See Figure 1
The Engine Coolant Temperature (ECT) sensor resistance changes in response to engine coolant temperature. The sensor resistance decreases as the coolant temperature increases, and increases as the coolant temperature decreases. This provides a reference signal to the ECM, which indicates engine coolant temperature. The signal sent to the ECM by the ECT sensor helps the ECM to determine spark advance, EGR flow rate, air/fuel ratio, and engine temperature. The ECT also is used for temperature gauge operation by sending its signal to the instrument cluster.
See Figures 2, 3, 4 and 5
- Turn the key to the ON position, with the engine OFF .
- Test the resistance of the sensor across the two terminals of the sensor.
- Using the chart in this section for a cross reference, check the resistance in relationship to the temperature of the engine.
- If the sensor is not within specifications, replace it.
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Drain and recycle the engine coolant.
- Remove any components necessary to access the sensor.
- Remove the connector from the sensor.
- Using the proper size socket, unscrew the sensor from its mounting location.
- Install the sensor in its mounting location and tighten it.
- Install the connector on the sensor.
- Install any components removed to access the sensor.
- Refill and bleed the engine cooling system.
- Connect the negative battery cable.
- Inspect for leaks.