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. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION.)
2. Place the ECT sensor in water with a thermometer, and heat the water gradually.










3. Measure the resistance between 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. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION.)

Circuit Open/Short Inspection
1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION.)




2. Inspect the following harnesses 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.