean Injector(s) - Perform power balance test using the Tech 2 scan tool.
• Fuel Contamination - Water, even in small amounts, near the in-tank Fuel Pump inlet can be delivered to
the injectors. The water causes a lean exhaust and can set a DTC P0151 and/or DTC P0131.
• Fuel Pressure - System will go lean if pressure is too low. It may be necessary to monitor fuel pressure
while driving the vehicle at various road speeds and/or loads to confirm. Refer to TABLE A-4.1 of the VX
Series Service Information.
• Exhaust Leaks - If there is an exhaust leak, the engine can cause outside air to be pulled into the exhaust
and past the sensor. Vacuum or crankcase leaks can cause a lean condition.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
EXHAUST GAS SENSOR
YE 97
BA
(1412)
(412) (413)
(1413)
GY/BGY
V BLU/B L.H
R.H
OR OR
DTC P0151 V6 PCM - LEFT HAND OXYGEN SENSOR (02S) SIGNAL VOLTAGE LOW
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. 1. Start engine.
2. Run engine until it reaches normal operating
temperature (Above 80 degrees C).
3. Continue to run at 1600 to 1800 RPM for two
minutes.
Does Tech 2 scan tool indicate O2 sensor voltage fixed
below specified value?
200 mV Go to Step 3
DTC P0151 is
intermittent, If no
additional DTCs
were stored, refer
to "Intermittents"
in Section 6C1-
2B S YMPT OMS.
3. Disconnect O2 sensor connector.
With engine idling, does Tech 2 scan tool display O2
sensor voltage between the specified values?
Between
350 mV and
550 mV
Go to Step 4 Go to Step 6
4. 1. Refer to step 4 Test above description first.
2. Perform the checks on the items as noted.
• MAF sensor operation
• Low fuel pressure
• Contaminated fuel ex haust manifold leaks ahead of O 2
sensor
• Lean injector (possibly restricted)
• O2 sensor earth circuit
Are all items checked found to be OK?
Go to Step 5 Verify Repair
DTC P0151 V6 PCM - LEFT HAND OXYGEN SENSOR (02S) SIGNAL VOLTAGE LOW (CONTINUED)
STEP ACTION VALUE YES NO
5. Replace Oxygen sensor.
Is action complete?
Verify repair
6. 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. With O2 sensor still disconnected, check O2 signal
circuit 412 for a short to earth.
Is a short to earth detected?
Go to Step 7 Go to Step 8
7. Repair circuit 412.
Is action complete? Verify Repair
8. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0152 V6 PCM -
LEFT HAND OXYGEN SENSOR (O2S) SIGNAL VOLTAGE HIGH
CIRCUIT DESCRIPTION:
The PCM supplies a voltage of about 450 millivolts between terminal "D4" and "D3". The Oxygen (O2) sensor
varies the voltage within a range of about 1 volt, if the exhaust is rich and down through about 100 millivolts if
exhaust is lean.
The sensor produces no voltage when it is below about 360 degrees C. An open sensor circuit or cold sensor
causes "Open Loop" operation.
CONDITIONS FOR RUNNING THE DTC
• No TP Sensor DTC’s are set.
• The system is in "Closed Loop”.
• Throttle angle is between 9% and 30%.
CONDITIONS FOR SETTING THE DTC
• The LH 02S signal voltage remains above 780 millivolts for 40 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• Once a 02S DTC is set, and current, the PCM will operate the fuel system in the “Open Loop” mode.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Using the Tech 2 scan tool, observe the Long Term Fuel Trim values at different RPM and air flow conditions.
The Tech 2 scan tool also displays the Long Term Fuel Trim cells, so the Long Term Fuel Trim values can be
checked in each of the cells to determine when the DTC P0132 may have been set. If the conditions for DTC
P0152 exists, the Long Term Fuel Trim values will be around - 22%.
VXPCM003
PCM
D5
C9
D4
D3
GY/B (1413)
G/Y (1412)
LEFT OXYGEN S ENSOR
RIGHT OXYGEN SENSOR
VB (413)
V (41 2)
RIGHT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL HI
RIGHT
OXYGEN
SENSOR
SIGNAL HI
IC
IC
M
I
C
R
O
450 mV
450 mV
YB198YE97
YE97
TEST DESCRIPTION: Number(s) below refer to step
number(s) on the diagnostic Table.
2. The O2 sensor MUST be at operating temperature before checking operation.
3. This step checks for a short to voltage on the O2 signal line.
7. Earthing circuit 412 causes a low O2 signal voltage. If the PCM and wiring are OK, the PCM should
recognise the low voltage and confirm the lean signal.
8. A DTC P0152 will most likely NOT be caused by a faulty O2 sensor. DTC P0152 indicates a rich exhaust
and diagnosis should begin with the items listed:
• Fuel pressure. System will go rich, if pressure is too high. The PCM can compensate for some increase.
However, if it gets too high, a DTC P0132 or DTC P0152 may be set. Refer to fuel system diagnosis
TABLE A-4.3 of the VX Series Service Information.
• Rich injector.
• Leaking injector. Refer to TABLE A-4.3 of the VX Series Service Information.
• Check for fuel contaminated oil.
• Short to voltage on circuit 412.
• HEI shielding. An open earth circuit 453 (ignition system) may result in EMI, or induced electrical "noise."
The PCM looks at this "noise" as reference pulses. The additional pulses result in a higher than actual
engine speed signal. The PCM then delivers too much fuel, causing system to go rich. Engine tachometer
will also show higher than actual engine speed, which can help in diagnosing this problem.
• Canister purge. Check for fuel saturation. If full of fuel, check canister control and hoses.
• MAF sensor. A shifted MAF sensor could cause the fuel system to go rich.
• Check for leaking fuel pressure regulator diaphragm by checking vacuum line to regulator for fuel.
• TP Sensor . An interm ittent T P sensor output will cause the system to go rich, due to a f alse indication of the
engine accelerating.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
EXHAUST GAS SENSOR
YE 97
BA
(1412)
(412) (413)
(1413)
GY/BGY
V BLU/B L.H
R.H
OR OR
DTC P0152 V6 PCM - LEFT HAND OXYGEN SENSOR (O2S) SIGNAL VOLTAGE HIGH
NOTE: Oxygen Sensor Contamination - If fuel containing lead or silicone is used, or engine repairs using
unapproved RTV gasket sealer are performed, the sensor may be contaminated. it may send a "false" rich
exhaust indication to the PCM, and the PCM will attempt to drive the fuel system lean to compensate. Poor
driveability or a Diagnostic Trouble Code P0132 could result. if this happens, the sensor will need to be
replaced, but every attempt to locate the source of contamination should be pursued.
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2. 1. Engine at normal operating temperature
(above 80 degrees C).
2. Run engine at approximately 1600 RPM to 1800
RPM for two minutes.
Is Tech 2 scan tool voltage above specified value?
750 mV Go to Step 3 DTC P0152 is
intermittent,
If no additional
DTC(s) were
stored, refer to
"Intermittents" in
Section 6C1-2B
SYMPTOMS of
the VX Series
Service
Information.
3. 1. Ignition "OFF".
2. Disconnect O2 sensor wiring harness.
3. With ohmmeter connected to earth, probe circuit
412 at O2 sensor wiring harness connector.
4. Ignition "ON".
Is voltmeter indicating less then specified value?
350 mV Got to Step 7 Go to Step 4
4. 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. Probe circuit 412 at O2 sensor wiring harness
connector.
4. Ignition "ON".
Is voltmeter indicating voltage below specified value ?
350 mV Go to Step 6 Go to Step 5
5. Repair circuit 412, shorted to voltage.
Is action complete? Verify Repair
6. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
7. 1. Disconnect O2 sensor wiring harness connector.
2. Jumper harness connector circuit 412 to earth.
With engine running, does Tech 2 scan tool display O2
voltage below specified value?
350 mV Go to Step 8 Go to Step 9
8. See step 8 above to perform additional checks for:
• High Fuel Pressure
• Map Sensor Operation
• Leaking Injectors
• Ignition Earth Circuit
• Canister Purge
• Engine Coolant Temperature Sensor Circuit
• Intake Air Temperature Sensor Circuit
• Throttle Position Sensor Operation
Do all additional checks in step 8 test above OK.?
Go to Step 8
above Verify Repair
9. 1. Ignition "OFF"
2. Disconnect PCM connectors.
3. Check O2 sensor earth circuit 750 for good
continuity between PCM connector terminal "D3"
and engine earth.
Is an "OPEN" circuit indicated?
Verify Repair Go to Step 10
10. Check PCM earth wire connection at engine. Must be a
clean and tight connection to the engine.
Is connection good?
Go to Step 6 Verify Repair
DTC P0154 V6 PCM -
NO LEFT HAND OXYGEN S E NS OR (O2S) SIGNAL
CIRCUIT DESCRIPTION:
The ex haust oxygen sens or is mounted in the ex haust pipe with the sensing portion exposed to exhaust gases.
After the sensor is hot (360 degrees C), it becomes a voltage generator, producing a "changing" voltage. This
voltage ranges from approximately 100 millivolts with a "lean" exhaust, to 900 millivolts with a "rich" exhaust.
When the sens or is c old (below 360 degrees C) it acts lik e an open c ircuit and produc es alm ost no voltage. T he
PCM supplies a very small "bias" voltage between terminals D4 and D3, normally about 450 millivolts. If
measured with the 10 megaohm digital voltmeter, it may measure as low as 350 millivolts. W hen the sensor is
hot, it's output overshadows this PCM supplied voltage.
When the fuel system is correctly operating in the closed-loop mode, the sensor output is changing several
times per second, going above and below a mid-point range of 490-500 millivolts at a hot idle. The PCM
compares the voltage between the sensor signal and sensor earth terminals and decides the needed fuel
mixture correction. The PCM also monitors the changing voltage, watching for transitions above and below the
mid- point range, to decide when to operate in the closed-loop m ode. An open circ uit, defective, or contaminated
sensor could caus e the voltage to stay within a 410- 477 m illivolt band too long, k eeping the system in open-loop
and setting a DTC P0154.
CONDITIONS FOR RUNNING THE DTC
• Engine run time is longer than 4 minutes.
• No TP Sensor DTC’s are set.
• The ECT sensor is more than 85°C.
• Throttle angle is more than 15%.
CONDITIONS FOR SETTING THE DTC
• The LH 02S voltage stays between 410-477 millivolts.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• Once a 02S DTC is set, and current, the PCM will operate the fuel system in the “Open Loop” mode.
VXPCM003
PCM
D5
C9
D4
D3
GY/B (1413)
G/Y (1412)
LEFT OXYGEN SENS OR
RIGHT OXYGEN SENSOR
VB (413)
V (41 2)
RIGHT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL HI
RIGHT
OXYGEN
SENSOR
SIGNAL HI
IC
IC
M
I
C
R
O
450 mV
450 mV
YB198YE97
YE97
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Norm al Tech 2 scan tool voltage varies between 100 mV to 999 m V while in "Clos ed Loop". DTC P0154 sets if
voltage remains between 410 and 477 millivolts, but the system will go "Open Loop" before the "Check
Powertrain" lamp is turned "ON".
Refer to "Interm ittents" in Section 6C1-2B SYM PTOMS of the VX Series Service Inform ation. To diagnose the
oxygen sensor, refer TABLE A-6.3. of the VX Series Service Information.
NOTE: Oxygen Sensor Contamination - If fuel containing lead or silicone is used, or engine repairs using
unapproved RTV gasket sealer are performed, the sensor may be contaminated. It may send a "False" rich
exhaust indication to the PCM, and the PCM will attempt to drive the fuel system lean to compensate. Poor
driveability or a Diagnostic Trouble Code 13 could result. If this happens, the sensor will need to be replaced,
but every attempt to locate the source of contamination should be pursued.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. The Tech 2 scan tool allows you to read the same oxygen sensor voltage the PCM is using for its
calculations.
3. This step simulates a lean exhaust indication to the PCM. If the PCM and wiring are OK, the PCM will see
the lean indication and the Tech 2 scan tool should display O2 voltage below 200 mV.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
EXHAUST GAS SENSOR
YE 97
BA
(1412)
(412) (413)
(1413)
GY/BGY
V BLU/B L.H
R.H
OR OR
DTC P0154 V6 PCM - NO LEFT HAND OXYGEN SENSOR (O2S) SIGNAL
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Engine at normal operating temperature
(above 85 degrees C).
2. Run engine at approximately 600 to 1800 RPM for
two minutes.
Is Tech 2 scan tool oxygen sensor voltage between
specified values?
410-477 mV
Go to Step 3 If no additional
DTCs were
stored, refer to
“Intermittents” in
Section 6C1-2B
SYMPTOMS.
3. 1. Ignition ON, engine stopped.
2. Disconnect O2 and jumper the O2 signal and low
circuits (PCM side) to earth.
3. Using Tech 2 scan tool, monitor O2 voltage.
Is the O2 voltage less than the specified value?
0.2 Volt
(200 mV) Go to Step 7 Go to Step 4
DTC P0154 V6 PCM - NO LEFT HAND OXYGEN SENSOR (O2S) SIGNAL (CONTINUED)
STEP ACTION VALUE YES NO
4. 1. Remove the jumper wire from the O2 signal circuit
(leaving the O2 low circuit jumpered to earth).
2. Using a DVM, measure voltage between the O2
signal circuit (PCM side) and earth.
Does the O2 signal voltage measure near the specified
value?
410-477 mV
Go to Step 5 Go to Step 6
5. 1. Ignition OFF.
2. Disconnect the PCM.
3. Check continuity of the O2 low circuit between the
PCM harness connector and the O2 harness
connector.
4. If the O2 low circuit measures over 5 ohms, repair
open or poor connection as necessary.
Was a problem found?
Verify Repair Go to Step 8
6. 1. Ignition OFF.
2. Disconnect the PCM.
3. Check continuity of the following circuits:
• The O2 signal circuit between the PCM harness
connector and the O2 harness connector.
• The O2 low circuit between the PCM harness
connector and the O2 harness connector.
4. If either circuit measures over 5 ohms, repair open or
poor connection as necessary.
Was a problem found?
Verify Repair Go to Step 9
7. 1. Check the following circuits for a poor terminal
connection at the O2 harness connector.
• O2 signal circuit.
• O2 low circuit.
2. If a problem is found, repair as necessary.
Was a problem found?
Verify Repair Go to Step 10
8. 3. Check for poor O2 low circuit terminal connection at
PCM.
4. If a problem is found, repair as necessary.
Was a problem found?
Verify Repair Go to Step 11
9. 1. Check the O2 signal circuit and the O2 low circuit for
a poor terminal connection at the PCM.
2. If a problem is found, repair as necessary.
Was a problem found?
Verify Repair Go to Step 11
10. Replace the O2 sensor.
Is action complete? Verify Repair
11. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
DTC P0170 V6 PCM -
LONG TERM FUEL TRIM (LTFT) DELTA HIGH
CIRCUIT DESCRIPTION:
The PCM controls left to right cylinder bank fuel delivery separately based on their respective oxygen sensor
signals. If the PCM detects too great a difference between the left to right cylinder bank Long Term Fuel Trim
values, it will set DTC P0170.
CONDITIONS FOR RUNNING THE DTC
• Engine is idling.
CONDITIONS FOR SETTING THE DTC
• The lef t hand long ter m f uel trim value varies f rom the r ight hand long term f uel trim value by more than 59%
for more than 32 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• With a current DTC P0170 set, the PCM will not illuminate the MIL (Check Powertrain Lamp). DTC P0170
will clear when the fault no longer exists and the ignition switch is cycled "OFF" and "ON".
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
• Lean or faulty injector(s) on one side of the engine.
• Cracked or fouled spark plug(s).
• Exhaust or inlet manifold leak.
• Make sure oxygen sensor leads are not swapped.
VXPCM003
PCM
D5
C9
D4
D3
GY/B (1413)
G/Y (1412)
LEFT OXYGEN SENS OR
RIGHT OXYGEN SENSOR
VB (413)
V (41 2)
RIGHT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL HI
RIGHT
OXYGEN
SENSOR
SIGNAL HI
IC
IC
M
I
C
R
O
450 mV
450 mV
YB198YE97
YE97
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. Check and repair other DTC(s) first.
3. Check for other mechanical problems causing DTC to set.
4. The bank that is the farthest from the neutral value of 0% is the bank which is out of fuel control.
DTC P0170 V6 PCM - LONG TERM FUEL TRIM (LTFT) DELTA HIGH
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. Are any other PCM DTC(s) set? Diagnose other
DTC(s) first Go to Step 3
3. Is there a Driveability complaint associated with this DTC
such as an Engine Miss, Lack of Power, or Poor Fuel
Economy?
Go to Step 7 Go to Step 4
4. 1. Start Engine and allow to warm up (Coolant
Temperature above 85 degrees C).
2. Install Tech 2 scan tool and note left and right bank
Long Term Fuel Trim values.
Is the left bank Long Term Fuel Trim values furtherFrom
0% then the right bank?
Go to Step 5 Go to Step 6
5. Perform Oxygen Sensor (O2S) Diagnosis, Table A-6.3 in
this Section.
Is action complete?
Verify Repair
6. 1. Start Engine and allow to warm up (Coolant
Temperature above 85 degrees C).
2. Install Tech 2 scan tool and note left and right bank
Long Term Fuel Trim values.
Is the right bank Long Term Fuel Trim values further
from 0% then the left bank?
Go to Step 5 DTC P0170 is
intermittent.
Refer "Diagnostic
Aids" above.
7. Perform the following tests in the order given until the
problem is corrected :
• Fuel System check, (refer Table A-4.3 in this
Section).
• Oscilloscope Engine, note and repair any Ignition
System problem found.
• Compression test each cylinder.
Is action complete?
Verify Repair
DTC P0173 V6 PCM -
SHORT TERM FUEL TRIM (STFT) DELTA HIGH
CIRCUIT DESCRIPTION:
The PCM controls left to right cylinder bank fuel delivery separately based on their respective oxygen sensor
signals. If the PCM detects too great a difference between the left to right cylinder bank Short Term (ST) Fuel
Trim values, it will set DTC P0173.
CONDITIONS FOR RUNNING THE DTC
• Engine is idling.
CONDITIONS FOR SETTING THE DTC
• The left hand short term fuel trim value varies from the right hand short term fuel trim value by more than
63% for more than 32 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• With a current DT C P0173 is set, the PCM will not illum inate the MIL ( Check Powertrain Lamp). DT C P0173
will clear when the fault no longer exists and the ignition switch is cycled "OFF" and "ON".
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
• Lean or faulty injector(s) on one side of the engine.
• Cracked or fouled spark plug(s).
• Exhaust or inlet manifold leak.
• Make sure oxygen sensor leads are not swapped.
VXPCM003
PCM
D5
C9
D4
D3
GY/B (1413)
G/Y (1412)
LEFT OXYGEN SENS OR
RIGHT OXYGEN SENSOR
VB (413)
V (41 2)
RIGHT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL LO
LEFT
OXYGEN
SENSOR
SIGNAL HI
RIGHT
OXYGEN
SENSOR
SIGNAL HI
IC
IC
M
I
C
R
O
450 mV
450 mV
YB198YE97
YE97
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. Check and repair other DTC(s) first.
3. Check for other mechanical problems causing DTC to set.
4. The bank that is the farthest from the neutral value of 0% is the bank which is out of fuel control.
DTC P0173 V6 PCM - SHORT TERM FUEL TRIM (STFT) DELTA HIGH
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. Are any other PCM DTC(s) set? Diagnose other
DTC(s) first Go to Step 3
3. Is there a Driveability complaint associated with this DTC
such as an Engine Miss, Lack of Power, or Poor Fuel
Economy?
Go to Step 7 Go to Step 4
4. 1. Start Engine and allow to warm up (Coolant
Temperature above 85 degrees C).
2. Install Tech 2 scan tool and note left and right bank
Short Term Fuel Trim values.
Is the left bank Short Term Fuel Trim values further
From 0% then the right bank?
Go to Step 5 Go to Step 6
5. Perform Oxygen Sensor (O2S) Diagnosis, Table A-6.3 in
this Section.
Is action complete?
Verify Repair
6. 1. Start Engine and allow to warm up (Coolant
Temperature above 85 degrees C).
2. Install Tech 2 scan tool and note left and right bank
Short Term Fuel Trim values.
Is the right bank Short Term Fuel Trim values further from
0% then the left bank?
Go to Step 5 DTC P0173 is
intermittent.
Refer "Diagnostic
Aids" above.
7. Perform the following tests in the order given until the
problem is corrected :
• Fuel system check, (refer to Table A- 4.3 in this
Section).
• Oscilloscope Engine, note and repair any Ignition
System problem found.
• Compression test each cylinder.
Is action complete ?
Verify Repair
DTC P0200 V6 PCM -
INJECTOR VOLTAGE MONITOR FAULT
CIRCUIT DESCRIPTION:
The injector voltage monitor line is used so that the PCM will know the exact voltage the fuel injectors are
operating at. This voltage is used to control the pulse width modulation of the fuel injectors. If the injector
voltage monitor line drops mor e than 2.2 volts for m ore than 3 seconds, Diagnostic T rouble Code (DT C) P0200
will set. This DTC will not turn "ON" the "Check Powertrain" lamp, but will have a DTC set in the PCM memory
that can be read with the Tech 2 scan tool and can be displayed by flashing out codes.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
• DTC P0561 is not set.
CONDITIONS FOR SETTING THE DTC
• Injector voltage monitor line voltage is 2.2 volts different than system voltage for 3 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• The PCM will use the battery feed input signal as the voltage value to control the fuel injectors base pulse
width.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
VXPCM017
# 2 # 4 # 6
# 1 # 3 # 5
PCM
C12
D12
E6
F2
E2
E4
F1
E5
C14
D16
BATTERY FEED
BATTERY FEED
O (740)
O (740)
BLU (841)
V (84 3)
GY (845)
INJECTOR CONTROL
IN JECTOR VOLTAGE
MONITOR LINE
IGNITION FEED
O/Y (479)
EFI RELAY
B/W (152)
P (3)
O/B (740)
IGN SW
M
I
C
R
O
R (481)
P (39 )
P/B
(39)
Y (84 6)
BR/Y (844)
G (842)
F31
F14
F34
+-
BATTERY
FS
FJ
R (2H)
(1040)
YE112
YB198
YB198YE112
YE39
YE114
YE39 YB199
YE22
YE22
DIAGNOSTIC AIDS:
W hen the injector voltage monitor line voltage drops more than 2.2 volts, the PCM will operate on an incorrect
value for 3 seconds until the DTC P0200 is set. Check PCM terminal connections for proper mating.
If DTC P0116, P0563 and P0200 are set, check for short to voltage on "Diagnostic Test" line, circuit 451.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. If the charging voltage is too high, this could set DTC P0200. If DTC P0563 is set, refer to that DTC first.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
INJECTORS
GY
(1)
(842)
(481)
Y
V
BLU
(6)
(4)
(2)
(846)
(843)
G
R
(845)
(841)
(5)
(844)
BR/Y
(3)
DTC P0200 V6 PCM - INJECTOR VOLTAGE MONITOR FAULT
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section
2. 1. This table assumes that no DTC P0561 is set and
the battery and charging systems are operating
properly.
2. Using the Tech 2 scan tool, display "Injector
Voltage" and "Battery Voltage".
Are they within the specified value of each other?
2.4 volts DTC P0200 is
intermittent, if no
additional DTCs
were stored, refer
to "Diagnostic
Aids" above.
Go to Step 3
3. Using DVM, backprobe PCM terminal "C14" with red lead
and connect black lead to PCM terminal "A5".
Is voltage measured within specified value of "Battery
Voltage" reading on Tech 2 scan tool?
2.4 volts Go to Step 5
Go to Step 4
4. Repair open in circuit 481 between splice and PCM
terminal "A5".
Is action complete?
Verify Repair
5. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0218 V6 PCM -
TRANSMISSION FLUID OVERTEMPERATURE
CIRCUIT DESCRIPTION:
The flow of transmission fluid starts in the bottom of the pan and is drawn through the filter, control valve body
assem bly, trans mission c ase and into the oil pump ass embly. T he oil pum p assembly pressurises the fluid and
directs it to the pressure regulator valve where it becomes the main supply of fluid to the various components
and hydraulic circuits in the transmission. Hot fluid exiting the torque converter flows through the converter
clutch apply valve and into the transmission cooler lines to the oil cooler located in the radiator (and auxiliary
cooler if equipped). From the cooler, fluid retur ns to cool and lubricate the f ront of the tr ansm ission. In forward
drive ranges, D4 f luid from the m anual valve is routed through an orif ice cup plug in the rear of the transmis sion
case to feed the rear lube fluid circuit.
W hen the PCM detects a high transm ission fluid temperature (TFT) f or a long period of time, then DTC P0218
sets.
As the transmission fluid temperature warms (normal transmission operating temperature 82 degrees C - 94
degrees C), the s ens or ( thermist or) res ist ance bec omes les s and the voltage will m eas ure about 1.5 to 2.0 volts .
If the fluid temperature becomes greater than 146 degrees C and does not drop below 137 degrees C for 30
minutes, a DTC P0218 will set.
When DTC P0218 sets the transmission fluid may be severely degraded.
CONDITIONS FOR RUNNING THE DTC
• DTC P0712 is not set.
CONDITIONS FOR SETTING THE DTC
• The TFT is at or greater than 137° C for 10 minutes (600 seconds).
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When a DTC P0218 sets, the PCM freezes shift adapts from being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
• Inspect the cooling system fluid level and condition.
• DTC P0218 may set approxim ately 30 minutes after DTC P0712 has set. Follow the diagnostic table for
DTC P0712 bef ore proceeding to the diagnostic table for DT C P0218. Repairing the condition that set DTC
P0712 will likely eliminate DTC P0218.
• The TFT temperature displayed on the scan tool should rise steadily to a normal operating temperature,
then stabilise.
• Inspect the torque converter stator for a possible problem.
• Ask about the customer's driving habits, trailer towing, etc.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. DTC P0712 may also set a DTC P0218. Go to the DTC P0712 table for diagnosis.
4. This step inspects for air restrictions and loss of transmission fluid flow, causing an extremely high TFT.
DTC P0218 V6 PCM - TRANSMISSION FLUID OVERTEMPERATURE
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs, use the scan
tool in order to record the DTC history for reference. The
Clear Info function will erase the data.
3. Record the DTC history.
4. Perform the transmission fluid checking procedure.
Refer to Transmission Fluid Checking Procedure.
Was the fluid checking procedure performed?
Go to Step 3 Go to
Transmission
Fluid Checking
Procedure
3 Is DTC P0712 also set? Go to “Diagnostic
Aids” above Go to Step 4
4 1. Inspect the cooling system for the following
conditions:
• Air flow restrictions
• Air flow blockage
• Debris
2. Inspect the transmission cooling system for the
following conditions:
• Air flow restrictions
• Air flow blockage
• Debris
• Damaged cooler lines
3. Repair restrictions if necessary.
Was a problem found?
Go to Step 7 Go to Step 5
5 1. Drive the vehicle in D4 with the TCC commanded
On.
2. Observer the TCC slip speed on the scan tool.
Is the TCC slip speed within the specified value?
-20 to +20
RPM Go to Step 6 Refer to Torque
Converter Clutch
Diagnosis
Symptoms
6 Perform the Line Pressure Check Procedure. Refer to
Section 7C-3 in VX Service Information.
Was a problem found?
Go to Step 7 Go to “Diagnostic
Aids” above
7 In order to verify your repair, perform the following
procedure:
1. Drive the vehicle to normal operating engine and
transmission temperature.
2. Observe the TFT during the entire drive.
Is the TFT less than the specified value during the entire
drive?
137°C System OK Begin the
diagnosis again.
Go to Step 1
DTC P0325 V6 PCM -
DSNEF SYSTEM FAULT
CIRCUIT DESCRIPTION:
The Knock sensor is used to detect engine detonation, and the PCM will retard the Electronic Spark Timing
(EST) based on the signal being received The Knock sensor produces an AC signal which varies in signal
amplitude and frequency depending upon the amount of Knock being experienced.
The PCM m onitor s the output of the DSNEF (Signal T o Nois e Enhancem ent Filter) circ uit. The PCM deter m ines
weather Knock is occurring by comparing the Knock sensor signal level with the voltage level on the DSNEF
circuit. T he DSNEF circuit allows the PCM to rej ect only f alse Knock s ignals by indicating the am ount of normal
engine mechanical noise present. Normal engine noise varies depending on engine speed and load. A normal
Knock condition could result in a Knock sensor signal from a few milliseconds to possibly as high as 100
milliseconds in length.
When the DSNEF circuit output is significantly longer than the longest expected "Normal" output it is assumed
the DSNEF circuitry has failed and DTC P0325 will set.
CONDITIONS FOR RUNNING THE DTC
• DTC The engine has been running for more than 10 seconds.
• DTC P0327 or P0332 are not set.
• Engine RPM is greater than 1000.
CONDITIONS FOR SETTING THE DTC
• The PCM’s DSNEF circuit indicates knocking for more than 10 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P0325 is set, and current, the PCM uses a default spark advance table.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Refer to "Intermittents" in Section 6C1-2B SYMPTOMS of the VX Series Service Information.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. This step checks to see if the Tech 2 scan tool is displaying Knock signal at all times.
3. This step checks to see if a audible Knock is being caused by the engine or transmission.
VXPCM007
PCM
M
I
C
R
O
DSNEF
DSNEF
LEFT HAND KNOCK
SENSOR SIGNAL I NPUT
RIGHT HAND KNOCK
SENSOR SIGNAL I NPUT
C10
C11
RIGHT
HAND
KNOCK
SENSOR
LEFT
HAND
KNOCK
SENSOR
+
-
+
-
BLU (815)
LBLU (826)
YB198
YE3YE3
DTC P0325 V6 PCMB - DSNEF SYSTEM FAULT
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. 1. Install Tech 2 "Scan " tool.
2. Ignition "ON", engine Idling.
3. Using Tech 2 scan tool, select "Knock Signal"
and "Knock Retard".
Is "Knock Signal" indication "Knock"?
Go to Step 3 Go to Step 4
3. With engine running, is a audible "Knock" condition
heard? Refer to Engine
Mechanical or
Transmission in
VX Service
Information to
repair
audible Knock
Go to Step 4
4. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0327 V6 PCM -
LEFT HAND KNOCK SE NS OR CIRCUIT FAULT
CIRCUIT DESCRIPTION:
The Knock Sensor (KS) system detects engine detonation. The PCM retards the spark timing based on the
signals from the knock sensors. T he knock sensors produce an AC voltage. The knock sensor voltages are an
input to the PCM. The amount of AC voltage produced is proportional to the amount of knock.
An operating engine produces a normal amount of engine mechanical vibration (noise). The knock sensors
produce an AC voltage signal from this noise. When an engine operates, the PCM learns the minimum and
maximum frequency of the noise the engine produces. When the PCM determines that this frequency is less
than or greater than the expected amount, a knock sensor DTC will set.
CONDITIONS FOR RUNNING THE DTC
• The engine has been running for more than 10 seconds.
• DTC P0325 is not set.
• The engine coolant temperature is greater than 35°C.
• The TP sensor signal is greater than 22%.
• The engine speed is greater than 1000 RPMs.
CONDITIONS FOR SETTING THE DTC
• There is no LH knock sensor signal or too high a knock sensor signal detected by the PCM for 3 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P0327 is set, and current, the PCM uses a default spark advance table.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
If circuit 815 is not open or shorted to earth, the most likely cause is an open circuit in the PCM. It is possible
that a faulty PCM could be the cause of the DTC P0327, and it should be replaced.
Refer to "Intermittents" in Section 6C1-2B SYMPTOMS of the VX Series Service Information.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. This Step determines if conditions for DTC P0327 still exist.
6. This Step determines if the knock sensor resistance is between 50,000 ohms and 100,000 ohms.
VXPCM007
PCM
M
I
C
R
O
DSNEF
DSNEF
LEFT HAND KNOCK
SENSOR SIGNAL I NPUT
RIGHT HAND KNOCK
SENSOR SIGNAL I NPUT
C10
C11
RIGHT
HAND
KNOCK
SENSOR
LEFT
HAND
KNOCK
SENSOR
+
-
+
-
BLU (815)
LBLU (826)
YB198
YE3YE3
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
YE3
KNOCK S ENSORS
BLU
(815)
LBLU
(826)
OR
DTC P0327 V6 PCM - left hand KNOCK SENSOR CIRCUIT fault
Step Action Value(s) Yes No
1 Did you perform the Powertrain On-Board Diagnostic
(OBD) System Check ? Go to Step 2 Go to OBD
System Check in
this Section
2 1. Install Tech 2 scan tool.
2. Record then clear DTC(s).
3. Start the engine.
4. Operate the vehicle, within the conditions required for
setting the DTC.
5. Select the Diagnostic Trouble Code (DTC) option,
using the Tech 2 scan tool.
Does the Tech 2 scan tool indicate that this DTC reset?
Go to Step 3 Refer to
Diagnostic Aids
3 1. Disconnect the LH Knock Sensor electrical connector.
2. Measure the resistance of the Knock Sensor by
connecting the DMM between the Knock Sensor
signal cir cuit ,on the sen sor si de, and the engin e bloc k
using the DMM J 39200.
3. Set the DMM to the 400K ohm scale.
Is the resistance of the Knock Sensor within the specified
range?
93-107KΩ Go to Step 4 Go to Step 6
4 1. Connect the DMM between the Knock Sensor signal
circuit, on the sensor side, and the engine block.
2. Set the DMM to the AC voltage scale.
3. Tap on the front of the engine while observing the
signal indicated on the DMM.
Is any signal indicated on the DMM while tapping on the
engine near the Knock Sensor?
Go to Step 5 Go to Step 6
5 1. Disconnect the PCM YB198 connector.
