Diagnostic Test

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC

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 the scan tool, read DTCs and record on the repair order.
Is the DTC active or pending?

Yes
- Perform the U0121-Lost Communication with Anti-Lock Brake Module diagnostic procedure. Refer to U0121-00-LOST COMMUNICATION WITH ANTI-LOCK BRAKE SYSTEM (ABS) CONTROL MODULE .
No
- Perform the Stored Lost Communication DTCs diagnostic procedure. Refer to STORED LOST COMMUNICATION DTCS .