Possible reasons for sudden automatic transmission failure:
Mechanical faults:
* Worn or broken friction discs, steel discs or O-rings
* Destruction of the planetary series
* Broken shaft or drive chain
*Transmission fluid leak due to a broken crankcase, lines or seals
Electrical faults:
* Malfunction of the automatic transmission control unit (TCM)
* Failure of solenoids that control gear shifting
* Malfunction of speed, selector position or pressure sensors
* Short circuit or break in electrical wiring
Transmission fluid problems:
* Insufficient level or lack of fluid
* Contaminated or poor quality fluid
* Hydraulic pump wear
Other possible reasons:
* Overloading or towing heavy loads in excess of recommended parameters
* Aggressive driving (sharp acceleration, braking and gear changes)
* Lack of regular maintenance (fluid replacement, filter)
* Manufacturing defect or defective components
Note: If the automatic transmission suddenly fails, you should not try to continue driving. You must immediately stop and contact technical assistance or have the vehicle towed to a service center for diagnosis and repair.