2. Check the KS signal circuit between the PCM and the
Knock Sensor connector for the following:
- An open
- A short to voltage
- A short to earth
Was a problem found?
Repair fault with
circuit wiring.
Clear DTC and
retest to ensure
repair OK
Go to Step 7
DTC P0327 V6 PCM - left hand KNOCK SENSOR CIRCUIT fault (continued)
Step Action Value(s) Yes No
6 Replace the Knock Sensor. Refer to Section 6C1-3
Knock Sens or Replacement in this Service In formation.
Is the action complete?
After Knock
Sensor replaced,
clear DTC and
retest to ensure
repair OK
7 Check the KS signal circuit for a poor terminal connection
at the PCM.
Was a problem found and corrected?
Repair fault with
terminal
connection. Clear
DTC and retest
to ensure repair
OK
Go to Step 8
8 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 9
9 Using the Tech 2 scan tool, check for any other DTCs.
Does the Tech 2 scan tool display any DTCs that you
have not diagnosed?
Go to the
applicable DTC
table
System OK
DTC P0332 V6 PCM -
RIGHT HAND KNOCK SENSOR CIRCUIT FAULT
CIRCUIT DESCRIPTION:
The Knock Sensor (KS) system detects engine detonation. The PCM retards the spark timing based on the
signals from the knock sensors. T he knock sensors produce an AC voltage. The knock sensor voltages are an
input to the PCM. The amount of AC voltage produced is proportional to the amount of knock.
An operating engine produces a normal amount of engine mechanical vibration (noise). The knock sensors
produce an AC voltage signal from this noise. When an engine operates, the PCM learns the minimum and
maximum frequency of the noise the engine produces. When the PCM determines that this frequency is less
than or greater than the expected amount, a knock sensor DTC will set.
CONDITIONS FOR RUNNING THE DTC
• The engine has been running for more than 10 seconds.
• DTC P0325 is not set.
• The engine coolant temperature is greater than 35°C.
• The TP sensor signal is greater than 22%.
• The engine speed is greater than 1000 RPMs.
CONDITIONS FOR SETTING THE DTC
• There is no RH knock sensor signal or too high a knock sensor signal detected by the PCM for 3 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P0332 is set, and current, the PCM uses a default spark advance table.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
If circuit 826 is not open or shorted to earth, the most likely cause is an open circuit in the PCM. It is possible
that a faulty PCM could be the cause of the DTC P0332, and it should be replaced.
Refer to "Intermittents" in Section 6C1-2B SYMPTOMS of the VX Series Service Information.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. This Step determines if conditions for DTC P0332 still exist.
6. This Step determines if the knock sensor resistance is between 93,000 and 107,000 ohms.
VXPCM007
PCM
M
I
C
R
O
DSNEF
DSNEF
LEFT HAND KNOCK
SENSOR SIGNAL I NPUT
RIGHT HAND KNOCK
SENSOR SIGNAL I NPUT
C10
C11
RIGHT
HAND
KNOCK
SENSOR
LEFT
HAND
KNOCK
SENSOR
+
-
+
-
BLU (815)
LBLU (826)
YB198
YE3YE3
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
YE3
KNOCK S ENSORS
BLU
(815)
LBLU
(826)
OR
DTC P0332 V6 PCM - right hand KNOCK SENSOR CIRCUIT fault
Step Action Value(s) Yes No
1 Did you perform the Powertrain On-Board Diagnostic
(OBD) System Check ? Go to Step 2 Go to OBD
System Check in
this Section
2 1. Install Tech 2 scan tool.
2. Record then clear DTC(s).
3. Start the engine.
4. Operate the vehicle, within the conditions required
for setting the DTC.
5. Select the Diagnostic Trouble Code (DTC) option,
using the Tech 2 scan tool.
Does the Tech 2 scan tool indicate that this DTC reset?
Go to Step 3 Refer to
Diagnostic Aids
3 1. Disconnect the RH Knock Sensor electrical
connector.
2. Measure the resistance of the Knock Sensor by
connecting the DMM between the Knock Sensor
signal cir cuit ,on the sen sor si de, and the engin e
block using the DMM J 39200.
3. Set the DMM to the 400K ohm scale.
Is the resistance of the Knock Sensor within the specified
range?
93-107KΩ Go to Step 4 Go to Step 6
4 1. Connect the DMM between the Knock Sensor signal
circuit, on the sensor side, and the engine block.
2. Set the DMM to the AC voltage scale.
3. Tap on the front of the engine while observing the
signal indicated on the DMM.
Is any signal indicated on the DMM while tapping on the
engine near the Knock Sensor?
Go to Step 5 Go to Step 6
5 1. Disconnect the PCM YB198 connector.
2. Check the KS signal circuit between the PCM and
the Knock Sensor connector for the following:
- An open
- A short to voltage
- A short to earth
Was a problem found?
Repair fault with
circuit wiring.
Clear DTC and
retest to ensure
repair OK
Go to Step 7
DTC P0332 V6 PCM - right hand KNOCK SENSOR CIRCUIT fault (continued)
Step Action Value(s) Yes No
6 Replace the Knock Sensor. Refer to Section 6C1-3
Knock Sensor Replacement of this Service Information.
Is the action complete?
After Knock
Sensor replaced,
clear DTC and
retest to ensure
repair OK
7 Check the KS signal circuit for a poor terminal connection
at the PCM.
Was a problem found and corrected?
Repair fault with
terminal
connection. Clear
DTC and retest
to ensure repair
OK
Go to Step 8
8 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 9
9 Using the Tech 2 scan tool, check for any other DTCs.
Does the Tech 2 scan tool display any DTCs that you
have not diagnosed?
Go to the
applicable DTC
table
System OK
DTC P0341 V6 PCM -
CAM/CRANK S E NSOR SIGNAL INTERMITTE NT
CIRCUIT DESCRIPTION:
During cranking, the ignition module monitors the dual crank sensor 3X signal. The 3X signal is used to
determ ine the cor rect c ylinder pair to s park f irst. After the 3X signal has been proc essed by the ignition module,
it sends a crankshaft reference pulse to the PCM. When the PCM receives this pulse it will command all six
injector s to open f or one pr im ing shot of fuel in all c ylinders. After the priming, the inj ectors are lef t "OFF " for the
next six crankshaft reference pulses from the ignition module (two crankshaft revolutions). This allows each
cylinder a chance to use the f uel from the priming shot. During this waiting period, a cam signal will have been
received by the PCM. Now the PCM begins to operate the injectors by energising each injector based on true
camshaft position. With the engine running, the PCM monitors the cam and 18X signal pulses it receives and
expects to see 36 18X signal pulses for each cam pulse.
CONDITIONS FOR RUNNING THE DTC
• The engine is cranking.
CONDITIONS FOR SETTING THE DTC
• An incorrect number of crankshaft reference pulses have been received since the previous camshaft
position signal.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• Once DT C P0341 is set, the PCM will determ ine the f uel injection sequence bas ed on the last fuel injection
pulse received. In the calculated SFI mode, the engine continues to start and run. However, with the fault
present, only a 1 in 6 chance of the correct injection sequence exists.
VXPCM009
PCM
B10
B6
B7
B9
B4
B3
CRANKSHAFT
REFERENCE LO
CAM
SENSOR
CONNECTOR
CAMSHAFT
POSITION
SENSOR
SIGNAL
CRANKSHAFT
REFERENCE HI
CRANKSHAFT
18X SIGNAL
BYPASS CONTROL
EST OUTPUT
module power supply - in
sensor power supply - out
cam signal - in
3x crank sensor - in
18x crank sensor - in
cam signal - out
tacho signal - out
crankshaft reference - out
18X cranksignal - out
bypass control
EST signal -in
P
N
M
L
K
J
H
G
F
E
D
C
B
A
DIS
MODULE
ABCD CBA
W/B (644)
GY/R (645)
B/R (453)
CRANK
SENSOR
CONN
L BLU/W
(646) BR (633)
BLU/Y (643)
BR (121)
B (63 0)
V (43 0)
L BLU/B (647)
T/B (4 24)
IGN SW
EFI RELAY
O/Y
(479) LOC. E3
YE39
YE111 YE39
YB187
YE63
YB187
YE57
YE34
LG
(482)
B/W
(152)P/B
(39)
IC
IC
IC
M
I
C
R
O
W (423)
F35
+-
BATTERY
FS
FJ
(1040)
P (3)
R (2H)
F14
TO INSTRUMENT CLUSTER
(TERMINAL 18)
ABS/ETC (TERMINAL 30)
CONDITIONS FOR CLEARING THE MIL/DTC
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
DTC P0341 indicates an intermittent fault and may not set immediately or under all conditions. Customer
comments of sym ptoms experienced may help isolate the cause of the condition. A poor connection or fault in
the cam s ensor circ uits 630, 633, 644, or 645 or a f aulty cam sensor may cause the PCM to re-initialis e injector
sequence when the fault occurs, causing a possible stumble or miss. A poor connection or fault in the 18X
signal cir cuit 647, crank sensor c ircuits 643, 644, or 645, the 18X portion of the cr ank sens or or bent or m issing
vanes on the harm onic balanc er interr upter rings will caus e the PCM to stop pulsing the injec tors when the f ault
occurs, causing an intermittent stumble or stall.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. Determines if conditions necessary to set DTC P0341 exist on this ignition cycle.
3. If 5 volts are not present at PCM harness connector terminal "B6", the cam sensor may be interfacing with
the magnet in the camshaft sprocket. Bumping the starter should correct this condition.
6. If a f ailure is induced in the 18X s ignal circuit, the 5 volts on the circ uit should change when the faulty wiring
or connection is manipulated.
NOTE: If DTC P0342 is set along with DTC P0341, use DTC P0342 table for diagnosis.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
DIRECT IGNITION MODUL E
YE 57
(647)
LBLU/B
W/B
(644)
B/R
(453)
LBLU/W
(646)
BLU/Y
(643)
V
(430)
T/B
(424)
(633)
BR
(645)
GY/R
LG
(482)
B
(630)
BR
(121)
W
(423)
PNMLKJHGFED
CBA
Y E63
CAM S EN SOR
(644)
W/B
GY/R
(645)
BR
(633)
CRANK SENSOR
YE 34
W/B
(644)
GY/R
(645)
BLU/Y
(643)
LBLU/W
(646)
DTC P0341 V6 PCM - CAM/CRANK SENSOR SIGNAL INTERMITTENT
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. 1. Install Tech 2 scan tool.
2. Start and idle engine.
3. Using Tech 2 scan tool, look at "IGN Cycles" in
DTC history.
Is DTC P0341 current?
Go to Step 3 DTC P0341 is
intermittent. If no
additional DTC's
were set, refer to
"Diagnostic Aids"
above.
3 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. Connect a DVM between PCM harness connector
terminal "B6" and earth.
4. Ignition "ON".
Is voltage at "B6” at specified value?
Approximately
5 volts Go to Step 5 Go to Step 4
4. Bump engine with starter.
Is voltage at "B6" at specified value? Approximately
5 volts Go to Step 5 Go to
DTC P0342
in this Section
DTC P0341 V6 PCM - CAM/CRANK SENSOR SIGNAL INTERMITTENT (CONTINUED)
Step Action Value(s) Yes No
5. Monitor voltage at "B6" while manipulating
powertrain wiring harness to PCM connector.
Does voltage remain steady as wiring is manipulated?
Go to Step 6 Go to Step 10
6. 1. Connect DVM between PCM harness connector
terminal "B7" and earth.
2. Monitor voltage at "B7" while manipulating ignition
harness, engine harness, and dash harness to PCM
connector.
Does voltage remain steady as wiring is manipulated?
Go to Step 7 Go to Step 8
7. Check for:
• Poor connections at PCM;
• Harmonic balancer interrupter ring vanes bent or
• missing;
• Faulty crank sensor (malfunctioning hot/cold).
Are all above OK?
Refer to
"Diagnostic Aids"
above.
Verify Repair
8. Check for poor connection at crankshaft position sensor
or ignition control module.
Was a fault found?
Verify Repair Go to Step 9
9. Repair intermittent open/short to earth in circuit 643, 644,
645 or 647.
Is action complete?
Verity Repair
10 Check for poor connection at camshaft position sensor or
ignition control module.
Was a fault found?
Verify Repair Go to Step 11
11. Repair intermittent open/short to earth in circuit 630, 633,
644 or 645.
Is action complete?
Verify Repair
DTC P0342 V6 PCM -
CAMSHAFT POSITION (CKP) SENSOR SIGNAL MISSING
CIRCUIT DESCRIPTION:
During cranking, the ignition module monitors the dual crank sensor 3X signal. The 3X signal is used to
determ ine the cor rect c ylinder pair to s park f irst. After the 3X signal has been proc essed by the ignition module,
it sends a crankshaft reference pulse to the PCM. When the PCM receives this pulse it will command all six
injectors to open for one priming shot of fuel in all cylinders. After the priming, all six of the injectors are left
"OFF" until the next crankshaft reference pulses from the ignition module (two crankshaft revolutions). This
allows each cylinder a chance to use the f uel from the prim ing shot. During this waiting period, a cam s ignal will
have been received by the PCM. Now the PCM begins to operate the injectors in sequential fuelling mode by
energising each inj ector bas ed on true cam s haft pos ition. However, if the c am shaf t position signal is not present
at startup, a DTC P0342 will set and the PCM will energise all six injectors at the same time and continue to
operate like this until the fault is corrected.
CONDITIONS FOR RUNNING THE DTC
• The engine is cranking.
CONDITIONS FOR SETTING THE DTC
• The PCM detects the Camshaft Position sensor signal is low when the signal should be high for 5.0
seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• Once DT C P0342 is set, the PCM will determ ine the f uel injection sequence bas ed on the last fuel injection
pulse received. In the calculated SFI mode, the engine continues to start and run. However, with the fault
present, only a 1 in 6 chance of the correct injection sequence exists.
VXPCM009
PCM
B10
B6
B7
B9
B4
B3
CRANKSHAFT
REFERENCE LO
CAM
SENSOR
CONNECTOR
CAMSHAFT
POSITION
SENSOR
SIGNAL
CRANKSHAFT
REFERENCE HI
CRANKSHAFT
18X SIGNAL
BYPASS CONTROL
EST OUTPUT
module power supply - in
sensor power supply - out
cam signal - in
3x crank sensor - in
18x crank sensor - in
cam signal - out
tacho signal - out
crankshaft reference - out
18X cranksignal - out
bypass control
EST signal -in
P
N
M
L
K
J
H
G
F
E
D
C
B
A
DIS
MODULE
ABCD CBA
W/B (644)
GY/R (645)
B/R (453)
CRANK
SENSOR
CONN
L BLU/W
(646) BR (633)
BLU/Y (643)
BR (121)
B (63 0)
V (43 0)
L BLU/B (647)
T/B (4 24)
IGN SW
EFI RELAY
O/Y
(479) LOC. E3
YE39
YE111 YE39
YB187
YE63
YB187
YE57
YE34
LG
(482)
B/W
(152)P/B
(39)
IC
IC
IC
M
I
C
R
O
W (423)
F35
+-
BATTERY
FS
FJ
(1040)
P (3)
R (2H)
F14
TO INSTRUMENT CLUSTER
(TERMINAL 18)
ABS/ETC (TERMINAL 30)
CONDITIONS FOR CLEARING THE MIL/DTC
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
An interm ittent may be caused by a poor connection, rubbed through wire insulation, or a wire br oken inside the
insulation.
Check for:
• Poor Connection or Damage Harness - Inspect PCM harness connectors for backed out terminal "B6",
improper mating, broken locks, improperly formed or damaged terminal, poor terminal to wire connection
and damaged harness.
• Intermittent Test - If connections and harness check OK, monitor a digital voltmeter connected from PCM
terminal "B6" to earth while moving related connectors and wiring harness. If the failure is induced, the
voltage reading will change. This may help to isolate the location of the malfunction.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. This step verifies proper operation of circuits 633, 644, and 645.
4. This s tep ver if ies the integr ity of circuit 630 f r om ignition module to PCM. If the voltage r eading of "B6" dr ops
slightly from 4.7 volts to appr oxim ately 4.1 volts, the cam shaft s ensor is pulling the s ignal line low, therefore
the connection to the PCM is not good or the PCM is f aulty. If the voltage rem ains at approxim ately 4.4 volts
and is steady, continue with diagnosis.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
DIRECT IGNITION MODUL E
YE 57
(647)
LBLU/B
W/B
(644)
B/R
(453)
LBLU/W
(646)
BLU/Y
(643)
V
(430)
T/B
(424)
(633)
BR
(645)
GY/R
LG
(482)
B
(630)
BR
(121)
W
(423)
PNMLKJHGFED
CBA
Y E63
CAM S EN SOR
(644)
W/B
GY/R
(645)
BR
(633)
CRANK SENSOR
YE 34
W/B
(644)
GY/R
(645)
BLU/Y
(643)
LBLU/W
(646)
DTC P0342 V6 PCM - CAMSHAFT POSITION (CKP) SENSOR SIGNAL MISSSING
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check
in this Section
2. 1. Install Tech 2 scan tool.
2. Ignition "ON", engine "OFF".
3. Record, then clear DTCs .
4. Start engine, idle for 1 minute.
5. Select DATA LIST.
Does Tech 2 scan tool display "Cam Signal" as
"Missing"?
Go to Step 3 DTC P0342 is
intermittent. If
no additional
DTCs were
stored, refer to
"Diagnostic
Aids" above.
3 1. Ignition "OFF".
2. Disconnect camshaft position sensor harness
connector from camshaft position sensor.
3. Ignition "ON", engine "OFF".
Using DVM, does voltage between harness connectors
pins "A-B and "B-C" measure between specified values?
"A-B"
5-7 volts
"B-C"
8-11 volts
Go to Step 4 Go to Step 11
DTC P0342 V6 PCM - CAMSHAFT POSITION (CKP) SENSOR SIGNAL MISSSING (CONTINUED)
STEP ACTION VALUE YES NO
4. 1. Ignition "OFF".
2. Reconnect camshaft position sensor harness to
camshaft position sensor.
3. Install DVM to backprobe PCM terminals B6 & A5
to measure voltage at PCM terminal B6.
4. Ignition "ON", engine "OFF".
Is voltage fixed at specified value?
Approximately
4.7 volts Go to Step 5 Go to Step 10
5. Start engine, idle 1 minute to stabilise system.
Is voltage reading of "B6" constantly varying around a
mid-point of specified value?
Approximately
4.1 volts Go to Step 9 Go to Step 6
6. 1. Ignition "OFF".
2. Disconnect camshaft position sensor harness
connector from camshaft position sensor.
3. Ignition "ON", engine "OFF".
4. Touch terminal "A" of camshaft position sensor
harness connector with a test light connected to
earth while observing voltmeter.
Does voltage reading at PCM terminal "B6" drop to
specified value?
0 volts Go to Step 7 Go to Step 8
7. Check the following:
• Poor connection at camshaft position sensor;
• Faulty camshaft position sensor;
• Missing camshaft magnet;
Is action complete?
Verify Repair
8. Replace faulty ignition control module.
Is action complete? Verify Repair
9. Check for poor connection at PCM terminal B6 or faulty
PCM.
Is action complete?
Verity Repair
10 Bump engine with starter.
Retest voltage at terminal "B6".
Is voltage fixed at specified value?
Approximately
4.7 volts Go to Step 5 Go to Step 17
11. Was one voltage reading low? Go to Step 12 Go to Step 16
12. Was the reading between harness connector pin "A-B
low? Go to Step 13 Go to Step 15
13. Check for open or short to earth in circuit 633.
Was a fault found? Verify Repair Go to Step 14
14. Check for poor ignition control module connection.
Was a fault found? Verify Repair Go to Step 8
15 Repair circuit 644 between splice and camshaft position
sensor connector.
Is action complete?
Verify Repair
16 Repair circuit 645 between splice and camshaft position
sensor connector.
Is action complete?
Verify Repair
17 Check circuit 630 for open or short to earth.
Was a fault found? Verify Repair Go to Step 18
18 Replace the camshaft position sensor.
Is action complete? Verify Repair
DTC P0374 V6 PCM -
18X REFERE NCE SIGNAL MISSING
CIRCUIT DESCRIPTION:
The 18X signal ( circuit 647) is used by the PCM to improve ignition tim ing accuracy during crank and at engine
speeds of up to 2000 RPM. The 18X signal circuit allows the use of EST m ode below 400 RPM, eliminating the
need to utilise bypass mode dur ing startup, and also allows the PCM to calculate tr ue crankshaf t position in 1/6
the time that use of the crankshaft reference signal would permit.
During norm al operation, the PCM uses the 18X signal to contr ol ignition timing until the engine speed exc eeds
2000 RPM, at which time the c rankshaf t reference s ignal (circuit 430) is us ed. When conditions for setting DTC
P0374 exist, the crankshaft reference signal is used by the PCM to control EST. This condition will cause
bypas s mode to be used f or ignition timing below 400 RPM and EST ignition timing to be degraded below 2000
RPM.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
• The MAF sensor input signal is greater than 2048 Hz.
CONDITIONS FOR SETTING THE DTC
• The PCM detects 253 crankshaft reference pulses and no 18X pulses.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P0374 is set and current (no 18X reference signal), the PCM uses the crankshaft reference
signal to determine engine speed. This condition will cause the EST to be degraded; no high resolution
spark.
VXPCM009
PCM
B10
B6
B7
B9
B4
B3
CRANKSHAFT
REFERENCE LO
CAM
SENSOR
CONNECTOR
CAMSHAFT
POSITION
SENSOR
SIGNAL
CRANKSHAFT
REFERENCE HI
CRANKSHAFT
18X SIGNAL
BYPASS CONTROL
EST OUTPUT
module power supply - in
sensor power supply - out
cam signal - in
3x crank sensor - in
18x crank sensor - in
cam signal - out
tacho signal - out
crankshaft reference - out
18X cranksignal - out
bypass control
EST signal -in
P
N
M
L
K
J
H
G
F
E
D
C
B
A
DIS
MODULE
ABCD CBA
W/B (644)
GY/R (645)
B/R (453)
CRANK
SENSOR
CONN
L BLU/W
(646) BR (633)
BLU/Y (643)
BR (121)
B (63 0)
V (43 0)
L BLU/B (647)
T/B (4 24)
IGN SW
EFI RELAY
O/Y
(479) LOC. E3
YE39
YE111 YE39
YB187
YE63
YB187
YE57
YE34
LG
(482)
B/W
(152)P/B
(39)
IC
IC
IC
M
I
C
R
O
W (423)
F35
+-
BATTERY
FS
FJ
(1040)
P (3)
R (2H)
F14
TO INSTRUMENT CLUSTER
(TERMINAL 18)
ABS/ETC (TERMINAL 30)
CONDITIONS FOR CLEARING THE MIL/DTC
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
An interm ittent may be caused by a poor connection, rubbed through wire insulation, or a wire br oken inside the
insulation.
Check for:
• Backed out connector terminals or broken down insulation in circuit 647.
• If connections and harness check OK, try monitoring voltage on circuit 647 with DVM while moving the
related wiring harness and connectors with the engine idling. This may help to isolate the location of the
malfunction.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
4. If a window on the harmonic balancer is interfering with the 18X Hall-Effect switch, the ignition module will
earth the 18X signal. Starter may have to be bumped several times to obtain a voltage reading.
5. Voltage reading should be lower than that obtained with engine not running, indicating a pulsed reference
signal.
8. Verifies that circuit 647 is not shorted to earth or open in the harness.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
DIRECT IGNITION MODUL E
YE 57
(647)
LBLU/B
W/B
(644)
B/R
(453)
LBLU/W
(646)
BLU/Y
(643)
V
(430)
T/B
(424)
(633)
BR
(645)
GY/R
LG
(482)
B
(630)
BR
(121)
W
(423)
PNMLKJHGFED
CBA
Y E63
CAM S EN SOR
(644)
W/B
GY/R
(645)
BR
(633)
CRANK SENSOR
YE 34
W/B
(644)
GY/R
(645)
BLU/Y
(643)
LBLU/W
(646)
DTC P0374 V6 PCM - 18X REFERENCE SIGNAL MISSING
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. 1. Ignition "OFF".
2. Install Tech 2 scan tool and clear DTCs.
3. Ignition "ON".
4. Start engine idle for 1 minute or until Diagnostic
Trouble Code P0374 sets.
Did Diagnostic Trouble Code P0374 set?
Go to Step 3 DTC P0374 is
intermittent. If no
additional DTC's
were stored, refer
"Diagnostic Aids"
above.
3 1. Backprobe PCM terminal B7 with a DVM connected
to earth.
2. Ignition "ON", engine "OFF", observe voltage on
PCM terminal B7.
Does voltage measure specified value?
Approximately
5 volts Go to Step 5 Go to Step 4
4. 1. Bump engine with starter.
2. Retest voltage at PCM terminal B7.
Does voltage measure specified value?
Approximately
5 volts Go to Step 5 Go to Step 8
DTC P0374 V6 PCM - 18X REFERENCE SIGNAL MISSING (CONTINUED)
STEP ACTION VALUE YES NO
5. 1. Start engine, idle 1 minute to stabilise system.
2. Observe voltage on PCM terminal B7.
Does voltage measure specified value?
Approximately
3 volts Go to Step 7 Go to Step 6
6. Check for poor ignition module connections.
Was a fault found? Verify Repair Go to Step 10
7. Check for poor connection at PCM B7.
Was a fault found? Verify Repair Go to Step 11
8. 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. Ignition "ON".
4. Measure voltage at PCM harness connector
terminal B7.
Does voltage measure specified value?
Approximately
5 volts Go to Step 11 Go to Step 9
9. Check circuit 647 open or shorted to earth.
Was a fault found? Verify Repair Go to Step 10
10. Replace faulty ignition control module.
Is action complete? Verify Repair
11. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0400 V6 PCM -
EGR FLOW FAULT INDICATED
CIRCUIT DESCRIPTION:
An Exhaus t Gas Recirculation (EGR) system is used to lower Ox ides of Nitr ogen (NOx) em iss ion levels caused
by high c om bustion tem peratur es. It acc om plishes this by feeding sm all amounts of exhaust gases back into the
com bustion cham ber. When the air/fuel m ixture is diluted with the exhaust gases, com bustion tem peratures are
reduced.
The linear EGR valve is designed to accurately supply exhaust gases to the engine without the use of intake
manifold vacuum. The valve controls exhaust flow going into the intake manifold from the exhaust manifold
through an orifice with a PCM controlled pintle. The PCM controls the pintle position using inputs from engine
RPM, Engine Coolant Temperature (ECT), and Mass Air Flow (MAF) sensor. The PCM then commands the
EGR valve to operate when necess ary by controlling the 12 volt signal through the PCM. T his can be m onitored
on a scan tool as the EGR POS COMMANDED.
The PCM monitors the results of its command through a feedback signal. By sending a 5 volt reference and a
earth signal to the EGR valve, a voltage signal representing the EGR valve pintle position is sent to the PCM.
This feedback signal can also be monitored on a scan tool and is the actual position of the EGR pintle. The
EGR POS FEEDBACK should always be near the commanded or EGR POS COMMANDED .
CONDITIONS FOR RUNNING THE DTC
• Engine speed is between 700 and 1100 RPM.
• The ECT sensor is greater than 80°C.
• Vehicle speed is above 37 KM/H.
• IAC Valve has not changed more than 5 counts.
• Throttle angle is less than 1%.
CONDITIONS FOR SETTING THE DTC
• Expected RPM drop during PCM EGR test is less than 50 RPMs.
E
A
DCB
E12
C8
C16
D6
EGR PINTLE POSITION
REFERENCE
VOLTAGE
SENSOR EARTH
PCM
5V
12V
M
I
C
R
O
V (435)
V/W (415)
LG (1456)
B (469)
B/R
(750)
THROTTLE
BODY EGR
VALVE
EXHAUST MANIFOLD
VXPCM029
YE109
YB199
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
CONDITIONS FOR CLEARING THE MIL/DTC
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Check for the following conditions:
A poor connection or damaged harness. Inspect the wiring harness for damage. If the harness appears to be
OK, observe the EG R POS FEEDBACK display on the scan tool while m oving connectors and wiring harnesses
related to the EGR valve. A change in the display will indicate the location of the fault.
Notice: If the EGR valve shows signs of excessive heat, check the exhaust system for blockage (possibly a
plugged converter).
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
1. T he OBD System Check prom pts the tec hnician to com plete som e bas ic chec k s and store the f reeze fram e
and f ault records data on the scan tool if applicable. This creates an electr onic copy of the data taken when
the fault occurred. The information is then stored on the scan tool for later reference.
2. This step verifies if the exhaust system has been modified.
3. Visually and physically inspect the EGR passages and valve for excessive carbon deposits or damage.
4. This step checks to see if the EGR ports are blocked.
3. This step verifies if the fault is present and also verifies if a repair corrected the problem.
E.G.R VALVE
(435)
(469) (1456)
V
BLG V/W B/R
(415)
(750)
DTC P0400 V6 PCM - EGR FLOW FAULT INDICATED
STEP ACTION VALUE(s) YES NO
1. Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
in this Section
2. 1. Inspect the exhaust system for modification of original
installed parts or leaks.
2. If a problem was found, repair exhaust system as
necessary.
Was a condition present that required repair?
Go to Step 5 Go to Step 3
3. 1. Remove the EGR valve.
2. Visually and physically inspect the pintle, valve
passages and the adapter for excessive deposits or
any kind of a restriction.
3. If a problem is found, clean or replace EGR system
components as necessary.
Was a condition present that required repair?
Go to Step 5 Go to Step 4
DTC P0400 V6 PCM - EGR FLOW FAULT INDICATED (CONTINUED)
STEP ACTION VALUE(s) YES NO
4. 1. Remove the EGR from the intake manifold.
2. Inspect the manifold EGR ports for a blockage caused
by excessive deposits other damage.
3. If a problem is found, correct the condition as
necessary.
Was a condition present that required repair?
Go to Step 5 Refer to
Diagnostic Aids
5. 1. Using the scan tool, clear the DTCs.
2. Start the engine and allow the engine to idle until the
specified engine coolant temperature is reached.
3. Operate the vehicle within the conditions for setting
this DTC as specified in the supporting text.
Does the scan tool indicate DTC P0400 set?
80°C Go to Step 2 System OK
DTC P0405 V6 PCM -
EGR POSITION FAULT
CIRCUIT DESCRIPTION:
The PCM m onitors the EGR valve pintle pos ition input to ensure that the valve responds properly to com mands
from the PCM and to detect a fault if the pintle position sensor and control circuits are open or shorted. If the
PCM detects a pintle position signal voltage outside the normal range of the pintle position sensor, or a signal
voltage that is not within a tolerance considered acceptable for proper EGR system operation, the PCM will set
a DTC P0405.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
• Battery voltage is greater than 11.2 volts
CONDITIONS FOR SETTING THE DTC
• The EGR position feedback is less than 0.32 volts for greater than on second.
Or
• The EGR commanded position is 10% greater or less than EGR position feedback for more than five
seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
CONDITIONS FOR CLEARING THE MIL/DTC
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
E
A
DCB
E12
C8
C16
D6
EGR PINTLE POSITION
REFERENCE
VOLTAGE
SENSOR EARTH
PCM
5V
12V
M
I
C
R
O
V (435)
V/W (415)
LG (1456)
B (469)
B/R
(750)
THROTTLE
BODY EGR
VALVE
EXHAUST MANIFOLD
VXPCM029
YE109
YB199
DIAGNOSTIC AIDS:
Check for the following conditions:
Excessive deposits on the EGR valve pintle or seat. Check for deposits that may interfere with the EGR valve
pintle extending completely or cause the pintle to stick.
Poor connection or damaged harnes s. Inspect the wiring harness for dam age. If the harnes s appears to be OK,
observe the EGR POS FEEDBACK display on the scan tool while moving connectors and wiring harnesses
related to the EGR valve. A change in the display will indicate the location of the fault.
If P0405 and P0530 are set, check for an open Earth circuit 469.
Notice: If the EGR valve shows signs of excessive heat, check the exhaust system for blockage (possibly a
plugged converter).
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. Commanding the EGR valve open determines whether the EGR system can control the EGR valve
accurately.
3. When the EGR valve electrical connector is disconnected, the scan tool should display the EGR POS
FEEDBACK as 0%. If it does not, go directly to step 11, as the fault lies either in the EGR signal circuit or
the PCM. A test light, when connected to earth, will glow dimly when the EGR valve is com manded to 25%,
and brighter as the EGR valve is commanded to 100%. If the test light flashes, check the sensor earth for
an open.
6. If the EGR valve 5 volt reference is shorted to voltage, the DVM will read battery voltage and an additional
DTC will be set and engine perf orm ance will be poor. When this circuit is open, an additional DTC m ay also
be set if the entir e circuit is open. O nly a DT C P0405 set indicates that the c ircuit is open between the EGR
valve electrical connector and the spliced circuit.
7. T he test light will have glowed br ightly in step 5 if the EGR c ontrol circuit was s horted to earth and the EGR
POS FEEDBACK on the scan tool will display 100%. A test light that did not illuminate, indicates that the
circuit may be open or shorted to earth.
9. If the 5 volt ref erence c ircuit is shorted to earth, an additional DT C will also be set. If no other DTC' s are set,
then the fault m ust be between the EGR valve elec trical c onnector and the 5 volt r efer ence splic e to the A/C
Pressure Sensor.
10. The EGR PO S FEEDBACK should r ead 0% bef or e jumping the 5 volt reference c irc uit to the s ignal circ uit. If
any other reading is present, then either the signal circuit or the PCM is at fault.
11. An open or short in the EGR valve sensor earth circuit will also cause an additional DTC to be set. If no
other DT C's ar e set, and the circ uit is found to be open or s horted, the fault is on the EG R valve side of the
spliced circuit.
