Self-Diagnostic System: Notes

ECU is equipped with a self-diagnostic system, which detects system failures or abnormalities. When malfunction occurs, Malfunction Indicator Light (MIL) on instrument panel is turned on.

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