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

Engine Coolant Temperature (ECT) Sensor

A thermistor built into the engine coolant temp. sensor changes the resistance value according to the engine coolant temp.

The structure of the sensor and connection to the ECM is the same as in the intake air temperature circuit malfunction.

If the ECM detects the DTC P0115, it operates the fail-safe function in which the engine coolant temp. is assumed to be 80 °C (176 °C).