Diagnostic Test

WARNING: This page is about a different car, the 2012 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

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.
1. Turn the ignition on.
2. With a scan tool, read DTCs.
  Is the DTC active at this time?
  
  Yes
  - Diagnose the U0002-00 CAN C BUS OFF PERFORMANCE as the U0001 CAN C BUS CIRCUIT test. Refer to U0001-CAN C BUS and perform the diagnostic procedure.
  No
  - Refer to DIAGNOSIS AND TESTING and perform the Stored Lost Communication DTCs diagnostic procedure.