Possible reasons:
*Mechanical failure:
* Worn or broken clutches
*Damage to internal gearbox components (eg gears)
* Torque converter malfunction
*Electrical fault:
* Malfunction of control solenoids
* Problems with the electronic control unit (ECU)
* Damage to electrical wiring
*Hydraulic problems:
* Insufficient transmission fluid level
* Clogged hydraulic filter
* Oil pump malfunction
Diagnostics:
To diagnose the problem, it is necessary to conduct a comprehensive examination, which may include:
* Inspection and check of transmission fluid level
* ECU diagnostics
* Checking solenoids and hydraulic system
*Physical inspection of transmission mechanical components (requires transmission removal)
Troubleshooting:
Repairs will depend on the specific cause of the problem. It may include:
* Replacement of worn or damaged components
* ECU reprogramming
* Flushing or replacing the hydraulic system
* Gearbox overhaul
Additional recommendations:
*If the problem occurs suddenly, stop the vehicle immediately and contact a professional mechanic.
* Automatic transmission problems can be expensive to repair. Regular transmission fluid maintenance and changes can help prevent serious breakdowns.
* Buying a used car with automatic transmission problems can be a risky proposition. Always have your vehicle inspected by a qualified mechanic before purchasing.