Mechanical problems
* Worn or broken clutch solenoids
*Damage to input or output shaft
*Gear jamming
* Damage to friction linings
*Damage to gearbox housing
Electrical faults
* Faulty wiring or connectors
* Failure of speed sensors
*Transmission control module (TCM) malfunction
* No power or short to ground
Hydraulic faults
* Leaks in the hydraulic circuit
* Faulty torque converter
* Contamination or wear of the hydraulic fluid
* Oil filter clogged
Software problems
* Bugs in TCM software
* Mismatch between the TCM and the engine or other vehicle systems
Other faults
* Worn or damaged flexplate
* Faulty crankshaft position sensor
* Contamination or damage to the automatic transmission fluid pressure sensor
* Low level or incorrect brand of automatic transmission fluid
Main symptoms of automatic transmission malfunctions
* Slipping or slipping of gears
* Difficulty or inability to shift gears
* Jerks or bumps when shifting gears
* Increased noise or vibration levels
* Automatic transmission fluid leak
* Limited torque transmission
*Transmission fault indicator lights up