Hydraulic Control Unit

The ABS hydraulic control unit and anti-lock brake control module (2B373) are a complete assembly. The assembly is located in the RH lower front corner of the engine compartment, next to the bottom of the white radiator coolant recovery reservoir (8A080) . The unit is mounted inside a bracket, which is affixed to the RH frame rail.

• The hydraulic portion of the hydraulic control unit modulates brake pressure at each wheel through the use of three internal solenoid valves.
• A brake fluid pump motor recirculates the brake fluid during ABS cycling.
• When the anti-lock brake control module detects an impending wheel lock, it modulates brake pressure to the appropriate brake caliper.
• The ABS anti-lock brake control module receives wheel speed readings from each brake anti-lock sensor, and uses this information to compare wheel speeds.
• By continuously monitoring and comparing the rotational speed of each wheel, the anti-lock brake control module activates the anti-lock braking system only when it senses an impending wheel lock-up under severe braking conditions. The anti-lock brake control module decides which wheels' brakes need to be controlled, and sends the appropriate signals to the hydraulic control unit (hydraulic portion of the assembly). Impending wheel lock conditions trigger signals from the hydraulic control unit that open and close the appropriate modulator solenoid valves. This may result in moderate pulsations in the brake pedal (2455) when applied. During normal braking (non-ABS stop), brake pedal feel will be the same as a vehicle with a standard brake system (non-ABS).