Coolant Temperature Sensor/Switch (For Computer): Description and Operation

Coolant Temperature Sensor (Output Characteristic):

Located at the side of throttle body, this sensor measures the temperature of the engine coolant. The ECT is a thermistor, that is, as coolant temperature lowers, resistance increases and as it rises, resistance decreases. By monitoring the voltage drop of the coolant temperature sensor, the ECM detects the engine coolant temperature and that affects most systems under the control of the ECM.