Engine Temperature Sensor: Testing and Inspection

ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION[LF, L3]

Resistance Inspection

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

1. Disconnect the ECT sensor connector.
2. Remove the ECT sensor.

Standard:

3. 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*1 *2, 2AK*3
- ECT sensor terminal B and PCM terminal 2AY*1, 2P*2, 2AA*3

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
*1 : California emission regulation applicable model
*2 : Except for California emission regulation applicable model with LF MTX, L3
*3 : Except for California emission regulation applicable model with LF ATX