Engine - Coolant Temperature Sensor/Switch: Testing and Inspection

NOTE: Perform the following test only when directed.

Resistance Inspection
1. Drain the engine coolant. (See COOLING SYSTEM SERVICE WARNINGS.) (See ENGINE COOLANT REPLACEMENT.)
2. Remove the ECT sensor. (Located above the starter)




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

Specification:

4. Measure the resistance between the ECT sensor terminals using an ohmmeter.
- If not as specified, replace the ECT sensor.
- If the ECT sensor is okay, but ECT V PID value or PCM terminal 38 voltage are out of specification, perform the "Circuit Open/Short Inspection".

Circuit Open/Short Inspection
1. Disconnect the PCM connector.




2. Connect the SST (104 Pin Breakout Box) with the PCM disconnected.
3. Tighten the connector attaching bolt.

Tightening torque
7.9 - 10.7 N.m {80 - 110 kgf.cm, 69.5 - 95.4 in.lbf}

4. Inspect the following wiring harness for open or short (Continuity check).

Open circuit
- If there is no continuity, the circuit is open. Repair or replace the harness.
- ECT sensor terminal 1 (harness-side) and 104 pin breakout box terminal 38
- ECT sensor terminal 2 (harness-side) and 104 pin breakout box terminal 91

Short circuit




- If there is continuity, the circuit is shorted. Repair or replace the harness.
- ECT sensor terminal 1 (harness-side) and power supply
- ECT sensor terminal 1 (harness-side) and body ground
- ECT sensor terminal 2 (harness-side) and power supply