Possible causes of jerking when shifting gears in a Toyota automatic transmission:
Mechanical problems:
* Worn or damaged friction discs or bands
* Torque converter problems
* Defects in automatic transmission solenoids or sensors
* Clogged or dirty oil filter
Software problems:
* Malfunction or automatic transmission software update
* Problems with the electronic control unit (ECU)
Problems with automatic transmission fluid:
* Low automatic transmission fluid level
* Contaminated or spoiled automatic transmission fluid
Other reasons:
* Spark plugs or ignition coils are faulty
* Faulty mass air flow (MAF) sensor
* Timing belt slippage
* Clogged catalytic converter
* Faulty power steering pump
Remedy:
* Check the level and condition of the automatic transmission fluid. If the fluid level is below normal or the fluid is dirty, it must be replaced.
* Use automatic transmission fluid recommended by the manufacturer. Using the wrong fluid can lead to problems with the automatic transmission.
* Inspect friction discs, bands and other automatic transmission components. Replace worn or damaged parts as necessary.
* Check automatic transmission solenoids and sensors. Faulty solenoids and sensors can cause the automatic transmission to malfunction.
* Update automatic transmission software. This can solve problems related to software bugs.
* Check and replace spark plugs and ignition coils. Faulty spark plugs or coils can cause rough shifting.
* Check the MAF sensor. A faulty MAF sensor can result in an incorrect air/fuel mixture, which can cause rough shifting.
* Check the timing belt. A slipping timing belt can cause serious engine and transmission problems.
* Check the catalytic converter. A clogged catalytic converter can restrict exhaust flow, which can cause rough shifting.
* Check the power steering pump. A faulty power steering pump can cause shifting problems.
If you cannot independently determine the cause of the automatic transmission jerking, contact an experienced mechanic for diagnosis and repair.