E.G.R VALVE
(435)
(469) (1456)
V
BLG V/W B/R
(415)
(750)
DTC P0405 V6 PCM - EGR POSITION FAULT
STEP ACTION VALUE(s) YES NO
1 Was the “On-Board Diagnostic (OBD) System Check”
performed? Go to Step 2 Go to OBD
System Check
2 1. Key "ON, engine "OFF".
2. Install a scan tool.
3. Command the EGR valve to the specified values.
Does the EGR POS COMMANDED follow the EGR
POS FEEDBACK?
0% to 98% Refer to
"Diagnostic Aids" Go to Step 3
3 1. Key "ON", engine "OFF".
2. Disconnect the EGR valve electrical connector.
3. With a test light connected to B+, probe the earth
circuit to the EGR valve.
Does the test light illuminate?
Go to Step 4 Go to Step 5
DTC P0405 V6 PCM - EGR POSITION FAULT (CONTINUED)
STEP ACTION VALUE(s) YES NO
4 1. Connect the test light to earth.
2. Probe the EGR control circuit to the EGR valve.
3. Command the EGR valve to the specified values.
Does the test light glow dimly and then glow brighter or
flash as the commanded percentage is raised?
0% to 98% Go to Step 6 Go to Step 7
5 Check for an open in the EGR valve earth circuit
and repair as necessary.
Was a repair necessary?
Verify Repair Go to Step 14
6 Using a DVM connected to earth, probe the 5 volt
reference circuit to the EGR valve.
Does the DVM read the specified value?
5.0V Go to Step 8 Go to Step 9
7 Check for an open or short in the EGR control circuit and
repair as necessary.
Was a repair necessary?
Verify Repair Go to Step 14
8 Using a DVM connected to B+, probe the EGR valve
sensor earth circuit.
Does the DVM read the specified value?
B+ Go to Step 10 Go to Step 11
9 Check for an open or short in the EGR valve 5 volt
reference circuit and repair as necessary.
Was a repair necessary?
Verify Repair Go to Step 14
10 Jumper the EGR valve 5 volt reference circuit to the
signal circuit.
Does the EGR POS FEEDBACK display the specified
value?
100% Go to Step 12 Go to Step 13
11 Check for an open in the EGR valve sensor earth circuit
and repair as necessary.
Was a repair necessary?
Verify Repair Go to Step 14
12 Replace the EGR valve.
Is the action complete? Verify Repair
13 Check for an open or short in the EGR valve signal circuit
and repair as necessary.
Was a repair necessary?
Verify Repair Go to Step 14
14 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0446 V6 PCM -
CANISTER PURGE CIRCUIT FAULT
CIRCUIT DESCRIPTION:
Quad Driver Modules (QDMs) are used by the PCM to turn "ON" many of the current-driven devices that are
needed to control various engine and transmission functions. Each QDM is capable of controlling up to 4
separate outputs by applying earth to the device which the PCM is commanding "ON".
The Quad Driver Modules (QDMs) used has the capability of diagnosing each output circuit individually. If DTC
P0446 is set, this indicates an improper voltage level has been detected on the QDM fault line which controls
the Canister Purge Solenoid.
CONDITIONS FOR RUNNING THE DTC
• The ignition is on.
CONDITIONS FOR SETTING THE DTC
• The PCM detects an incorrect voltage on the EVAP purge solenoid driver circuit for 5 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
Check for the following conditions:
• Poor connection at PCM. Inspect harness connections for backed out terminals, improper mating , broken
locks, improper formed or damaged terminals, and poor terminal to wire connection.
• Damaged har ness. Inspec t the wiring harness for dam age. If the har ness appears to be O K, disconnect the
PCM, turn the ignition "ON" and obser ve a voltmeter connected to the Canister Purge Solenoid driver circuit
at the PCM harness connector while moving connectors and wiring harness related to the Canister Purge
Solenoid. A change in voltage will indicate the location of the fault.
If DTC P0446 cannot be duplicated, the information included in the DTC History can be useful in determining
how many ignition cycles have passed since the DTC was last set.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. Normally, ignition feed voltage present on the output driver circuit with the PCM disconnected and the
ignition "ON".
3. Chec ks f or a s horted c omponent or a s hort to B+ or the Q uad driver cir cuit. Either c ondition would result in a
measured current of over 1.5 amps. Also checks for a component that is going open while being operated,
resulting in a measured current of 0 amps.
4. Checks for a faulty Canister Purge Solenoid.
A
B
CANISTER PURGE
SOLENOID V ALVE
PCM
CANISTER PURGE
VXPCM027
A10
G/Y (428)
MANIFOLD
VACUUM
TO CARBON
CANISTER
B/W
(152)
LOC. E3
M
I
C
R
O
YE39YE39
YE99
YE111
YB187
F14
IGN SW
EFI
RELAY
+
-
BATTERY
FS
FJ
P (3) P/B
(39)
(1040) O/Y (479)
R (2H)
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
CANNISTER P URGE
(439) (428)
PG/Y
B
A
DTC P0446 V6 PCM - CANISTER PURGE CIRCUIT FAULT
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2. 1. Ignition "OFF"., disconnect the PCM.
2. Ignition "ON".
3. Using voltmeter, measure voltage between the
Canister Purge Solenoid driver circuit at the PCM
harness connector and earth.
Is voltage near the specified value?
B+ Go to Step 3 Go to Step 6
3. 1. Digital volt/ohmmeter set to 10 amp scale, install
digital volt/ohmmeter to measure current between
the Canister Purge Solenoid driver and earth.
2. Monitor the current reading on the digital
volt/ohmmeter for at least 2 minutes.
Does the current reading remain between the specified
values?
0.1 amp
To
1.5 amps
Go to Step 11 Go to Step 4
4. 1. Disconnect the Canister Purge Solenoid (leave the
PCM disconnected).
2. Using digital volt/ohmmeter, measure voltage
between the Canister Purge Solenoid driver circuit
and earth.
Is voltage at specified value?
0 volts Go to Step 14 Go to Step 5
5. Locate and repair short to voltage in the Canister Purge
Solenoid driver circuit.
Is action complete?
Verify Repair
6. Check the ignition feed fuse for the Canister Purge
Solenoid.
Is the fuse blown?
Go to Step 7 Go to Step 8
7. 1. Locate and repair short to earth in ignition feed
circuit for the Canister Purge Solenoid.
2. Replace fuse.
Is action complete?
Verify Repair
8. 1. Disconnect the Canister Purge Solenoid.
2. Ignition "ON".
3. Measure voltage between the ignition feed circuit for
the Canister Purge Solenoid and earth.
Is voltage near the specified value?
B+ Go to Step 9 Go to Step 13
9. Check the Canister Purge Solenoid driver circuit for an
open or a short to earth.
Was a problem found?
Verify Repair Go to Step 10
10. Check the Canister Purge Solenoid driver circuit and the
ignition feed circuit for a poor connection at the Canister
Purge Solenoid and the PCM.
Was a problem found?
Verify Repair Replace
Canister Purge
Solenoid and
Verify Repair.
DTC P0446 V6 PCM - CANISTER PURGE CIRCUIT FAULT (CONTINUED)
STEP ACTION VALUE YES NO
11. 1. Ignition "OFF", reconnect the PCM and disconnect
the Canister Purge Solenoid.
2. Ignition "ON, connect a test light between the
Canister Purge Solenoid driver circuit and the
ignition feed circuit at the Canister Purge Solenoid
connector.
3. Using the Tech 2 scan tool, select, PURGE.
4. Cycle the Canister Purge Solenoid "ON" and "OFF".
Does the test light flash "ON" and "OFF"?
Refer to
"Diagnostic Aids"
above.
Go to Step 12
12. Check the Canister Purge Solenoid driver for a poor
connection at the PCM.
Was a problem found?
Verify Repair Go to Step 15
13. Locate and repair open ignition feed circuit to the
Canister Purge Solenoid.
Is action complete?
Verify Repair
15. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0502 V6 PCM -
NO VEHICLE SPEED SIGNAL
CIRCUIT DESCRIPTION:
The Vehicle Speed Sensor Assembly (VSS Assy.) provides vehicle speed information to the PCM. The VSS
Assy. is a Permanent Magnet (PM) generator. The PM generator produces a pulsing AC voltage. The AC
voltage level and the number of pulses increase with the speed of the vehicle. The PCM then converts the
pulsing voltage to vehicle speed. The PCM uses this information for calculations. A scan tool can display the
vehicle speed.
W hen the PCM detects a low or no vehicle speed, when there is high engine speed in a drive r ange, then DTC
P0502 sets.
CONDITIONS FOR RUNNING THE DTC
Automatic Transmission
• The transmission is not in Park or Neutral.
• The engine speed is greater than 3000 RPM.
• The TP Sensor angle is between 10% and 99%.
Manual Transmission
• The engine speed is between 1400 and 3000 RPM.
• The throttle is closed (throttle angle less than 1%).
• Engine load very low, MAF less than 95 mg/cyl.
• Vehicle in gear.
• Vehicle is decelerating from road speed.
CONDITIONS FOR SETTING THE DTC
Automatic Transmission
• The VSS indicates an output shaft speed of less than 3 km/h for 3 seconds.
Manual Transmission
• The VSS indicates no output shaft speed for more than 4 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• For the automatic transmission, when this DTC sets, the PCM will command second gear only, The PCM
will command maxim um line pressure, The PCM will freeze shift adapts from being updated, The PCM will
inhibit TCC engagement.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
V/W (123)
VEHICLE SPEED
M
I
C
R
O
VXPCM016
INSTRUMENT
M
I
C
R
O
VEHICLE SPEED
PCM
C1
D1
D2
V
EH IC LE SPEED
SENSOR
IC
BLU/W
(831)
(AUTO)
BLU
(831)
(MAN)
T
(832)
(AUTO)
BR
(832)
(MAN)
SPEEDOMETER
YB66
YE110 YB198
YB195 (AUTO)
YB132 (MAN)
DIAGNOSTIC AIDS:
• Inspect the wiring for poor electrical connections at the PCM. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
- Corrosion
• When diagnosing for an inter m ittent short or open c ondition, m ass age the wiring harness while watc hing the
test equipment for a change.
• Check cir cuits 831 and 832 f or the proper c onnections to be s ure they are clean and tight and the harness is
routed correctly.
• The scan tool should indicate a vehicle speed whenever the drive wheels are turning greater than 3 km/h.
• The vehicle speed sensor resistance should be between 1470-2140 Ω at 20°C, and 2270-2820 Ω at 100° C.
• Refer to "Intermittents" in Section 6C1-2B Symptoms of the VX Series Service Information.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. This step tests the integrity of the VSS Assy.
4. This step tests the VSS Assy. circuit.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
(831)
BLU/W
T
(832)
MANUAL TRANS SPEED SENDER
(831)
(832)
BR
BLU
DTC P0502 V6 PCM - NO VEHICLE SPEED SIGNAL
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check.
2 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs, use the scan
tool in order to record the DTC history for reference. The
Clear Info function will erase the data.
3. Record the DTC history.
4. Clear the DTC.
5. Raise the drive wheels.
Note: Do not perform this test without supporting the rear
axle assembly or the lower control arms on vehicles with
independent rear suspension so that the drive shafts are
in a normal horizontal position.
6. Start the engine.
7. Place the transmission in any drive gear.
W ith the rear wheels rotating, does the scan tool Vehicle
Speed increase with the drive wheel speed?
Go to
“Diagnostic Aids”
above
Go to Step 3
3 1. Turn the ignition switch to the OFF position.
2. Disconnect the VSS connector from the VSS
assembly.
3. Using the J 35616 Connector Test Adapter Kit,
connect the J 39200 DVM to the VSS terminals.
4. Select AC volts.
5. Place the transmission selector in the neutral
position.
6. Rotate the drive wheels by hand, ensuring that the
driveshaft is turning.
With rear wheels rotating, is the DVM voltage greater
than the specified value?
0.5 volts AC Go to Step 4 Go to Step 11
4 1. Turn the ignition switch to the OFF position.
2. Reconnect the VSS connector to the VSS Assy.
3. Disconnect the PCM connector from the PCM.
4. Connect the DVM test leads to the connector
terminals D5 (T) and C6 (Blu/W).
5. Place the transmission selector in the neutral
position.
6. Rotate the drive wheels by hand, ensuring that the
driveshaft is turning.
With rear wheels rotating, is the DVM voltage greater
than the specified value?
0.5 volts AC Go to Step 13 Go to Step 5
5 1. Select Ω (Ohms), on the DVM.
2. Measure the resistance between the connector
terminals D1 and D2.
Is the circuit resistance within the specified range?
1470-2820 Ω Go to Step 6 Go to Step 8
6 Connect the DVM between the connector terminal
D1 and earth.
Is the circuit resistance less than the specified value?
250k Ω Go to Step 7 Go to Diagnostic
Aids
7 1. Check circuit 831 and circuit 832 for a short to earth.
2. Repair the circuit if necessary.
Was the short to earth condition found and corrected?
Go to Step 14 Go to
“Diagnostic Aids”
above
DTC P0502 V6 PCM - NO VEHICLE SPEED SIGNAL (CONTINUED)
STEP ACTION VALUE YES NO
8 Is the resistance reading in step 6 greater than the
specified value? 2820 Ω Go to Step 10 Go to Step 9
9 1. Check circuit 831 and circuit 832 for a shorted
together condition.
2. Repair the circuit if necessary.
Was a shorted together condition found and corrected ?
Go to Step 14 Go to
“Diagnostic Aids”
above
10 1. Check circuit 831 and circuit 832 for an open
condition.
2. Repair the circuit if necessary.
Was an open condition found and corrected ?
Go to Step 14 Go to
“Diagnostic Aids”
above
11 1. Remove the VSS Assembly.
2. Inspect the VSS Output Sensor Rotor for damage or
misalignment.
Did you find a condition?
Refer to
Section 7B-1
Manual
Transmission -
V6 Engine or
Section 7C-4
Automatic
Transmission in
VX Service
Information.
Go to Step 12
12 Replace the VSS Assy. Refer to Service Operations.
Is the action complete? Go to Step 14
13 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 14
14 In order to verify your repair, perform the following
procedure:
1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle ensuring that the vehicle speed
is greater than 10 km/h and observe the scan tool
Vehicle Speed.
Is the scan tool Vehicle Speed greater than the specified
value?
10 km/h System OK Go to Step 2
DTC P0503 V6 PCM -
VEHICLE SPEED SENSOR INTERMITTENT SIGNAL
CIRCUIT DESCRIPTION:
The Vehicle Speed Sensor (VSS) circ uit consists of a m agnetic induction type sensor and vehicle speed s ensor
wiring. Gear teeth pressed on the output shaft of the transmission induce an alternating current in the vehicle
speed sensor. This alternating current is transmitted to the PCM.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
CONDITIONS FOR SETTING THE DTC
• T wo decisive speed r eadings have a diff erence of m ore than 1000 RPM in any drive range (diff erence m ust
be more than 2048 RPM in park or neutral). This test checks the vehicle speed sensor signal to the PCM.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When Diagnostic Trouble Code P0503 is set, the transmission will have maximum line pressure and
com m and 3r d gear only. If DT C P0503 is set while in 4th gear, the vehicle will stay in 4th gear. However, as
the vehicle is coasting to stop the transmission will downshift norm ally from 4 to 3. Once the downshift into
3rd gear has occurred, the vehicle will stay in 3rd gear.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
DTC P0503 is used to detect an intermittent failure. If a hard VSS fault exists, it will set DTC P0502.
DTC P0503 will set if the vehicle is operating at a road speed and something happens to the VSS signal.
Check all connections for proper retention. Check that wiring harness for VSS are not routed near high voltage
sources such as spark plug cables which could induce a false signal onto the VSS signal.
DTC P0503 c ould possibly be set by rapidly accelerating the vehic le in a loose m aterial (s uch as s and or gravel)
where the wheels can be spinning faster than actual vehicle speed then having the spinning wheel rapidly
decrease when it contacts a hard surface. Review DTC history to identify when DTC P0503 was set.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. This test checks the vehicle speed sensor signal to the powertrain control module.
V/W (123)
VEHICLE SPEED
M
I
C
R
O
VXPCM016
INSTRUMENT
M
I
C
R
O
VEHICLE SPEED
PCM
C1
D1
D2
V
EH IC LE SPEED
SENSOR
IC
BLU/W
(831)
(AUTO)
BLU
(831)
(MAN)
T
(832)
(AUTO)
BR
(832)
(MAN)
SPEEDOMETER
YB66
YE110 YB198
YB195 (AUTO)
YB132 (MAN)
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
(831)
BLU/W
T
(832)
MANUAL TRANS SPEED SENDER
(831)
(832)
BR
BLU
DTC P0503 V6 PCM - VEHICLE SPEED SENSOR INTERMITTENT SIGNAL
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD System
Check in this
Section
2. 1. Clear DTC, set Tech 2 scan tool to display "Vehicle
Speed" in the snapshot mode and set to trigger on
DTC P0503.
2. Drive vehicle at different speeds and road
conditions.
Is DTC P0503 set again?
Go to Step 3 DTC P0503 Is
intermittent. If no
additional DTC's
were stored, refer
to "Diagnostic
Aids" above.
3. 1. Raise drive wheels.
NOTE: Do not perform this test without supporting the
rear axle assembly (five link suspension) or lower
control arms on vehicles with independent rear
suspension so that the drive shafts are in a normal
horizontal position. on vehicles with IRS, running
the vehicle in gear with the wheels hanging down at
full travel may damage the drive shaft.
2. Engine idling in gear.
Does Tech 2 scan tool display "Vehicle Speed" above
specified value?
0 km/h Go to Step 4 Go to
DTC P0502
in this Section
4. Wiggle and tug on connector at vehicle speed sensor.
Does Tech 2 scan tool display "Vehicle Speed" drop to
specified value?
0 km/h Go to step 6 Go to step 5
5. Wiggle and tug on connectors at Powertrain Control
Module.
Does Tech 2 scan tool display "Vehicle Speed" above
specified value?
0 km/h Go to step 6 Refer to
”Diagnostic Aids”
above
6. Repair connector terminals.
Is action complete? Verify Repair
DTC P0506 V6 PCM -
IDLE SPEED ERROR
CIRCUIT DESCRIPTION:
The IAC valve is a stepper m otor. Stepper m otors have c oils that the PCM turns ON and OFF several tim es per
second. This allows for an incremental clockwise and counter clockwise rotation of a pintle valve. The pintle
valve has a threaded shaf t that either extends or retracts with each puls e of the PCM. The controlled pulses are
called steps or counts. The PCM controls the air entering into the engine at idle through the IAC valve. To
increase the idle speed, the PCM will command the pintle valve away from the throttle body. This allows more
air to bypass the throttle blade and thus increase engine RPM. To decrease the engine RPM at idle, the PCM
will comm and the pintle valve toward the throttle body seat to restrict air from entering into the engine and thus
reduce engine RPM.
CONDITIONS FOR RUNNING THE DTC
• Engine is Idling.
• No TP Sensor, IAT Sensor DTCs are set.
• DTC P0507 is not set.
• The IAT is less than 73°C.
• No vehicle speed indicated.
• Conditions present for 5 seconds.
CONDITIONS FOR SETTING THE DTC
• Engine speed is 200 RPM below the desired idle speed for 5 seconds and the IAC has been opened to its
maximum position (255 steps).
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
CONDITIONS FOR CLEARING THE MIL/DTC
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
VXPCM025
PCM
C5
C4
C3
C2
LG/W (443)
A
B
C
D
IAC VALVE
IAC
COIL B LO
IAC
COIL A LO
IAC
COIL B HI
IAC
COIL A HI
12V
12V
12V
12V
M
I
C
R
O
LG/B (444)
LBLU (441)
LBLU/B (442)
YB198
YE36
DIAGNOSTIC AIDS:
A slow, unstable, or fast idle may be caused by a non-IAC system problem that cannot be compensated by the
IAC valve. Out of c ontrol range IAC T ech 2 scan tool c ounts will be above 60 if idle is too low and zero c ounts if
idle is too high. The following checks should be made to repair a non-IAC system problem:
• Vacuum Leak (High Idle).
If idle is too high, stop the engine. Fully extend (low) IAC with Tech 2 scan tool. Start engine.
If idle speed is above 800 RPM, locate and correct vacuum leak including PCV system. Also, check for
binding of throttle blade or linkage.
• System too lean (High Air/Fuel Ratio).
The idle speed may be too high or too low. Engine speed may be too high or too low. Engine speed may
vary up and down and disconnec ting the IAC valve does not help. DTC P0132 m ay be set. Tec h 2 scan tool
O2 voltage will be less than 300 mV. Check for low regulated f uel pressure, water in the fuel or a restricted
injector.
• System too rich (Low Air/Fuel Ratio).
The idle speed will be too low. Tech 2 scan tool IAC counts will usually be above 80. System is obviously
rich and may exhibit black smoke in exhaust. Tech 2 scan tool O2 voltage will be fixed above 800 mV.
Check for high fuel pressure, leaking or sticking injector. Silicon contam inated O2 sensor Tech 2 scan tool
voltage will be slow to respond.
• Throttle Body.
Remove the IAC valve and inspect bore for foreign material.
• IAC valve Electrical Connections.
The IAC valve connections should be carefully checked for proper contact tension.
• PCV Valve.
An incorrect or faulty PCV valve may result in an incorrect idle speed.
• Refer to "Rough, Unstable, Incorrect Idle or Stalling" in Section 6C1-2B SYMPTOMS, of the VX Series
Service Information.
• If intermittent poor driveability or idle symptoms are resolved by disconnecting the IAC, carefully recheck
connections, valve terminal resistance, or replace IAC.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. The Tech 2 scan tool RPM control mode is used to extend and retract the IAC valve. The valve should
move smoothly within the specified range. If the idle speed is commanded (IAC extended) too low (below
600 RPM), the engine m ay stall. T his may be normal and would not indicate a problem . Retracting the IAC
beyond its controlled range (above 1675 RPM) will cause a delay before the RPM's start dropping, this too
is normal.
3. This test uses the Tech 2 scan to command the IAC controlled idle speed. The PCM issues commands to
obtain com m ended idle s peed. T he test lights each should flash indic ated a good circuit as the PCM is sues
commands. W hile the sequence is not important, if either light is OFF or does not flash, check the circuits
for faults, beginning with poor terminal contacts.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
IDLE AIR CO NTROL VALVE
(442)
(441) (444)
(443)
LBLU/B
LBLU LG/B
LG/W
DTC P0506 V6 PCM - IDLE SPEED ERROR
STEP ACTION VALUE YES NO
1 Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to the OBD
System Check in
this Section
2 1. Install a Tech 2 scan tool.
2. Start the engine and allow the engine to idle until the
specified temperature is reached.
3. Transmission in park or neutral.
4. Set the park brake.
5. Turn the A/C OFF.
6. Using the Tech 2 scan tool cycle the IAC valve from
600 RPM to 1675 RPM.
Does the engine speed change smoothly when
Commanded?
80°C Go to Step 3 Go to Step 5
3 1. Ignition OFF.
2. Disconnect the IAC valve electrical connector.
3. Measure the resistance across the IAC valve
terminals A and B.
4. Measure the resistance across the IAC valve
terminals C and D.
Are the resistance readings across terminals A and B,
and terminals C and D within the specified values?
40-80 ohms Go to Step 4 Go to Step 13
4 1. Measure the resistance across the IAC valve
terminals B and C.
2. Measure the resistance across the IAC valve
terminals A and D.
Are the resistance readings across terminals B and C,
and terminals A and D within the specified values?
Infinite IAC valve control
circuits are OK.
Refer to
Diagnostic Aids
above.
Go to Step 13
5 1. Disconnect the IAC valve electrical connector
2. Ignition ON engine OFF.
3. With a test light connected to earth,. Probe the IAC
valve electrical connectors.
Does the test light illuminate on two terminals?
Go to Step 6 Go to Step 7
6 With a test light connected to B+, probe the IAC valve
electrical connector terminals.
Does the test light illuminate on two terminals?
Go to Step 8 Go to Step 7
7 Check for an open or a short in the IAC valve HI and Lo
circuits.
Was a problem found?
Go to Step 12 Go to Step 14
8 1. Start the engine and allow to idle.
2. With a test light connected to earth, probe the IAC
valve electrical terminals?
Does the test light flash ON and OFF on all the
Terminals?
Go to Step 10 Go to Step 9
9 Did the test light remain ON steady for the terminals that
did not flash? Go to Step 7 Go to Step 11
10 Check the IAC passages for a restriction.
Was a fault found? Go to Step 15 Go to Step 13
11 Check the PCM electrical connector for proper tension at
the terminals.
Was a problem found?
Go to Step 12 Go to Step 14
12 Repair the circuit or the connector as necessary.
Is the action complete? Verify Repair
DTC P0506 V6 PCM - IDLE SPEED ERROR (CONTINUED)
STEP ACTION VALUE YES NO
13 Replace the IAC valve.
Is the action complete? Verify Repair
14 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
15 Clean the passages as necessary.
Is the action complete? Verify Repair
DTC P0507 V6 PCM -
VACUUM LEAK
CIRCUIT DESCRIPTION:
The PCM controls engine idle speed by adjusting the position of the Idle Air Control (IAC) m otor pintle. T he IAC
is a bi-directional motor driven by two coils. The PCM sends pulses (steps) to the IAC to extend or retract the
IAC pintle into a passage in the throttle body to decrease or increase air flow. The commanded IAC position
(displayed in counts) can be monitored on the scan tool; a lower number of counts indicates less commanded
airflow (pintle extended). This method allows highly accurate control of idle speed and quick response to
changes in engine load. If the PCM detects a c ondition where too high of an idle s peed is pres ent, the PCM will
send 50 counts (steps) to the IAC motor. If the RPM increases more than 50 RPM it is accepted that the IAC
motor is moving and theref ore the fault is a vacuum leak, and DT C P0507 will set. If the RPM does not change
when the PCM commands the IAC to respond to a commanded count (steps), the PCM will set a DTC P0506.
CONDITIONS FOR RUNNING THE DTC
• Engine is Idling.
• No TP Sensor, IAT Sensor DTCs are set.
• DTC P0506 is not set.
• The IAT is less than 73°C.
• No vehicle speed indicated.
• Conditions present for 5 seconds.
CONDITIONS FOR SETTING THE DTC
• If the PCM detects a condition where a high idle speed is present and the IAC has been closed (0 steps);
the PCM will command the IAC motor to open 50 steps. If the RPM increase more than 50 RPM it is
accepted that the IAC motor is moving and therefore the fault is a vacuum leak.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
CONDITIONS FOR CLEARING THE MIL/DTC
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
VXPCM025
PCM
C5
C4
C3
C2
LG/W (443)
A
B
C
D
IAC VALVE
IAC
COIL B LO
IAC
COIL A LO
IAC
COIL B HI
IAC
COIL A HI
12V
12V
12V
12V
M
I
C
R
O
LG/B (444)
LBLU (441)
LBLU/B (442)
YB198
YE36
DIAGNOSTIC AIDS:
Check the IAC air passage for possible foreign material.
Code P0507 may also be set by other system faults. Refer to Section 6C1-2B SYMPTOMS, of the VX Series
Service Information for diagnostic by symptoms.
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. The importance of this step cannot be stressed too strongly. It can lead to correcting a problem without
further checks and save valuable time.
4. By r estricting vacuum supply hoses, you are isolating which vacuum circuit m ay have a vac uum leak. When
the leak is stopped, the engine should respond immediately.
DTC P0507 V6 PCM - VACUUM LEAK
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. 1. Ignition Off.
2. Perform a visual/physical check of all the vacuum
hoses and air duct between the Mass Air Flow
Sensor and the throttle body for: Cracks, Splits,
Kinks, Connections and in their proper location.
Was a problem found?
Verify Repair Go to Step 3
3. 1. Ignition "ON", engine running.
2. Listen for a hissing sound as evidence of a vacuum
leak.
Was a problem found?
Verify Repair Go to Step 4
4. 1. Ignition "ON", engine running.
2. Using pliers, restrict each vacuum hose near the
intake manifold and listen for the engine RPM to
change when hoses are restricted.
Did RPM change when with vacuum hoses restricted?
Repair vacuum
leak in hose or
vacuum circuit.
Verify Repair
Go to Step 5
5. Inspect suspect areas of the intake system such as:
• The intake manifold gaskets;
• PCV system;
• Throttle body vacuum hose connections;
• Throttle body gasket;
• Oil dipstick seal and oil fill cap for sources of
unmetered air;
• IACV O-ring;
Was a problem found?
Verify Repair Go to Step 6
6. Clear DTC and drive vehicle.
Does DTC reset? Go to Step 7 Repair Complete
7. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P0530 V6 PCM -
A/C REFRIGERANT PRESSURE SENSOR CIRCUIT FAULT
CIRCUIT DESCRIPTION:
The A/C refrigerant pressure Sensor responds to changes in the A/C refrigerant high side pressure. This input
to the PCM indicates how m uch load the A/C compr essor is putting on the engine and is one of the factors used
by the PCM to determ ine the Idle Air Control (IAC) valve position for idle speed. The circuits consist of a 5 volt
reference and a earth circuit, both provided by the PCM, and a signal circuit from the Sensor to the PCM. The
signal is a voltage which is proportional to A/C pressure. The Sensors operating range is between 0 and 3160
kPa ( 0-468 psi). At 0 kpa, the signal voltage will be about 0.1 volts, varying to about 4.9 volts at 3160 kPa.
CONDITIONS FOR RUNNING THE DTC
• Engine Coolant Temperature is below 119°C.
• Intake Air Temperature is below 90°C.
• Engine RPM is below 2000.
• Engine has been running for less than 10 seconds.
CONDITIONS FOR SETTING THE DTC
• A/C Refrigerant Pressure Sensor signal voltage is greater than 4.9 volts, or less than 0.2 volts.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• W hen DTC P0530 is set, the low speed cooling fan will operate f or 5 seconds, then the high speed fan will
turn "ON, and remain "ON" until the fault is removed.
CONDITIONS FOR CLEARING THE MIL/DTC
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC
DIAGNOSTIC AIDS:
• DTC P0530 will only set with a short to voltage or a open circuit. A short to earth will not set the DTC, but
the A/C system will be inoperative.
• DTC P0530 sets when the signal voltage falls outside the normal possible range of the sensor. Repair any
A/C pressure problems before using this table.
• Any c ircuitry, that is suspec ted as caus ing the interm ittent com plaint, s hould be thoroughly check f or bac k ed
out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to
wiring connections or physical damage to the wiring harness.
• If P0405 and P0530 are set, check for an open Earth circuit 469.
VXPCM001
PCM
M
I
C
R
O
D10
D6
C
B
A
A/C
PRESSURE
SENSOR
C16
SENSOR EARTH
A/C PRESSURE
SENSOR SIGNAL
REFERENCE
VOLTAGE
5V 5V
V/W (415)
B(469)
G/B (259)
TO
IAT AND TFT SENSOR
AND EGR
YE113 YB198
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
3. This s tep c hecks to see if the low voltage s ignal was due to an open in the s ignal circ uit, the 5 volt r ef er ence
circuit or if the PCM is faulty.
4. An open in a shared earth circuit can cause other DTC's to be set. If no other DTC's were set, the circuit
must be open between the sensor and the circuit splice.
8. Determines if the low voltage signal was from the sensor or the signal circuit. Jum pering the signal circuit to
the 5 volt reference checks the circuits, connections and the PCM.
9. An open in a s hared 5 volt r ef erenc e c irc uit c an caus e other DTC's to be s et. If no other DTC's were set, the
circuit must have an open between the sensor and the circuits wiring harness splice.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
A/C PRESSURE SENSOR
YE113
(469)
(415)
(259)
G/B B
V/W
DTC P0530 V6 PCM - A/C REFRIGERANT PRESSURE SENSOR CIRCUIT FAULT
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. 1. Ignition ON, engine OFF.
2. Install scan tool, and display A/C pressure Sensor
voltage.
Is the A/C pressure Sensor voltage at or above the
specified value?
4.0V Go to Step 3 Go to Step 7
3. Disconnect the A/C pressure Sensor electrical
connector.
Does scan tool display A/C pressure Sensor voltage at
or below the specified value?
0.2 V Go to Step 4 Go to Step 11
4. 1. Ignition "OFF".
2. Using test light connected to B+, probe A/C
pressure Sensor earth circuit at harness
electrical connector.
Does test light illuminate?
Go to Step 5 Go to Step 12
5. Check for a poor connection at A/C pressure Sensor.
Was a problem found? Verify Repair Go to Step 6
6. Replace A/C pressure Sensor.
Is action complete? Verify Repair
7. Is the A/C pressure Sensor voltage at or below the
specified value? 0.2 V Go to Step 8 Go to Step 15
8. 1. Disconnect A/C pressure Sensor electrical
connector.
2. Using fused jumper wire, jumper the A/C pressure
Sensor 5 volt reference circuit and signal circuits
together at harness connector.
Does scan tool indicate A/C pressure Sensor voltage at
or above the specified value?
4.0 V Go to Step 6 Go to Step 9
DTC P0530 V6 PCM - A/C REFRIGERANT PRESSURE SENSOR CIRCUIT FAULT (CONTINUED)
STEP ACTION VALUE YES NO
9. 1. Remove the jumper wire.
2. Connect a DVM between the A/C pressure Sensor
5 volt reference circuit and earth circuit at the
harness connector.
Does the DVM read at or between the specified value?
4.0 - 5.0 V Go to Step 10 Go to Step 13
10. Repair open or short to earth in A/C pressure Sensor
signal circuit.
Is action complete?
Verify Repair
11. Check A/C pressure Sensor signal circuit for short to
voltage.
Was a problem found?
