Engine Controls - Self-Diagnostics - Introduction: Summary

If no Diagnostic Trouble Code (DTC) is present but a driveability problem still exists, proceed to TROUBLE SHOOTING - NO CODES article for symptom diagnostic or intermittent diagnosis procedures.

After confirming that the circuits and components of a suspect system are functioning properly and clearing DTCs, the ECM PROM may require replacement if DTCs reset. Replacement procedure is not available from manufacturer.