Diagnostic Test

WARNING: This page is about a different car, the 2012 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

VERIFY THE DTC IS ACTIVE
NOTE:
Make sure the IOD fuse is installed and the battery is fully charged before proceeding.
1. Turn the ignition on.
2. With the scan tool, read active DTCs.
  Is the DTC active at this time?
  
  Yes
  - Refer to U0121-LOST COMMUNICATION WITH ABS and perform the U0121-00-Lost Communication with Antilock Brake System (ABS) Control Module diagnostic procedure.
  No
  - Refer to COMMUNICATION - DIAGNOSIS AND TESTING and perform the Stored Lost Communication DTCs diagnostic procedure.