Verify Repair Go to Step 14
12. Repair open in earth circuit to A/C pressure Sensor.
Is action complete? Verify Repair
13. Repair open in 5 volt reference circuit.
Is action complete? Verify Repair
14. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
15. 1. Using a scan tool, clear DTC.
2. Start engine and idle at normal operating
temperature.
3. Operate vehicle A/C system and note A/C pressure
Sensor voltage on scan tool.
Is voltage displayed at or between the specified value?
0.2 - 4.6 V System OK,
refer to
Diagnostic Aids
Go to Step 2
DTC P0560 V6 PCM -
SYSTEM VOLTAGE TOO HIGH (LONG TIME)
CIRCUIT DESCRIPTION:
Circuit 39 is the ignition voltage feed circuit to terminal D16 f or the PCM. Circuit 740 is the battery voltage feed
circuit to term inals C12 and D12 for the PCM. W hen the PCM detects a high voltage for a long tim e, then DTC
P0560 sets.
CONDITIONS FOR RUNNING THE DTC
• The ignition is on.
• ECT is at or above 85°C.
CONDITIONS FOR SETTING THE DTC
• The engine is running and the PCM ignition voltage is greater than 16 volts for more than 109 minutes.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• During the time fault is present, the pressure control solenoid is turned "OFF", the transmission shifts
immediately to 3rd gear and TCC operation is inhibited.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
VXPCM017
# 2 # 4 # 6
# 1 # 3 # 5
PCM
C12
D12
E6
F2
E2
E4
F1
E5
C14
D16
BATTERY FEED
BATTERY FEED
O (740)
O (740)
BLU (841)
V (84 3)
GY (845)
INJECTOR CONTROL
IN JECTOR VOLTAGE
MONITOR LINE
IGNITION FEED
O/Y (479)
EFI RELAY
B/W (152)
P (3)
O/B (740)
IGN SW
M
I
C
R
O
R (481)
P (39 )
P/B
(39)
Y (84 6)
BR/Y (844)
G (842)
F31
F14
F34
+-
BATTERY
FS
FJ
R (2H)
(1040)
YE112
YB198
YB198YE112
YE39
YE114
YE39 YB199
YE22
YE22
DIAGNOSTIC AIDS:
• Inspect the wiring for poor electrical connections at the PCM. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
• When diagnosing for an inter m ittent short or open c ondition, m ass age the wiring harness while watc hing the
test equipment for a change.
• Charging the battery with a battery charger may set DTCs. Jump starting an engine may set DTCs.
• If DT Cs set when you operate an acces sory, inspect the applicable wiring for f aulty connections. Inspect the
wiring for excessive current draw.
• Inspect the following items for faulty connections:
- The starter solenoid
- The fusible link
- The generator terminals
- Battery cables
• Inspect the belts for excessive wear. Inspect the belts for proper tension.
TEST DESCRIPTION:
The numbers below refer to the step numbers on the diagnostic Table.
4. This step tests the charging system voltage.
1. This step tests PCM battery voltage.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
YB66
INSTRUMENTS
T
BLU/B
BR/W
(234)
(25)
(14)
(10)
(875)
(155)
(1340)
G/W
(44)
(121)
(8)
(30)
BLU/Y
G
O/Y
P/BLU
BR/R
V/W
(33)
(946)
(1220)
(88)
(15)
(123)
(85)
(19)
GY
W
V/R
BR
BR/O
Y/R
B/Y
LBLU
BLU
DTC P0560 V6 PCM - SYSTEM VOLTAGE TOO HIGH (LONG TIME)
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs, use the scan
tool in order to record the DTC history. The Clear Info
function will erase the data.
3. Record the DTC history.
4. Using the J 39200 DVM, measure the battery voltage
across the battery terminals. Record the
measurement for future reference.
Is the voltage higher than the specified value?
10 volts Go to Step 3 Go to Battery
Diagnosis
3 1. Start the engine.
2. Warm the engine to the operating temperature.
Is the generator/check engine light ON?
85°C Go to Charging
System
Diagnosis
Go to Step 4
4 1. Increase the engine speed to 2000 RPM for 15
seconds.
2. Observe the DVM battery voltage.
Is the DVM battery voltage greater than the specified
value?
15 volts Go to Charging
System
Diagnosis
Go to Step 5
5 1. Increase the engine speed to 2000 RPM.
2. Observe the scan tool Battery Voltage.
Is the scan tool Battery Voltage greater than the specified
value?
15.5 volts Go to Step 6 System Checks
OK, Go to
“Diagnostic Aids”
above
6 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 7
7 In order to verify your repair, perform the following
procedure:
1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle under the following conditions:
• Start the vehicle.
• Warm the engine to normal operating
temperature.
Is the scan tool Battery Voltage within the specified
range?
13-15.5 volts System OK Go to Step 2
DTC P0561 V6 PCM -
SYSTEM VOLTAGE UNSTABLE
CIRCUIT DESCRIPTION:
Diagnostic Trouble Code (DTC) P0561 will set when the ignition is "ON" and PCM terminal "D16" voltage
changed more than 2.5 volts in 100 milliseconds.
CONDITIONS FOR RUNNING THE DTC
• The ignition is on.
• Conditions present for at least 10 seconds.
CONDITIONS FOR SETTING THE DTC
• System voltage changes more than 2.5 volts in 100 millivolts.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P0561 sets, the PCM turns off all transmission output devices, and freezes shift adapts from
being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
VXPCM017
# 2 # 4 # 6
# 1 # 3 # 5
PCM
C12
D12
E6
F2
E2
E4
F1
E5
C14
D16
BATTERY FEED
BATTERY FEED
O (740)
O (740)
BLU (841)
V (84 3)
GY (845)
INJECTOR CONTROL
IN JECTOR VOLTAGE
MONITOR LINE
IGNITION FEED
O/Y (479)
EFI RELAY
B/W (152)
P (3)
O/B (740)
IGN SW
M
I
C
R
O
R (481)
P (39 )
P/B
(39)
Y (84 6)
BR/Y (844)
G (842)
F31
F14
F34
+-
BATTERY
FS
FJ
R (2H)
(1040)
YE112
YB198
YB198YE112
YE39
YE114
YE39 YB199
YE22
YE22
DIAGNOSTIC AIDS:
• Inspect the wiring for poor electrical connections at the PCM. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
• When attempting to diagnose an intermittent problem, use the snapshot mode of the Tech 2 scan tool, to
review diagnostic information.
• Charging the battery with a battery charger may set DTCs. Jump starting an engine may set DTCs.
• If DT Cs set when you operate an acces sory, inspect the applicable wiring for f aulty connections. Inspect the
wiring for excessive current draw.
• Inspect the following items for faulty connections:
- The starter solenoid
- The fusible link
- The generator terminals
- Battery cables
• Inspect the belts for excessive wear. Inspect the belts for proper tension.
TEST DESCRIPTION:
The numbers below refer to the step numbers on the diagnostic Table.
2. Diagnostic Trouble Code P0561 will set if: The last 25% of the samples for ignition feed voltage changes
more than 2.5 volts in 100 milliseconds.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
DTC P0561 V6 PCM - SYSTEM VOLTAGE UNSTABLE
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. 1. Install Tech 2 scan tool and set up snapshot
mode to trigger on DTC P0561.
2. Ignition "ON".
3. Wiggle the PCM connector.
Does "System Voltage" reading change sharply as
Connector is wiggled?
Go to Step 7
Go to Step 3
DTC P0561 V6 PCM - SYSTEM VOLTAGE UNSTABLE (CONTINUED)
STEP ACTION VALUE YES NO
3. Wiggle and tug the harness at the PCM.
Does "System Voltage" reading change sharply as
harness is wiggled?
Go to Step 7 Go to Step 4
4. Lightly tap on the PCM.
Does "System Voltage" reading change sharply as PCM
is tapped?
Go to Step 5 DTC P0561 is
intermittent. If no
additional DTC's
were stored, refer
to "Diagnostic
Aids" above.
5. Verify that PCM is securely mounted to vehicle
Is PCM securely mounted? Go to Step 6
Verify Repair
6. Replace PCM.
Refer to Section 6C1-3 SERVICE OPERATIONS of the
VX Series Service Information, for PCM Programming
and Security Link procedure.
Is action complete?
Verify Repair
7. Check PCM connector for corrosion.
Is corrosion present? Go to Step 8
Go to Step 9
8. Clean corroded terminals with electronic part cleaner.
Is action complete? Verify Repair
9. Check tightness of the female terminal grip with a spare
male terminal.
Are terminals tight?
Go to Step 10 Verify Repair
10. Remove PCM connector strain relief and remove terminal
from connector to check for broken or bent locking tang.
Is locking tang OK?
Find intermittent
open in
powertrain wiring
harness.
Replace terminal
DTC P0562 V6 PCM -
SYSTEM VOLTAGE LOW
CIRCUIT DESCRIPTION:
Circuit 39 is the ignition voltage feed circuit to terminal D16 f or the PCM. Circuit 740 is the battery voltage feed
circuit to terminals C12 and D12 for the PCM. W hen the PCM detects a low voltage for a short period of time,
then DTC P0562 sets.
CONDITIONS FOR RUNNING THE DTC
• The ignition is on.
• Conditions present for at least 4 seconds.
CONDITIONS FOR SETTING THE DTC
• The system voltage is less than 7.3 volts with the TFT at or above -40°C.
Or
• The system voltage is less than 10 volts with the TFT at or below 151°C.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P0562 sets, the PCM turns off all transmission output devices, and freezes shift adapts from
being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
VXPCM017
# 2 # 4 # 6
# 1 # 3 # 5
PCM
C12
D12
E6
F2
E2
E4
F1
E5
C14
D16
BATTERY FEED
BATTERY FEED
O (740)
O (740)
BLU (841)
V (84 3)
GY (845)
INJECTOR CONTROL
IN JECTOR VOLTAGE
MONITOR LINE
IGNITION FEED
O/Y (479)
EFI RELAY
B/W (152)
P (3)
O/B (740)
IGN SW
M
I
C
R
O
R (481)
P (39 )
P/B
(39)
Y (84 6)
BR/Y (844)
G (842)
F31
F14
F34
+-
BATTERY
FS
FJ
R (2H)
(1040)
YE112
YB198
YB198YE112
YE39
YE114
YE39 YB199
YE22
YE22
DIAGNOSTIC AIDS:
• Inspect the wiring for poor electrical connections at the PCM. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
• When attempting to diagnose an intermittent problem, use the snapshot mode of the Tech 2 scan tool, to
review diagnostic information.
• Inspect the belts for excessive wear. Inspect the belts for proper tension.
• Minimu m voltage allowed for Diagnostic T rouble Code P0562 to s et is on a graduated s cale and will change
with temperature. Minimum voltage at - 40 degrees C is 7.3 volts, minimum voltage at 151 degrees C is
10.0 volts, 8.6 volts is the minimum voltage at 90 degrees C.
TEST DESCRIPTION:
The numbers below refer to the step numbers on the diagnostic Table.
4. This step tests the charging system voltage.
6. This step tests for proper voltage to the PCM on circuits 39 and 740.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
YB66
INSTRUMENTS
T
BLU/B
BR/W
(234)
(25)
(14)
(10)
(875)
(155)
(1340)
G/W
(44)
(121)
(8)
(30)
BLU/Y
G
O/Y
P/BLU
BR/R
V/W
(33)
(946)
(1220)
(88)
(15)
(123)
(85)
(19)
GY
W
V/R
BR
BR/O
Y/R
B/Y
LBLU
BLU
DTC P0562 V6 PCM - SYSTEM VOLTAGE LOW
STEP ACTION VALUE YES NO
1. Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2. 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs, use the scan
tool in order to record the DTC history for reference. The
Clear Info function will erase the data.
3. Record the DTC history.
4. Using the J 39200 DVM, measure the battery voltage
across the battery terminals.
Is the voltage higher than the specified value?
10 volts Go to Step 3 Go to Battery
Diagnosis,
3. 1. Start the engine.
2. Warm the engine to normal operating temperature.
Is the generator/check engine light ON?
Go to Charging
System
Diagnosis
Go to Step 4
DTC P0562 V6 PCM - SYSTEM VOLTAGE LOW (CONTINUED)
STEP ACTION VALUE YES NO
4. 1. Turn on the headlights and the heater blower motor.
2. Increase the engine speed to 1500 RPM.
3. Observe the DVM battery voltage and record your
reading for reference.
Is the DVM voltage within the specified range?
13-15 volts Go to Step 5 Go to Charging
System
Diagnosis
5. 1. Increase the engine speed to 1500 RPM.
2. Observe the scan tool battery voltage.
Is the scan tool Battery Voltage within the specified
range?
13-15 volts System Checks
OK, Go to
“Diagnostic Aids”
above
Go to Step 6
6. 1. Turn the ignition switch to OFF position.
2. Locate terminals D16, C12 and D12 in the PCM
connector (24 pin). Do not disconnect the PCM
connector.
3. Connect the DVM black lead to earth.
4. Start the engine.
5. Run the engine at 1500 RPM with the headlights and
the blower motor on.
6. Using the J 39200 DVM and J 35616 Connector Test
Adapter Kit, backprobe terminals D16, C12 and D12
to measure the battery voltage input at the PCM
connector.
Is there a voltage variance between the voltage
measured at the battery (taken in Step 4) and at terminals
D16, C12 and D12 that is greater than the specified
value?
0.5 volts Go to Step 7 Go to Step 10
7. Does terminal D16 (circuit 39) have the voltage variance? Go to Step 8 Go to Step 9
8. Repair the high resistance condition in circuit 39.
Is the action complete? Go to Step 11
9. Repair the high resistance condition in circuit 740.
Is the action complete? Go to Step 11
10. Replace PCM.
Refer to Section 6C1-3 SERVICE OPERATIONS of the
VX Series Service Information, for PCM Programming
and Security Link procedure.
Is action complete?
Go to Step 11
11. In order to verify your repair, perform the following
procedure:
Operate the vehicle under the following conditions:
• Start the vehicle.
• Warm the engine to normal operating
temperature.
Is the scan tool Battery Voltage within the specified
range?
13-15.5 volts System OK Begin the
diagnosis again.
Go to Step 1
DTC P0563 V6 PCM -
SYSTEM VOLTAGE TOO HIGH
CIRCUIT DESCRIPTION:
Circuit 39 is the ignition voltage feed circuit to terminal D16 f or the PCM. Circuit 740 is the battery voltage feed
circuit to terminals C12 and D12 f or the PCM. When the PCM detects a HIG H voltage for a s hort period of tim e,
then DTC P0563 sets.
CONDITIONS FOR RUNNING THE DTC
• The ignition is on.
• ECT is at or above 85°C.
• Conditions present for at least 4 seconds.
CONDITIONS FOR SETTING THE DTC
• Voltage at PCM ignition feed terminal is more than 19.5 volts for more than 2 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P0563 sets, the PCM turns off all transmission output devices, and freezes shift adapts from
being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
VXPCM017
# 2 # 4 # 6
# 1 # 3 # 5
PCM
C12
D12
E6
F2
E2
E4
F1
E5
C14
D16
BATTERY FEED
BATTERY FEED
O (740)
O (740)
BLU (841)
V (84 3)
GY (845)
INJECTOR CONTROL
IN JECTOR VOLTAGE
MONITOR LINE
IGNITION FEED
O/Y (479)
EFI RELAY
B/W (152)
P (3)
O/B (740)
IGN SW
M
I
C
R
O
R (481)
P (39 )
P/B
(39)
Y (84 6)
BR/Y (844)
G (842)
F31
F14
F34
+-
BATTERY
FS
FJ
R (2H)
(1040)
YE112
YB198
YB198YE112
YE39
YE114
YE39 YB199
YE22
YE22
DIAGNOSTIC AIDS:
• Inspect the wiring for poor electrical connections at the PCM. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
• When diagnosing for an inter m ittent short or open c ondition, m ass age the wiring harness while watc hing the
test equipment for a change.
• Charging the battery with a battery charger may set DTCs. Jump starting an engine may set DTCs.
• If DT Cs set when you operate an acces sory, inspect the applicable wiring for f aulty connections. Inspect the
wiring for excessive current draw.
• Inspect the following items for faulty connections:
- The starter solenoid
- The fusible link
- The generator terminals
- Battery cables
• Inspect the belts for excessive wear. Inspect the belts for proper tension.
TEST DESCRIPTION:
The numbers below refer to the step numbers on the diagnostic Table.
4. This step tests the charging system voltage.
5. This step checks battery voltage of the PCM, using the scan tool.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
DTC P0563 V6 PCM - SYSTEM VOLTAGE TOO HIGH
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs, use the scan
tool in order to record the DTC history. The Clear Info
function will erase the data.
3. Record the DTC history.
4. Using the J 39200 DVM , measure the battery v oltage
across the battery terminals. Record the
measurement for future reference.
Is the voltage higher than the specified value?
10 volts Go to Step 3 Go to Battery
Diagnosis
3 1. Start the engine.
2. Warm the engine to the operating temperature.
Is the generator/check engine light ON?
85°C Go to Charging
System
Diagnosis in
Section 6D1-1 of
the VX Series
Service
Information
Go to Step 4
4 1. Increase the engine speed to 2000 RPM for 15
seconds.
2. Observe the DVM battery voltage and record your
reading.
Did the DVM battery voltage exceed the specified value?
16.0 volts Go to Charging
System
Diagnosis
Section 6D1-1 of
the VX Series
Service
Information
Go to Step 5
5 1. Increase the engine speed to 2000 RPM.
2. Observe the scan tool Battery Voltage.
Is the scan tool Battery Voltage within 0.5 volts of your
recorded voltage in step 4?
System Checks
OK, Go to
“Diagnostic Aids”
above
Go to Step 6
6 Replace PCM.
Refer to Section 6C1-3 SERVICE OPERATIONS of the
VX Series Service Informationof the VX Series Service
Information, for PCM Programming and Security Link
procedure.
Is action complete?
Go to Step 7
7 In order to verify your repair, perform the following
procedure:
1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle under the following conditions:
• Start the vehicle.
• Warm the engine to normal operating
temperature.
Is the scan tool Battery Voltage within the specified
range?
13-15.5 volts System OK Begin the
diagnosis again.
Go to Step 1
4226
1
DTC P0601 V6 PCM -
POWERTRAIN CONTROL MODULE (PCM) MEMORY
CIRCUIT DESCRIPTION
The PCM EEPROM contains data which is essential to running the engine and transmission. The PCM
continuously checks the integrity of this data.
CONDITIONS FOR RUNNING THE DTC
• The ignition switch is in the crank position or the run position.
CONDITIONS FOR SETTING THE DTC
• The PCM is unable to correctly read data from the EEPROM (flash memory).
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS
• Replace the PCM even if this DTC exists only in history.
• For an intermittent, Refer to Section 6C1-2B Symptoms of the VX Series Service Information.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. This DTC indicates an internal PCM problem.
DTC P0601 V6 PCM - POWERTRAIN CONTROL MODULE (PCM) MEMORY
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 3
3. 1. Install the scan tool.
2. Operate the vehicle within the Conditions for
Running the DTC as specified in the supporting text.
Does the scan tool indicate that this DYC reset?
Go to Step 2 Go to Step 4
4. Using the scan tool, check for any other DTCs.
Does the scan tool display and DTCs that you have not
diagnosed?
Go to applicable
DTC table System OK
DTC P0712 V6 PCM -
TRANSMISSION FLUID TEMPERATURE (TFT) SIGNAL VOLTAGE LOW
CIRCUIT DESCRIPTION
The Autom atic T ransm ission Fluid T emper ature (TF T) sens or is a therm istor within the Automatic Transm ission
Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.). The TFT sensor controls the signal
voltage to the PCM. The PCM supplies a 5-volt reference signal to the sensor on circuit 1227. When the
transm ission f luid is cold, the sensor resistance will be high. The PCM will then detect a high s ignal voltage. As
the transmission fluid temperature increases to the normal operating temperature, the sensor resistance
becomes less and the voltage decreases.
When the PCM detects a continuous short to earth in the TFT signal circuit or in the TFT sensor, then a DTC
P0712 will set.
CONDITIONS FOR RUNNING THE DTC
• The ignition switch is on.
CONDITIONS FOR SETTING THE DTC
• The TFT sensor indicates a signal voltage less than 0.2 volts for 10 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When this DTC sets , the PCM uses a transm iss ion fluid tem peratur e default value based on engine coolant,
engine run time and IAT at startup, the PCM will freeze shift adapts from being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
VXPCM034
PCM
F11
F12
D13
D6
TFP SIGNAL A
TFP SIGNAL B
TRANSMISSION FLUID
TEMPERATURE (TFT)
SENSOR SIGNAL
SENSOR EARTH
N
C
R
E
D
A
B
P
L
M
TRANSMISSION FLUID
TEMPERATURE
(TF T ) SENSOR
AUTOMATIC TRANSMISSION FLUID
PRESSURE SWITCH ASSEMBLY
BR/Y (1224)
Y (1225)
GY (1226)
B/Y (1227)
B (46 9)
12V
12V
5V
F13 TFP SIGNAL C
12V
M
I
C
R
O
TO
A
/C PRESSURE SENSOR
AND IAT SENSOR
YB199
YB187
YB198
YB129
DIAGNOSTIC AIDS
• Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical
connections at the transmission pass-through connector. Look for the following conditions:
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Corrosion
• When diagnosing for an inter m ittent short or open c ondition, m ass age the wiring harness while watc hing the
test equipment for a change.
• Use the Temperature vs Resistance table when testing the T FT sensor at various temperature levels. T est
the TFT sensor in order to evaluate the possibility of a skewed (mis-scaled) sensor. A skewed sensor can
result in delayed garage shifts or TCC complaints.
• The s can tool can display the transm ission fluid tem perature in degrees. After the transm ission is operating,
the fluid temperature should rise steadily to a normal operating temperature, then stabilise.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. This step tests for a short to earth or a skewed sensor.
4. This step creates an open within the transmission in order to test for an internal fault.
TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR TEMPERATURE TO RESISTANCE TA BLE
Temperature TFT Resistance Signal
Degrees °C Minimum Ω
ΩΩ
Ω Normal Ω
ΩΩ
Ω Maximum Ω
ΩΩ
Ω Volts
-40 90636 100707 110778 5.0
-30 47416 52684 57952 4.78
-20 25809 28677 31545 4.34
-10 14558 16176 17784 3.89
0 8481 9423 10365 3.45
10 5104 5671 6238 3.01
20 3164 3515 3867 2.56
30 2013 2237 2461 1.8
40 1313 1459 1605 1.1
50 876 973 1070 3.25
60 600 667 734 2.88
70 420 467 514 2.56
80 299 332 365 2.24
90 217 241 265 1.7
100 159 177 195 1.42
110 119 132 145 1.15
120 89.9 99.9 109.9 0.87
130 69.1 76.8 84.5 0.6
140 53.8 59.8 65.8 0.32
150 42.5 47.2 51.9 0
A shunt in the PCM becomes active as the transmission temperature increases beyond
50 °C. As the temperature decreases, the internal shunt deactivates at 40 °C.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
DTC P0712 V6 PCM - TRA NSMISSION FLUID TEMPERATURE (TFT) SIGNAL VOLTAGE LOW
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2 Perform the transmission fluid checking procedure.
Have you performed the fluid checking procedure?
Go to Step 3 Go to
Transmission
Fluid Checking
Procedure
3 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs use the scan tool
in order to record the DTC history. The Clear Info function
will erase the data.
3. Record the DTC history.
Does the scan tool display a TFT voltage less than the
specified value?
0.33 volts Go to Step 4 Go to
“Diagnostic Aids”
above
4 1. Turn the ignition OFF.
2. Disconnect the transmission pass-through connector.
3. With the engine OFF, turn the ignition switch to the
RUN position.
Does the scan tool display a TFT voltage greater than the
specified value?
4.92 volts Go to Step 5 Go to Step 9
5 1. Install the J 39775 Jumper Harness on the
transmission side of the pass-through connector.
2. Using the J 39200 DVM and J 35616 Connector Test
Adapter Kit, measure the resistance between terminal
L and terminal M.
Is the resistance within specifications?
3088-3942Ω
@ 20° C
159-198Ω
@100° C
Go to
“Diagnostic Aids”
above
Go to Step 6
6 1. Check the internal Automatic Transmission Wiring
Harness Assembly for a short to earth.
2. Replace the harness if necessary.
Did you find and correct the problem?
Go to Step 11 Go to Step 7
7 1. Disconnect the internal Automatic Transmission
Wiring Harness Assembly at the TFT sensor.
2. Measure the resistance of the TFT sensor.
Is the resistance within specifications?
3088-3942Ω
@ 20° C
159-198 Ω @
100° C
Go to
“Diagnostic Aids”
above
Go to Step 8
8 Replace the TFT Sensor (this is part of the TFP Val.
Position Sw.). Refer to Section 6C1-3 Service Operations
of the VX Series Service Information.
Is the action complete?
Go to Step 11
DTC P0712 V6 PCM - TRA NSMISSION FLUID TEMPERATURE (TFT) SIGNAL VOLTAGE LOW (CONT)
STEP ACTION VALUE YES NO
9 Check circuit 1227 for a short to earth. Repair the circuit if
necessary.
Did you find a problem?
Go to Step 11 Go to Step 10
10 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 11
11 In order to verify your repair, perform the following
procedure:
1. Select DTC.
2. Select Clear Info.
3. With the engine OFF, turn the ignition switch to the
RUN position.
Does the scan tool indicate a TFT voltage greater than the
specified value?
0.33 volts System OK Begin the
diagnosis again.
Go to Step 1
DTC P0713 V6 PCM
TRANSMISSION FLUID TEMPERATURE (TFT) SIGNAL VOLTAGE HIGH
CIRCUIT DESCRIPTION
The Autom atic T ransm ission Fluid T emper ature (TF T) sens or is a therm istor within the Automatic Transm ission
Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.). The TFT sensor controls the signal
voltage to the PCM. The PCM supplies a 5-volt reference signal to the sensor on circuit 1227. When the
transm ission f luid is cold, the sensor resistance will be high. The PCM will then detect a high s ignal voltage. As
the transmission fluid temperature increases to the normal operating temperature, the sensor resistance
becomes less and the voltage decreases.
When the PCM detects a c ontinuous open or s hor t to voltage in the T F T s ignal c ircuit or in the TFT s ensor , then
a DTC P0713 will set.
CONDITIONS FOR RUNNING THE DTC
• The ignition switch is on.
CONDITIONS FOR SETTING THE DTC
• The TFT sensor indicates a signal voltage greater than 4.92 volts for 6.8 minutes (409 seconds).
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When this DTC sets , the PCM uses a transm iss ion fluid tem peratur e default value based on engine coolant,
engine run time and IAT at startup, the PCM will freeze shift adapts from being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
VXPCM034
PCM
F11
F12
D13
D6
TFP SIGNAL A
TFP SIGNAL B
TRANSMISSION FLUID
TEMPERATURE (TFT)
SENSOR SIGNAL
SENSOR EARTH
N
C
R
E
D
A
B
P
L
M
TRANSMISSION FLUID
TEMPERATURE
(TF T ) SENSOR
AUTOMATIC TRANSMISSION FLUID
PRESSURE SWITCH ASSEMBLY
BR/Y (1224)
Y (1225)
GY (1226)
B/Y (1227)
B (46 9)
12V
12V
5V
F13 TFP SIGNAL C
12V
M
I
C
R
O
TO
A
/C PRESSURE SENSOR
AND IAT SENSOR
YB199
YB187
YB198
YB129
DIAGNOSTIC AIDS
• Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical
connections at the transmission pass-through connector. Look for the following conditions:
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Corrosion
• Corrosion when diagnosing for an intermittent short or open condition, massage the wiring harness while
watching the test equipment for a change.
• Use the Temperature vs Resistance table when testing the T FT sensor at various temperature levels. T est
the TFT sensor in order to evaluate the possibility of a skewed (mis-scaled) sensor. A skewed sensor can
result in delayed garage shifts or TCC complaints.
• The s can tool can display the transm ission fluid tem perature in degrees. After the transm ission is operating,
the fluid temperature should rise steadily to a normal operating temperature, then stabilise.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3 This step verifies that a problem exists in the TFT sensor circuit.
4 This s tep s imulates a T F T s ens or DTC P0712. If the PCM r ec ognises high temperatur e, the PCM and wiring
are functioning normally.
5 This step tests the TFT sensor and Automatic Transmission Wiring Harness Assembly.
TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR TEMPERATURE TO RESISTANCE TA BLE
Temperature TFT Resistance Signal
Degrees °C Minimum Ω
ΩΩ
Ω Normal Ω
ΩΩ
Ω Maximum Ω
ΩΩ
Ω Volts
-40 90636 100707 110778 5.0
-30 47416 52684 57952 4.78
-20 25809 28677 31545 4.34
-10 14558 16176 17784 3.89
0 8481 9423 10365 3.45
10 5104 5671 6238 3.01
20 3164 3515 3867 2.56
30 2013 2237 2461 1.8
40 1313 1459 1605 1.1
50 876 973 1070 3.25
60 600 667 734 2.88
70 420 467 514 2.56
80 299 332 365 2.24
90 217 241 265 1.7
100 159 177 195 1.42
110 119 132 145 1.15
120 89.9 99.9 109.9 0.87
130 69.1 76.8 84.5 0.6
140 53.8 59.8 65.8 0.32
150 42.5 47.2 51.9 0
A shunt in the PCM becomes active as the transmission temperature increases beyond
50 °C. As the temperature decreases, the internal shunt deactivates at 40 °C.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
DTC P0713 V6 PCM - TRA NSMISSION FLUID TEMPERATURE (TFT) SIGNAL VOLTAGE HIGH
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2 Perform the transmission fluid checking procedure.
Have you performed the fluid checking procedure?
Go to Step 3 Go to
Transmission
Fluid Checking
Procedure
3 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs, use the scan
tool in order to record the DTC history for reference. The
Clear Info function will erase the data.
3. Record the DTC history.
Does the scan tool display a TFT Sensor voltage greater
than the specified value?
4.92 volts Go to Step 4 Go to “Diagnostic
Aids” above
4 1. Turn the ignition OFF. 0.2 volts Go to Step 5 Go to Step 9
5 1. Turn the ignition OFF.
2. Install the J 39775 Jumper Harness on the
transmission side of the pass-through connector.
3. Using the J 39200 DVM and J 35616 Connector Test
Adapter Kit, measure the resistance between
terminal L and terminal M.
Is the resistance within specification?
3088-3942 Ω
at 20° C
159-198 Ω
at 100° C
Go to
“Diagnostic Aids”
above
Go to Step 6
6 1. Check the internal Automatic Transmission Wiring
Harness Assembly for a open condition.
2. Replace the harness if necessary.
Did you find and correct the problem?
Go to Step 12 Go to Step 7
7 1. Disconnect the internal Automatic Transmission
Wiring Harness Assembly at the TFT sensor.
2. Measure the resistance of the TFT sensor.
Is the resistance within specifications?
3088-3942 Ω
at 20° C
159-198 Ω at
100° C
Go to
“Diagnostic Aids”
above
Go to Step 8
DTC P0713 V6 PCM - TRANSMISSION FLUID TEMPERATURE (TFT) SIGNAL VOLTAGE HIGH (CONT.)
STEP ACTION VALUE YES NO
8 Replace the TFT Sensor (this is part of the TFP Val.
Position Sw.). Refer to Service Operations in Section
6C1-3 Service Operations of the VX Series Service
Information.
Is the replacement complete?
Go to Step 12
9 Check circuit 1227 for an open or short to B+. Repair the
circuit if necessary.
Did you find a problem?
Go to Step 12 Go to Step 10
10 Check circuit 469 for an open. Repair the circuit if
necessary.
Did you find a problem?
Go to Step 12 Go to Step 11
11 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 12
12 In order to verify your repair, perform the following
procedure:
1. Select DTC.
2. Select Clear Info.
3. With the engine OFF, turn the ignition switch to the
RUN position.
Does the scan tool indicate a TFT voltage less than the
specified value?
4.92 volts System OK Begin the
diagnosis again.
Go to Step 1
DTC P0730 V6 PCM -
2-3 SHIFT SOLENOID B CIRCUIT VOLTAGE HIGH
CIRCUIT DESCRIPTION
The 2- 3 Shift Solenoid Valve (2-3 SS Valve) controls the f luid flow acting on the 1-2 and 3-4 sh ift valves. T he 2-
3 SS Valve is a norm ally-open exhaust valve that is used with the 1-2 Shif t Solenoid Valve in order to allow four
diff erent shifting combinations . The s olenoid attaches to the control valve body within the transmiss ion. The 2-3
SS Valve receives voltage through circuit 339. The PCM controls the solenoid by providing the ground path on
circuit 1223.
When the PCM detects a short to voltage in the 2-3 SS Valve circuit or the 2-3 SS Valve, then DTC P0730 sets.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
CONDITIONS FOR SETTING THE DTC
• The PCM commands the solenoid ON and the voltage input remains high (B+).
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When this DT C sets, the PCM will com m and D2 line pres sure, T he PCM inhibits 3- 2 downshift if the vehicle
speed is greater than 48 km/h, The PCM will freeze shift adapts from being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
3–2 Downshift
Control
Solenoid
1–2 Shift
Solenoid A
2–3 Shift
Solenoid B
YB 129 Transmission
Pass-Thru Connector
Torque
Converter
Clutch (TCC)
(PWM)
Solenoid
Torque
Converter
Clutch (TCC)
Enable
Solenoid
Pressure
Control
Solenoid
A
B
A
B
4284
A
B
A
B
EF32
EFI
Relay
P/ BLU (339)
G/W (897)
LG (1222)
Y/B (1223)
GY/R (422)
BR (418)
R (1228)
GY/BLU (1229)
A1 3–2 Cont r ol
Solenoid
1–2 Shift
Solenoid
2–3 Shift
Solenoid
TCC Enable
Solenoid
TCC PWM
Solenoid
Pressure Control
Solenoid High
Pressure Control
Solenoid Low
B1
A2
A12
A11
E9
E13
S
A
B
T
U
C
D
A
B
A
B
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
YE110
YB187
YB199
DIAGNOSTIC AIDS
Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections
at the transmission pass-through connector. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
• Moisture intrusion when diagnosing for an intermittent short or open condition, massage the wiring harness
while watching the test equipment for a change.
