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.

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.

Disconnect the wire at the coolant temperature sender to determine if the sending unit needs to be replaced or if the wire to the gauge is shorted to ground or the gauge is faulty.

Start by disconnecting the negative battery cable and partially draining the cooling system for access. Disconnect the electrical connector from the ECT sensor to prepare for further steps.

89422-35010 IS FOR THE ECM