Malfunction Indicator Lamp: Description and Operation

MALFUNCTION INDICATOR LAMP (SERVICE ENGINE SOON)




Among the on-board diagnostic items, a Malfunction Indicator Lamp
(SERVICE ENGINE SOON) illuminates to notify the driver of an emission control malfunction.

However, when an irregular signal returns to normal and the engine control module (ECM) judges that it has returned to normal, the Malfunction Indicator Lamp (SERVICE ENGINE SOON) is switched off.

Moreover, when the ignition switch is turned off, the lamp is switched off. Even if the ignition switch is turned on again, the lamp does not illuminate until the malfunction is detected.

Immediately after the ignition switch is turned on, the Malfunction Indicator Lamp (SERVICE ENGINE SOON) is lit for 20 seconds to indicate that the Malfunction Indicator Lamp (SERVICE ENGINE SOON) operates normally.