Main Control

The ABS control unit detects the wheel speed based on the wheel speed sensor signal it received, then it calculates the vehicle speed based on the detected wheel speed. The control unit detects the vehicle deceleration based on the rate of deceleration. The control unit calculates the slip rate of each wheel and transmits the control signal to the modulator unit solenoid valve when the slip rate is high. See Fig 1 .

Fig 1: Identifying ABS Control Unit Circuit Path

Courtesy of AMERICAN HONDA MOTOR CO., INC.