Exhaust Gas RECIRCULATION (EGR) System: Operation

When the engine coolant temperature is low, when the engine is at idle or when a wide open throttle operation is performed, the EGR valve (Stepper Motor) is kept closed, achieving no EGR. After warming up of the engine, the EGR valve (Stepper Motor) can be opened by the powertrain control module (PCM).

The PCM monitors the EGR system and illuminates the check engine/malfunction indicator lamp to indicate that there is a malfunction.