Diagnostic Test

VERIFY THE DTC IS ACTIVE 

1. Turn the ignition on.
2. With the scan tool, read the active DTCs.

   Is the DTC active at this time?

   Yes 

   • Perform the U0100-87-Lost Communication with ECM/PCM diagnostic procedure. Refer to  DIAGNOSIS AND TESTING  .

   No 

   • Perform the Stored Lost Communication DTCs diagnostic procedure. Refer to  DIAGNOSIS AND TESTING  .