TESTING

1. Disengage the engine wiring harness connector from the ECT sensor.
2. Connect an ohmmeter between the ECT sensor terminals, and set the ohmmeter scale on 200,000 ohms.
3. With the engine cold and the ignition switch in the OFF position, measure and note the ECT sensor resistance. Attach the engine wiring harness connector to the sensor.
4. Start the engine and allow the engine to warm up to normal operating temperature.
5. Once the engine has reached normal operating temperature, turn the engine OFF
6. Once again, detach the engine wiring harness connector from the ECT sensor.
7. Measure and note the ECT sensor resistance, then compare the cold and hot ECT sensor resistance measurements with the accompanying chart.
8. Replace the ECT sensor if the readings do not approximate those in the chart, otherwise reattach the engine wiring harness connector to the sensor.

   Fig. 1: Checking the resistance of the engine coolant temperature sensor still installed on the engine

   Fig. 2: If the sensor is removed, submerge the end of the coolant temperature sensor in cold or hot water and check resistance

   Fig. 3: IAT and ECT sensor specifications chart — B Series Pick-up and Navajo models

   Fig. 4: ECT sensor specifications chart — MPV models