Transmission Control Module (TCM) - 8HP45

U0002-CAN C BUS OFF PERFORMANCE

For a complete wiring diagram Refer to the Wiring Information.

Theory of Operation

The vehicle control modules communicate over the CAN C BUS. The Transmission Control Module (TCM) continuously monitors BUS activity. The CAN C BUS is used to communicate transmission MIL status to the PCM. If the PCM is unable to communicate with the TCM, a DTC sets and the PCM will illuminate the MIL.

- When Monitored:
Every 7 msec with:

1) Engine speed greater than 500 rpm.

2) Battery voltage between 10 and 16 volts.

- Set Condition:
CAN C BUS messages are not received for 10 seconds.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.

Diagnostic Test
VERIFY DTC IS ACTIVE

NOTE: For vehicle communication problems, use the scan tool to refer to the Network Review Screen. The screen depicts a high level view of the vehicle network. Fault and problem areas appear in red. Selecting any of the network components allows access to the source of the problem.

1. Turn the ignition ON.
2. With the scan tool, read active DTCs.

Is this DTC active?

Yes

- Body Control Module (BCM) and perform the U0002-CAN C BUS OFF PERFORMANCE diagnostic procedure.

No

- Manufacturer Code Charts and perform the STORED LOST COMMUNICATION DTCs diagnostic procedure.