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

Engine Coolant Sensor Locations:

Location
Engine coolant temperature sensor, located in the thermostat housing at the rear of the engine.

Construction
The Coolant Temperature Sensor is a thermistor type sensor.

Operation
As engine temperature increases, sensor resistance decreases.

The ECM calculates engine temperature from the sensor output voltage and provides optimum fuel enrichment when the engine is cold.