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

Coolant Temperature Sensor:

PURPOSE
The coolant temperature sensor reports engine temperature to the ECU. Temperature information is used to properly compute air/fuel and ignition configurations.

LOCATION
The sensor is threaded into the water jacket on L.H. side of intake manifold.


CONSTRUCTION
The coolant temperature sensor has two terminals, each connected to a separate thermistor element. One is utilized by the EFC System control unit and the other is for the temperature gauge. This sensor can also be referred to as a thermosensor.

OPERATION
Water temperature data is sent to the ECU whenever the ignition is on. Changes in sensor temperature alter the thermistor resistance. When a known voltage is passed through the sensor, the output voltage is dependant upon the resistance off the sensor.