With Malfunction Indicator Lamp

DESCRIPTION
The check engine light is intended to alert the driver of certain malfunctions in the engine control system.

If such a fault occurs, the processor will substitute a value or values and continue operating. This process is called "Limited Operating Strategy (LOS). In some cases this action may result in a slight change in driveability.


System OK
The Check Engine Light will remain on while the key is in the RUN position, and go off once the vehicle has started.

System Not OK
If the Check Engine Light should remain on after the vehicle has started, run Key On Engine Off Test to completion. If the light continues to remain on, GO to Pinpoint Test PGC. If the Check Engine Light never comes on, GO to Pinpoint Test. If the light comes on for a period then goes off, and a Service Code is present, the fault is intermittent.


NOTE: When EEC is in Self-Test, the Check Engine Light will also flash Service Codes.