Diagnostic Test

WARNING: This page is about a different car, the 2011 RAM Pickup and 2011 RAM Cab & Chassis. 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. and perform the U0001-Can C Bus diagnostic procedure. Refer to U0001-CAN C BUS for 1500, 2500 & 3500 or U0001-CAN C BUS CIRCUIT for 3500 CAB & CHASSIS, 4500 & 5500 .
  No
  - Perform the STORED LOST COMMUNICATION DTCS for 1500, 2500 and 3500, or STORED LOST COMMUNICATION DTCS for 3500 Cab & Chassis, 4500 and 5500, diagnostic procedure .