Possible reasons for the transmission jerking in a Ford Kuga:
Transmission fluid problems:
* Low level
* Contaminated liquid
* Stuck oil filter
Problems with gearbox mechanics:
* Worn gears
* Damaged solenoids
* Faulty friction discs
Electronics problems:
* Faulty Transmission Control Module (TCM)
*Speed sensors failure
*Wiring problems
Engine problems:
* Worn spark plugs or ignition coils
* Clogged fuel filter
* Worn timing belt
Other possible reasons:
* Worn engine or transmission mounts
* Faulty oxygen sensor
* Dirty throttle valve
Recommendations for diagnosis and elimination:
1. Check the level and condition of the transmission fluid. If the level is low, add the recommended fluid. If the fluid is dirty or has a burnt odor, replace it.
2. Perform computer diagnostics. This will help identify trouble codes that may indicate the source of the problem.
3. Check transmission solenoids. Measure the resistance and voltage of the solenoids to determine their functionality.
4. Inspect the friction discs. If they are worn or damaged, replace them.
5. Check TCM. Read trouble codes from the TCM and check the wiring.
6. Carry out engine diagnostics. Make sure the engine is running properly, as engine problems can affect transmission performance.
7. Check the engine and transmission mounts. Worn mounts can cause excessive vibration, which results in jerking.
8. Replace the oxygen sensor. A faulty oxygen sensor can result in an incorrect air-fuel mixture, which can cause jerking.
9. Clean the throttle valve. A dirty throttle body can cause uneven fuel delivery, which can also cause jerking.
If you are unsure of the cause of the jerking, take it to a qualified mechanic for diagnosis and repair.