Among the on-board diagnostic items, a check engine/malfunction indicator light comes on to notify the driver of a emission control component irregularity. If the irregularity detected returns to normal or the PCM judges that the component has returned to normal, the check engine/malfunction indicator light will be turned off. Moreover, if the ignition is turned OFF and then the engine is restarted, the check engine/malfunction indicator light will not be turned on until a malfunction is detected.
The check engine/malfunction indicator light will come on immediately after the ignition switch is turned ON. The light should stay lit for 5 seconds and then will go off. This indicates that the check engine/malfunction indicator lamp is operating normally. This does not signify a problem with the system.
NOTE: The check engine/malfunction indicator lamp will come on when the terminal for the ignition timing adjustment is shorted to ground. Therefore, it is not abnormal that the light comes on even when the terminal for ignition timing is shorted at time of ignition timing adjustment.
To test the light, perform the following: