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.

ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool, select view DTCs.
  Does the scan tool display as active: U0100-LOST COMMUNICATION WITH THE ECM/PCM?
  
  Yes
  - Refer to U0100-LOST COMMUNICATION WITH ECM/PCM for 1500, 2500 & 3500 or U0100-LOST COMMUNICATION WITH ECM/PCM for 3500 CAB & CHASSIS, 4500 & 5500 . and perform the U0100-Lost Communication with PCM diagnostic procedure.
  No
  - Refer to appropriate Electrical Diagnostic Information . and perform the Stored Lost Communication DTCs diagnostic procedure.