Engine Temperature Sensor: Testing and Inspection

ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION[LF]

NOTE
- Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

Resistance Inspection
1. Remove the battery cover.
2. Disconnect the negative battery cable.
3. Disconnect the ECT sensor connector.
4. Remove the ECT sensor.




5. Place the ECT sensor in the water and while increasing the water temperature, measure the resistance between ECT sensor terminals A and B.
- If the monitor item status/specification (reference) is not within the specification, even though the ECT sensor resistance is within the specification, perform the "Circuit Open/Short Inspection".
- If not within the specification, replace the ECT sensor.

Circuit Open/Short Inspection










1. Disconnect the PCM connector.
2. Inspect the following wiring harnesses for an open or short circuit. (Continuity inspection)

Open circuit
If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
- ECT sensor terminal A and PCM terminal 2AH
- ECT sensor terminal B and PCM terminal 2AY

Short circuit
- If there is continuity, there is a short circuit. Repair or replace the wiring harness.
- ECT sensor terminal A and power supply
- ECT sensor terminal A and body ground
- ECT sensor terminal B and power supply