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

ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION

NOTE: Perform the following inspection only when directed

ECT Sensor Resistance Inspection
1. Drain the engine coolant (See COOLING SYSTEM SERVICE WARNINGS).
2. Remove the ECT sensor (located above the starter).
3. Place the ECT sensor in water with a thermometer, and heat the water gradually







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

Circuit Open/Short Inspection

1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION)




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

Open circuit
- If there is no continuity, there is an open circuit Repair or replace the wiring harness
- ECT sensor terminal A (harness-side) and PCM terminal 1M (harness-side)
- ECT sensor terminal B (harness-side) and PCM terminal 2H (harness-side)

Short circuit
- If there is continuity, there is a short circuit Repair or replace the wiring harness
- 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