See Figure 1
Most engine functions are affected by the coolant temperature. Determining whether the engine is hot or cold is largely dependent on the temperature of the coolant. An accurate temperature signal to the ECM is supplied by the coolant temperature sensor. The coolant temperature sensor is a thermistor mounted in the engine coolant stream. A thermistor is an electrical device that varies its resistance in relation to changes in temperature. Low coolant temperature produces a high resistance and high coolant temperature produces low resistance. The ECM supplies a signal of 5 volts to the coolant temperature sensor through a resistor in the ECM and measures the voltage. The voltage will be high when the engine is cold and low when the engine is hot.
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Drain the cooling system to an appropriate and clean container for reuse.
- Disconnect the electrical wiring from the coolant temperature sensor.
- Remove the coolant temperature sensor.
- Install the coolant temperature sensor.
- Connect the electrical wiring.
- Fill the cooling system.
- Connect the negative battery cable.
- Start the engine and check for leaks.