How
Each wheel hub has multi segment rotor, or disc, which turns at the same speed as the road wheel. Each rotor has a stationary pickup sensor which converts wheel speed into electrical impulses. The impulses from each wheel are fed into a central computer. The central computer compares the wheel speeds against each other, and the de-acceleration rate.
The main braking system is equipped with a "Modulator." The modulator can control the amount of braking force applied to each wheel brake when called upon by the ABS central computer. Under normal braking the ABS has no influence on the brakes, and in no circumstances can it operate below 10kmh.
The computer tells the modulator to adjust the braking force to that wheel, so that it will not lock
Under braking, where one or more wheel slows down faster than the others, about to lock, this is detected by the central computer. The computer tells the modulator to adjust the braking force to that wheel, so that it will not lock. This communication between wheel - central computer - modulator occurs many times a second. On each occasion an adjustment can occur until the "offending" wheel assumes the same braking speed as the other wheels, ensuring optimal braking performance. As these adjustments are carried out "kickback" or "pulsing" will be felt at the brake pedal.