EGR Temperature Sensor

The EGR temperature sensor is located in EGR passage on intake manifold. Sensor is used on California models only. Sensor's thermistor changes resistance with respect to exhaust gas temperature. High temperature causes low resistance. Low temperature causes high resistance. A reference voltage (supplied and monitored by ECM) is modified by sensor resistance. ECM uses EGR temperature sensor signal to determine if EGR action is occurring when requested by ECM.