Vehicle brake system and method for increasing brake pressure in a first wheel brake cylinder and limiting brake pressure in a second wheel brake cylinder of a vehicle brake system

A vehicle brake system, comprising:

• at least one brake pressure buildup device;
• a first wheel brake cylinder having a first wheel inlet valve assigned to the first wheel brake cylinder and a first wheel outlet valve assigned to the first wheel brake cylinder, a flow of brake fluid through at least the first wheel inlet valve in its open state into the first wheel brake cylinder being brought about by an operation, brought about by driver's force and/or motorically, of the at least one brake pressure buildup device;
• a second wheel brake cylinder having a second wheel inlet valve assigned to the second wheel brake cylinder and a second wheel outlet valve assigned to the second wheel brake cylinder, a flow of brake fluid through at least the second wheel inlet valve in its open state into the second wheel brake cylinder being brought about by the operation of the at least one brake pressure buildup device;
• and
• a control device by which, during the operation of the at least one brake pressure buildup device, the first wheel inlet valve can be controlled into its open state, the first wheel outlet valve can be controlled into its closed state, the second wheel inlet valve can be controlled into its closed state, and the second wheel outlet valve can be controlled at least at times into its open state, so that a first brake pressure in the first wheel brake cylinder can be increased while an increase of a second brake pressure in the second wheel brake cylinder is simultaneously at least limitable;
• wherein the control device is configured to, during the operation of the at least one brake pressure buildup device, control the second wheel outlet valve with a pulse width-modulated signal in such a way that the second wheel outlet valve controlled by the pulse width-modulated signal is permanently in its open state.