ABS system operation (Audi 100 C3)

As soon as the wheel slows down or starts to slip, which indicates the beginning of its blocking, the electromagnetic valve, following signals from the electronic control unit, interrupts the supply of brake fluid to the wheel cylinder of the wheel brake mechanism, thereby maintaining the required braking pressure.

If the wheel does not unlock, the electromagnetic valve directs the brake fluid to the bleed line, thereby reducing the brake pressure. As a result, the wheel's grip on the road surface is restored. After that, the brake fluid pressure supplied to the wheel's brake mechanism increases and the regulation cycle is repeated.

Control over ABS operation

The ABS system is checked for operability using the control lamp in the instrument cluster. The lamp lights up when the ignition is turned on and should go out immediately after the engine starts.

If the system malfunctions, the electronic unit stops issuing control pulses, and the vehicle is braking in the normal manner (without regulation). The indicator lamp in the instrument cluster lights up constantly.

The switch marked "ABS" allows you to turn off the anti-lock brake system to check the functionality of the brakes or the wheels for locking.