1. Visual inspection
* Inspect the sensor for damage, corrosion, or loose connections.
* Check the wiring connecting the sensor to the automatic transmission ECU. Make sure it is not damaged and connected securely.
2. Resistance check
* Measure the resistance between the sensor terminals using a multimeter.
* Compare the measured value with that specified in the vehicle data sheet or the sensor manufacturer’s specifications.
*If the resistance is significantly different from the specified value, the sensor may be faulty.
3. Voltage check
*Connect one lead of the multimeter to the signal terminal of the sensor and the other lead to ground.
* Start the engine and let it warm up.
* The voltage at the signal terminal must correspond to that specified in the vehicle’s technical data sheet or in the specifications of the sensor manufacturer.
*If the voltage differs significantly from the specified voltage, the sensor may be faulty.
4. Check using a scanner
* Connect the OBD2 scanner to the vehicle diagnostic connector.
* Make sure that the scanner has the ability to read the automatic transmission oil temperature.
* Read the current automatic transmission oil temperature and compare it with the readings of other temperature sensors in the car.
* A difference in readings may indicate a malfunction of the automatic transmission oil temperature sensor.
5. Check for heating
* Connect the automatic transmission oil temperature sensor to a power source with regulated voltage.
* Gradually increase the voltage and measure the resistance of the sensor.
* The resistance of the sensor should decrease as it heats up.
* If the resistance does not decrease or changes abruptly, the sensor may be faulty.
Note: Before performing any checks, make sure the engine and transmission are cool and the battery is disconnected. Contact a qualified mechanic if you have any doubts about checking or replacing the automatic transmission oil temperature sensor.