In principle, with each braking, the ABS must perform two tasks, providing:
- A) Longitudinal stability on roads of different types of coverage (asphalt, concrete, etc.) and in different states (icy, wet, covered with mud, snow, etc.).
- 6) Handling and maneuverability of the car under these conditions.
These requirements require significant comments. ABS does not override the laws of physics. The system cannot prevent the consequences of braking when there is insufficient distance from the vehicle in front, when cornering at unacceptably high speeds, or when there is a risk of aquaplaning. These consequences still remain on the conscience of the driver.
The presence of ABS, which provides increased safety potential, should not provoke you to unnecessarily risky driving.
Features of driving with ABS
After starting the engine, the yellow ABS warning light on the instrument panel should go out. The system is automatically activated only after reaching a speed of about 8 km/h. When it falls below 3 km / h, ABS is turned off, so theoretically at the very last stage of braking the wheels can lock up, but in practice this is no longer of fundamental importance.
ABS implements the regulation process in a fraction of a second. Pulsation of the pedal under the foot means that braking occurs within the range of this regulation, in other words, that the driver is driving in the limit mode. In addition, the crackling caused by the ABS process reminds the driver to adjust the speed to the driving conditions that have changed due to a decrease in (for example, due to ice) friction coefficient (or clutch) between tires and road.
On roads with loose surfaces (e.g. sand or snow) the braking distance may be longer than when the wheels are locked.
This also applies to driving with snow chains. Much more important, however, is the gain in terms of longitudinal stability and controllability of the car.
To keep the ABS in full working order, it is forbidden to make changes to it. Work on the system must only be carried out by a BMW specialist. Driving with mixed tires (e.g. after installing a spare wheel in combination with three other wheels fitted with tires with a winter tread pattern) may limit the functionality of the ABS. Therefore, the removed wheel must be reinstalled as soon as possible.
A malfunction signal is the yellow ABS warning light on the instrument panel. In this case, the brake system continues to operate normally, as on vehicles without ABS. In order to prevent the possible mutual superposition of two faults from affecting the braking system, the necessary repairs must be carried out as soon as possible.