Hydraulic Control Unit
WARNING: This page is about a different car, the 2007 Chrysler PT Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
The hydraulic control unit (HCU) is mounted to the ABM as part of the ICU. The HCU controls the flow of brake fluid to the brakes using a series of valves and accumulators. A pump/motor is mounted on the HCU to empty the accumulators during ABS events and to build pressure during traction control events.