ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION

Note

• Before performing the following inspection, make sure to follow the troubleshooting flowchart. (See Troubleshooting Procedure.)

Resistance Inspection

1. Disconnect the ECT sensor connector.

2. Remove the ECT sensor.

3. Place the detection part of the ECT sensor in water and verify that the resistance between ECT sensor terminals A and B is as indicated in the table while gradually increasing water temperature.

• If the monitor item condition/specification (reference) is not within the specification, even though the resistance is within the specification, perform the "Circuit Open/Short Inspection".

• If not within the specification, replace the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION.)

ECT sensor resistance

Water temperature (°C {°F})	Resistance (ohm)
20 {68}	2,205-2,695
80 {176}	287-349
91 {196}	227-240

ECT sensor characteristics graph (reference)

Circuit Open/Short Inspection

1. Disconnect the PCM connector.

2. Disconnect the ECT sensor connector.

3. Inspect the following wiring harnesses for open or short circuit. (Continuity inspection)

Open circuit

• If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness.

– ECT sensor terminal A and PCM terminal 2K

– ECT sensor terminal B and PCM terminal 1U

Short circuit

• If there is continuity at the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness.

– ECT sensor terminal A and body ground

– ECT sensor terminal A and power supply