Anti-Lock Brake System

In anti-lock braking mode (wheel speed signals indicate a wheel is about to lock-up), Hydraulic and Electronic Control Unit (HECU) decreases pressure as necessary to prevent wheel lock-up. This function continues as long as necessary during braking. During normal braking, HECU controls distribution of fluid pressure to front and rear wheels.

The ABS system also has self-diagnostic system and fail-safe system to aid in servicing. When system detects a malfunction, HECU disables anti-lock braking and allows normal braking only. System then stores a Diagnostic Trouble Code (DTC) and illuminates ABS warning light. DTCs are retrieved for diagnosis through use of a HI-SCAN (PRO) or generic scan tool. See DIAGNOSIS & TESTING  .