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

CIRCUIT DESCRIPTION
A thermistor built into the engine coolant temp. sensor changes the resistance value according to the coolant temperature.
The structure of the sensor and connection to the ECM is the same as in the intake air temp. circuit malfunction.
If the ECM records the DTC Poll 5, it operates the fail safe function, in which the engine coolant temp. is assumed to be 80 °C (176 °F).