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

Location
The coolant temperature sensor is located in the thermostat housing.

Coolant Temperature Sensor:

Construction
The Coolant Temperature Sensor is a thermistor type sensor.

Coolant Temperature Sensor Circuit:

Operation
As engine temperature increases, sensor resistance decreases. The ECM monitors engine temperature by the sensor output voltage and provides optimum fuel enrichment when the engine is cold.