Fully automatic transmission

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

The automatic transmission consists of a torque converter, a planetary gear, and hydraulic and electrically actuated clutch and brakes.

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

The automatic transmission is controlled by the electronic control unit. The electronic unit, based on more extensive information, sets the optimal mode of operation of the gearbox for each operating mode. To control the gearbox, there are no manually switched modes, such as economical and sporty. The control unit, based on information about the speed of the vehicle, the position of the accelerator pedal, as well as the manner of movement, selects the appropriate gear. Also, the moment of gear shifting is affected by driving conditions, the presence of a trailer and the wind.

If any of the sensors or solenoid valves is 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 allowed for a distance of up to 50 km at a maximum speed of 50 km/h. All-wheel drive vehicles with automatic transmission must not be towed with one axle of the vehicle raised.

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

Do not remove the transmission from the vehicle for repair before the problem has been professionally identified, as most tests require the transmission to be in the vehicle.