U1113-LOST AC PRESSURE MESSAGE

For a complete wiring diagram Refer to Section 8W

When Monitored:
Continuously while the system is active.
Set Condition:
An invalid message has been received over the bus from the Front Control Module (FCM).

Possible Causes

INTERMITTENT DTC

CAN BUS OPEN OR SHORTED CONDITION

FRONT CONTROL MODULE (FCM)

ENGINE CONTROL MODULE (ECM)

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

Diagnostic Test

1. ACTIVE DTC

NOTE: Diagnose all CAN B and C communication DTCs before continuing.

Ignition on, engine not running.
With a scan tool, view DTCs.

Is the status Active for this DTC?

Yes

Go To 2

No

Refer to the INTERMITTENT CONDITION Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2. COMMUNICATION DTCS PRESENT IN THE TOTALLY INTEGRATED POWER MODULE (TIPM)

With a scan tool check for DTCs in the TIPM.

Are there any CAN bus DTCs active in the TIPM at this time?

Yes

Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for additional vehicle communication diagnostic procedures.

Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

No

Replace and program the Engine Control Module (ECM) in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)