Acura 3.5 RL Manual page 835

Anti-lock Brake System (ABS)
Features/Construction (cont'd)
ABS Control
The ABS control unit detects the wheel speed based on the wheel sensor signal it received, then it calculates the vehicle
speed based on the detected wheel speed. The control unit detects the vehicle speed during deceleration based on the
rate of deceleration.
The ABS control unit calculates the slip rate of each wheel, and it transmits the control signal to the modulator unit
solenoid valve when the slip rate is high.
The pressure reduction control has 3-modes: pressure reduction, pressure retaining, and pressure intensifying.
ABS CONTROL UNIT