Possible reasons for emergency operation of the automatic transmission:
Mechanical problems:
* Worn or damaged clutches, discs or clutch bands
* Seized or deformed bearings or planetary gear
*Transmission fluid leak
* Clogged oil filter or automatic transmission radiator
* Faulty gear selector position sensor
Electrical problems:
* Faulty input/output shaft speed sensor
* Throttle position sensor malfunction
* Faulty shift control solenoids
* Break or short circuit in the automatic transmission wiring
* Malfunction of the electronic control unit (ECU) of the automatic transmission
Hydraulic problems:
* Torque converter malfunction
* Clogged or faulty oil pump
* Insufficient transmission fluid pressure
* Clogged or blocked hydraulic passages
Other factors:
*Low transmission fluid level
* Using the wrong transmission fluid
* Automatic transmission overheating
* Driving in difficult conditions (such as with a trailer or over rough terrain)
* Poor maintenance (irregular transmission fluid and filter changes)