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

Coolant Temperature Sensor:

PURPOSE
The ECM uses engine temperature information to calculate the following:
^ Injection quantity
^ Ignition timing
^ Canister purge
^ Idle speed
^ Radiator fan operation

Coolant Temperature Sensor Range Chart:

OPERATION
The coolant temperature sensor contains a thermistor whose resistance changes with the temperature. The ECM sends a reference voltage to the sensor and measures changes in resistance as the engine temperature varies.