Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection

ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION

NOTE: Perform the following inspection only when directed.

Resistance Inspection

1. Remove the ECT sensor.




2. Place the ECT sensor in water with a thermometer, and heat the water gradually.







3. Measure the resistance between the ECT sensor terminals A and B using an ohmmeter.
- If the ECT sensor is okay, but the PID value is out of specification, perform the "Circuit Open/Short Inspection".
- If not as specified, replace the ECT sensor.

Circuit Open/Short Inspection

1. Disconnect the PCM connector.




2. Inspect the following harness for open or short circuit. (Continuity check)

Open circuit

- ECT sensor terminal A (harness-side) and PCM terminal 38 (harness-side)
- ECT sensor terminal B (harness-side) and PCM terminal 91 (harness-side)

Short circuit

- ECT sensor terminal A (harness-side) and power supply
- ECT sensor terminal A (harness-side) and body GND
- ECT sensor terminal B (harness-side) and power supply