• Refer to the following Table for the correct On and Off states of the shift solenoids.
GEAR 1-2-SHIFT
SOLENOID 2-3 SHIFT
SOLENOID
1 ON ON
2 OFF ON
3 OFF OFF
4 ON OFF
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step tests the function of the 2-3 SS valve and the automatic transmission wiring harness assembly.
3. This step tests the ability of the PCM and the wiring to control the earth circuit.
YB187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
ENGINE CONNECTOR 1
YE110
O/W
(304)
(1426)
BLU/W
G/W
(339)
P/BLU
(465)
(123)
V/W
(1427)
B/W
Y
(1049)
DTC P0730 V6 PCM - 2-3 SHIFT SOLENOID B CIRCUIT VOLTAGE HIGH
Step Action Value(s) Yes No
1 Was the Powertrain On-Board Diagnostic (OBD) System
Check performed? Go to Step 2 Go to Powertrain
OBD System
Check Table.
2 Using the transmission Miscellaneous Tests function on
the Scan Tool, command the 2-3 SS valve ON and OFF
three times while listening to the bottom of the
transmission pan (a stethoscope may be necessary).
Did the solenoid click when commanded?
Go to
Diagnostic Aids Go to Step 3
3 1. Turn the ignition OFF.
2. Disconnect the transmission 20-way (YB 129)
connector (additional DTCs may set).
3. Install the J 39775 jumper harness on the engine
side of the 20-way (YB 129) connector.
4. Install a test lamp from J 39775 jumper harness
cavity E to cavity B.
5. Using the transmission Miscellaneous Tests function
on the Scan Tool, command the 2-3 SS valve ON
and OFF three times.
Is the test lamp ON when the 2-3 SS valve is
commanded ON, and OFF when commanded OFF?
Go to Step 6 Go to Step 4
DTC P0730 V6 PCM - 2-3 SHIFT SOLENOID B CIRCUIT VOLTAGE HIGH (CONTINUED)
Step Action Value(s) Yes No
4 1. Inspect circuit 1223 (Y/B) of the powertrain wiring
harness for a short to voltage condition.
2. Repair the circuit if necessary.
Did you find a short to voltage condition?
Go to Step 12 Go to Step 5
5 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step12
6 1. Install the J 39775 jumper harness on the
transmission side of the 20-way (YB 129) connector.
2. With the J 39200 digital multimeter (DMM) and the
J 35616 connector test adapter kit, measure the
resistance between terminals B and E.
Is the resistance within the range indicated?
19-31 Ω Go to Step 8 Go to Step 7
7 1. Disconnect the A/T wiring harness assembly from
the 2-3 SS valve.
2. Measure the resistance of the 2-3 SS valve.
Is the resistance within the range indicated?
19-31 Ω Go to Step 10 Go to Step 11
8 Using the J 39200 DMM, measure the resistance
between terminal B and earth, and between terminal E
and earth.
Are both readings greater than the specified value?
250 K Ω Go to Diagnostic
Aids Go to Step 9
9 1. Disconnect the A/T wiring harness assembly from
the 2-3 SS valve.
2. Using the J 39200 DMM, measure the resistance
from the component's terminals to earth.
Are both readings greater than the specified value?
250 K Ω Go to Step 10 Go to Step 11
10 Replace the automatic transmission wiring harness
assembly.
Refer to Control Valve Body and Wiring Harness
replacement in Section 7C5-5 in VX Service Information.
Is the replacement complete?
Go to Step 12
11 Replace the 2-3 SS valve. Refer to Service Operations in
Section 6C1-3 of the VX Series Service Information.
Is the replacement complete?
Go to Step 12
12 Perform the following procedure in order to verify the
repair:
Drive the vehicle in D and ensure the following conditions
are met:
- The PCM commands the 2-3 SS valve ON and the
voltage input drops to zero.
- The PCM commands the 2-3 SS valve OFF and the
voltage input increases to B+.
- All conditions are met for 5 seconds.
Were the above conditions verified?
System OK Go to Step 1
DTC P0740 V6 PCM -
TORQUE CONVERTER CLUTCH (TCC) ENABLE SOLENOID CIRCUIT FAULT
CIRCUIT DESCRIPTION
The torque converter clutch (TCC) solenoid valve is an electrical device that is used with the torque converter
clutch pulse width modulation (TCC PW M) solenoid valve in order to control TCC apply and release. The TCC
solenoid valve attaches to the transmission case assembly extending into the pump cover. The TCC solenoid
valve receives ignition voltage through circuit 339. The powertrain control module (PCM) controls the solenoid
by providing the earth path on circuit 422. The PCM monitors the throttle position (TP) voltage, the vehicle
speed and other inputs in order to determine when to energise the TCC solenoid valve.
When the PCM detects a continuous open or a short to earth in the TCC solenoid valve circuit or in the TCC
solenoid valve, then DTC P0740 sets.
CONDITIONS FOR RUNNING THE DTC
• The system voltage is 8-18 volts.
• The engine speed is greater than 300 RPM for 5 seconds.
• The engine is not in fuel cutoff.
CONDITIONS FOR SETTING THE DTC
• DTC P0740 sets if either of the following conditions occurs for 5 seconds:
- The PCM commands the solenoid ON and the voltage input remains high (B+).
- The PCM commands the solenoid OFF and the voltage input remains low (0 volt).
ACTION TAKEN WHEN THE DTC SETS
• The PCM does not illuminate the check powertrain lamp (MIL).
• 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 stores DTC P0740 in PCM history during the second consecutive trip in which the conditions for
setting the DTC are met.
3–2 Downshift
Control
Solenoid
1–2 Shift
Solenoid A
2–3 Shift
Solenoid B
YB 129 Transmission
Pass-Thru Connector
Torque
Converter
Clutch (TCC)
(PWM)
Solenoid
Torque
Converter
Clutch (TCC)
Enable
Solenoid
Pressure
Control
Solenoid
A
B
A
B
4284
A
B
A
B
EF32
EFI
Relay
P/ BLU (339)
G/W (897)
LG (1222)
Y/B (1223)
GY/R (422)
BR (418)
R (1228)
GY/BLU (1229)
A1 3–2 Cont r ol
Solenoid
1–2 Shift
Solenoid
2–3 Shift
Solenoid
TCC Enable
Solenoid
TCC PWM
Solenoid
Pressure Control
Solenoid High
Pressure Control
Solenoid Low
B1
A2
A12
A11
E9
E13
S
A
B
T
U
C
D
A
B
A
B
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
YE110
YB187
YB199
CONDITIONS FOR CLEARING THE DTC
• 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.
DIAGNOSTIC AIDS
• Inspect the wiring at the PCM, the transmission connector and all other circuit connecting points for the
following conditions:
- A backed out terminal
- A damaged terminal
- Reduced terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
- Corrosion
• When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the
test equipment for a change.
• With the TCC engaged, the TCC slip speed should be -20 to +40 RPM.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step tests for voltage to the solenoid.
4. This step tests the ability of the PCM and wiring to control the earth circuit.
6. This step tests the resistance of the TCC solenoid valve and the automatic transmission (A/T) wiring harness
assembly.
YB187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
ENGINE CONNECTOR 1
YE110
O/W
(304)
(1426)
BLU/W
G/W
(339)
P/BLU
(465)
(123)
V/W
(1427)
B/W
Y
(1049)
DTC P0740 V6 PCM - TORQUE CONVERTER CLUTCH (TCC) ENABLE SOLENOID CIRCUIT FAULT
Step Action Value(s) Yes No
1 Was the Powertrain On-Board Diagnostic (OBD) System
Check performed? Go to Step 2 Go to Powertrain
OBD System
Check Table.
2
1. Install the Tech 2 Scan Tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTC, use the Scan
Tool in order to record the History Data. Using the scan
tool, clear the History Data.
3. Record the DTC Histor y Data.
4. Clear the DTC.
Are any of the following DTCs also set?
• P0753
• P0730
• P0785
• P1860
Go to Step 3
Go to Step 4
DTC P0740 V6 PCM - TORQUE CONVERTER CLUTCH (TCC) ENABLE SOLENOID CIRCUIT FAULT
(CONT.)
Step Action Value(s) Yes No
3
1. Inspect fuse F32.
2. If the fuse is open, inspect the following components
for a short to earth condition:
- Circuit 339 (P/BLU)
- The solenoids
- The A/T wiring harness assembly
3. Repair the circuit, the solenoids, and the harness if
necessary.
Did you find a short to earth condition?
Go to Step 12
Go to Step 4
4
1. Turn the ignition switch OFF.
2. Disconnect the transmission 20-way connector
(additional DTCs may set).
3. Install the J 39775 jumper harness on the engine side
of the 20-way connector.
4. With the engine OFF, turn the ignition switch to the
RUN position.
5. Connect a test lamp from cavity E of the J 39775
jumper harness to earth.
6. Refer to AT Inline Harness Connector End View of the
VX Series Service Information.
Is the test lamp ON?
Go to Step 6
Go to Step 5
5
IMPORTANT: The condition that affects this circuit may
exist in other connecting branches of the circuit. Refer to
Power Distribution Diagrams in VX Service Information,
Section 12P for complete circuit distribution.
Repair the open or short to earth in ignition feed circuit
339 (P/BLU) to the TCC solenoid valve.
Is the repair complete?
Go to Step 12
6
1. Install the test lamp from cavities E to T of the
J 39775 jumper harness.
2. Using the transmission Miscellaneous Tests function
on the Scan Tool, command the TCC solenoid valve
ON and OFF three times.
Does the test lamp turn ON when the TCC solenoid valve
is commanded ON, and OFF when commanded OFF?
Go to Step 8
Go to Step 7
7
1. Inspect circuit 422 (GY/R) of the engine wiring
harness for an open, short to earth or short to power
condition.
2. Repair the circuit if necessary.
Did you find an open, short to earth or short to power
condition?
Go to Step 12
Go to Step 9
8
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 between terminals T and E.
Is the resistance within the specified range?
21-33 Ω
Go to Step 10
Go to Step 11
9
Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step
12
DTC P0740 V6 PCM - TORQUE CONVERTER CLUTCH (TCC) ENABLE SOLENOID CIRCUIT FAULT
(CONT.)
Step Action Value(s) Yes No
10
Measure the resistance between terminal E and earth,
and between terminal T and earth.
Are both readings greater than the specified value?
250 K Ω
Go to
Diagnostic Aids
Go to Step 11
11
Replace the automatic transmission wiring harness
assembly (this includes the TCC solenoid valve).
Refer to Control Valve Body and Wiring Harness
replacement in Section 7C4, in VX Service Information.
Is the replacement complete?
Go to Step 12
12
Perform the following procedure in order to verify the
repair:
1. Select DTC.
2. Select Clear Info.
3. Drive the vehicle in D with the TCC ON and OFF.
Ensure the following conditions are met:
- The PCM commands the TCC solenoid valve ON,
and the voltage input drops to zero.
- The PCM commands the TCC solenoid valve OFF,
and the voltage input increases to B+.
- All conditions are met for 5 seconds.
Were the above conditions verified?
System OK
Go to Step 1
DTC P0741 V6 PCM -
TORQUE CONVERTER CLUTCH (TCC) STUCK ON
CIRCUIT DESCRIPTION
The PCM energises the Torque Converter Clutch Solenoid Valve (TCC Solenoid Valve) by creating an earth
path on circuit 422. When circuit 422 is earthed (energised) by the PCM, the TCC Solenoid Valve stops
converter signal oil from exhausting. This causes converter signal oil pressure to increase and move the TCC
valve. T he TCC Solenoid Valve de-energis es when the PCM no longer provides a path to earth. When the T CC
Solenoid Valve de-energises, the valve exhausts fluid and releases the TCC.
Diagnostic Trouble Code P0741 is for determining a mechanical fault which will cause the Torque Converter
Clutch to be stuck "ON." An electrical fault in the torque converter clutch solenoid circuit which could cause the
torque converter clutch to be "Stuck ON" is diagnosed in DTC P0740.
When the PCM detects low torque converter slip when the PCM commands the TCC OFF, then DTC P0741
sets.
CONDITIONS FOR RUNNING THE DTC
• No TP DTCs set.
• No VSS DTCs set.
• No TFP Valve Position Switch DTC P1810 is set.
• No TCC Solenoid Valve DTC P0740 is set.
• No TCC PWM Solenoid Valve DTC P1860 is set.
• The TP angle is greater than 25%.
• The engine RPM is greater than 450 for 8 seconds.
• The commanded gear is not 1st.
• The gear range is D4 or D3.
• The PCM commands TCC OFF.
CONDITIONS FOR SETTING THE DTC
• DTC P0741 sets if the following conditions occur three times:
- The TCC slip speed is –20 to +30 RPM for 4 seconds.
M
I
C
R
O
PCM
Torque
Converter
Assembly
TCC Enable
Solenoid
4285
A12
GY/R(422)
Ignition
Switch
Fuse
F32
BR 418
P/BLU(339)
TCC
Pwm
Sol
(N.C.)
Cooler
Cooler
Cooler
Release
Apply
Cooler
Conv FD
Conv FD
Reg Apply
EX
Apply
Release
Decrease
Line
Line
Reg Ap
CC Signal
Reg Apply
Reg Apply Isolator
Torque Sig
Rev Input
Rev Input
AFL (From Press Cont Sol)
Lube
Line (From Pump)
A11
TCC PWM
Solenoid
CONVERTER CLUTCH VALVE
YB187
YB187
YB129
YB129
YB129
EX
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When this DTC sets, the PCM will freeze shift adapts from being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS
• The TCC fluid will mechanically apply the TCC, possibly causing an engine stall, under the following
conditions:
- The TCC is mechanically stuck ON
- The parking brake is applied
- Any gear range is selected
- A stuck TP sensor may set DTC 69.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. This step inspects the mechanical state of the TCC. When the PCM commands the TCC Solenoid Valve
OFF, the slip speed should increase to greater than +50 RPM.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
ENGINE CONNECTOR 1
YE110
O/W
(304)
(1426)
BLU/W
G/W
(339)
P/BLU
(465)
(123)
V/W
(1427)
B/W
Y
(1049)
DTC P0741 V6 PCM - TORQUE CONVERTER CLUTCH (TCC) STUCK ON
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs, use the
scan tool in order to record the DTC history for
reference. The Clear Info function will erase the data.
3. Record the DTC history.
4. Using the scan tool, verify the TP Sensor operation.
Are the TP Sensor values within the normal range (shown
in the value column)?
0.6–5.0 volts Go to Step 3 Go to
“Diagnostic Aids”
above
3 Drive the vehicle in the D4 drive range in fourth gear
under steady acceleration, with a TP angle greater than
25%.
W hile the displayed TCC Solenoid status is No, does the
scan tool display a Trans Slip Speed within the specified
range?
-20 to +30
RPM Go to Step 4 Go to
“Diagnostic Aids”
above
DTC P0741 V6 PCM - TORQUE CONVERTER CLUTCH (TCC) STUCK ON (CONTINUED)
STEP ACTION VALUE YES NO
4 The TCC is mechanically stuck ON. Inspect for the
following conditions:
• A clogged exhaust orifice in the TCC Solenoid
Valve.
• The converter clutch apply valve is stuck in the
apply position.
• A misaligned or damaged valve body gasket.
• A restricted release passage.
• A restricted transmission cooler line.
Did you find and correct a problem?
Go to Step 5 Go to Symptoms-
No TCC Release
5 In order to verify your repair, perform the following
procedure:
Operate the vehicle under the following conditions:
• Hold the throttle at 25% and accelerate to 88
km/h.
• Ensure that the Trans Slip Speed is -50 to
+2500 RPM for 4 seconds, with the TCC
commanded OFF.
W as the slip speed greater than 50 RPM in 2nd, 3rd and
4th gears when the TCC was commanded OFF?
System OK Begin the
diagnosis again.
Go to Step 1
DTC P0748 V6 PCM -
PRESSURE CONTROL (P C) SOLENOID CURRENT ERROR
CIRCUIT DESCRIPTION:
The Pressure Control Solenoid Valve (PC Solenoid Valve) is a PCM controlled device which regulates the
transmission line pressure. The PCM compares the TP voltage, the engine speed and other inputs in order to
determine the appropriate line pressure for a given load. The PCM applies a varying amperage to the PC
Solenoid Valve in order to regulate the pressure. The applied amperage can vary from 0.1 to 1.1 amps. The
PCM monitors the amperage.
W hen the PCM detects a continuous open or short to earth in the PC Solenoid Valve circ uit or the PC Solenoid
Valve, then a DTC P0748 sets.
Once a DTC P0748 is s et, the pr ess ur e c ontrol s olenoid is dis abled and f ull line pr ess ur e will be applied until the
next time the ignition key is cycled. If upon restart, the current error does not exist, a DTC P0748 will remain
stored but the pressure control solenoid will resume normal function.
CONDITIONS FOR RUNNING THE DTC
• No DTC P0562 is set.
• The system voltage is between 10 and 16 volts.
• The engine is running.
CONDITIONS FOR SETTING THE DTC
• The PC s olenoid valve duty cycle reaches its high lim it (approxim ately 95%) or low lim it (appr oximately 0%)
for 200 milliseconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• W hen this DTC sets, the PCM will command the PC solenoid valve OFF, The PCM will freeze shift adapts
from being updated.
3–2 Downshift
Control
Solenoid
1–2 Shift
Solenoid A
2–3 Shift
Solenoid B
YB 129 Transmission
Pass-Thru Connector
Torque
Converter
Clutch (TCC)
(PWM)
Solenoid
Torque
Converter
Clutch (TCC)
Enable
Solenoid
Pressure
Control
Solenoid
A
B
A
B
4284
A
B
A
B
EF32
EFI
Relay
P/ BLU (339)
G/W (897)
LG (1222)
Y/B (1223)
GY/R (422)
BR (418)
R (1228)
GY/BLU (1229)
A1 3–2 Cont r ol
Solenoid
1–2 Shift
Solenoid
2–3 Shift
Solenoid
TCC Enable
Solenoid
TCC PWM
Solenoid
Pressure Control
Solenoid High
Pressure Control
Solenoid Low
B1
A2
A12
A11
E9
E13
S
A
B
T
U
C
D
A
B
A
B
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
YE110
YB187
YB199
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS
• Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical
connections at the transmission pass-through connector. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
- Corrosion
• When diagnosing for an inter m ittent short or open c ondition, m ass age the wiring harness while watc hing the
test equipment for a change.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step tests the ability of the PCM to command the PC Solenoid Valve.
3. This step tests the PC Solenoid Valve and Automatic Transmission Wiring Harness Assembly for correct
resistance.
P.C.M CONNECTOR 3
YB1 99
E1
F1
G
(842)
BLU
(841)
GY
(845)
Y
(846)
B/R
(750)
R
(1228)
G/W
(465)
V
(435)
GY/BLU
(1229)
(843)
V
(844)
BR/Y
(771)
BLU/W
(766)
W
(750)
B/R
Y
(772)
GY
(773)
BR/Y
(1224)
Y
(1225)
GY
(1226)
BLU
(774)
BLU/R
(31)
E16
F16
P
(39))
B/BLU
(1062)
(936)
BLU/O
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
DTC P0748 V6 PCM - PRESSURE CONTROL (PC) SOLENOID CURRENT ERROR
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs, use the scan
tool in order to record the DTC history for reference. The
Clear Info function will erase the data.
3. Record the DTC history.
4. While the engine is operating, put the transmission in
Park position.
5. Using the transmission output control function on the
scan tool, apply 0.1 amp through 1.0 amp while
observing Commanded PCS and Actual PCS
amperage.
Is the Actual PCS amperage always within the specified
value of the Commanded PCS amperage?
0.16 amp Go to
“Diagnostic Aids”
above
Go to Step 3
DTC P0748 V6 PCM - PRESSURE CONTROL (PC) SOLENOID CURRENT ERROR (CONTINUED)
STEP ACTION VALUE YES NO
3 1. Turn the ignition OFF.
2. Disconnect the transmission pass-through connector.
3. Install the J 39775 Jumper Harness on the
transmission side of the pass-through connector.
4. Using the J 39200 DVM and J 35616 Connector Test
Adapter Kit, measure the resistance between
terminal C and terminal D.
Is the resistance within the specified range?
3-7 Ω Go to Step 8 Go to Step 4
4 Is the resistance greater than the specified value? 7 Ω Go to Step 5 Go to Step 6
5 1. Check the Automatic Transmission Wiring Harness
Assembly for an open.
2. Replace the harness if necessary. Refer to Service
Operations.
Did you find and correct the problem?
Go to Step 15 Go to Step 10
6 Is the resistance less than the specified value? 3 Ω Go to Step 7 Go to Step 10
7 1. Check the Automatic Transmission Wiring Harness
Assembly for a shorted together condition.
2. Replace the harness if necessary. Refer to Service
Operations in Section 7C-5 in VX Service
Information.
Did you find and correct the problem?
Go to Step 15 Go to Step 10
8 Using the J 39200 DVM and J 35616 Connector Test
Adapter Kit, measure the resistance from terminal C to
the transmission case.
Is the resistance less than the specified value?
9 Ω Go to Step 9 Go to Step 11
9 1. Check the Automatic Transmission Wiring Harness
Assembly for a short to earth.
2. Replace the harness if necessary. Refer to Service
Operations.
Did you find and correct the problem?
Go to Step 15 Go to Step 10
10 Replace the PC Solenoid Valve. Refer to Section 6C1-3
Service Operations of the VX Series Service Information.
Is the action complete?
Go to Step 15
11 1. Disconnect the J 39775 Jumper Harness from the
transmission side of the pass-through connector.
2. Reconnect the transmission pass-through connector.
3. Disconnect the PCM connector 3 (BLUE 32 pin).
4. Using the J 39200 DVM and the J 35616 Connector
Test Adapter Kit, measure the resistance from
terminal E15 to earth.
Is the resistance greater than the specified value?
9 Ω Go to Step 12 Go to Step 13
12 1. Check circuit 1228 and circuit 1229 for an open.
2. Repair the circuits if necessary.
Did you find and correct the problem?
Go to Step 15 Go to Step 14
13 1. Check circuit 1228 and circuit 1229 for a short to
earth.
2. Repair the circuits if necessary.
Did you find and correct the problem?
Go to Step 15
14 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 15
DTC P0748 V6 PCM - PRESSURE CONTROL (PC) SOLENOID CURRENT ERROR (CONTINUED)
STEP ACTION VALUE YES NO
15 In order to verify your repair, perform the following
procedure:
Operate the vehicle under the following conditions:
• The engine is running.
• Observe the Actual PCS amperage and the
Commanded PCS amperage.
Is the difference between the Actual PCS amperage and
the Commanded PCS amperage less than the specified
value?
0.16 amp System OK Begin the
diagnosis again.
Go to Step 1
DTC P0753 V6 PCM
1-2 SHIFT SOLENOID A CIRCUIT VOLTAGE HIGH
CIRCUIT DESCRIPTION
The 1-2 Shift Solenoid Valve (1-2 SS Valve) controls the fluid flow acting on the 2-3 shift valves. The 1-2 SS
Valve is a normally-open exhaust valve that is used with the 2-3 Shift Solenoid Valve in order to allow four
diff erent shifting combinations . The s olenoid attaches to the control valve body within the transmiss ion. The 1-2
SS Valve receives ignition voltage through circuit 339. The PCM controls the solenoid by providing a path to
earth on circuit 1222.
When the PCM detects a short to voltage in the 1-2 SS Valve circuit or the 1-2 SS Valve, then DTC P0753 sets.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
CONDITIONS FOR SETTING THE DTC
• The PCM commands the solenoid ON and the voltage input remains high (B+).
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When this DT C sets, the PCM will com m and D2 line pres sure, T he PCM inhibits 3- 2 downshift if the vehicle
speed is greater than 48 km/h, The PCM will freeze shift adapts from being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
3–2 Downshift
Control
Solenoid
1–2 Shift
Solenoid A
2–3 Shift
Solenoid B
YB 129 Transmission
Pass-Thru Connector
Torque
Converter
Clutch (TCC)
(PWM)
Solenoid
Torque
Converter
Clutch (TCC)
Enable
Solenoid
Pressure
Control
Solenoid
A
B
A
B
4284
A
B
A
B
EF32
EFI
Relay
P/ BLU (339)
G/W (897)
LG (1222)
Y/B (1223)
GY/R (422)
BR (418)
R (1228)
GY/BLU (1229)
A1 3–2 Cont r ol
Solenoid
1–2 Shift
Solenoid
2–3 Shift
Solenoid
TCC Enable
Solenoid
TCC PWM
Solenoid
Pressure Control
Solenoid High
Pressure Control
Solenoid Low
B1
A2
A12
A11
E9
E13
S
A
B
T
U
C
D
A
B
A
B
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
YE110
YB187
YB199
DIAGNOSTIC AIDS
Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections
at the transmission pass-through connector. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
• Moisture intrusion when diagnosing for an intermittent short or open condition, massage the wiring harness
while watching the test equipment for a change.
• Refer to the following Table for the correct On and Off states of the shift solenoids.
GEAR 1-2-SHIFT
SOLENOID 2-3 SHIFT
SOLENOID
1 ON ON
2 OFF ON
3 OFF OFF
4 ON OFF
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step tests the function of the 1-2 SS valve and the automatic transmission wiring harness assembly.
3. This step tests the ability of the PCM and the wiring to control the earth circuit.
YB187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
ENGINE CONNECTOR 1
YE110
O/W
(304)
(1426)
BLU/W
G/W
(339)
P/BLU
(465)
(123)
V/W
(1427)
B/W
Y
(1049)
DTC P0753 V6 PCM - 1-2 SHIFT SOLENOID A CIRCUIT VOLTAGE HIGH
Step Action Value(s) Yes No
1 Was the Powertrain On-Board Diagnostic (OBD) System
Check performed? Go to Step 2 Go to Powertrain
OBD System
Check Table.
2 Using the transmission Miscellaneous Tests function on
the Scan Tool, command the 1-2 SS valve ON and OFF
three times while listening to the bottom of the
transmission pan (a stethoscope may be necessary).
Did the solenoid click when commanded?
Go to
Diagnostic Aids Go to Step 3
3 1. Turn the ignition OFF.
2. Disconnect the transmission 20-way (YB 129)
connector (additional DTCs may set).
3. Install the J 39775 jumper harness on the engine
side of the 20-way (YB 129) connector.
4. Install a test lamp from J 39775 jumper harness
cavity E to cavity A.
5. Using the transmission Miscellaneous Tests function
on the Scan Tool, command the 2-3 SS valve ON
and OFF three times.
Is the test lamp ON when the 1-2 SS valve is
commanded ON, and OFF when commanded OFF?
Go to Step 6 Go to Step 4
DTC P0753 V6 PCM - 1-2 SHIFT SOLENOID A CIRCUIT VOLTAGE HIGH (CONTINUED)
Step Action Value(s) Yes No
4 1. Inspect circuit 1222 (LG) of the powertrain wiring
harness for a short to voltage condition.
2. Repair the circuit if necessary.
Did you find a short to voltage condition?
Go to Step 12 Go to Step 5
5 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step12
6 1. Install the J 39775 jumper harness on the
transmission side of the 20-way (YB 129) connector.
2. With the J 39200 digital multimeter (DMM) and the
J 35616 connector test adapter kit, measure the
resistance between terminals A and E.
Is the resistance within the range indicated?
19-31 Ω Go to Step 8 Go to Step 7
7 1. Disconnect the A/T wiring harness assembly from the
1-2 SS valve.
2. Measure the resistance of the 1-2 SS valve.
Is the resistance within the range indicated?
19-31 Ω Go to Step 10 Go to Step 11
8 Using the J 39200 DMM, measure the resistance
between terminal A and earth, and between terminal E
and earth.
Are both readings greater than the specified value?
250 K Ω Go to Diagnostic
Aids Go to Step 9
9 1. Disconnect the A/T wiring harness assembly from the
1-2 SS valve.
2. Using the J 39200 DMM, measure the resistance from
the component's terminals to earth.
Are both readings greater than the specified value?
250 K Ω Go to Step 10 Go to Step 11
10 Replace the automatic transmission wiring harness
assembly.
Refer to Control Valve Body and Wiring Harness
replacement in Section 7C5-5 in VX Service Information.
Is the replacement complete?
Go to Step 12
11 Replace the 1-2 SS valve. Refer to Service Operations
Section 6C1-3 Service Operations of the VX Series
Service Information.
Is the replacement complete?
Go to Step 12
12 Perform the following procedure in order to verify the
repair:
Drive the vehicle in D and ensure the following conditions
are met:
- The PCM commands the 1-2 SS valve ON and the
voltage input drops to zero.
- The PCM commands the 1-2 SS valve OFF and the
voltage input increases to B+.
- All conditions are met for 5 seconds.
Were the above conditions verified?
System OK Go to Step 1
DTC P0756 V6 PCM
1-2 SHIFT SOLENOID A CIRCUIT VOLTAGE LOW
CIRCUIT DESCRIPTION
The 1-2 Shift Solenoid Valve (1-2 SS Valve) controls the fluid flow acting on the 2-3 shift valves. The 1-2 SS
Valve is a normally-open exhaust valve that is used with the 2-3 Shift Solenoid Valve in order to allow four
diff erent shifting combinations . The s olenoid attaches to the control valve body within the transmiss ion. The 1-2
SS Valve receives ignition voltage through circuit 339. The PCM controls the solenoid by providing a path to
earth on circuit 1222.
When the PCM detects a c ontinuous open or s hort to earth in the 1- 2 SS Valve circuit or the 1-2 SS Valve, then
DTC P0756 sets.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
CONDITIONS FOR SETTING THE DTC
• The PCM commands the solenoid OFF and the voltage input remains low (0volts)
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When this DT C sets, the PCM will com m and D2 line pres sure, T he PCM inhibits 3- 2 downshift if the vehicle
speed is greater than 48 km/h, The PCM will freeze shift adapts from being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
3–2 Downshift
Control
Solenoid
1–2 Shift
Solenoid A
2–3 Shift
Solenoid B
YB 129 Transmission
Pass-Thru Connector
Torque
Converter
Clutch (TCC)
(PWM)
Solenoid
Torque
Converter
Clutch (TCC)
Enable
Solenoid
Pressure
Control
Solenoid
A
B
A
B
4284
A
B
A
B
EF32
EFI
Relay
P/ BLU (339)
G/W (897)
LG (1222)
Y/B (1223)
GY/R (422)
BR (418)
R (1228)
GY/BLU (1229)
A1 3–2 Cont r ol
Solenoid
1–2 Shift
Solenoid
2–3 Shift
Solenoid
TCC Enable
Solenoid
TCC PWM
Solenoid
Pressure Control
Solenoid High
Pressure Control
Solenoid Low
B1
A2
A12
A11
E9
E13
S
A
B
T
U
C
D
A
B
A
B
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
YE110
YB187
YB199
DIAGNOSTIC AIDS
Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections
at the transmission pass-through connector. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
• Moisture intrusion when diagnosing for an intermittent short or open condition, massage the wiring harness
while watching the test equipment for a change.
• Refer to the following Table for the correct On and Off states of the shift solenoids.
GEAR 1-2-SHIFT
SOLENOID 2-3 SHIFT
SOLENOID
1 ON ON
2 OFF ON
3 OFF OFF
4 ON OFF
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
4. This step tests the function of the 1-2 SS valve and the automatic transmission wiring harness assembly.
5. This step tests for power to the 1-2 SS valve from the ignition through the fuse.
7. This step tests the ability of the PCM and the wiring to control the earth circuit.
10. This step measures the resistance of the A/T wiring harness assembly and the 1-2 SS valve.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
ENGINE CONNECTOR 1
YE110
O/W
(304)
(1426)
BLU/W
G/W
(339)
P/BLU
(465)
(123)
V/W
(1427)
B/W
Y
(1049)
DTC P0756 V6 PCM - 1-2 SHIFT SOLENOID A CIRCUIT VOLTAGE LOW
Step Action Value(s) Yes No
1 Was the Powertrain On-Board Diagnostic (OBD) System
Check performed? Go to Step 2 Go to Powertrain
OBD System
Check Table.
2 1. Install the Tech 2 Scan Tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTC, use the Scan
Tool in order to record the History Data. Using the scan
tool , clear the History Data.
3. Record the DTC Histor y Data.
4. Clear the DTC.
Are any of the following DTCs also set?
• P0740
• P0730
• P0753
• P0757
• P0785
• P1860
Go to Step 3 Go to Step 4
3 1. Inspect fuse F32.
2. If the fuse is open, inspect the following components
for a short to earth condition:
- Circuit 339 (P/BLU)
- The solenoids
- The A/T wiring harness assembly
3. Repair the circuit, the solenoids, and the harness if
necessary.
Did you find a short to earth condition?
Go to Step 16 Go to Step 5
4 Using the transmission Miscellaneous Tests function on
the Scan Tool, command the 1-2 SS valve ON and OFF
three times while listening to the bottom of the
transmission pan (a stethoscope may be necessary).
Did the solenoid click when commanded?
Go to Diagnostic
Aids Go to Step 5
5 1. Turn the ignition OFF.
2. Disconnect the transmission 20-way (YB 129)
connector (additional DTCs may set).
3. Install the J 39775 jumper harness on the engine side
of the 20-way (YB 129) connector.
