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Diagnostic Test

VERIFY THE DTC IS ACTIVE
1. Ignition on, engine not running.
2. With the scan tool, read the DTCs.
  Is the DTC Active at this time?
  
  Yes
  - Refer to U0100-00-LOST COMMUNICATION WITH ECM/PCM and perform the U0100-Lost Communication with ECM/PCM diagnostic procedure.
  No
  - Refer to COMMUNICATION - DIAGNOSIS AND TESTING and perform the Stored Lost Communication DTCs diagnostic procedure.