Self-Diagnostic System: Notes

ECM is equipped with a self-diagnostic system, which detects system failures or abnormalities. When malfunction occurs, Malfunction Indicator Light (MIL) on is turned on. MIL is located in center of instrument cluster (models with tachometer) or right side of instrument cluster (models without tachometer), under engine symbol marked CHECK.

By analyzing various input signals, ECM detects system malfunctions related to various operating parameter sensors. ECM stores trouble codes associated with the detected failure until the diagnostic system is cleared. For further information, see TESTS W/CODES article in the ENGINE PERFORMANCE section.