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

Reference Data:

COMPONENT DESCRIPTION
The engine coolant temperature sensor is located near the No. 2 injector. The sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

CAUTION: Do not use ECM ground terminals when measuring voltage.
Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals such as the body ground.