4. With the engine OFF, turn the ignition switch to the
RUN position.
5. Connect a test lamp from J 39775 jumper harness
cavity E to earth.
Is the test lamp ON?
Go to Step 7 Go to Step 6
6 Repair the open or short to earth in ignition feed circuit
339 to the 1-2 SS valve.
Is the repair complete?
Go to Step 16
7 1. Install a test lamp from J 39775 jumper harness cavity
E to cavity A.
2. Using the transmission Miscellaneous Tests function
on the Scan Tool, command the 1-2 SS valve ON and
OFF three times.
Is the test lamp ON when the 1-2 SS valve is
commanded ON, and OFF when commanded OFF?
Go to Step 10 Go to Step 8
8 1. Inspect circuit 1222 (LG) of the powertrain wiring
harness for an open or short to earth condition.
2. Repair the circuit if necessary.
Did you find an open or short to earth condition?
Go to Step 16 Go to Step 9
DTC P0756 V6 PCM - 1-2 SHIFT SOLENOID A CIRCUIT VOLTAGE LOW (CONTINUED)
Step Action Value(s) Yes No
9 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step16
10 1. Install the J 39775 jumper harness on the
transmission side of the 20-way (YB 129) connector.
2. With the J 39200 digital multimeter (DMM) and the
J 35616 connector test adapter kit, measure the
resistance between terminals A and E.
Is the resistance within the range indicated?
19-31 Ω Go to Step 12 Go to Step 11
11 1. Disconnect the A/T wiring harness assembly from
the 1-2 SS valve.
2. Measure the resistance of the 1-2 SS valve.
Is the resistance within the range indicated?
19-31 Ω Go to Step 14 Go to Step 15
12 Using the J 39200 DMM, measure the resistance
between terminal A and earth, and between terminal E
and earth.
Are both readings greater than the specified value?
250 K Ω Go to Diagnostic
Aids Go to Step 13
13 1. Disconnect the A/T wiring harness assembly from 2.
the 1-2 SS valve.
2. Using the J 39200 DMM, measure the resistance
from the component's terminals to earth.
Are both readings greater than the specified value?
250 K Ω Go to Step 14 Go to Step 15
14 Replace the automatic transmission wiring harness
assembly.
Refer to Control Valve Body and Wiring Harness
replacement in Section 7C5-5 in VX Service Information.
Is the replacement complete?
Go to Step 16
15 Replace the 1-2 SS valve. Refer to Section 6C1-3
Service Operations of the VX Series Service Information.
Is the replacement complete?
Go to Step 16
16 Perform the following procedure in order to verify the
repair:
Drive the vehicle in D and ensure the following conditions
are met:
- The PCM commands the 1-2 SS valve ON and the
voltage input drops to zero.
- The PCM commands the 1-2 SS valve OFF and the
voltage input increases to B+.
- All conditions are met for 5 seconds.
Were the above conditions verified?
System OK Go to Step 1
DTC P0757 V6 PCM -
2-3 SHIFT SOLENOID B CIRCUIT VOLTAGE LOW
CIRCUIT DESCRIPTION
The 2- 3 Shift Solenoid Valve (2-3 SS Valve) controls the f luid flow acting on the 1-2 and 3-4 sh ift valves. T he 2-
3 SS Valve is a norm ally-open exhaust valve that is used with the 1-2 Shif t Solenoid Valve in order to allow four
diff erent shifting combinations . The s olenoid attaches to the control valve body within the transmiss ion. The 2-3
SS Valve receives voltage through circuit 339. The PCM controls the solenoid by providing the ground path on
circuit 1223.
When the PCM detects a c ontinuous open or s hort to earth in the 2- 3 SS Valve circuit or the 2-3 SS Valve, then
DTC P0757 sets.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
CONDITIONS FOR SETTING THE DTC
• The PCM commands the solenoid OFF and the voltage input remains low (0volts)
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When this DT C sets, the PCM will com m and D2 line pres sure, T he PCM inhibits 3- 2 downshift if the vehicle
speed is greater than 48 km/h, The PCM will freeze shift adapts from being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
3–2 Downshift
Control
Solenoid
1–2 Shift
Solenoid A
2–3 Shift
Solenoid B
YB 129 Transmission
Pass-Thru Connector
Torque
Converter
Clutch (TCC)
(PWM)
Solenoid
Torque
Converter
Clutch (TCC)
Enable
Solenoid
Pressure
Control
Solenoid
A
B
A
B
4284
A
B
A
B
EF32
EFI
Relay
P/ BLU (339)
G/W (897)
LG (1222)
Y/B (1223)
GY/R (422)
BR (418)
R (1228)
GY/BLU (1229)
A1 3–2 Cont r ol
Solenoid
1–2 Shift
Solenoid
2–3 Shift
Solenoid
TCC Enable
Solenoid
TCC PWM
Solenoid
Pressure Control
Solenoid High
Pressure Control
Solenoid Low
B1
A2
A12
A11
E9
E13
S
A
B
T
U
C
D
A
B
A
B
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
YE110
YB187
YB199
DIAGNOSTIC AIDS
Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections
at the transmission pass-through connector. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
• Moisture intrusion when diagnosing for an intermittent short or open condition, massage the wiring harness
while watching the test equipment for a change.
• Refer to the following Table for the correct On and Off states of the shift solenoids.
GEAR 1-2-SHIFT
SOLENOID 2-3 SHIFT
SOLENOID
1 ON ON
2 OFF ON
3 OFF OFF
4 ON OFF
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
4. This step tests the function of the 2-3 SS valve and the automatic transmission wiring harness assembly.
5. This step tests for power to the 2-3 SS valve from the ignition through the fuse.
7. This step tests the ability of the PCM and the wiring to control the earth circuit.
10. This step measures the resistance of the A/T wiring harness assembly and the 2-3 SS valve.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
ENGINE CONNECTOR 1
YE110
O/W
(304)
(1426)
BLU/W
G/W
(339)
P/BLU
(465)
(123)
V/W
(1427)
B/W
Y
(1049)
DTC P0757 V6 PCM - 2-3 SHIFT SOLENOID B CIRCUIT VOLTAGE LOW
Step Action Value(s) Yes No
1 Was the Powertrain On-Board Diagnostic (OBD) System
Check performed? Go to Step 2 Go to Powertrain
OBD System
Check Table.
2 1. Install the Tech 2 Scan Tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTC, use the Scan
Tool in order to record the History Data. Using the scan
tool , clear the History Data.
3. Record the DTC History Data.
4. Clear the DTC.
Are any of the following DTCs also set?
• P0730
• P0740
• P0753
• P0756
• P0785
• P1860
Go to Step 3 Go to Step 4
3 1. Inspect fuse F32.
2. If the fuse is open, inspect the following components
for a short to earth condition:
- Circuit 339 (P/BLU)
- The solenoids
- The A/T wiring harness assembly
3. Repair the circuit, the solenoids, and the harness if
necessary.
Did you find a short to earth condition?
Go to Step 16 Go to Step 5
4 Using the transmission Miscellaneous Tests function on
the Scan Tool, command the 2-3 SS valve ON and OFF
three times while listening to the bottom of the
transmission pan (a stethoscope may be necessary).
Did the solenoid click when commanded?
Go to
Diagnostic Aids Go to Step 5
5 1. Turn the ignition OFF.
2. Disconnect the transmission 20-way (YB 129)
connector (additional DTCs may set).
3. Install the J 39775 jumper harness on the engine
side of the 20-way (YB 129) connector.
4. With the engine OFF, turn the ignition switch to the
RUN position.
5. Connect a test lamp from J 39775 jumper harness
cavity E to earth.
Is the test lamp ON?
Go to Step 7 Go to Step 6
6 Repair the open or short to earth in ignition feed circuit
339 to the 2-3 SS valve.
Is the repair complete?
Go to Step 16
7 1. Install a test lamp from J 39775 jumper harness
cavity E to cavity B.
2. Using the transmission Miscellaneous Tests function
on the Scan Tool, command the 2-3 SS valve ON
and OFF three times.
Is the test lamp ON when the 2-3 SS valve is
commanded ON, and OFF when commanded OFF?
Go to Step 10 Go to Step 8
DTC P0757 V6 PCM - 2-3 SHIFT SOLENOID B CIRCUIT VOLTAGE LOW (CONTINUED)
Step Action Value(s) Yes No
8 1. Inspect circuit 1223 (Y/B) of the powertrain wiring
harness for an open or short to earth condition.
2. Repair the circuit if necessary.
Did you find an open or short to earth condition?
Go to Step 16 Go to Step 9
9 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step16
10 1. Install the J 39775 jumper harness on the
transmission side of the 20-way (YB 129) connector.
2. With the J 39200 digital multimeter (DMM) and the
J 35616 connector test adapter kit, measure the
resistance between terminals B and E.
Is the resistance within the range indicated?
19-31 Ω Go to Step 12 Go to Step 11
11 1. Disconnect the A/T wiring harness assembly from
the 2-3 SS valve.
2. Measure the resistance of the 2-3 SS valve.
Is the resistance within the range indicated?
19-31 Ω Go to Step 14 Go to Step 15
12 Using the J 39200 DMM, measure the resistance
between terminal B and earth, and between terminal E
and earth.
Are both readings greater than the specified value?
250 K Ω Go to Diagnostic
Aids Go to Step 13
13 1. Disconnect the A/T wiring harness assembly from
the 2-3 SS valve.
2. Using the J 39200 DMM, measure the resistance
from the component's terminals to earth.
Are both readings greater than the specified value?
250 K Ω Go to Step 14 Go to Step 15
14 Replace the automatic transmission wiring harness
assembly.
Refer to Control Valve Body and Wiring Harness
replacement in Section 7C5-5 in VX Service Information.
Is the replacement complete?
Go to Step 16
15 Replace the 2-3 SS valve. Refer to Service Operations
Section 6C1-3 Service of the VX Series Service
Information.
Is the replacement complete?
Go to Step 16
16 Perform the following procedure in order to verify the
repair:
Drive the vehicle in D and ensure the following conditions
are met:
- The PCM commands the 2-3 SS valve ON and the
voltage input drops to zero.
- The PCM commands the 2-3 SS valve OFF and the
voltage input increases to B+.
- All conditions are met for 5 seconds.
Were the above conditions verified?
System OK Go to Step 1
DTC P0785 V6 PCM
3-2 DOWNSHIFT CONTROL SOLE NOID CIRCUIT FAULT
CIRCUIT DESCRIPTION
The 3-2 Shif t Solenoid (SS) valve is a norm ally-closed, 3-port, on/of f device that c ontrols the 3-2 downshif t. The
solenoid attaches to the control valve body within the transmission. The solenoid receives ignition voltage
through circuit 339. The Powertrain Control Module (PCM) controls the solenoid by providing an earth path on
circuit 897. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The PCM varies the timing
between the 3-4 clutch release and the 2-4 band apply depending on the vehicle speed and the throttle position.
W hen the PCM detects a continuous open or short to earth in the 3-2 SS valve assembly circuit or the 3-2 SS
valve assembly, then DTC P0785 sets.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
CONDITIONS FOR SETTING THE DTC
DTC P0785 sets if either of the following conditions occur for 5 seconds:
• The PCM commands the solenoid ON and the voltage input remains high (B+).
or
• The PCM commands the solenoid OFF and the voltage input remains low (0volts)
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When this DTC sets, the PCM will command maximum line pressure, and inhibits TCC engagement..
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
3–2 Downshift
Control
Solenoid
1–2 Shift
Solenoid A
2–3 Shift
Solenoid B
YB 129 Transmission
Pass-Thru Connector
Torque
Converter
Clutch (TCC)
(PWM)
Solenoid
Torque
Converter
Clutch (TCC)
Enable
Solenoid
Pressure
Control
Solenoid
A
B
A
B
4284
A
B
A
B
EF32
EFI
Relay
P/ BLU (339)
G/W (897)
LG (1222)
Y/B (1223)
GY/R (422)
BR (418)
R (1228)
GY/BLU (1229)
A1 3–2 Cont r ol
Solenoid
1–2 Shift
Solenoid
2–3 Shift
Solenoid
TCC Enable
Solenoid
TCC PWM
Solenoid
Pressure Control
Solenoid High
Pressure Control
Solenoid Low
B1
A2
A12
A11
E9
E13
S
A
B
T
U
C
D
A
B
A
B
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
YE110
YB187
YB199
DIAGNOSTIC AIDS
• Inspect the wiring at the PCM, the transmission connector and all other circuit connecting points for the
following conditions:
- A backed out terminal
- A damaged terminal
- Reduced terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
- Corrosion
• When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the
test equipment for a change.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
4. This step tests the ability of the PCM to control the solenoid.
5. This step tests for power to the 3-2 SS valve assembly.
7. This step tests the ability of the PCM and the wiring to control the earth circuit.
10. This step measures the resistance of the A/T wiring harness assembly and the 3-2 SS valve assembly.
YB187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
ENGINE CONNECTOR 1
YE110
O/W
(304)
(1426)
BLU/W
G/W
(339)
P/BLU
(465)
(123)
V/W
(1427)
B/W
Y
(1049)
DTC P0785 V6 PCM - 3-2 DOWNSHIFT CONTROL SOLENOID CIRCUIT FAULT
Step Action Value(s) Yes No
1 Was the Powertrain On-Board Diagnostic (OBD) System
Check performed? Go to Step 2 Go to Powertrain
OBD System
Check Table.
2 3. Install the Tech 2 Scan Tool.
4. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTC, use the Scan
Tool in order to record the History Data. Using the scan
tool, clear the History Data.
5. Record the DTC Histor y Data.
6. Clear the DTC.
Are any of the following DTCs also set?
• P0740
• P0753
• P0758
• P1860
Go to Step 3 Go to Step 4
3 1. Inspect fuse F32.
2. If the fuse is open, inspect the following components
for a short to earth condition:
- Circuit 339
- The solenoids
- The A/T wiring harness assembly
3. Repair the circuit, the solenoids, and the harness if
necessary.
Did you find a short to earth condition?
Go to Step 16 Go to Step 5
DTC P0785 V6 PCM - 3-2 DOWNSHIFT CONTROL SOLENOID CIRCUIT FAULT (CONTINUED)
Step Action Value(s) Yes No
4 IMPORTANT: the 3-2 shift solenoid valve will rapidly
apply when commanded ON by the Scan Tool.
Using the transmission Miscellaneous Tests function on
the Scan Tool, command the 3-2 SS valve ON and OFF
three times while listening to the bottom of the
transmission pan (a stethoscope may be necessary).
Did the solenoid click when commanded?
Go to
Diagnostic Aids Go to Step 5
5 1. Turn the ignition OFF.
2. Disconnect the transmission 20-way (YB 129)
connector (additional DTCs may set).
3. Install the J 39775 jumper harness on the engine side
of the 20-way (YB 129) connector.
4. With the engine OFF, turn the ignition switch to the
RUN position.
5. Connect a test lamp from J 39775 jumper harness
cavity E to earth.
Is the test lamp ON?
Go to Step 7 Go to Step 6
6 Repair the open or short to earth in ignition feed circuit
339 to the 3-2 SS valve assembly.
Is the repair complete?
Go to Step 16
7 1. Install a test lamp from J 39775 jumper harness cavity
E to cavity S.
IMPORTANT: The 3-2 shift solenoid will rapidly apply
when commanded ON by the Scan Tool.
2. Using the transmission Miscellaneous Tests function
on the Scan Tool, command the 3-2 SS valve ON and
OFF three times.
Is the test lamp ON when the solenoid is commanded ON
and OFF, when the solenoid is commanded OFF?
Go to Step 10 Go to Step 8
8 1. Inspect circuit 897 of the powertrain wiring harness for
an open, short to earth or short to power condition.
2. Repair the circuit if necessary.
Did you find an open, short to earth or short to power
condition?
Go to Step 16 Go to Step 9
9 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step16
10 1. Install the J 39775 jumper harness on the
transmission side of the 20-way (YB 129) connector.
2. With the J 39200 digital multimeter (DMM) and the
J 35616 connector test adapter kit, measure the
resistance between terminals S and E.
Is the resistance within the range indicated?
20-32 Ω Go to Step 12 Go to Step 11
11 1. Disconnect the A/T wiring harness assembly from the
3-2 SS valve assembly.
2. Measure the resistance of the 3-2 SS valve assembly.
Is the resistance within the range indicated?
20-32 Ω Go to Step 14 Go to Step 15
12 Measure the resistance between terminal S and earth,
and between terminal E and earth.
Are both readings greater than the specified value?
250 K Ω Go to Diagnostic
Aids Go to Step 13
13 1. Disconnect the A/T wiring harness assembly from the
3-2 SS valve assembly.
2. Measure the resistance from the component’s
terminals to earth.
Are both measurements greater than the specified value?
250 K Ω Go to Step 14 Go to Step 15
DTC P0785 V6 PCM - 3-2 DOWNSHIFT CONTROL SOLENOID CIRCUIT FAULT (CONTINUED)
Step Action Value(s) Yes No
14 Replace the automatic transmission wiring harness
assembly.
Refer to Control Valve Body and Wiring Harness
replacement in Section 7C5-5 in VX Service Information.
Is the replacement complete?
Go to Step 16
15 Replace the 3-2 SS valve. Refer to Service Operations
Section 6C1-3 of the VX Series Service Information.
Is the replacement complete?
Go to Step 16
16 Perform the following procedure in order to verify the
repair:
1. Select DTC.
2. Select Clear Info.
3. Drive the vehicle in 3 or D and perform a 3-2
downshift. Ensure the following conditions are met:
- The PCM commands the 3-2 SS valve ON and the
voltage input drops to zero.
- The PCM commands the 3-2 SS valve OFF and the
voltage input increases to B+.
- All conditions are met for 5 seconds.
Were the above conditions verified?
System OK Go to Step 1
DTC P1064 V6 PCM
LOW SPEED FAN – NO BCM RESPONSE
CIRCUIT DESCRIPTION;
The PCM determ ines operation of the two speed engine cooling fan based on A/C request signal input, engine
coolant temperature and vehicle speed.
The engine cooling fan low speed relay (labeled LO FAN in relay housing) is energised by the BCM. W hen the
PCM determines that the engine cooling fan low speed relay should be turned "ON", the PCM will send a
message on circuit 1221 to the BCM. This message will ask the BCM to earth circuit 473 and energise the
engine cooling fan low speed relay. After the BCM provides the earth for circuit 473, the BCM will send a
message back to the PCM saying that the earth circuit was commanded.
When the BCM does not receive communications from the PCM when the ignition is switched "ON", then the
starter motor will be enabled after a one second delay.
CONDITIONS FOR RUNNING THE DTC
• Engine is idling.
• PCM supplies a signal to the BCM.
CONDITIONS FOR SETTING THE DTC
• The PCM sends a request to the BCM to turn on the engine cooling fan low speed relay via the serial data
normal mode message and the BCM does not send a message back to the PCM.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P1255 is set, the engine will not start if DTC P1255 is current.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
Battery
FS
FU Fa n 1 O/B LU ( 204)
O/B ( 208)
FT Fan 2
RR
(001) (203)
O/B
(740) O
(740) A5/A6
F31
G
Y
O/Y
(250)
BLU/Y
(533)
B
BLU
(1040) Battery Ma in Power
Hi gh Series BC M Term inals Nominat ed Fi rst
Low
Sp ee d Fan
B7/B7
E2/D2
B10/B11
A1/A5
Serial Data
High
Current Earth
El ectroni c Earth
BLU/W (304)
Ser ia l Data
High
Speed
Fan
85 85
B12
C13
87 30
O/B (473)
R/B (1221)
B/P (157)
B/G
(151)
B/Y (155)
Loc. E3
4270-B
Loc. E2
86
87
87A
86 30
Blue
Fusible
Link
Loc.
E1
Engine
Cooling
Fan Rela y
(High Speed)
Engine Cooling
Fan Rela y
(Low Speed)
Engine
Cooling
Fans
M
I
C
R
O
P
R
O
C
E
S
S
O
R
M
I
C
R
O
BCM
PCM
YB176
YB165
YB174
YB163
YB174
YB163
YB175
YE112
YB198
YB187
YB164
YB176
YB165
YE139
YE139
YE140
YE140
YE43 YE103
YE103
YE43
DIAGNOSTIC AIDS
The Tech 2 scan tool has a special test to check this signal. To access this special test, select F3: BCM, then
select F1: THEFT STATUS. The Tech 2 scan tool will either display "OK TO START" or "NO START".
• Dirty, Damaged, or Loos e Connections or Dam aged Harness - Check for any damage to the harness which
could cause an intermittent open or short to earth or backed out terminals at the PCM connectors, broken
locks, improperly formed or damaged terminals.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. If the engine c ranks af ter a one s econd delay it m eans the BCM did not s ee a mess age f r om the PCM when
the ignition was turned "ON".
3. An open or short to earth on circuit 1221 will disable any communication of serial data.
DTC P1064 V6 PCM - LOW SPEED FAN – NO BCM RESPONSE
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. Is DTC P1255 set? Go to
DTC P1255
Diagnostic Table
in this Section
Go to Step 3
3. 1. Engine at idle speed.
2. Using Tech 2 scan tool, select "LOW FAN".
Does Tech 2 scan tool "BCM Response" display change
from "FAN OFF" to "FAN ON" when test is enabled?
Go to Step 4
Go to
Table A-12.1
in this Section
4. Does Tech 2 scan tool "BCM Response" display change
from "FAN OFF" to "FAN ON" when test is enabled? DTC P1064 is
intermittent.
Refer to
"Diagnostic Aids"
above.
Refer
Section 12J-1
LOW SERIES
BCM or
Section 12J-2
HIGH SERIES
BCM in VX
Service
Information for
additional
diagnosis.
DTC P1116 V6 PCM
ENGINE COOLANT TEMPERATURE (ECT) SIGNAL VOLTAGE UNSTABLE
CIRCUIT DESCRIPTION:
The Engine Coolant Temperature (ECT) sensor is a thermistor located in a coolant passage on the engine.
When engine coolant temperature is cold, the sensor has a high resistance. As temperature increases, the
resistance of the sensor decreases. The PCM provides a f ive volt signal to the engine coolant sensor, which is
also connected to PCM earth. The PCM reads the voltage drop on the signal line to determine engine coolant
temperature.
CONDITIONS FOR RUNNING THE DTC
• Time since engine started is greater than 10 seconds.
• DTC P0117, P0118 or P1628 are not set.
CONDITIONS FOR SETTING THE DTC
• ECT reading changes more than 400 mV in 200
milliseconds.
• Above conditions present for at least 10 seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• The PCM will substitute a coolant temperature default value. The PCM arrives at this default, or substitute
value, by switching to a starting point, then counting upwards to 95°C at a rate of 11 degrees per minute.
• When DTC P1116 is set, the PCM will turn "ON" the engine cooling fan.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
When attempting to diagnose an inter m ittent problem , use the s napshot m ode of the Tech 2 scan tool, to review
diagnostic information.
This DTC is more likely to set on a cold engine than on a hot engine because of the pull up resistors in the
PCM.
If DTC P0563, P1116 and P0200 are set, check for short to voltage on "Diagnostic Test" line. circuit 451.
VXPCM004
C6
D11
B
A
ENGINE COOLANT
TEMPERATURE SENSOR
SENSOR EARTH
ETC SENSOR SIGNAL
5V
4k
348
Ω
Ω
Y (41 0)
B/Y (452)
M
I
C
R
O
YE106
TO
THROTTLE POSITION
SENSOR
YB198
ECT SENSOR TABLE TEMP. TO RESISTANCE VALUES (APPROXIMATE)
C OHMS
110 134
100 180
90 244
70 474
40 1,483
30 2,268
20 3,555
0 9,517
-10 16,320
-20 28,939
TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic Table.
2. This step checks the wiring of the sensor for a intermittent fault.
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
COOLANT TEM P SENSO R
YE106
Y
(410)
B/Y
(452)
DTC P1116 V6 PCM - ENGINE COOLANT TEMPERA TURE (ECT) SIGNAL VOLTAGE UNSTABLE
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. 1. Install Tech 2 scan tool and set up snapshot
mode to trigger on DTC P0116.
2. Watch the Tech 2 scan tool while wiggling
the ECT sensor connector.
Does the "Eng. Coolant Temp" reading change sharply?
Go to Step 8 Go to Step 3
3. Wiggle and tug the ECT sensor harness.
Does the "Eng. Coolant Temp" reading change sharply? Go to Step 9 Go to Step 4
4. Wiggle and tug the harness at the PCM.
Does the "Eng. Coolant Temp" reading change sharply? Go to Step 10 Go to Step 5
5. Lightly tap on the PCM.
Does the "Eng. Coolant Temp" reading change sharply? Go to Step 6 DTC P1116 is
intermittent.
Refer "Diagnostic
Aids" above.
6. Make sure PCM is mounted securely to vehicle.
Was a problem found? Verify Repair Go to Step 7
7. Replace PCM.
Refer to section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Security Link
procedure.
Is action complete?
Verify Repair
DTC P1116 V6 PCM - ENGINE COOLANT TEMPERATURE (ECT) SIGNAL VOLTAGE UNSTABLE (CONT.)
STEP ACTION VALUE YES NO
8. 1. Check ECT sensor connector.
2. Check the tightness of the female terminal grip
with a spare male terminal.
3. Inspect connectors for corrosion. If connectors
are corroded, try cleaning with electronic part
cleaner and retest.
4. If these repairs do not resolve the problem,
replace terminals.
Is action complete?
Verify Repairs
9. 1. Check for an open in the ECT harness.
2. Check for broken strands of wire in ECT sensor
harness.
3. Check for cuts or pinches in ECT sensor harness.
4. Make repairs as necessary.
Is action complete?
Verify Repairs
10. 1. Check the ECT sensor connection at the PCM.
2. Check tightness of the female terminal grip with a
spare male terminal.
3. Inspect connectors for corrosion. If connectors
are corroded, try cleaning with electronic parts
cleaner and retest.
4. Remove connector strain relief and remove
terminal from connector to check for broken
locking tang.
Is action complete?
Verify Repairs
DTC P1255 V6 PCM -
THEFT DETERRENT SIGNAL MIS SING
CIRCUIT DESCRIPTION:
When the ignition is turned from off to on, the BCM will transm it security information to the PCM, via the serial
data bus, c ircuit 1221. The PCM c ompares the r eceived sec urity information with its stored s ecurity inform ation
and if matched, the PCM will enable the starter relay, continue to enable the injectors and transmit an ‘OK to
START’ message to the BCM via the serial data bus. The BCM will then switch from this short loop mode to
long loop m ode and each contr ol m odule on the ser ial data bus is poll ed, in tur n. The BCM wil l only transm it the
correct security information to the PCM if it has been disarmed via the remote coded key.
If the BCM is unable t o com municate with the PCM within 0.5 s econds of the igniti on being s witch on, the BCM
will open the solid state auxiliary serial data bus isolator, disconnecting all control modules connected to the
auxiliary data bus, circuit 1220. The isolation of the auxiliary data bus during this period, eliminates the
possibility of a control module failure, other than the BCM or PCM, causing a pr oblem on the bus, tha t may be
inhibiting the BCM from communicating with the PCM and preventing the engine from starting.
The BCM will continue t o operate in this way unti l the PCM resp onds with an acknowledgem ent or a m aximum
of five seconds, after which the BCM will close the auxiliary data bus and switch to the standard polling
sequence.
CONDITIONS FOR RUNNING THE DTC
• The ignition is on.
• Conditions present for at least 10 seconds.
CONDITIONS FOR SETTING THE DTC
• The PCM does not detect the BCM message.
VXPCM033
PCM
BCM
A13
SERIAL
DATA
STARTER
ENABLE
5V
SERIAL
DATA
MAIN
5V
BATTERY
FS
F31
A5/A6O/B (740)
(1040)
BATTERY M AIN POWER
FJ
R (2H)
F14
E20/D6P/B (39) IGNITION ON
15a 15 50
30 ACC
IGN
START
IGNITION SWI TCH
P (3)
B/Y
(155)
B
(150)
LOC. E3
LOC. G1 451691
DATA LINK
CONNECTOR
B/Y (155) ELECTRONIC EARTH
HIGH CURRENT
EARTH
A1/A5
LOC. E3
B/G (151) B10/B11
LOC. E3
E2/D2
E9/D3
E3/D13 SERIAL
DATA AUX.
R/B (1221)
GY/BLU
(1434)
GY
(434)
G/W (1220)
G/W (1220)
NEUTRAL START
BACK-UP SW.
( MANUAL
TRANS)
STARTER
MOTOR
M
START
RELAY
TO SRS
CONTROL
MODULE
TO INSTRUMENTS
ECC AND ABS/ETC
CONTROL MODULES
V (5)
A8
R (001 )
V (6 )
YB176
YB175
YB175
YB174
YB175
YB176
YB165
YB164
YB164
YB165
YB164
YB165
YB128
YB44
YE112
YB35
YB35
YE49
YE49
YB187
YB44
87 86
30 85
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM re cords the operating con ditions at t he time the diagnostic f ails. The PCM stores t his inform ation
in the History Data.
• When DTC P1255 is set and current, the engine will not start.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DTC c lears af ter fort y consecut ive warm - up cycles, if th is or an y other e m ission rela ted dia gnost ic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS
The Tech 2 scan tool has a special test to check this signal. To access this special test, select F3: BCM, then
select F1: THEFT STATUS. The Tech 2 scan tool will either display "OK TO START" or "NO START".
• Dirty, Dam aged, or Loos e Conn ectio ns or Dam aged Harness - Check f or any dam age to th e har ness which
could cause an intermittent open or short to earth or backed out terminals at the PCM connectors, broken
locks, improperly formed or damaged terminals.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. If the engine cr anks af ter a one sec on d de lay it means the BC M d id not s ee a mess age f r om the PCM when
the ignition was turn ed "O N ".
3. An open or short to earth on circuit 1221 will disable any communication of serial data. An open will be
indicate d by a cons tant hi gh vo ltage ( approx im ately 5 volts ), whereas a shor t to ear th would b e indica ted b y
an 0 volts on this circuit
P.C.M CONNECTOR 1
YB198
C1
C16
D1
D16
V/W
(123)
LG/B
(444)
(442)
LBLU/B
LBLU
(441)
(443)
LG/W
(452)
B/Y
(417)
BLU LG
(1456)
GY
(1412)
BLU
(815)
LBLU
(826)
O
(740)
R/B
(1221)
R
(481)
GY
(416)
(413)
BLU/B
V
(412)
GY/B
(1413)
B
(469)
(472)
BR
W/B
(451)
(259)
G/B
Y
(410)
O
(740)
(1227)
B/Y
P
(39)
BLU/W
T
(832)
(831)
V/W
(415)
(432)
L/G
YB175
B.C.M CONNECTOR 3
BERLINA & CALAIS
LBLU
Y/R
O/BLU
B
BLU/W
W/BLU
(43)
(39)
(97)
(83)
(94)
O/W
Y/B
B/R
(161)
(143)
(640)
(1150)
(260)
(1144)
(840)
Y
P/B
GY
LBLU
(494)
W
(160)
V/R
R/B
W/G
B/Y
GY/B
(229)
(1221)
(1220)
(556)
(96)
(261)
G/W
Y
Y/B
W
W/R
(266)
(1220)
(272)
(717)
(308)
BR/G
(271)
R/W
GY/R
(1391)
B.C.M CONNECTOR 3
EXECUTIVE
YB164
(83)
(97)
W/G
(229)
B/G
W/BLU
(266)
(1144)
P/BLU
G/W
BLU/W
(1220)
(494)
BR/G
GY
(1220)
B
GY
(1391)
LBLU
(151)
(271)
R/B
R/W
(1150)
(291)
V/R
(8)
O
P/B
B/R
Y
GY/R
(1221)
(94)
(39) (44)
(248)
10
20 1
11
DATA LINK CO NNECTO R
YB128
(863)
O/B BLU/B R/B
(1221)
(740)
16 9
(1220)
(155)
B/Y G/W
W/B
(451)
B
(150)
Y
(1049)
1
8
ENGINE CONNECTO R 3
YE112
(1221)
(42)
(121)
BR/BLU
BR/R
R/B O/B
LG
P/B
BLU
(740)
(24)
(39)
(774)
LBLU
(411)
S/C ONLY
DTC P1255 V6 PCM - THEFT DETERRENT SIGNAL MISSING
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section.
2. Attempt to start vehicle.
Does engine crank after a one second delay when
ignition is sw itche d "ON"?
Go to Step 3 DTC P1255 is
intermittent, refer
to "Diagnostic
Aids" above.
3. Ignition "ON ".
Does voltage between DLC terminal "9" and earth equal
specified value?
3 -5 volts
(Variable) Refer to
Section 12F
"THEFT
DETERRENT" in
VX Service
Information for
further diagnosis .
Go to Step 4
4. Check for poor connection at PCM terminal and/or open
or shorted circuit 1221.
Was a problem found?
Verify Repair Go to Step 5
5. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P1351 V6 PCM -
IGNITION ELECTRONIC SPARK TIMING (EST) CIRCUIT FAULT
CIRCUIT DESCRIPTION;
There are two modes of ignition system operation: BYPASS mode, and ELECTRONIC SPARK TIMING mode.
The Bypass m ode is norm ally used while s tarting the engine, while the Electronic Spark T iming m ode is used to
allow the PCM to control the ignition system after the engine is running. The PCM controls a "Bypass control
circuit", used to control the ignition module between the two different ignition system modes.
The PCM's Electronic Spark Timing (EST) output circuitry generates EST output pulses anytime crankshaft
reference input pulses are received. The PCM also monitors it's EST output terminal, to monitor if and when
EST pulses are present.
When the ignition system is operating in the Bypass mode (such as when the engine is cranking), the ignition
module earths the EST pulses com ing from the PCM. Because the EST pulses should be earthed through the
ignition module during Bypass mode operation., the PCM should not detect EST pulses on it's EST output
terminal.
