Diagnostic Test

WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

VERIFY DTC IS ACTIVE
NOTE:
Make sure the battery is fully charged before proceeding.
1. Turn the ignition on.
2. With the scan tool, read the active DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Refer to DTC INDEX - 2500 HD & 3500 HD and perform the U0121-87-Lost Communication with Anti-lock Brake System (ABS) Control Module diagnostic procedure.
  No
  - Refer to DIAGNOSIS AND TESTING and perform the Stored Lost Communication DTCs diagnostic procedure.