U1113-LOST A/C PRESSURE MESSAGE

For a complete wiring diagram Refer to Section 8W.

When Monitored:
Ignition on.
Set Condition:
The PCM doesn't receive the A/C Pressure signal over the CAN C bus from the FCM. The circuit is continuously monitored. One Trip fault.

Possible Causes

CAN C BUS CIRCUIT OPEN OR SHORTED

FRONT CONTROL MODULE

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

The A/C Pressure Transducer signal is a direct input to the FCM. The FCM sends the PCM the A/C pressure signal over the CAN C bus.

1.ACTIVE DTC

Is the DTC Active at this time?

Yes

Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2.U0141-LOST COMMUNICATION WITH FRONT CONTROL MODULE ALSO ACTIVE

Is the U0141-NO BUS MESSAGE RECEIVED FROM THE FCM also set?

Yes

Follow the diagnostics for U0141-LOST COMMUNICATION WITH FRONT CONTROL MODULE
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)