U1004

U1004-CAN C BUS TRANSMIT PERFORMANCE

For a complete wiring diagram refer to Diagrams/Electrical

- When Monitored:

Continuously while the system is active and there are no ECM system voltage DTCs present.

- Set Condition:

The ECM is reporting an error condition when attempting to transmit a CAN bus message.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.


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. Checking for an Intermittent DTC


2. COMMUNICATION DTCS PRESENT

With a scan tool check for any other communication DTCs present in other modules on the CAN C bus.

Are there any CAN C bus DTCs active at this time?

Yes

- Refer to Communication for additional vehicle communication diagnostic procedures.

No

- Replace and program the Engine Control Module (ECM).
- Perform the ECM Verification Test Ver. 1. ECM Verification Test