Possible reasons for the automatic transmission jerking on the Kia Rio 3:
Transmission oil problems:
* Insufficient oil level or clogged oil
* Using the wrong type of oil
Problems with the hydraulic control unit:
* Damaged or clogged solenoids
* Problems with the hydraulic system
Mechanical problems:
* Worn gears, couplings or bearings
* Damaged timing chain
* Faulty hydraulic converter
Electrical problems:
* Faulty speed or gear position sensor
*Wiring problems
* Failure of the electronic control unit (ECU) of the gearbox
Other possible reasons:
* Engine problems (insufficient power or revs)
* Malfunction of the mass air flow (MAF) sensor
*Clutch slippage
Solution:
1. Check the level and condition of the oil in the gearbox. If the oil is low or dirty, replace it.
2. Carry out diagnostics using a scanner. This can help identify specific trouble codes that indicate the root cause of the jerking.
3. Check hydraulic control unit and solenoids. They may need to be cleaned, repaired or replaced.
4. Inspect mechanical components. If there are worn or damaged parts, replace them.
5. Repair any electrical problems found. This may include replacing faulty sensors or repairing wiring.
6. Check the engine and other related components. Make sure they are working properly.