Mechanical problems
* Slipping: There is a feeling of slipping or loss of power when shifting gears.
*Hard shifting: Gear shifts with effort or delay.
*Transmission Fluid Leak: There is red or brown fluid leaking under the vehicle.
* Noise or Vibration: Noise or vibration is heard or felt from the transmission when shifting gears.
* Burning smell: There is a strong burning smell coming from the transmission.
Electrical faults
* Gear does not engage: The automatic transmission does not engage in any gear at all.
* Driverless gear shifting: Gears change independently without interaction with the gear lever.
* Solenoid failure: The solenoids that control gear shifting are faulty or not receiving power.
*Speed Sensor Failure: The speed sensor that tells the ECM (engine control module) about vehicle speed is faulty.
* Problems with the ECM: The ECM itself, which controls the operation of the automatic transmission, is faulty.
Other faults
* Clogged transmission fluid filter: A clogged filter will restrict fluid flow and can cause shifting problems.
* Worn clutches: The clutches used to engage gears are worn or damaged, causing slippage or rough shifting.
* Defective torque converter: The torque converter that links the engine and transmission may not operate properly, causing noise, vibration, or slippage.
* Shaft or Gear Corrosion: Transmission shafts or gears can become corroded, causing binding or damage.
* Software: In some cases, problems with automatic transmissions may be associated with errors in the software that controls its operation.