If the EST output circuit wire between the PCM and the ignition module has an "open circuit" fault, then the
ignition module c an not ear th the PCM's EST output pulses . If the PCM detec ts two EST puls es during the f ir st 3
crankshaft reference input pulses, indicating the EST circuit is open, the PCM will set a DTC P1351.
DTC P1351 c an also be set if the Bypass control circ uit is shor ted to voltage. If this where to happen, the PCM's
EST monitor would not sense the EST signal being earthed in the ignition module while cranking , and DTC
P1351 would be set.
CONDITIONS FOR RUNNING THE DTC
• The ignition is on.
CONDITIONS FOR SETTING THE DTC
• PCM had detected at least 2 EST output pulses, during the first 3 crankshaft reference signal pulses
received from the ignition module, while cranking to start the engine.
VXPCM009
PCM
B10
B6
B7
B9
B4
B3
CRANKSHAFT
REFERENCE LO
CAM
SENSOR
CONNECTOR
CAMSHAFT
POSITION
SENSOR
SIGNAL
CRANKSHAFT
REFERENCE HI
CRANKSHAFT
18X SIGNAL
BYPASS CONTROL
EST OUTPUT
module power supply - in
sensor power supply - out
cam signal - in
3x crank sensor - in
18x crank sensor - in
cam signal - out
tacho signal - out
crankshaft reference - out
18X cranksignal - out
bypass control
EST signal -in
P
N
M
L
K
J
H
G
F
E
D
C
B
A
DIS
MODULE
ABCD CBA
W/B (644)
GY/R (645)
B/R (453)
CRANK
SENSOR
CONN
L BLU/W
(646) BR (633)
BLU/Y (643)
BR (121)
B (63 0)
V (43 0)
L BLU/B (647)
T/B (4 24)
IGN SW
EFI RELAY
O/Y
(479) LOC. E3
YE39
YE111 YE39
YB187
YE63
YB187
YE57
YE34
LG
(482)
B/W
(152)P/B
(39)
IC
IC
IC
M
I
C
R
O
W (423)
F35
+-
BATTERY
FS
FJ
(1040)
P (3)
R (2H)
F14
TO INSTRUMENT CLUSTER
(TERMINAL 18)
ABS/ETC (TERMINAL 30)
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P1351 is set and current, the PCM will operate in the Bypass spark mode.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS
• Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and poor terminal to wire connection.
• Damaged Har ness. Ins pect the wiring harness f or dam age. If the harness appears to be O K, disconnect the
ignition module, turn the ignition "ON". Connect and observe a voltmeter connected between the Bypass
control circuit and +B, while m oving c onnectors and wiring harness related to the ignition m odule. A change
in voltage will indicate the location of the fault.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
4. This Step checks to see if circuit 424 is shorted to voltage.
8. This Step checks to see if circuit 423 is open.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
DIRECT IGNITION MODULE
YE57
(647)
LBLU/B
W/B
(644)
B/R
(453)
LBLU/W
(646)
BLU/Y
(643)
V
(430)
T/B
(424)
(633)
BR
(645)
GY/R
LG
(482)
B
(630)
BR
(121)
W
(423)
PNMLKJHGFED
CBA
YE111
ENGINE CONNECTOR 2
(482)
(481)
R
LG
GY
G
(434)
(129)
P
(439)
(59)
(366)
LG/B
GW/B
(451)
DTC P1351 V6 PCM - IGNITION ELECTRONIC SPARK TIMING (EST) CIRCUIT FAULT
STEP VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. 1. Clear DTC P1351.
2. Start engine and run above 1600 RPM.
3. Observe DTC(s).
Did DTC P1351 set?
Go to Step 3 DTC P1351 is
intermittent. If no
additional DTC's
were stored, refer
to "Diagnostic
Aids" above.
3. 1. Ignition "OFF".
2. Disconnect ignition module 14 pin connector.
3. Probe ignition module harness connector terminal
"B" with a voltmeter connected to earth.
4. Ignition "ON".
Is voltage greater then the specified value?
0.5 V Go to Step 4 Go to Step 7
4. 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. Ignition "ON".
Is voltage still present at ignition module harness
Connector terminal "B"?
Go to Step 5 Go to Step 10
5. Repair short to voltage in Bypass circuit 424.
Is action complete? Verify Repair
DTC P1351 V6 PCM - IGNITION ELECTRONIC SPARK TIMING (EST) CIRCUIT FAULT (CONTINUED)
STEP VALUE YES NO
6. Replace ignition module.
Is action complete? Verify Repair
7. 1. Ignition "OFF".
2. Reconnect 14 pin connector to ignition module.
3. Backprobe PCM connector B3 with voltmeter
connected to earth.
4. Ignition "ON", crank engine.
Is voltage approximately at specified value while
cranking or with engine running?
2 volts Go to Step 8 Go to Step 9
8. Check for faulty connection, or an open in the EST circuit
423 between the PCM terminal and the ignition module
harness connector terminal "A"
Was a fault found?
Verify Repair Go to Step 6
9. Check PCM for faulty connection.
Was a faulty connection found ? Verify Repair Go to Step 10
10. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P1361 V6 PCM -
IGNITION BYPASS CIRCUIT FAULT
CIRCUIT DESCRIPTION;
There are two modes of ignition system operation: BYPASS mode, and ELECTRONIC SPARK TIMING mode.
The Bypass m ode is norm ally used while s tarting the engine, while the Electronic Spark T iming m ode is used to
allow the PCM to control the ignition system after the engine is running. The PCM controls a "Bypass control
circuit", used to control the ignition module between the two different ignition system modes.
The PCM's Electronic Spark Timing (EST) output circuitry generates EST output pulses anytime crankshaft
reference input pulses are received. The PCM also monitors it's EST output terminal, to monitor if and when
EST pulses are present.
When the ignition system is operating in the Bypass mode (such as when the engine is cranking), the ignition
module earths the EST pulses com ing from the PCM. Because the EST pulses should be earthed through the
ignition module during Bypass mode operation., the PCM should not detect EST pulses on it's EST output
terminal.
W hen the engine is star ted, the PCM applies 5 volts to the Bypass control circ uit. W hen r eceived by the ignition
module, this 5 volts control causes the ignition module to release the earth from the EST pulses coming from
the PCM. The ignition module will then us e the EST pulses to operate the ignition s ystem . When this occ ur s, the
PCM will correctly detect EST pulses at it's EST output terminal.
If the Bypass control cir cuit has as open fault or s hort to earth, or if the EST circuit has a short to earth or short
to voltage, the PCM cannot control the ignition m odule to release the EST pulses from being earthed. Because
the PCM also monitors it's EST output terminal for EST pulses, if it detects no EST pulses after it has "turned
on" the 5 volts to the Bypass contr ol circuit, and the engine s peed goes above 1600 RPM, a DTC P1361 will be
set.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
CONDITIONS FOR SETTING THE DTC
• The PCM has commanded EST.
• The PCM has detected no EST output pulses for 1000 ms with the engine RPM below 200, or no EST
pulses received for 200 ms with engine RPM greater than 200..
VXPCM009
PCM
B10
B6
B7
B9
B4
B3
CRANKSHAFT
REFERENCE LO
CAM
SENSOR
CONNECTOR
CAMSHAFT
POSITION
SENSOR
SIGNAL
CRANKSHAFT
REFERENCE HI
CRANKSHAFT
18X SIGNAL
BYPASS CONTROL
EST OUTPUT
module power supply - in
sensor power supply - out
cam signal - in
3x crank sensor - in
18x crank sensor - in
cam signal - out
tacho signal - out
crankshaft reference - out
18X cranksignal - out
bypass control
EST signal -in
P
N
M
L
K
J
H
G
F
E
D
C
B
A
DIS
MODULE
ABCD CBA
W/B (644)
GY/R (645)
B/R (453)
CRANK
SENSOR
CONN
L BLU/W
(646) BR (633)
BLU/Y (643)
BR (121)
B (63 0)
V (43 0)
L BLU/B (647)
T/B (4 24)
IGN SW
EFI RELAY
O/Y
(479) LOC. E3
YE39
YE111 YE39
YB187
YE63
YB187
YE57
YE34
LG
(482)
B/W
(152)P/B
(39)
IC
IC
IC
M
I
C
R
O
W (423)
F35
+-
BATTERY
FS
FJ
(1040)
P (3)
R (2H)
F14
TO INSTRUMENT CLUSTER
(TERMINAL 18)
ABS/ETC (TERMINAL 30)
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the tim e the diagnostic fails. T he PCM stores this information
in the History Data.
• When DTC P1361 is set and current, the PCM will operate in the Bypass spark mode.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A Histor y DT C clears after f orty c onsecutive warm -up cycles, if this or any other em ission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS
• Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and poor terminal to wire connection.
• Damaged Har ness. Ins pect the wiring harness for dam age. If the harness appears to be O K, disconnec t the
ignition module, turn the ignition "ON". Connect and observe a voltmeter connected between the Bypass
control circuit and B+, while m oving c onnectors and wiring harness related to the ignition m odule. A change
in voltage will indicate the location of the fault.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
4. This step checks to see if circuit 423 is shorted to voltage.
7. This step checks to see if circuit 423 is shorted to earth.
10. This step checks to see if circuit 424 is shorted to earth.
12. This step checks to see if circuit 424 is open.
13. This step checks to see if the ignition module is capable of switching from Bypass to EST mode.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
DIRE CT IGNITION MODU LE
YE57
(647)
LBLU/B
W/B
(644)
B/R
(453)
LBLU/W
(646)
BLU/Y
(643)
V
(430)
T/B
(424)
(633)
BR
(645)
GY/R
LG
(482)
B
(630)
BR
(121)
W
(423)
PNMLKJHGFED
CBA
YE111
ENGINE CONNECTOR 2
(482)
(481)
R
LG
GY
G
(434)
(129)
P
(439)
(59)
(366)
LG/B
GW/B
(451)
DTC P1361 V6 PCM - IGNITION BYPASS CIRCUIT FAULT
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check.
2. 1. Clear DTC P1361.
2. Start engine, and run above 1600 RPM.
3. Observe DTC(s).
Did DTC P1361 set ?
Go to Step 3 DTC P1361
is intermittent.
Refer to
"Diagnostic Aids"
above
3. 1. Ignition "OFF".
2. Disconnect ignition module 14 pin connector.
3. Probe ignition module harness connector terminal
"A" with a voltmeter to earth.
4. Ignition "ON".
Is voltage greater then the specified value?
0.5 V Go to Step 4 Go to Step 6
4. 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. Ignition "ON".
Is voltage still present at ignition module harness
Connector terminal "A" ?
Go to Step 5 Go to Step 15
5. Repair short to voltage on circuit 423.
Is action complete ? Verify Repair
DTC P1361 V6 PCM - IGNITION BYPASS CIRCUIT FAULT (CONTINUED)
STEP ACTION VALUE YES NO
6. 1. Ignition "ON".
2. Probe ignition module harness connector circuit
423 with a test light connected to battery voltage.
Is test light "ON" ?
Go to Step 7 Go to Step 9
7. 1. Ignition "OFF
2. Disconnect PCM connectors.
3. Probe ignition module connector circuit 423 with a
test light connected to battery voltage.
Is test light "ON" ?
Go to Step 8 Go to Step 14
8. Repair short to earth in circuit 423.
Is action complete Verify Repair
9. 1. Ignition "ON".
2. Disconnect ignition module 14 pin connector.
3. With test light connected to battery voltage, probe
ignition module harness connector circuit 424.
Is test light "ON" ?
Go to Step 10 Go to Step 12
10. 1. Ignition "OFF".
2. Disconnect PCM connectors.
3. Ignition "ON".
4. Disconnect ignition module 14 pin connector.
5. With test light connected to battery voltage, probe
ignition module harness connector circuit 424.
Is test light "ON" ?
Go to Step 11 Go to Step 14
11. Repair short to earth on circuit 424.
Is action complete ? Verify Repair
12.
1. Ignition "OFF".
2. Disconnect PCM connectors.
3. Check for faulty connection or open circuit 424.
Is fault found ?
Verify Repair Go to Step 13
13. 1. Ignition "OFF".
2. Reconnect ignition module 14 pin connector.
3. Disconnect PCM connectors.
3. Ignition "ON".
4. Probe PCM harness connector circuit 423 with an
ohmmeter connected to earth.
5. Probe PCM harness connector circuit 424 with a
test light connected to battery voltage.
As the test light contacts circuit 424, does resistance
switch from under the specified value to over the
specified value ?
300 ohms
to
6000 ohms
Go to Step 14 Go to Step 15
14. Replace PCM.
Refer to Section 6C1-3 SERVICE OPERATIONS of the
VX Series Service Information, for PCM Programming
and Security Link procedure.
Is action complete?
Verify Repair
15. Replace ignition module.
Is action complete ? Verify Repair
DTC P1372 V6 PCM
NO REFERENCE PULSES WHILE CRANKING
CIRCUIT DESCRIPTION:
This DTC is intended to help in diagnosing a no-start condition. Any time the engine is turning, the ignition m odule
should generate the crankshaft reference pulses that the PCM should be receiving. Fuel injection pulses are
"timed" from the cr ankshaft pulses, and without them no inj ection pulses will occur. T he PCM can determ ine when
these crankshaft pulses should be present, but aren't.
As with any engine while being crank ed, there is a sm all amount of inlet manif old vacuum . Also while crank ing, the
battery voltage will be less than 11 volts. If the PCM's MAF sensor input detects manifold vacuum and the ignition
voltage input detects less than 11 volts and there are no reference input pulses, a DTC P1372 set.
NOTE: It is possible for the ignition system to provide spark, yet there may not be any reference pulses at the
PCM.
CONDITIONS FOR RUNNING THE DTC
• No MAF sensor DTC is set.
• Battery voltage is at or below 11 volts.
• The MAF sensor input signal is greater than 2048 Hz.
CONDITIONS FOR SETTING THE DTC
• No crank shaft r eference input puls es are received at the PCM c ranks haft refe rence input terminal for at leas t 2
seconds.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) 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 History Data.
VXPCM009
PCM
B10
B6
B7
B9
B4
B3
CRANKSHAFT
REFERENCE LO
CAM
SENSOR
CONNECTOR
CAMSHAFT
POSITION
SENSOR
SIGNAL
CRANKSHAFT
REFERENCE HI
CRANKSHAFT
18X SIGNAL
BYPASS CONTROL
EST OUTPUT
module power supply - in
sensor power supply - out
cam signal - in
3x crank sensor - in
18x crank sensor - in
cam signal - out
tacho signal - out
crankshaft reference - out
18X cranksignal - out
bypass control
EST signal -in
P
N
M
L
K
J
H
G
F
E
D
C
B
A
DIS
MODULE
ABCD CBA
W/B (644)
GY/R (645)
B/R (453)
CRANK
SENSOR
CONN
L BLU/W
(646) BR (633)
BLU/Y (643)
BR (121)
B (63 0)
V (43 0)
L BLU/B (647)
T/B (4 24)
IGN SW
EFI RELAY
O/Y
(479) LOC. E3
YE39
YE111 YE39
YB187
YE63
YB187
YE57
YE34
LG
(482)
B/W
(152)P/B
(39)
IC
IC
IC
M
I
C
R
O
W (423)
F35
+-
BATTERY
FS
FJ
(1040)
P (3)
R (2H)
F14
TO INSTRUMENT CLUSTER
(TERMINAL 18)
ABS/ETC (TERMINAL 30)
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS
• Poor c onnection at PCM. Inspect harnes s connector s for bac ked out term inals, im proper m ating, brok en lock s,
improperly formed or damaged terminals, and poor terminal to wire connection.
• Damaged Harness. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the
ignition module, turn the ignition "ON". Connect and observe a voltmeter connected between the Bypass
control circuit and B+, while moving connectors and wiring harness related to the ignition m odule. A change in
voltage will indicate the location of the fault.
NOTE: Use ST-125 spark checker or equivalent to check for adequate spark. An ST-125 requires about 25,000
volts (25 Kilovolts or 25 k V) to "spark ". Do not use a s park plug in open air ear thed to the engine as an indication of
suff icient "spark ". Only a few kilovolts are required to jum p the gap of a spark plug outside of the engine, and that
would be an inadequate test of the ignition system.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. If engine starts, the problem is not present now. While the PCM monitors 3 inputs to determine DTC P1372,
only a lack of reference input signal pulses can set the DTC. If a problem occurred on the MAF or ignition
voltage inputs, other problems would be apparent.
NOTE: Even one crankshaft reference pulse while cranking will cause DTC P1372 to NOT set.
3. Spark on all three wires on the same side of the engine proves the DIS coil pack to be OK. No spark on any
lead means the DIS ignition system is suspect of causing the DTC P1372. If the DIS ignition system cannot
generate any spark, it cannot generate the crankshaft reference signal either.
Refer to TABLE A-8.1 in this Sec tion to determine the caus e. If there is spark on only 1 or 2 s park plug leads,
the crank sensor is probably OK, but there could be a problem with the coil pac k or DIS m odule. TABLE A-8.1
in this Section should determine the problem.
4. The voltage should be either "OFF" (less than 1 volt) or "ON" (more than 3 volts). This is the square-wave,
digital "ON-OFF" reference signal generated by the ignition module. The voltage could be either reading,
depending on where the reluctor wheel stopped turning.
5. This is again the reference signal. W hen the reluctor wheel is turning, the signal changes from under 1 volt to
over 3 volts, back and forth, eight times per reluctor wheel revolution. Since it changes quickly, the voltmeter
can indicate only an average voltage. (expected reading - approximately 2 volts.)
6. A loose connection at PCM terminal "B9" could cause an intermittent voltage measurement to be seen.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
DIRECT IGNITIO N MODULE
YE 57
(647)
LBLU/B
W/B
(644)
B/R
(453)
LBLU/W
(646)
BLU/Y
(643)
V
(430)
T/B
(424)
(633)
BR
(645)
GY/R
LG
(482)
B
(630)
BR
(121)
W
(423)
PNMLKJHGFED
CBA
YE111
ENGINE CONNECTOR 2
(482)
(481)
R
LG
GY
G
(434)
(129)
P
(439)
(59)
(366)
LG/B
GW/B
(451)
DTC P1372 V6 PCM - NO REFERENCE PULSES WHILE CRANKING
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System check
performed? Go to Step 2 Go to OBD
System Check
in this Section
2. Attempt to start engine.
Did engine start and continue to run? DTC P1372 is
intermittent. If no
additional DTC's
were stored, refer
to "Intermittents"
in Section 6C1-
2B S YMPT OMS.
Go to Step 3
3. 1. Remove the spark plug leads from two spark
plugs.
2. Connect ST-125 spark checker (See note above) to
each lead individually, and check for spark while
cranking the engine.
Was spark evident on both leads? (A few sparks and then
nothing is considered no spark.)
Go to Step 4 Go to
Table A-8.1
in this Section
4. 1. Ignition "OFF".
2. Disconnect PCM.
3. Backprobe PCM harness connector terminal "B9"
to earth with a digital voltmeter set to read "DC
volts".
4. Ignition "ON".
Is the voltage at the specified value?
Go to Step 5 Go to Step 9
5. 1. Ignition "OFF".
2. Disconnect PCM.
3. Backprobe PCM harness connector terminal "B9"
to earth with a digital voltmeter set to read "DC
Volts".
4. Ignition "ON" .
5. While observing digital voltmeter, crank the engine.
Is voltage measured approximately the specified value?
2 - 3 volts Go to Step 6 Go to Step 8
6. Check PCM terminal "B9" for a loose connection.
Was a fault found? Verify Repair
Go to Step 7
7. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
8. Check circuit 430 for a faulty connection or an open or
short to earth.
Was a fault found?
Verify Repair Go to Step 9
9. Replace Ignition Module
Is action complete? Verify Repair
Approx.
5 volts
DTC P1571 V6 PCM -
REQUESTED TORQUE OUT OF RANGE
CIRCUIT DESCRIPTION:
The Anti-Lock Brake System/Electronic Traction Control (ABS/ETC) Module (Traction Control) controls the PWM
signal on the torque request circuit while monitoring the wheel speed sensors to detect slippage. The PCM
monitor s the PW M signal and reduces engine torque as needed by retar ding ignition timing, decreas ing boost duty
cycle, increasing air/fuel ratio, or in severe cases, shutting OFF up to five (5) injectors. The PCM sends a PWM
signal to the ABS/ETC m odule on the torque achieved cir cuit inform ing the ABS/ETC m odule of response m ade to
the torque request signal. A problem with the torque Request circuit should cause DTC P1571 and a ABS/ETC
DTC to set and traction control to be disabled. Refer to Section 12L ABS & ABS/ETC in VX Service Information
for information on ABS/ETC operation and DTC diagnosis.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
CONDITIONS FOR SETTING THE DTC
• The PCM detects the incorrect voltage on the Requested Torque circuit.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) 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 History Data.
• W hen DT C P1571 is set, tr action control will be disabled and a corr esponding DTC will be set in the ABS/ET S
module.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
12V
E
30
M
I
C
R
O
BR/R(121)
BR (121)
ENGINE SPEED
DIS
12V
12V
B11
B8
27
13
REQUESTED
TORQUE (M MR)
MMI ACTUAL
TORQUE (M MI)
O/W (1426)
M
I
C
R
O
B/W (1247)
M
I
C
R
O
BATTERY POWER
15
+
-
BATTERY
FJ
ABS/ETC
IGNITION
SWITCH
15a 15 50
30
OFF/ON
LOCK
ACC
IGN
START
F27
P (3)
VXPCM024
PCM
R (8 55)
MMR
YE112
YE57 YB66
TO
TERMINAL 18 (TACHOMETER)
YB187 YE110
YE98
YB44
YB44
DIAGNOSTIC AIDS
Check for the following conditions:
• Poor c onnection at PCM. Inspect harnes s connector s for bac ked out term inals, im proper m ating, brok en lock s,
improper formed or damaged terminals, and poor terminal to wire connection.
• Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the
PCM, turn the ignition ON and observe a voltmeter connected to the Torque Request circuit at the PCM
harness connector while m oving connector s and wiring harness es related to the ABS/ETC m odule. If a voltage
is indicated the fault is in the harness.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. The PCM supplies 4 to 5 volts on the Torque Reques t circuit. W ith the PCM disconnec ted, there should be no
voltage on the circuit.
6. This step checks to see if the Torque Request circuit is shorted to voltage.
11. This step checks to see if the ABS/ECT system is functioning properly.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
ENGINE CONNECTOR 1
YE110
O/W
(304)
(1426)
BLU/W
G/W
(339)
P/BLU
(465)
(123)
V/W
(1427)
B/W
Y
(1049)
A.B.S & T.C.S MODULATOR AND CONTROL MO DULE
YE 98
1
15
16
27
31
26
19
20
(885)
(884)
(833)
(830)
(873)
(872)
(883)
(882)
B
BLU
W
R
BR
GY
Y
(855)
(20)
(1426)
(863)
(1220)
BLU/B
G/W
O/W
BLU/R
R
V
R/W
BR/R
B/W
G
Y/R
B
R
R
B/O
(1429)
(121)
(1427)
(875)
(88)
(150)
(2R)
(2R)
(154)
GY/B
(1687)
DTC P1571 V6 PCM - REQUESTED TORQUE OUT OF RANGE
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. 1. Ignition "OFF".
2. Disconnect the PCM connectors.
3. Ignition "ON".
4. Using volt/ohmmeter, measure voltage between the
torque Request circuit at the PCM harness
connector and earth.
Is voltage at the specified value?
0 V Go to Step 3 Go to Step 6
DTC P1571 V6 PCM - REQUESTED TORQUE OUT OF RANGE (CONTINUED)
STEP ACTION VALUE YES NO
3. 1. Ignition "OFF".
2. Reconnect the PCM connectors.
3. Disconnect the ABS/ECT connector.
4. Ignition "ON".
5. Using volt/ohmmeter, measure voltage between the
torque Request circuit at the ABS/ECT harness
connector and earth.
Is voltage at the specified value?
4-5 V Go to Step 4 Go to Step 8
4. Check for poor connection at ABS/ECT module.
Was a problem found? Verify Repair Go to Step 5
5. Replace ABS/ECT module.
Is action complete? Verify Repair
6. 1. Ignition "OFF".
2. Disconnect the ABS/ECT module connector.
3. Ignition "ON".
4. Using volt/ohmmeter, measure voltage between the
torque Request circuit at the PCM harness
connector and earth.
Is voltage at the specified value?
0 V Go to Step 5 Go to Step 7
7. Locate and repair short to voltage in Torque Request
circuit.
Is action complete?
8. Check for an open or short to earth in the Torque
Request circuit between the PCM and the ABS/ECT
module.
Was a problem found?
Verify Repair Go to Step 9
9. Check for poor connection at PCM harness connectors.
Was a problem found? Verify Repair Go to Step 10
10. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 12
11. 1. Ignition "OFF".
2. Reconnect the ABS/ECT connector, and the PCM
connectors.
3. Raise the rear of the vehicle, and support the rear
wheel trailing arms.
4. Backprobe PCM harness connector for the Torque
Request circuit with a volt/ohmmeter connected to
earth.
5. Ignition "ON", and the engine running in park.
Is the voltage near the specified value?
4-5 V Go to Step 12 Go to Step 2
12. With the engine still running in park, and the
volt/ohmmeter still connected to the Torque Request
circuit, shift the transmission into D range and let the
rear wheels turn. Snap the throttle and note the voltage
on the volt/ohmmeter.
Does the volt/ohmmeter switch from the First specified
value to the Second specified value ( and stay at the
second value) when traction control is activated?
First
4-5 V
Second
1-2 V
ABS/ECT
System is
working properly
Go to Step 2
4226
1
1. Powertrain Control Module (PCM)
DTC P1627 V6 PCM -
PCM – ANALOG TO DIGITAL (A/D) CONVERSION ERROR
DTC P1627 V6 PCM - PCM - ANALOG TO DIGITAL (A/D) CONVERSION ERROR
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check in
this Section
2. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify repair
DTC P1628 V6 PCM -
PCM ERROR – ENGINE COOLANT TEMPERATURE
CIRCUIT DESCRIPTION;
The PCM uses two different internal pull-up resistors to increase resolution throughout the entire range of engine
operating temperatures. When the engine coolant temperature is less than 50 degrees C, the 4K ohm resistor is
used. W hen temperature is above 50 degrees C, the PCM switches to the 348 ohm resistor. If the pull-up resistor
does not switch, DTC P1628 will set.
CONDITIONS FOR RUNNING THE DTC
• The engine run time is longer than 10 seconds.
CONDITIONS FOR SETTING THE DTC
• The pull-up resistor inside the PCM switches and there is less than a 60mV change in the engine coolant
temperature signal.
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in
the History Data.
• When an ECT sensor circuit fault is detected, and current, the PCM will substitute a coolant temperature
default value. T he PCM arrives at this default, or substitute value, by switching to a starting point, then c ounting
upwards to 95°C at a rate of 11 degrees per minute.
• When DTC P1628 is set, the PCM will turn "ON" the engine cooling fan.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS
W hen a DTC P0116, P0117, P0118 and P1628 is current, the PCM will turn on the electric engine cooling fan(s).
This is a FAIL-SAFE action by the PCM to prevent a possible engine overheat condition, since these DTC’s
indicate an unknown actual engine coolant temperature.
If the ECT sensor circ uit opens with the ignition off , the PCM will interpret -30°C and deliver enough f uel to start the
engine at room temperature. If the actual ambient temperature is above 0°C, the engine may flood and not start
unless CLEAR FLOOD MODE is used by fully depressing the accelerator while cranking. In the CLEAR FLOOD
MODE the injectors pulse width is set to zero milliseconds.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. DTC P1628 is an internal fault within the PCM. The PCM must be replaced!
VXPCM004
C6
D11
B
A
ENGINE COOLANT
TEMPERATURE SENSOR
SENSOR EARTH
ETC SENSOR SIGNAL
5V
4k
348
Ω
Ω
Y (41 0)
B/Y (452)
M
I
C
R
O
YE106
TO
THROTTLE POSITION
SENSOR
YB198
DTC P1628 V6 PCM - PCM ERROR – ENGINE COOLANT TEMPERATURE
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2. Go to OBD
System Check in
this Section.
2. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P1642 V6 PCM
LPG ENABLE SIGNAL OUT OF RANGE
CIRCUIT DESCRIPTION;
The PCM m onitors the voltage at term inal F4 to deter mine the status of the fuel mode s witch. W hen the fuel m ode
switch is open, the voltage at PCM terminal F4 will be 0 volts. W hen the LPG fuel mode switch is closed, batter y
voltage will be applied to PCM terminal F4 via the ignition switch fuse F14 circuit, 39 (Pink/Black wire), the fuel
mode switch and circuit 936 (Blue/Orange wire). This will cause the voltage at terminal F4 to be pulled up to 12
volts whenever the fuel mode switch is depressed. This high voltage is seen by the PCM as a fuel mode switch
input signal. When the PCM sees a high voltage at terminal F4 the PCM will toggle between the LPG and petrol
operatin g modes. The PCM wil l on ly toggle be t ween th e Petrol and LPG mode if the i gnition is o n an d th e en gin e is
not running or the engine is running above 1300 RPM.
When operating in the LPG Mode, the PCM will supply an earth signal from PCM terminal A3 to the LPG Smart
Unit. This signal enables LPG system operation. If there is a fault with the LPG Enable circuit 937 (White/Green
wire), DTC P1642 will set.
CONDITIONS FOR RUNNING THE DTC
• The engine in operating in the LPG mode.
CONDITIONS FOR SETTING THE DTC
• The voltage at PCM terminal A3 is too high for greater that one second.
Or
• The voltage at PCM terminal A3 is too low for greater that one second.
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) 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 History Data.
• The PCM will default to the Petrol fuel mode for vehicle operation.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
4374
PCM
Y/G
CONTROL
SIGNAL
2-3mA
B/Y
P/G
43
30V
2A
W/G
B/R
BLU/R
2
5
6
1
LPG
TANK
SENDER
SMART UNIT
W/G
(937) A3 ENABLE
LPG
P
(39)
12V
M
I
C
R
O
B/R
(750)
LOC. E4
LOC. E3
LOC. E5/E15
B
(155)
B/Y
(155)
TO
INSTRUMENTS
TERMINAL
NUMBER 10
TO
FUSE F14
YB51
YE110
YB187
YE114
YR50
YR50
YR51 YR51
YB51
YE2
YR50
YR51
FUEL MODE SWITCH
YB199
YE110
YB30
YE68
YB51
YE112
DIAGNOSTIC AIDS
Check for the following conditions:
• Poor connection at PCM. Inspect harness connect ors for backed out term inals, improper mating, broken locks,
improper formed or damaged terminals, and poor terminal to wire connection.
• Dirty, Damaged, or Loose Connections or Damaged Harness - Check for any damage to the harness which
could cause an intermittent open or short to earth or backed out terminals at the PCM connectors, broken
locks, improperly formed or damaged terminals.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step verifies that B+ is supplied from the LPG T ank Smart Unit to the PCM terminal A3. If there is no B+
on circuit 937 and the circuit is not open or earthed or shorted to voltage, the LPG Tank Smart Unit is faulty.
3. This step is checking circuit 937 for a short to voltage or a faulty PCM.
6. This step is checking the power supply to the LPG Tank Smart Unit. If fuse F14 is open, there will be other
DTC’s set. Verify all DTC’s are checked and corrected.
9. This step verifies a good earth circuit at the LPG Tank Smart Unit.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
L.P.G TANK CONNECTOR
SEDAN
(937)
W/G
(750)
B/R
B
(155)
(1030)
Y
BLU/Y
(965)
(39)
P
WAGON
L.P.G TANK CONNECTOR
(965)
(1030)
YBLU/Y
(155)
B
(39)
P
(937)
W/G
(750)
B/R
(937)
W/G
(750)
B
(155)
(1030)
Y
BLU/Y
(965)
(39)
P
ENGINE CONNECTOR 1
YE110
O/W
(304)
(1426)
BLU/W
G/W
(339)
P/BLU
(465)
(123)
V/W
(1427)
B/W
Y
(1049)
ENGINE CONNE CTOR 3
YE112
(1221)
(42)
(121)
BR/BLU
BR/R
R/B O/B
LG
P/B
BLU
(740)
(24)
(39)
(774)
LBLU
(411)
S/C ONLY
LOCATION E3 EARTH CONNECTOR
RIGHT HAND INNER FENDER
YE114
(151)
B/G
(157)
B/R
(150) (155)
BB/Y
(152)
B/W
(157)
B/R
DTC P1642 V6 PCM - LPG ENABLE SIGNAL OUT OF RANGE
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2. 1. Ignition "OFF", disconnect the PCM Brown A/B
connector.
2. Ignition "ON".
3. Using Digital Multimeter, measure voltage for the
LPG Tank Smart Unit circuit 937 at PCM terminal A3
at the PCM harness connector and earth.
Is voltage near the specified value?
B+ Go to Step 3 Go to Step 5
3. 1. Ignition "OFF", disconnect LPG Tank Smart Unit.
2. Ignition "ON".
3. Using Digital Multimeter, measure voltage between
the LPG Tank Smart Unit circuit 937 at PCM terminal
A3 at the PCM harness connector and earth.
Is voltage near the specified value?
0 Volts Go to Step 11 Go to Step 4
4. Repair short to voltage in LPG Enable circuit from the
LPG Tank Smart Unit to PCM terminal A3.
Is action complete?
Verify Repair
DTC P1642 V6 PCM - LPG ENABLE SIGNAL OUT OF RANGE (CONTINUED)
STEP ACTION VALUE YES NO
5. Check for an open or short to earth in circuit 937 between
the LPG Tank Smart Unit and PCM terminal A3.
