EGR Temperature Sensor: Description and Operation

EGR TEMPERATURE SENSOR

The EGR temperature sensor measures the temperature of the exhaust gases returned to the intake manifold. The ECM determines whether or not the EGR system is in operation by detecting the variations in temperature.

The sensor employs a temperature-sensitive resistance with a Negative Temperature Coefficient (NTC). The ECM supplies a nominal (unloaded) voltage of 5 Volts to one of the sensor terminals, across an internal resistance. The second terminal is grounded.

The voltage across the sensor varies with the temperature of the recirculated gases and, as a result, the sensor resistance. The voltage, which may vary from 0 Volts to 5 Volts, is high when the sensor is cold and low when the sensor is hot.

The sensor is mounted in the EGR valve.