Coolant Temperature Sensor/Switch (For Computer): Description and Operation
CIRCUIT DESCRIPTIONA thermistor built into the engine coolant temperature sensor changes the resistance value according to the engine coolant temperature.
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 DTC P0115, it operates the fail safe function in which the engine coolant temperature is assumed to be 80°C (176°F).