Tools and materials:
* Transmission fluid (ATF) and dipstick for automatic transmission
* OBD2 diagnostic scanner (optional)
* Lift or jacks and stands
Visual inspection:
* Check for ATF leaks under the pan or around the oil seals.
* Inspect the pan for metal shavings or other signs of wear.
* Check the condition of the automatic transmission wiring harness for damage or wear.
Checking ATF level:
1. Start the engine and warm it up to operating temperature.
2. Move the automatic transmission selector to all positions for a few seconds.
3. Place the vehicle in park gear on a level surface.
4. Pull out the automatic transmission dipstick, wipe it with a clean cloth and reinsert it.
5. Pull the dipstick out again and check the fluid level. It should be between the Min and Max marks.
Diagnosis of breakdowns using the OBD2 diagnostic scanner:
1. Connect the diagnostic scanner to the OBD2 connector in the car.
2. Turn on the scanner and select the automatic transmission module.
3. Check for fault codes that may indicate problems with the automatic transmission.
Test drive:
1. Accelerate to a moderate speed and listen for any unusual noise or vibration from the automatic transmission.
2. Try changing gears in different modes, such as Drive, Sport and Manual.
3. Press the brake pedal while driving and check whether the automatic transmission responds quickly to reducing speed and changing gear.
Other signs of automatic transmission malfunction:
* Gear slippage or delay in shifting
* ATF leakage or burning fluid odor
* Difficulty shifting gears
* Switch to emergency operation mode (check engine light will light up)
Warning: Diagnosing an automatic transmission can be a complex task, requiring special tools and knowledge. If you suspect an automatic transmission problem, it is highly recommended that you contact a qualified mechanic for further diagnosis and repair.