Lexus 89422-35010 Sensor, Water Temperature (For E.F.I.)

To start with, the Coolant Temperature Sensor uses a thermistor that adjusts its resistance based on temperature changes. This resistance variation directly affects the voltage signal sent from the sensor to the PCM. Problems with the ECT sensor circuits will trigger a diagnostic trouble code. To check the ECT sensor, detach the electrical connector and measure the resistance between the sensor's terminals using an ohmmeter. The resistance should be between 2,500 and 3,000 ohms at room temperature. When the sensor is warmed in water, the resistance should decrease to around 250 to 300 ohms at 180 degrees F. If the test results are incorrect, you will need to replace the ECT sensor. Then replace the sensor, drain about one gallon of coolant, wrap the threads of the new sensor with Teflon sealing tape, disconnect the electrical connector, and detach the old sensor. After that, the installation is the reverse step of the removal process. Finally, you can refill the cooling system.

To troubleshoot the coolant temperature gauge, check the fuses. If the gauge is not working, disconnect the wire at the Coolant Temperature Sensor and observe the gauge's behavior and if the reading drops, replace the sending unit. If the reading remains high, there may be a short in the wire. If the gauge fails to show any indication once the engine warms up, disconnect the wire at the sending unit and use a jumper wire to connect it to clean ground on the engine. Then, if the gauge still doesn't respond, there may be an open circuit. In order to remove the sending unit, drain the coolant, disconnect the wiring connector, and remove the unit using a wrench. Once you are installing the new unit, tighten it securely without using thread sealer. Finally, connect the wiring connector, refill the cooling system, and check for any coolant leakage or issues with the gauge's function.

Depending on the model, either unscrew the ECT sensor from the water outlet housing or, for 2GR-FKS models, carefully remove the retaining clip and pull out the ECT sensor.

Unscrew the ECT sensor from the cylinder head after disconnecting the electrical connector. It's advised to apply Teflon tape to the sensor's threads before installing it back onto the cylinder head. During installation, ensure secure tightening of the sensor, reconnect the electrical connector, refill any drained coolant if necessary, and verify proper sensor operation after starting the engine.

89422-35010 IS FOR THE ECM