ABS stands for the anti-lock braking system on a car. This prevents brakes from locking up when they are suddenly applied on a slippery road.
When brakes skid, they have less traction. They do not grip the road properly. Anti-lock braking systems allow drivers to steer while they are slowing down safely. There are several parts to the system. The speed sensor components tell the ABS how the wheels are acting. The valve for each brake controls the amount of pressure in the system. A pump replaces pressure that has been released by the valves. The computerized controller regulates the system. When the ABS is engaged, the activity of the valves causes the driver to notice a pulsing sensation in the brakes.