Secondary Cooling System Engine Coolant Temperature 2 (ECT2) Sensor
The secondary cooling system ECT2 sensor is a thermistor device in which resistance changes with temperature. The electrical resistance of a thermistor decreases as the temperature increases, and resistance increases as the temperature decreases. The varying resistance affects the voltage drop across the sensor terminals and provides electrical signals to the powertrain control module (PCM) corresponding to temperature.
The secondary cooling system ECT2 sensor is located in the exhaust gas recirculation (EGR) cooler. The secondary cooling system ECT2 sensor measures the temperature of the secondary cooling system and provides a feedback signal to the PCM. The PCM uses the secondary cooling system ECT2 sensor input to control the EGR cooler bypass valve.