Possible causes of the malfunction:
Mechanical problems:
* Wear of gearbox discs and clutches
* Torque converter malfunction
*Transmission fluid leak
* Problems with sensors or electronics
Electrical problems:
* Faulty gear shift solenoids
* Problems with wiring or transmission control module (TCM)
Transmission fluid problems:
*Low fluid level
* Contaminated or old fluid
Other reasons:
* Oil pump wear
* Clogged transmission filter
* Engine or transmission problems
Symptoms of malfunction:
* Difficulty shifting gears
* Gear slippage
* Delay when shifting gears
* Vibration or noise when shifting gears
What to do:
1. Check the level and condition of the transmission fluid. If the level is low, add fluid and check for leaks. If the fluid is dark or has a burning smell, it needs to be replaced.
2. Replace the transmission filter. This will help remove contaminants that may be preventing the transmission from operating.
3. Check the shift solenoids. If the solenoids are faulty, they may not provide the necessary pressure to shift smoothly.
4. Scan the transmission for trouble codes. Trouble codes can point to a specific problem that is causing difficulty shifting gears.
5. Contact an experienced mechanic. If you are unable to correct the problem yourself, have the transmission diagnosed and repaired by a qualified mechanic.