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

Engine Coolant Temperature Sensor Wiring Diagram:

Purpose:
The coolant temperature sensor provides the ECM with information regarding coolant temperature.

Operation:
The computer sends a 5.0 volt signal to the coolant temperature sensor through a resistor in the ECM and measures the voltage. The voltage will be high or low depending on coolant temperature. By varying the voltage, the computer will sense engine coolant temperature.

Location:
The engine coolant temperature sensor is a thermistor that is located in the engine coolant flow.