Anti-Lock Brake Mode

ABS has been designed to improve controllability and steerability of vehicle during braking that would cause one or more wheels to lock up. ABS system accomplishes this objective by controlling hydraulic pressure applied to each wheel. Anti-lock braking occurs only when brakelight switch is closed and EBCM determines one or more wheels is about to lose traction during braking. EBCM will then control Brake Pressure Modulator Valve (BPMV) to change brake pressures several times each second to keep wheel(s) from locking and provide driver with maximum vehicle controllability. The result is greatly improved braking, enabling driver to more easily maintain steerability and to bring vehicle to a controlled stop.

Total brake pressure during ABS is limited to brake pressure present when ABS was entered. Also, any time wheel brake pressure exceeds brake pressure at master cylinder (caused by reduced force on brake pedal), a check valve in BPMV unseats and a small volume of brake fluid is returned to master cylinder.