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).
Theory of Operation
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.
Diagnostic Test
1. ACTIVE DTCIgnition on, engine not running.
With the scan tool, view PCM DTCs.
Is the DTC Active at this time?
Yes
- 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 FRONT CONTROL MODULE ALSO ACTIVE
With the scan tool view DTCs.
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)
No
- Replace and program the Powertrain Control Module per Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)