Engine Temperature Sensor: Testing and Inspection
ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTIONNOTE: Before performing the following inspection, make sure to follow the troubleshooting flowchart. (See FOREWORD.) Flow of Diagnosis
Resistance Inspection
1. Disconnect the ECT sensor connector.
2. Remove the ECT sensor.
ECT Sensor Characteristics Graph (Reference):
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.
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