Diagnostic Test
- VERIFY THE DTC IS ACTIVE NOTE:
For vehicle communication problems, use the scan tool to refer to the network review screen. This 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.
- Ignition on, engine not running.
- With a scan tool, read DTCs.
Is the DTC active at this time?
Yes
- Refer to the DTC INDEX article and perform the U0101-LOST COMMUNICATION WITH TCM diagnostic procedure.
No
- Refer to DIAGNOSIS AND TESTING and perform the STORED LOST COMMUNICATION DTCs diagnostic procedure.