Anti-Lock Brake System (ABS), Function Survey - GF42.30-P-0003-06GG

Model 463 

ABS is ready for operation when the vehicle has exceeded a speed of 8 km/h after starting off. A control is possible down to a speed of 3 km/h.

The speeds of the front and rear wheels are recorded and processed separately in the ABS control module.

By linking the individual wheel speeds a reference speed is calculated which represents the approximate vehicle speed. The slip signals are derived from the comparison of wheel speed and reference speed.

The ABS control mode starts if the ABS control module (N47-7 or N30) recognizes from the wheel speed signals that one or more wheels is tending to lock when braking.

First the brake pressure is kept constant (an increase in brake pressure is prevented). If a tendency to lock continues, the brake pressure is reduced (brake fluid is pumped back) until the wheel starts to accelerate again. After that the brake pressure is kept constant again. If the continued acceleration of a wheel exceeds a set value, a pressure increase is permitted again.

These control processes repeat continuously during ABS braking until the brake pedal is released or down to a speed of 3 km/h.