Self-Diagnostic System: Notes

The PCM/VCM is equipped with a self-diagnostic system which detects system failures or abnormalities. When a malfunction occurs, PCM/VCM illuminates the SERVICE ENGINE/THROTTLE SOON light located on instrument panel. When malfunction is detected and light is turned on, a corresponding trouble code is stored in PCM/VCM memory. Malfunctions are designated as either "hard failures" or "intermittent failures". For procedures on retrieving stored codes, see appropriate TESTS W/CODES article.