Stage 1: Checking the level and condition of the automatic transmission fluid
* Check the automatic transmission fluid level with the engine running and the selector in the “Parking” position.
* The liquid must be clean, without the smell of burning and metal particles.
Step 2: Visual inspection
* Inspect the automatic transmission for leaks, cracks or other damage.
* Check sensor connectors and wiring for damage or looseness.
Stage 3: Acceleration Test
* Warm up the engine and transmission.
* Press the accelerator pedal sharply from the “Parking” position.
* The transmission should shift smoothly, without slipping or hesitation.
Step 4: Torque Converter Lockup Test
* Accelerate the car to a speed of about 80 km/h.
* Keep the gas pedal in one position.
* The speed should stabilize and the engine should run at lower speeds. This indicates that the torque converter is locked.
Step 5: Shift Test
*Ride at different speeds and load conditions.
* Pay attention to smooth and timely gear changes.
* Listen for unusual noises or vibrations while shifting gears.
Step 6: Scan Trouble Codes
* Connect the diagnostic scanner to the vehicle’s OBD-II port.
*Check for automatic transmission related fault codes.
Step 7: Checking the automatic transmission fluid pressure
* Install a pressure gauge in the automatic transmission fluid pressure line.
* Start the engine and change gears.
* Compare the pressure readings with those indicated in the technical manual.
Step 8: Checking Electronic Components
* Check speed sensors, solenoids and other electronic components of the automatic transmission using a multimeter.
* Look for signs of opens, shorts, or abnormal signals.
Important: Automatic transmission diagnostics must be carried out by a qualified mechanic with the appropriate equipment and experience.