Fully automatic transmission (VW Passat B5)

Passat vehicles are equipped with four- or five-speed fully automatic transmissions.

The automatic transmission consists of a torque converter, a planetary gear, as well as a clutch and brakes with hydraulic and electrical drive.

Torque from the engine is transmitted to the transmission through a torque converter, which functions as a fluid clutch and acts as an automatic clutch, also providing torque transmission during acceleration.

The automatic transmission is controlled by an electronic control unit. The electronic unit, based on more extensive information, sets the optimal transmission mode for each operating mode. There are no manually switchable modes for controlling the transmission, such as economical and sporty. The control unit selects the appropriate gear based on information about the vehicle speed, the position of the accelerator pedal, and the driving style. The presence of a trailer and wind also affect the moment of gear shifting.

If any of the sensors or magnetic valves are faulty, the transmission control unit switches to emergency mode and the fault is recorded in the unit's memory.

Towing a car with an automatic transmission on wheels is permitted for a distance of up to 50 km at a maximum speed of 50 km/h. All-wheel drive cars with an automatic transmission are prohibited from being towed by raising one axle of the car.

The gearbox is a very complex unit and its repair must be carried out in a specialized workshop. Before repairing the gearbox, it is necessary to determine the nature of the fault, which can be electrical, mechanical or hydraulic.

Do not remove the transmission from the vehicle for repairs until the fault has been professionally identified, as most tests require the transmission to be in the vehicle.