Diagnostic Test

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 the DTC INDEX article and perform the U0121-00-Lost Communication with Anti-lock Brake System (ABS) Control Module diagnostic procedure.
  No
  - Refer to DIAGNOSIS AND TESTING and perform the Stored Lost Communication DTCs diagnostic procedure.