Exhaust Gas Temperature (EGT) Sensor
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The EGT sensor is a thermistor sensor. The EGT sensor is an input to the PCM and measures the temperature of the exhaust gas passing through the exhaust system. The electrical resistance of the sensor decreases as the temperature increases, and resistance increases as the temperature decreases. The varying resistance changes the voltage drop across the sensor terminals and provides electrical signals to the PCM corresponding to temperature.
The PCM uses the input from the EGT sensor to monitor the particulate filter temperature. The EGT sensors are located in the exhaust system downstream of the particulate filter.