Electronic brake system components (VW Passat B6)

The brake system of the Passat includes a whole complex of electronic devices. The car is equipped with an anti-lock braking system (ABS), which prevents the wheels from locking during sudden braking.

Therefore, even during sharp braking, the car remains controllable, since the ABS system distributes the braking force between individual wheels. Thus, blocking of wheels on one side is impossible.

The ABS control unit is connected to the hydraulic system and constantly receives information about the rotation speed of each wheel from sensors. In the control unit, the information received from the sensors is compared with the programmed values. If the difference in the rotation speed of one or more wheels indicates a risk of locking, the unit activates the hydraulic unit. The pressure in the system of the corresponding wheel is reduced until the wheel begins to rotate freely and is braked again. Depending on the condition of the road surface, this process occurs in a matter of milliseconds.

ABS malfunctions do not affect the brake system and the booster as a whole. The brakes work normally even without ABS. The brakes are amplified by a pneumatic booster, which increases the braking force by 60%. In models with gasoline engines, the necessary vacuum is provided by the suction pipe. Gasoline engines with automatic transmission are equipped with a vacuum pump. Diesel engines are also equipped with a vacuum pump or a dual pump to ensure fuel supply and create a vacuum.

The function of the brake regulator installed on early models is performed by a control unit with a special program for distributing the braking force on the rear axle. Other electronically controlled units of the braking system are the anti-skid system (ASR), the device (EDS) increasing the wheel's grip on the road, and the electronic program of stabilization of the course stability (ESP).

(The article is posted on the portal VWmanual.ru)