See Figure 1
The Engine Coolant Temperature (ECT) sensor detects the temperature of engine coolant and supplies that information to the computer control module. The ECT sensor is located on the cylinder head or on the intake manifold. The sensor signal is used to modify ignition timing, EGR flow and air/fuel ratio as a function of engine coolant temperature.
- 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. Then, measure 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
- Disconnect the negative battery cable.
- Drain the cooling system to a level below the sensor.
- Disengage the electrical connector from the ECT sensor.
- Remove the ECT sensor.
- Installation is the reverse of the removal procedure. Properly refill and bleed the cooling system.