Method 1: Using a diagnostic scanner
1. Connect the diagnostic scan tool to your vehicle’s diagnostic port.
2. Turn on the ignition, but do not start the engine.
3. Enter the «Modules» or «Electronic control units» section.
4. Locate the transmission control module (TCM) or transmission.
5. Select the automatic transmission temperature sensor parameter.
6. Check temperature readings. It should be within the normal operating range (usually 80 to 120 °C).
Method 2: Resistance Measurement
1. Disconnect the automatic transmission temperature sensor connector.
2. Take a multimeter and set it to resistance (ohms) measurement mode.
3. Connect one probe to the sensor terminal marked «T» or «Temp».
4. Connect the other probe to the terminal marked «G» or «Ground».
5. Compare the resulting resistance with the values specified in your vehicle’s technical manual. The resistance should change depending on the temperature.
Method 3: Using a Thermometer
1. Start the engine and let it run for a few minutes.
2. Open the hood and find the automatic transmission pan.
3. Insert a K-tip thermometer into the pan drain plug.
4. Read the temperature readings. It should be within the normal operating range (usually 80 to 120 °C).
Interpretation of results:
*Normal reading: Resistance or temperature is within the specified ranges. The automatic transmission temperature sensor is working properly.
* Low Resistance or High Temperature: The automatic transmission temperature sensor may produce high signals, indicating a problem.
* High resistance or low temperature: The automatic transmission temperature sensor may produce low signals, which also indicates a malfunction.
If the test results indicate a malfunction of the automatic transmission temperature sensor, it must be replaced.