Abs Hold Pressure Control Mode
The control process or valve positions shown in the figure relate to the FR brake. If a wheel tends to lock during the braking process, ABS prevents a further pressure build-up on affected wheel. The ESP control module introduces the hold pressure phase from the slip values of the braked wheels. The hold pressure phase is introduced by actuating the solenoid valve (y8). The solenoid valves (y8 and y9) remain closed in this control phase, with the result that the pressure in the FR brake caliper remains constant.