Malfunction Indicator Lamp: Description and Operation

DESCRIPTION

The Service Engine Soon (SES) light is used to inform the driver when the system detects a malfunction in a monitored device or circuit. It can also be used to display trouble codes to assist diagnosing fuel injection problems.

OPERATION

The SES light should be lit when the ignition is turned "ON", and go out after the engine starts. If the light does not go out after starting the engine, a problem has been detected that affects emissions &/or driveability. If this is the case, the vehicle should be serviced.

NOTE: Not all malfunctions will set trouble codes. Also, some codes may be present in computer memory and not light the SES light. See TROUBLE CODE DESCRIPTION under DIAGNOSIS, TESTING AND INSPECTION PROCEDURES/TESTING PROCEDURES.