ESP (ESC) Control Module
The ESP consists of an ECU (Electronic Control Unit) and a HCU (Hydraulic Control Unit).
The HCU contains a Pump Motor, Solenoid Valves, and Accumulator. The HCU increases, decreases, or maintains the hydraulic pressure supplied to a wheel by operating the return pump according to ESP control signal when ABS control is active.
The ECU monitors various sensor and switch inputs. These inputs are used to make a decision on how to operate HCU components.