The engine coolant temperature sensor changes the resistance in response to the engine coolant temperature. The sensor decreases the resistance as the surrounding temperature increases. This provides a signal to the PCM that indicates the engine coolant temperature.
See Figures 1 and 2
- Disconnect the temperature sensor.
- Connect an ohmmeter between the sensor terminals and set the ohmmeter scale on 200,000 ohms.
- Measure the resistance with the engine off and cool and with the engine running and warmed up. Compare the resistance values obtained with the chart.
- Replace the sensor if the readings are incorrect.
REMOVAL & INSTALLATION
- Drain the engine cooling system slightly.
- Disconnect the negative battery cable.
- Detach the wiring connection from the sensor.
- Remove the coolant temperature sensor from the intake manifold.
- Clean the sensor area of any debris.
- Install a new sensor into the intake manifold. Tighten the 6-14 ft. lbs. (8-19 Nm).
- Attach the sensor wiring to the unit.
- Connect the negative battery cable.
- Fill the engine cooling system with a 50/50 coolant water mixture.
- Start the engine and top off the cooling system.