Diagnostic Test

VERIFY THE 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.

Turn the ignition on.
With a scan tool, select View DTCs.
Is the DTC active at this time?

Yes
- Perform the U0001-CAN C BUS circuit diagnostic procedure. Refer to DTC INDEX - EXCEPT 500L .
No
- Perform the STORED LOST COMMUNICATION DTCS diagnostic procedure. Refer to DIAGNOSIS AND TESTING .