When Monitored:
Ignition on.
Set Condition:
The PCM doesn’t receive the A/C Pressure signal over the CAN C bus from the TIPM. The circuit is contin-
uously monitored. One Trip fault.
Possible Causes
CAN C BUS CIRCUIT OPEN OR SHORTED
TOTALLY INTEGRATED POWER MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The A/C Pressure Transducer signal is a direct input to the TIPM. The TIPM sends the PCM the A/C pressure signal
over the CAN C bus.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With the scan tool read Powertrain DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.U0141-LOST COMMUNICATION WITH TOTALLY INTEGRATED POWER MODULE ALSO ACTIVE
With the scan tool read DTCs.
Is the U0141-NO BUS MESSAGE RECEIVED FROM THE FRONT CONTROL MODULE (TIPM) also set?
Ye s>>
Follow the diagnostics for U0141-LOST COMMUNICATION WITH FRONT CONTROL MODULE (TIPM)
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
When Monitored:
Ignition on.
Set Condition:
The PCM doesn’t receive a vehicle speed signal from the Anti-lock brake Module over the CAN C bus. One
Trip fault.
Possible Causes
CAN C BUS CIRCUIT OPEN OR SHORTED
ANTI-LOCK BRAKE MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING) .
Theory of Operation
The PCM receives the vehicle speed signal over the CAN C bus from the Anti-lock Brake Module.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With the scan tool read Powertrain DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.U0121-LOST COMMUNICATION WITH ABS MODULE ALSO SET
With the scan tool continue reading DTCs.
Is the U0121-LOST COMMUNICATION WITH ABS MODULE also set?
Ye s>>
Follow the diagnostics for U0121-LOST COMMUNICATION WITH ABS MODULE
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
When Monitored:
Ignition on.
Set Condition:
The fuel volume message the PCM is receiving is implausible. The circuit iscontinuously monitored. One Trip
fault.
Possible Causes
CAN B OPEN OR SHORTED
CLUSTER MODULE
TOTALLY INTEGRATED POWER MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The Totally Integrated Power Module isn’t receiving a fuel volume signal over CAN B from the Cluster Module. The
TIPM has to send the PCM a fuel volume signal over CAN C. The signal the TIPM sendsoverCANCisimplau-
sible.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.CAN B BUS HARDWARE DTCS ALSO ACTIVE
With a scan tool check for DTCs in the TIPM.
Are any CAN B Hardware related DTCs active at this time?
Ye s>>
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for the
appropriate diagnostic procedures.
Perform BODY VERIFICATION TEST – VER 1.
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
When Monitored:
Ignition on.
Set Condition:
The PCM gets an implausible signal over the CAN C circuit from the ABS Module. The circuit is continuously
monitored. One Trip fault.
Possible Causes
CAN C BUS CIRCUIT SHORTED
CAN C BUS CIRCUIT OPEN
ABS MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The ABS Module sends vehicle speed information over the CAN C Bus circuit tothe PCM.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the U1412-IMPLAUSIBLE VEHICLE SPEED SIGNAL RECEIVED active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.U0001-NO COMMUNICATION ON THE CAN C BUS CIRCUIT IS ACTIVE
Continue reading DTCs.
Is the U0001-NO COMMUNICATION ON THE CAN C BUS CIRCUIT ACTIVE at this time?
Ye s>>
Refer to the Diagnostic Procedure for the U0001-NO COMMUNICATION ON THE CANCBUSCIR-
CUIT.
No>>
Go To 3
3.ABS MODULE IS ACTIVE ON THE CAN C BUS
With the scan tool, select ECU View.
Verify that the ABS Module active on the bus.
Is the ABS Module active on the bus?
Ye s>>
Go To 4
No>>
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for No
Response diagnostic procedures.
Perform BODY VERIFICATION TEST – VER 1.
When Monitored:
Ignition on.
Set Condition:
The PCM gets an implausible signal over the CAN C circuit from the ABS Module. The circuit is continuously
monitored. One Trip fault.
Possible Causes
VEHICLE SPEED SENSOR FAULT ACTIVE IN ANTI-LOCK BRAKE MODULE
CAN C BUS CIRCUIT SHORTED
CAN C BUS CIRCUIT OPEN
ABS MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The ABS Module sends an implausible distance signal over the CAN C Bus circuit to the PCM.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the U1417-IMPLAUSIBLE LEFT WHEEL DISTANCE SIGNAL RECEIVED active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.ABS MODULE IS ACTIVE ON THE CAN C BUS
With the scan tool, select ECU View.
Verify that the ABS Module active on the bus.
Is the ABS Module active on the bus?
Ye s>>
Go To 3
No>>
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for No
Response diagnostic procedures.
