Diagnostic Test

WARNING: This page is about a different car, the 2013 Fiat 500c and 2013 Fiat 500. However, it is still accessible from the selected car via links, so may be relevant.

VERIFY THE DIAGNOSTIC TROUBLE CODE (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: U0100-LOST COMMUNICATION WITH ECM/PCM?
  
  Yes
  - Refer to DIAGNOSIS AND TESTING and perform the U1701-87-Lost Communication with PCM diagnostic procedure.
  No
  - Refer to DIAGNOSIS AND TESTING and perform the Stored Lost Communication DTCs diagnostic procedure.