Was a problem found?
Verify Repair Go to Step 6
6. Check the fused power feed circuit 39 and fuse F14 for
the LPG Tank Smart Unit.
Is the fuse faulty?
Go to Step 8 Go to Step 7
7. Check for an open in circuit 39 power feed circuit to the
LPG Tank Smart Unit.
Was a problem found?
Verify Repair Go to Step 9
8. 1. Locate and repair short to earth in fuse power feed
circuit for the LPG Tank Smart Unit.
2. Replace fuse.
Is action complete?
Verify Repair
9. Check for an open in the LPG Tank Smart Unit earth
circuit 750.
Was a problem found?
Verify Repair Go to Step 10
10. Replace LPG Tank Smart Unit. Refer to Section 8A2,
LPG System in VX Service Information for replac ement.
Is action complete?
Verify Repair
11. Check for poor connection at PCM terminal A3.
Was a problem found? Verify Repair Go to Step 12
12. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
DTC P1643 V6 PCM
LPG FUEL CONTROL V ALVE (FCV) PULSE WIDTH MODULATION (PWM)
SIGNAL OUT OF RANGE
CIRCUIT DESCRIPTION:
The PCM m onitors the voltage at term inal F4 to deter mine the status of the fuel mode s witch. W hen the fuel m ode
switch is open, the voltage at PCM terminal F4 will be 0 volts. W hen the LPG fuel mode switch is closed, batter y
voltage will be applied to PCM terminal F4 via the ignition switch fuse F14 circuit, 39 (Pink/Black wire), the fuel
mode switch and circuit 936 (Blue/Orange wire). This will cause the voltage at terminal F4 to be pulled up to 12
volts whenever the fuel mode switch is depressed. This high voltage is seen by the PCM as a fuel mode switch
input signal. When the PCM sees a high voltage at terminal F4 the PCM will toggle between the LPG and petrol
operatin g modes. The PCM wil l on ly toggle be t ween th e Petrol and LPG mode if the i gnition is o n an d th e en gin e is
not running or the engine is running above 1300 RPM.
W hen operating in t he LPG m ode the PCM contr ols the a ir fuel ratio by sending a Pulse W idth Modulat ion (PW M)
signal to the Fuel Control Valve (FCV) to control the vacuum supply to the converter for precise air/fuel ratio
control, based on the following inputs: RPM, MAF, IAT, ECT and TP. This mode of operation is LPG open loop
mode.
Once the ox ygen sensor s are ac tive and the P CM is o perating i n the Closed Loo p fueling m ode, the PC M will s end
a Pulse Width Modulation (PWM) signal to the Fuel Control Valve (FCV) based on the right hand oxygen sensor
voltage. This mode of operation is the LPG closed loop mode. If there is a fault with the FCV circuit, DTC P1643
will set.
CONDITIONS FOR RUNNING THE DTC
• The engine is operating in the LPG mode.
CONDITIONS FOR SETTING THE DTC
• The voltage at PCM terminal E16 is too high for greater that one second.
Or
• The voltage at PCM terminal E16 is too low for greater that one second.
4374
PCM
Y/G
CONTROL
SIGNAL
2-3mA
B/Y
P/G
43
30V
2A
W/G
B/R
BLU/R
2
5
6
1
LPG
TANK
SENDER
SMART UNIT
W/G
(937) A3 ENABLE
LPG
P
(39)
12V
M
I
C
R
O
B/R
(750)
LOC. E4
LOC. E3
LOC. E5/E15
B
(155)
B/Y
(155)
TO
INSTRUMENTS
TERMINAL
NUMBER 10
TO
FUSE F14
YB51
YE110
YB187
YE114
YR50
YR50
YR51 YR51
YB51
YE2
YR50
YR51
FUEL MODE SWITCH
YB199
YE110
YB30
YE68
YB51
YE112
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) 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 History Data.
• The PCM will default to the Petrol fuel mode for vehicle operation regardless of the LPG switch position.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS
Check for the following conditions:
• Poor conn ection at PC M. Inspect harness connectors for back ed out terminals, improper m ating, broken locks,
improper formed or damaged terminals, and poor terminal to wire connection.
• Dirty, Damaged, or Loose Connections or Damaged Harness - Check for any damage to the harness which
could cause an intermittent open or short to earth or backed out terminals at the PCM connectors, broken
locks, improperly formed or damaged terminals.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. Normally, power feed voltage present on the output circuit with the PCM disconnected and the ignition on.
3. Checks for a shorted component or a short to B+ or the PCM driver circuit. Either condition would result in a
measured current of over 1.5 amps. Also checks for a component that is going open while being operated,
resulting in a measured current of 0 amps.
4. This step checks for a faulty Fuel Control Valve.
11. T his s tep check s to see if t he PCM is capa ble of con troll ing t he LPG Fu el C ontrol Val ve us ing t he T ec h 2 scan
tool.
P.C.M CONNECTOR 3
YB1 99
E1
F1
G
(842)
BLU
(841)
GY
(845)
Y
(846)
B/R
(750)
R
(1228)
G/W
(465)
V
(435)
GY/BLU
(1229)
(843)
V
(844)
BR/Y
(771)
BLU/W
(766)
W
(750)
B/R
Y
(772)
GY
(773)
BR/Y
(1224)
Y
(1225)
GY
(1226)
BLU
(774)
BLU/R
(31)
E16
F16
P
(39))
B/BLU
(1062)
(936)
BLU/O
FUEL CONTROL VALVE
(39)
(1062)
PB/BL U
B
A
DTC P1643 - LPG FUEL CONTROL VALVE (FCV) PULSE WIDTH MODULATION (PWM)
SIGNAL OUT OF RANGE
STEP ACTION VALUE YES NO
1. Was the "On-Board Diagnostic" (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2. 1. Ignition "OFF", disconnect the PCM Tan E/F
connector.
2. Ignition "ON".
3. Using Digital Multimeter, measure voltage at the Fuel
Control Valve circuit 1062 at the PCM terminal E16
harness connector and earth.
Is voltage near the specified value?
B+ Go to Step 3 Go to Step 6
3. 1. Ignition “OFF” reconnect the PC M Tan E/F connector.
2. Digital Multimeter set to 10-amp scale, install Digital
Multimeter to measure current between the Fuel
Control Valve and earth.
3. Monitor the current reading on the Digital Multimeter
for at least 2 minutes.
4. Ignition “ON”, engine running.
5. Increase engine RPM to above 1500 and hold.
6. Turn “ON” the LPG system and monitor Digital
Multimeter.
Does the current reading remain between the specified
values?
0.1 amp
To
1.5 amps
Go to Step 11 Go to Step 4
4. 1. Disconnect the Fuel Control Valve and PCM Tan E/F
connector.
2. Using Digital Multimeter, measure voltage between the
Fuel Control Valve circuit 1062 and earth.
Is voltage at specified value?
0 volts Go to Step 15 Go to Step 5
5. Locate and repair short to voltage in the Fuel Control Valve
circuit 1062.
Is action complete?
Verify Repair
6. Check the power feed circuit and fuse F14 for the Fuel
Control Valve.
Is the fuse faulty?
Go to Step 7 Go to Step 8
7. 1. Locate and repair short to earth in power feed circuit
for the Fuel Control Valve.
2. Replace fuse.
Is action complete?
Verify Repair
8. 1. Disconnect the Fuel Control Valve.
2. Ignition "ON".
3. Measure voltage between the power feed circuit 39 for
the Fuel Control Valve and earth.
Is voltage near the specified value?
B+ Go to Step 9 Go to Step 13
9. Check the Fuel Control Valve circuit 1062 for an open or a
short to earth.
Was a problem found?
Verify Repair Go to Step 10
10. Check the Fuel Control Valve circuit 1062 and the power
feed circuit for a poor connection at the Fuel Control Valve
and the PCM.
Was a problem found?
Verify Repair Go to Step 15
11. 1. Ignition "OFF" dis con nec t the Fuel Control Valve.
2. Ignition "ON, connect a test light between the Fuel
Control Valve circuit and the power feed circuit at the
Fuel Control Valve connector.
3. Using the Tech 2 scan tool, select LPG Enable Test.
Does the test light illuminate for 2 seconds (test light will
flicker)?
Refer to
"Diagnostic Aids"
above.
Go to Step 12
DTC P1643 - LPG FUEL CONTROL VALVE (FCV) PULSE WIDTH MODULATION (PWM) SIGNAL
OUT OF RANGE (CONTINUED)
STEP ACTION VALUE YES NO
12. Check the Fuel Control Valve circuit 1062 for a poor
connection at the PCM.
Was a problem found?
Verify Repair Go to Step 14
13. Locate and repair open power feed circuit 39 to the Fuel
Control Valve.
Is action complete?
Verify Repair
14. Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Verify Repair
15. Replace Fuel Control Valve. Refer to Section 8A2, LPG
System in VX Service Information for replacement.
Is action complete?
Verify Repair
DTC P1810 V6 PCM -
TRANSMISSION FLUID PRESSURE MANUAL VALVE POSITION SWITCH
ASSEMBLY MALFUNCTION
CIRCUIT DESCRIPTION:
The Automatic Transmission Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.) consists of five
pressure switches (two normally-closed and three normally-open) and a Transmission Fluid Temperature (TFT)
sensor combined into one unit. The combined unit mounts on the valve body. The PCM supplies the battery
voltage f or each range s ignal. By earthing one or more of the circuits through various com binations of the pressur e
switches, the PCM detects which manual valve position you select. The PCM compares the actual voltage
com bination of the s witches to a T FP Val. Pos ition Sw. com bination Table stored in mem or y. T he TFP Val. Position
Sw. cannot distinguish between Park and Neutral because the monitored valve body pressures are identical. W ith
the engine OFF and the ignition switch in the RUN position, the TFP Val. Position Sw. indicates Park/Neutral.
Disconnecting the transmission pass-through connector removes the earthing potential for the three range signals
to the PCM. In this case, with the engine OFF, and the ignition switch in the RUN position, D2 will be indicated.
When the PCM detects an invalid state of the TFP Val. Position Sw. or the TFP Val. Position Sw. circuit by
deciphering the TFP Val. Position Sw. inputs, then DTC P1810 set.
CONDITIONS FOR RUNNING THE DTC
• The engine is running.
• The vehicle automatic transmission is in gear.
CONDITIONS FOR SETTING THE DTC
Condition 1
• The PCM detects an illegal TFP manual valve position switch state for 60 seconds.
Condition 2
• The engine s peed is less than 80 RPM for 0.1 s econd; then the engine speed is 80- 550 RPM for 0.07 s econds;
then the engine speed is greater than 500 RPM.
• The PCM detects a gear range of D2, D4, or Reverse 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 Park or Neutral when operating in D4.
• All conditions are met for 10 seconds.
VXPCM034
PCM
F11
F12
D13
D6
TFP SIGNAL A
TFP SIGNAL B
TRANSMISSION FLUID
TEMPERATURE (TFT)
SENSOR SIGNAL
SENSOR EARTH
N
C
R
E
D
A
B
P
L
M
TRANSMISSION FLUID
TEMPERATURE
(TF T ) SENSOR
AUTOMATIC TRANSMISSION FLUID
PRESSURE SWITCH ASSEMBLY
BR/Y (1224)
Y (1225)
GY (1226)
B/Y (1227)
B (46 9)
12V
12V
5V
F13 TFP SIGNAL C
12V
M
I
C
R
O
TO
A
/C PRESSURE SENSOR
AND IAT SENSOR
YB199
YB187
YB198
YB129
ACTION TAKEN WHEN THE DTC SETS
• The PCM illuminates the Malfunction Indicator Lamp (MIL) 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 History Data.
• When DTC P1810 is set, the PCM will inhibit TCC engagement, command D2 line pressure, and freeze shift
adapts from being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• The PCM turns the MIL OFF after the first ignition cycle that the diagnostic runs and does not fail.
• A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic
does not report any failure.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
• Refer to the TFP Val. Position Sw. Logic Table for the normal range signals and the illegal combinations.
• Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical
connections at the transmission pass-through connector. Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
• When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the
test equipment for a change. Refer to Automatic Transmission Fluid Pressure Manual Valve Position Switch
Resistance Check or Functional Test Procedure for further information.
TFP VALVE POSITION SWITCH LOGIC
Gear
Position Range Signal
Switch A Range Signal
Switch B Range Signal
Switch C
P Open 12V Closed 0V Open 12V
R Closed 0V Closed 0V Open 12V
N Open 12V Closed 0V Open 12V
D Open 12V Closed 0V Closed 0V
3 Open 12V Open 12V Closed 0V
2 Open 12V Open 12V Open 12V
1 Closed 0V Open 12V Open 12V
Illegal Closed 0V Open 12V Closed 0V
Illegal Closed 0V Closed 0V Closed 0V
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. This step compares the indicated range signal to the manual valve position that is actually selected.
4. This step tests for correct voltage from the PCM to the transmission pass-through connector terminals.
P.C.M CONNECTOR 3
YB1 99
E1
F1
G
(842)
BLU
(841)
GY
(845)
Y
(846)
B/R
(750)
R
(1228)
G/W
(465)
V
(435)
GY/BLU
(1229)
(843)
V
(844)
BR/Y
(771)
BLU/W
(766)
W
(750)
B/R
Y
(772)
GY
(773)
BR/Y
(1224)
Y
(1225)
GY
(1226)
BLU
(774)
BLU/R
(31)
E16
F16
P
(39))
B/BLU
(1062)
(936)
BLU/O
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
DTC P1810 V6 PCM - TRANSMISSION FLUID PRESSURE MANUAL VALVE POSITION SWITCH ASSEMBLY
MALFUNCTION
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2 Perform the following inspections:
1. Ensure that the transmission linkage from the select
lever to the manual valve is adjusted properly.
2. Perform the fluid checking procedure/inspection.
Did you perform the inspections?
Go to Step 3 Perform the
Inspections
3 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs, use the
scan tool in order to record the DTC history for
reference. The Clear Info function will erase the data.
3. Record the DTC history.
4. While the engine is idling at normal operating
temperature, apply the parking brake.
5. Select each transmission range: P, R, N, D4, D3, D2,
and D1.
Does each selected transmission range match the scan
tool TFP Switc h A/B/C display?
• Refer to the TFP Val. Position Sw. Logic Table.
Go to
“Diagnostic Aids”
above
Go to Step 4
4 1. Turn the ignition OFF.
2. Disconnect the transmission pass-through connector
(additional DTCs may set).
3. Install the J 39775 Jumper Harness on the engine
side of the transmission pass-through connector.
4. With the engine OFF, turn the ignition switch to the
RUN position.
5. Using the J 39200 DVM and J 35616 Connector Test
Adapter Kit, check for voltage at connector terminals
N, R, and P.
Is B+ displayed on all three circuits?
Go to Step 6 Go to Step 5
5 1. Check the circuits that did not indicate B+ for an
open or a short to earth.
2. Repair the circuits if necessary.
Did you find and correct the problem?
Go to Step 13 Go to Step 7
DTC P1810 V6 PCM - TRANSMISSION FLUID PRESSURE MANUAL VALVE POSITION SWITCH ASSEMBLY
MALFUNCTION (CONTINUED)
STEP ACTION VALUE YES NO
6 In order to verify that circuit 1224, circuit 1225, and circuit
1226 are not shorted together, use a fused jumper to
earth, on each circuit while monitoring the scan tool TFP
Switch A/B/C display.
When a range signal circuit is earthed, are any other
range signal circuits affected?
Go to Step 8 Go to Step 9
7 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 13
8 Repair the affected wiring as necessary.
Is the action complete? Go to Step 13
9 1. Turn the ignition switch to the OFF position.
2. Reconnect the pass-through connector.
3. Select the PARK position.
4. Start the engine.
5. Apply the brakes.
6. Move the shift selector through all gear ranges, while
observing the A and C range signals on the scan
tool.
Does either range signal always indicate 0 volts/ON?
Go to Step 10 Intermittent
Problem Go to
“Diagnostic Aids”
above
10 1. Turn the ignition switch to the OFF position.
2. Disconnect the transmission pass-through connector.
3. Remove the transmission pan.
4. Remove the internal wiring harness connector from
the TFP Valve Position Switch.
5. Check the internal wiring harness circuits 1224 and
1226 for a short to earth.
Did you find a short to earth condition on either circuit?
Go to Step 12 Go to Step 11
11 Replace the TFP Valve Position Switch. Refer to Service
Operations, Section 6C2-3 of the VX Series Service
Information.
Is the action complete?
Go to Step 13
12 Replace the internal A/T W iring Harness Assembly Refer
to Service Operations in Section 7C-5 Automatic
Transmission in VX Service Information.
Is the replacement complete?
Go to Step 13
13 In order to verify your repair, perform the following
procedure:
1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle under the following conditions:
• With the engine OFF, turn the ignition switch to
the RUN position for at least 2 seconds.
• Start the vehicle and idle for 5 seconds.
• Select each transmission range: P, R, N, D4,
D3, D2 and D1.
• Compare the scan tool TFP Sw. A/B/C/ display,
to the TFP Valve Position Sw. Logic Table.
Does each shifter position range signal match the scan
tool TFP Sw. A/B/C dis p lay?
System OK Begin the
diagnosis again.
Go to Step 1
DTC P1860 V6 PCM -
TORQUE CONVERTER CLUTCH (TCC) PULSE WIDTH MODULATION (PWM)
SOLENOID FAULT
CIRCUIT DESCRIPTION:
The T orque Conver ter Clutch Puls e Width Modulation Solenoid Valve (TCC PWM Solenoid Valve) controls the fluid
acting on the converter clutch valve. The converter clutch valve controls the TCC application and release. The
solenoid attaches to the control valve body within the transmission. The solenoid receives ignition voltage through
circuit 339. The PCM controls the solenoid by providing a earth path on circuit 418. Current flows through the
solenoid coil according to the duty cycle (percentage of ON and OFF time). The TCC PWM Solenoid Valve
provides a smooth engagement of the torque converter clutch by operating during a duty cycle percent of ON time.
The TCC" PWM" solenoid is used in combination with the TCC Enable solenoid to regulate fluid to the torque
converter, and is attached to the control valve body within the transmission. The use of the Torque Converter
Clutch Pulse Width Modulated, (TCC PWM) solenoid provides the ability of being able to control more precisely,
the rate of Torque Converter Clutch (TCC) apply and release.
When the PCM detects a continuous open or short to earth in the TCC PWM Solenoid Valve circuit or the TCC
PWM Solenoid Valve, then DTC P1860 sets.
CONDITIONS FOR RUNNING THE DTC
• The system voltage is 8-18 volts.
• The engine speed is greater than 300 RPM for 5 seconds.
• The engine is not in fuel cutoff.
• The PCM commands first gear.
• The TCC duty cycle is less than 10% or greater than 90%.
CONDITIONS FOR SETTING THE DTC
• The PCM commands the solenoid ON and the voltage input remains high (B+)
or
• The PCM commands the solenoid OFF and the voltage input remains low (0volts).
• Either condition for 5 seconds.
3–2 Downshift
Control
Solenoid
1–2 Shift
Solenoid A
2–3 Shift
Solenoid B
YB 129 Transmission
Pass-Thru Connector
Torque
Converter
Clutch (TCC)
(PWM)
Solenoid
Torque
Converter
Clutch (TCC)
Enable
Solenoid
Pressure
Control
Solenoid
A
B
A
B
4284
A
B
A
B
EF32
EFI
Relay
P/ BLU (339)
G/W (897)
LG (1222)
Y/B (1223)
GY/R (422)
BR (418)
R (1228)
GY/BLU (1229)
A1 3–2 Cont r ol
Solenoid
1–2 Shift
Solenoid
2–3 Shift
Solenoid
TCC Enable
Solenoid
TCC PWM
Solenoid
Pressure Control
Solenoid High
Pressure Control
Solenoid Low
B1
A2
A12
A11
E9
E13
S
A
B
T
U
C
D
A
B
A
B
PCM
M
I
C
R
O
P
R
O
C
E
S
S
O
R
YE110
YB187
YB199
ACTION TAKEN WHEN THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in
the History Data.
• When this DTC sets, the PCM will freeze shift adapts from being updated.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS:
• Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections
at the transmission pass-through connector.
• Look for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
• When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the
test equipment for a change.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. An open fuse indicates a short circuit in circuit 339. A short in any of the five solenoids fed by circuit 339 may
cause an open fuse.
4. This step tests for voltage to the solenoid.
6. This step tests the ability of the PCM and wiring to control the earth circuit.
7. This step tests the resistance of the TCC PWM Solenoid Valve and the Automatic Transmission Wiring
Harness Assembly.
YB 187
P.C.M CONNECTOR 2
A1 A12
B1 B12
G/W
(897)
(1223)
Y/B
B/R
(750)
BR/W
(792)
LG/B
(366)
GY/BLU
(1434)
G/Y
(428)
BR
(418)
GY/R
(422)
LG
(1222)
W
(423)
T/B
(424)
B/R
(750)
B
(630)
LBLU/B
(647)
O
(1426)
V
(430)
B/R
(453)
B/W
(1427)
BLU/W
(304)
W/G
(937))
TRANSMISSION CONNECTOR
GY/BLU
(1229)
R
(1228)
Y/B
(1223)
LG
(1222)
P/BLU
(339)
(1227)
B/Y
(1230)
B/W
GY/R
(422)
BR
(418)
BR/Y
(1224)
(1226)
GY
Y
(1225)
(897)
G/W
(V8)
B
(469) (V6)
OR
ENGINE CONNECTOR 1
YE110
O/W
(304)
(1426)
BLU/W
G/W
(339)
P/BLU
(465)
(123)
V/W
(1427)
B/W
Y
(1049)
DTC P1860 V6 PCM - TORQUE CONVERTER CLUTCH (TCC) PULSE WIDTH MODULATION (PWM)
SOLENOID FAULT
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
IMPORTANT: Before clearing the DTCs, use the scan
tool in order to record the DTC history for reference. The
Clear Info function will erase the data.
3. Record the DTC history.
4. If DTCs P0740, P0753, P0758 or P0785, are also
set, inspect the F32 fuse for an open.
Is the fuse open?
Go to Step 3 Go to Step 4
3 1. Check circuit 339 for a short to earth.
2. Check each of the five solenoids for being internally
shorted or shorted to earth.
3. Check the A/T Wiring Harness Assembly for a short
to earth on each of the five solenoid circuits.
4. Make the repair/replacement if necessary.
Did you find and correct a problem?
Go to Step 15 Go to
“Diagnostic Aids”
above
4 1. Turn the ignition OFF.
2. Disconnect the transmission pass-through connector
(additional DTCs may set).
3. Install J 39775 Jumper Harness on the engine
harness connector.
4. With the engine OFF, turn the ignition switch to the
RUN position.
5. Connect a lest lamp from J 39775 Jumper Harness
cavity E to earth.
Is the test lamp on?
Go to Step 6 Go to Step 5
5 Repair the open in the ignition feed circuit 339 to the TCC
PWM Solenoid Valve.
Is the repair complete?
Go to Step 15
6 1. Install the test lamp from cavity E to cavity U of the J
39775 Jumper Harness.
2. Command the TCC PWM Solenoid Valve ON and
OFF three times.
Does the test lamp turn ON when the TCC PWM
Solenoid Valve is commanded ON, and OFF when
commanded OFF?
Go to Step 8 Go to Step 7
7 Check circuit 418 for an open, short to B+, or a short to
earth. Repair the circuit if necessary.
Did you find and correct the problem?
Go to Step 15 Go to Step 9
8 1. Install J 39775 Jumper Harness on the transmission
pass-through connector.
2. Using the J 39200 DVM and the J 35616 Connector
Test Adapter Kit, measure the resistance between
terminals E and U.
Is the resistance within the specified range?
10-15 Ω Go to Step 11 Go to Step 10
9 Replace PCM.
Refer to Section 6C1-3 Service Operations of the VX
Series Service Information, for PCM Programming and
Security Link procedure.
Is action complete?
Go to Step 15
DTC P1860 V6 PCM - TORQUE CONVERTER CLUTCH (TCC) PULSE WIDTH MODULATION (PWM)
SOLENOID FAULT (CONTINUED)
STEP ACTION VALUE YES NO
10 1. Disconnect the Automatic Transmission Wiring
harness Assembly at the TCC PWM Solenoid Valve.
2. Measure the resistance of the TCC PWM Solenoid
Valve.
Is the resistance within the specified range?
10-15 Ω Go to Step 13 Go to Step 14
11 Measure the resistance between terminal E and earth,
and between terminal U and earth.
Are both readings greater than the specified value?
250 K Ω Go to
“Diagnostic Aids”
above
Go to Step 12
12 1. Disconnect the Automatic Transmission Wiring
Harness Assembly at the TCC PWM Solenoid Valve.
2. Measure the resistance between each of the
component terminals and a known good earth.
Are both readings greater than the specified value?
250 K Ω Go to Step 13 Go to Step 14
13 Replace the Automatic Transmission Wiring Harness
Assembly. Refer to Service Operations in Section 7C-5 in
VX Service Information.
Is the action complete?
Go to Step 15
14 Replace the TCC PWM Solenoid Valve. Refer to Section
6C1-3 Service Operations of the VX Series Service
Information.
Is the action complete?
Go to Step 15
15 In order to verify your repair, perform the following
procedure:
Operate the vehicle under the following conditions while
observing the TCC PWM Solenoid and TCC Slip Speed:
• The PCM commands the TCC PWM Solenoid
Valve ON, and the TCC Slip Speed is -20 to +20
rpm.
• The PCM commands the TCC PWM Solenoid
Valve OFF, and the TCC Slip Speed is greater
than rpm 50.
Are both of the TCC Slip conditions met for at least
4 seconds?
System OK Begin the
diagnosis again
Go to Step 1
DTC P1870 V6 PCM -
TRANSMISSION SLIPPING
CIRCUIT DESCRIPTION:
The PCM m onitors the diff erence between the engine speed and the transm ission output speed. In D3 drive range
with the TCC engaged, the engine speed should closely match the transmission output speed. In D4 drive range,
with the TCC engaged, the Trans Slip Speed should be -20 to +20 RPM.
When the PCM detects an excessive transmission slip speed when the TCC should be engaged, then DTC P1870
will set.
CONDITIONS FOR RUNNING THE DTC
• No Throttle Position DTCs P0122 or P0123.
• No VSS assembly DTCs P0502 or P0503.
• No TCC solenoid valve DTC P0740.
• No 1-2 SS valve DTC P0753.
• No 2-3 SS valve DTC P0730.
• 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.
M
I
C
R
O
PCM
Torque
Converter
Assembly
TCC Enable
Solenoid
4285
A12
GY/R(422)
Ignition
Switch
Fuse
F32
BR 418
P/BLU(339)
TCC
Pwm
Sol
(N.C.)
Cooler
Cooler
Cooler
Release
Apply
Cooler
Conv FD
Conv FD
Reg Apply
EX
Apply
Release
Decrease
Line
Line
Reg Ap
CC Signal
Reg Apply
Reg Apply Isolator
Torque Sig
Rev Input
Rev Input
AFL (From Press Cont Sol)
Lube
Line (From Pump)
A11
TCC PWM
Solenoid
CONVERTER CLUTCH VALVE
YB187
YB187
YB129
YB129
YB129
EX
Techline
CONDITIONS FOR SETTING THE DTC
• 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 80-800 RPM for 7 seconds.
IMPORTANT:
The following actions may occur before the DTC sets.
• If the T CC is com m anded O N and at m axim um duty cyc le for 5 s econds, the T hrottle Position angle is 10-40%,
and the transm ission slip c ounter has increm ented to either 1 or 2 ( out of 3 to increm ent 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 s lip speed is 80- 800 RPM for 7 s econds , then the PCM will comm and m axim um 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 s lip s peed is 80-800 RPM f or 7 s econds , then the f ail c ounter
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 THE DTC SETS
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The Malfunction Indicator Lamp (MIL) will not be illuminated.
• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in
the History Data.
• When this DTC s ets, the PCM will freeze shif t adapts fr om being updated, inhibits 4th gear if the trans mission is
in hot mode, and command maximum line pressure.
CONDITIONS FOR CLEARING THE MIL/DTC
• A History DTC clears after forty consecutive warm-up cycles.
• Use a Tech 2 scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS
• Internal transmission failures may set DTC P1870.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. This step tests the torque converter for slippage while in a commanded lock-up state.
DTC P1870 V6 PCM - TRA NSMISSION SLIPPING
STEP ACTION VALUE YES NO
1 Was the On-Board Diagnostic (OBD) System Check
performed? Go to Step 2 Go to OBD
System Check
2 Perform the transmission fluid checking procedure.
Have you performed the transmission fluid checking
procedure?
Go to Step 3 Go to
Transmission
Fluid Checking
Procedure
3 1. Install the scan tool.
2. With the engine OFF, turn the ignition switch to the
RUN position.
3. Drive the vehicle in 4th gear with the TCC engaged.
Is the TCC Slip Speed between the specified values for
7 seconds?
300-1000
RPM Go to Step 4 Go to
“Diagnostic Aids”
above
DTC P1870 V6 PCM - TRANSMISSION SLIPPING (CONTINUED)
STEP ACTION VALUE YES NO
4 Inspect the Torque Converter Clutch Solenoid Valve
(TCC Solenoid Valve) for the following conditions:
• Internal malfunction (such as sediment or damage)
• Damaged seals
Inspect the Torque Converter Clutch Pulse Width
Modulation Solenoid Valve (TCC PWM Solenoid Valve)
for the following conditions:
• Internal malfunction (such as sediment or damage)
• Damaged seals
Did you find and correct the problem?
Go to Step 13 Go to Step 5
5 Inspect the 1-2 Shift Solenoid Valve (1-2 SS Valve) for
the following conditions:
• Internal malfunction (such as sediment or damage)
• Damaged seals
Inspect the 2-3 Shift Solenoid Valve (2-3 SS Valve) for
the following conditions:
• Internal malfunction (such as sediment or damage)
• Damaged seals
Did you find and correct the problem?
Go to Step 13 Go to Step 6
6 Inspect the valve body assembly for a stuck TCC signal
valve. Refer to Unit Repair.
Did you find and correct the problem?
Go to Step 13 Go to Step 7
7 Inspect the torque converter assembly for the following
conditions:
• Stator roller clutch not holding
• Internal damage
Did you find and correct the problem?
Go to Step 13 Go to Step 8
8 Inspect the oil pump assembly for the following
conditions:
• Stuck converter clutch valve
• Converter clutch valve assembled backward
• Mispositioned converter clutch valve retaining ring
• Mispositioned pump to case gasket
• Restricted orifice cup plugs
• Damaged orifice cup plugs
• Over-tightened, or unevenly tightened pump body to
cover bolts
Did you find and correct the problem?
Go to Step 13 Go to Step 9
9 Inspect the input housing and shaft assembly for the
following conditions:
• Cut turbine shaft o-ring seal
• Damaged turbine shaft o-ring seal
• Restricted turbine shaft retainer and ball assembly
• Damaged turbine shaft retainer and ball assembly
Did you find and correct the problem?
Go to Step 13 Go to Step 10
DTC P1870 V6 PCM - TRANSMISSION SLIPPING (CONTINUED)
STEP ACTION VALUE YES NO
10 Inspect the 2-4 band assembly for the following
conditions:
• Worn 2-4 band
• Damaged 2-4 band
• Mispositioned 2-4 band
• Misassembled 2-4 band
• The band anchor pin is not engaged
• Restricted apply passages in the 2-4 servo assembly
• Blocked apply passages in the 2-4 servo assembly
• Nicks or burrs on the servo pin
• Nicks or burrs on the pin bore in the case
• Damaged fourth servo piston
• Misassembled fourth servo piston
• Damaged band apply pin
• Incorrect band apply pin
• Damaged servo bore in the case
• Missing piston seals
• Cut piston seals
• Damaged piston seals
• Porosity in the pistons
• Porosity in the cover
• Porosity in the case
• Damaged piston seal grooves
• Plugged orifice cup plug
• Missing orifice cup plug
Did you find and correct the problem?
Go to Step 13 Go to Step 11
11 Inspect the forward clutch assembly for the following
conditions:
• Worn clutch plates
• Porosity in the forward clutch piston
• Damaged forward clutch piston
• Missing forward clutch piston inner and outer seals
• Cut forward clutch piston inner and outer seals
• Damaged forward clutch piston inner and outer seals
• Missing input housing to forward clutch housing
o-ring seal
• Cut input housing to forward clutch housing o-ring
seal
• Damaged input housing to forward clutch housing
o-ring seal
• Damaged forward clutch housing
• Damaged forward clutch housing retainer and ball
assembly
• Forward clutch housing retainer and ball assembly is
not sealing
Did you find and correct problem?
Go to Step 13 Go to Step 12
DTC P1870 V6 PCM - TRANSMISSION SLIPPING (CONTINUED)
STEP ACTION VALUE YES NO
12 Inspect the 3-4 clutch assembly for the following
conditions:
• Worn clutch plates
• Porosity in the 3-4 clutch piston
• Damaged 3-4 clutch piston
• Missing 3-4 clutch inner and outer seals
• Cut 3-4 clutch inner and outer seals
• Damaged 3-4 clutch inner and outer seals
• Damaged 3-4 clutch spring assembly
• Damaged 3-4 clutch apply ring
• Damaged piston seal grooves
• Plugged orifice cup plug
• Missing orifice cup plug
Did you find and correct the problem?
Go to Step 13 Go to
“Diagnostic Aids”
above
13 In order to verify your repair, operate the vehicle under
the following conditions:
• Drive the vehicle in D4 with the TCC ON and a
throttle position of 16-50%.
Did the vehicle obtain a Trans Slip Speed of -20 to +40
RPM?
System OK Begin the
diagnosis again.
Go to Step 1