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

Water Temperature Sensor (THW):

The Coolant Temperature Sensor, located on the front, RH side of the engine, monitors coolant temperature with a thermistor whose resistance varies according to engine temperature. The ECU uses this signal to control overdrive on electronic transmissions, spark control, air injection system and EVAP system. The THW inputs the ECU through terminal 2.