ASR Pressure Reduction Control Mode
The control process and valve positions shown in the figure relate to the RR brake. If the brake pressure required to prevent drive slip is too high, the ASR pressure reduction control mode starts. The pressure reduction phase is introduced by opening the switchover solenoid valve (y13). The solenoid valve (y12) remains closed. The returning brake fluid flows back to the brake fluid reservoir via the high-pressure/return pump (p2) through the switchover solenoid valve (y19) via the master brake cylinder. The self-priming high-pressure/return pump (p2) is also actuated in these control phases.