Anti-lock brake system (ABS/ABD) notes on operational faults

Wheel bearing play/air gap

If the wheel bearing play is too large, the wobble which occurs can influence the signals of the speed sensors. A voltage drop may occur if the distance between the speed sensor and rotor is too large. In this case, the input circuit is not yet triggered and the limit speed (vmin) is not achieved.

Rotor

Teeth which have worn down or broken off, dirt at the rotor or a rotor with the wrong number of teeth will affect the signals of the speed sensors and lead to an error message.

Tire size

Malfunctions can occur if tires of different sizes are fitted. Therefore always install tires of the same size. It is quite safe to install summer and winter tires of the same size on all wheels of an axle.