EGR Temperature Sensor: Description and Operation

California model vehicles are equipped with an EGR Temperature Sensor which serves to verify that the EGR Valve is operating as designed. This is done by monitoring the temperature of the exhaust passage downstream of the EGR valve. The Control Unit expects to see an increased voltage return signal from the EGR temperature sensor whenever the EGR valve is commanded to be operating. In the event of a malfunction the Control Unit will set a trouble code and illuminate the CHECK ENGINE LIGHT.