Diagnostic Test

WARNING: This page is about a different car, the 2011 RAM Pickup. 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.
  Is the DTC Active at this time?
  
  Yes
  - Refer to U0100-LOST COMMUNICATION WITH ECM/PCM for 2500 & 3500 or U0100-LOST COMMUNICATION WITH ECM/PCM for 3500 Cab & Chassis, 4500 & 5500 . and perform the U0100-Lost Communication with ECM/PCM diagnostic procedure.
  No
  - Perform the STORED LOST COMMUNICATION DTCS for 2500 and 3500, or STORED LOST COMMUNICATION DTCS for 3500 Cab & Chassis, 4500 and 5500 diagnostic procedure . and perform the Stored Lost Communication DTCs diagnostic procedure.