Anti-Lock Operation: Notes

During anti-lock brake operation, the front hydraulic circuits become "dynamic" as boost pressure replaces master cylinder pressure through the main valve. The 4 wheel sensors input to the ECU, which processes the information and modulates the 3 sets of solenoid valves in the valve block to control the pressure in the 3 hydraulic circuits to prevent wheel lock-up. See Figure . Because both rear wheels are on the same hydraulic circuit, a single wheel lock by either rear wheel will result in control of both rear wheels according to the needs of the one locking wheel.

When the brakes are applied and anti-lock operation engages, the system components function as follows: Also see Figure .