Tools and equipment:
* Multimeter
* OBD2 scanner (optional)
Procedure:
1. Make sure the car is in park and the engine is turned off.
2. Find the automatic transmission speed sensor. It is usually located on the transmission housing near the shift cable.
3. Disconnect the electrical connector from the sensor.
4. Set the multimeter to resistance (ohms) mode.
5. Connect one multimeter probe to the input terminal of the sensor (usually the orange or blue wire).
6. Connect another multimeter probe to the sensor output pin (usually white or black wire).
7. Slowly rotate the transmission output shaft by hand. You should see a change in resistance on the multimeter.
8. Compare the resistance readings with those indicated in the technical specifications. Resistance typically ranges from 50 to 500 ohms in neutral and increases as the output shaft is rotated.
Interpretation of results:
* If the resistance changes when the output shaft rotates: the automatic transmission speed sensor is working normally.
* If the resistance does not change: the automatic transmission speed sensor may be faulty or there is no signal.
*If the resistance is too low (less than 50 ohms): there may be a short circuit in the sensor or wiring.
* If the resistance is too high (more than 500 ohms): there may be a break in the sensor or wiring.
Additional steps:
*If you are using an OBD2 scanner, you may receive a trouble code (DTC) for the automatic transmission speed sensor.
*You can also perform a continuity check on the wiring between the sensor and the transmission ECU.
*If you find that the sensor is faulty, please replace it.