Automatic transmission

At the request of the owner, VW PASSAT, in addition to models with diesel engines and a 75 hp gasoline engine, can be equipped with an automatic transmission. The automatic transmission has 4 ranges of positions for moving forward, which are switched automatically.

The automatic transmission is controlled by an electronic control unit. The control unit receives signals from sensors about the position of the gear selector, the temperature of the oil in the gearbox, the speed of the gearbox shaft, and also receives information from the control unit for the injection system about the instantaneous load of the engine. With the help of four solenoid valves, the control unit controls the process of switching modes of the gearbox. This results in low fuel consumption, smooth shifting processes and the choice of driving mode: economical or sporty.

If the input signals are disturbed or the solenoid valves are defective, a switch to the time program is carried out, the malfunction that occurs simultaneously during the trip is recorded as a code in the memory device and can later be determined using a VW reader.

To assess the performance of automatic transmission and correct troubleshooting, experience with such gearboxes and knowledge of the principle of their operation is necessary. This knowledge can only be acquired through long professional experience.