Visual inspection:
* Check the level and condition of the automatic transmission fluid (ATF). It should have a reddish color and a non-burnt smell.
* Inspect the automatic transmission pan for leaks or damage.
* Check connecting hoses and wiring for wear or damage.
Check in motion:
* Start the engine and enter the ‘Parking’ mode.
* Move the gear shift lever to each position and check whether the gear engages smoothly and without jerking.
* Drive away in ‘D’ mode and accelerate. Pay attention to the smoothness of the gear shift and the absence of slippage.
* Reduce speed and brake. Check whether engine braking occurs and gears shift down.
Diagnostic test:
* Connect a scanner to read fault codes that may indicate problems with the automatic transmission.
* Run the automatic transmission adaptation procedure or reset the adaptive values, if indicated in the fault codes.
Other checks:
* Check the engine and transmission mounts. Worn bearings can cause vibrations or shocks when shifting gears.
* Check the condition of the torque converter cushion. Excessive wear or damage may result in noise or vibration.
* Check the wiring of the electronic transmission control module (TCM). Problems with electrical wiring can lead to incorrect operation of the automatic transmission.
Signs of automatic transmission malfunctions:
* Slipping or slipping of gears
* Difficulty shifting gears
* Jerks or jerks when shifting
* Extraneous noise or vibration
* Leaks or insufficient ATF level
* The automatic transmission fault indicator lights up on the dashboard