Fail-Safe Function

If an abnormality is detected, ABS control unit turns off fail-safe relays and motor relay. In this condition ABS is prevented from functioning, yet basic brake system continues to operate normally.

ABS indicator light illuminates:

• When fluid pressure pump runs more than 120 seconds.
• When parking brake is applied for more than 30 seconds while the vehicle is being driven.
• When rear wheel(s) is/are locked more than a specified time.
• When wheel rotation signal is not transmitted due to faulty wire or sensor.
• When operation time of solenoid valve(s) exceeds a predetermined valve and ABS control unit finds an open in solenoid circuit.
• When output signals from both main functions in ABS control unit are not transmitted to solenoid valve(s).

Fig 1: ABS Control Unit Functions

Courtesy of AMERICAN HONDA MOTOR CO., INC.