Perform BODY VERIFICATION TEST – VER 1.
3.DTCS STORED OR ACTIVE IN THE ABS MODULE
Check for DTCs in the ABS Module.
Are any DTCs active or stored in the ABS Module?
Ye s>>
Refer to section 5 - BRAKES - ABS ELECTRICAL DIAGNOSTICS and perform the diagnostics for the
DTCs in the ABS Module.
Perform ABS VERIFICATION TEST – VER 1
No>>
Go to 4
When Monitored:
Ignition on.
Set Condition:
The PCM gets an implausible signal over the CAN C circuit from the ABS Module. The circuit is continuously
monitored. One Trip fault.
Possible Causes
VEHICLE SPEED SENSOR FAULT ACTIVE IN ANTI-LOCK BRAKE MODULE
CAN C BUS CIRCUIT SHORTED
CAN C BUS CIRCUIT OPEN
ABS MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The ABS Module sends an implausible distance signal over the CAN C Bus circuit to the PCM.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the U1418-IMPLAUSIBLE RIGHT WHEEL DISTANCE SIGNAL RECEIVED active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.ABS MODULE IS ACTIVE ON THE CAN C BUS
With the scan tool, select ECU View.
Verify that the ABS Module active on the bus.
Is the ABS Module active on the bus?
Ye s>>
Go To 3
No>>
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for No
Response diagnostic procedures.
Perform BODY VERIFICATION TEST – VER 1.
3.DTCS STORED OR ACTIVE IN THE ABS MODULE
Check for DTCs in the ABS Module.
Are any DTCs active or stored in the ABS Module?
Ye s>>
Refer to section 5 - BRAKES - ABS ELECTRICAL DIAGNOSTICS and perform the diagnostics for the
DTCs in the ABS Module.
Perform ABS VERIFICATION TEST – VER 1
No>>
Go to 4
Possible Causes
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP INLET STRAINER PLUGGED
(A109) FUEL PUMP RELAY OUTPUT CIRCUIT OPEN
FUEL PUMP RELAY
FUEL PUMP
Diagnostic Test
1.FUEL PUMP OPERATION
Ignition on, engine not running.
With a scan tool, actuate the Fuel System test.
NOTE: It may be necessary to use a mechanics stethoscope in the next step.
Listen for fuel pump operation at the fuel tank.
Does the Fuel Pump operate?
Ye s>>
Go To 2
No>>
Go To 5
CAUTION: Stop All Actuations.
2.FUEL PRESSURE
Turn the ignition off.
WARNING: The fuel system is under a constant pressure (even with the engineoff). Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure mustbe released. Failure to follow
these instructions can result in personal injury or death.
Install a fuel pressure gauge at the engine.
Ignition on, engine not running.
With the scan tool, actuate the ASD FuelSystem test and observe the fuel pressure gauge.
NOTE: NOTE: Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
Choose a conclusion that best matches your fuel pressure reading.
Below Specification
Go To 3
Within Specification
Te s t C o m p l e t e .
Above Specification
Replace the fuel filter/fuel pressure regulator.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
CAUTION: Stop All Actuations.
3.RESTRICTED FUEL SUPPLY LINE
Turn the ignition off.
WARNING: The fuel system is under a constant pressure even with the engine off. Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure mustbe released.
Raise vehicle on hoist, and disconnect the fuel pressure line at the fuel pump module.
Install special tool #6539 (5/16
) or #6631(3/8) fuel line adapter and the fuel pressure gauge between the fuel sup-
ply line and the fuel pump module.
Ignition on, engine not running.
With the scan tool, actuate the ASD FuelSystem test and observe the fuel pressure gauge.
NOTE: Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
CAUTION: Stop All Actuations.
Is the fuel pressure within specification now?
Ye s>>
Repair/replace fuel supply line as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.CHECKING FUEL INLET STRAINER
Turn the ignition off.
WARNING: The fuel system is under a constant pressure (even with the engineoff). Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure mustbe released. Failure to follow
these instructions can result in personal injury or death.
Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer.
Is the Fuel Inlet Strainer plugged?
Ye s>>
Replace the Fuel Pump Inlet Strainer.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace the Fuel Pump Module.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
5.(A109) FUEL PUMP RELAY OUTPUT CIRCUIT OPEN
Turn the ignition off.
Remove the Fuel Pump Relay from the IPM.
Disconnect the Fuel Pump Module harness connector.
Measure the resistance of the (A109) Fuel Pump Relay Output circuit
from the relay connector to the fuel pump module connector.
Is the resistance below 5.0 ohms?
Ye s>>
Replace the Fuel Pump Relay.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Repair the open in the (A109) Fuel Pump Relay Output cir-
cuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)