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

PURPOSE/OPERATION
The engine coolant temperature sensor measures coolant temperature to control fuel enrichment. As engine temperature increases, sensor resistance decreases. The engine control module monitors engine temperature and provides optimum fuel enrichment when the engine is cold. A temperature sensitive resistor or thermistor sealed in a brass, threaded tube. The sensing part is contained in the bulb end of the tube allowing penetration into the cooling system for accurate measurement of coolant temperature.