Potential causes of shifting jerks in an automatic transmission:
Mechanical problems:
* Worn or damaged clutches and steel discs
* Contaminated or faulty transmission oil
*Low transmission oil level
* Worn or damaged valve body
* Torque converter malfunction
Electrical problems:
*Faulty throttle position sensor
* Faulty air flow sensor
* Faulty input shaft speed sensor
* Faulty output shaft position sensor
* Problems with wiring or connectors
Software problems:
* Incorrect Transmission Control Module (TCM) software
* Unsynchronized transmission calibration
Other reasons:
* Stuck or dirty valves in the valve body
* Worn or damaged transmission filters
* Contaminated or faulty oil in the torque converter
* Worn transmission seals or gaskets
Diagnostics:
To accurately diagnose the cause of jerking when shifting gears in an automatic transmission, you need:
* Visual inspection and check of transmission oil level
* Read trouble codes using OBD-II scanner
* Checking the operation of sensors and other electrical components
* Oil pressure and speed data analysis
* Test drive using specialized diagnostic equipment