Brake system for a vehicle and method for operating a brake system

A method for operating a brake system comprising:

• during normal operation of a brake system in a low-load mode, pressurizing a volume flow of pressure fluid from a pressure fluid reservoir exclusively by an electrofluidic pressure generation unit, and,
• during normal operation of the brake system in a high-load mode, bringing a volume flow of pressure fluid from the pressure fluid reservoir by the electrofluidic pressure generation unit to a first pressure level and operating an electrofluidic pressure increase unit to increase pressure fluid from the first pressure level to a second, higher pressure level, and,
• in a first malfunction mode of the brake system in a low-load mode, pressurizing the volume flow of pressure fluid from the pressure fluid reservoir exclusively by a main cylinder unit, and,
• in the first malfunction mode of the brake system in a high-load mode, bringing a volume flow of pressure fluid from the pressure fluid reservoir by operation of the main cylinder unit to a first pressure level and bringing by operation of the electrofluidic pressure increase unit from the first pressure level to a second, higher pressure level, and,
• in a second malfunction mode of the brake system, pressurizing a volume flow of pressure fluid from the pressure fluid reservoir exclusively by operation of the electrofluidic pressure increase unit, and,
• in a third malfunction mode of the brake system, bringing a volume flow of pressure fluid from the pressure fluid reservoir by operation of the main cylinder unit to a first pressure level and bringing by operation of the electrofluidic pressure increase unit from the first pressure level to a second, higher pressure level, and,
• in a fourth malfunction mode of the brake system, bringing a volume flow of pressure fluid from the pressure fluid reservoir by operation of the electrofluidic pressure generation unit to a first pressure level and bringing by operation of the electrofluidic pressure increase unit from the first pressure level to a second, higher pressure level,
• wherein the electrofluidic pressure generation unit and the main cylinder unit are configured as a coherent structural block, and the pressure increase unit is configured as a separate supplementary module that is not a component of the coherent structural block, wherein the pressure increase unit comprises a bypass fluid path that circumvents a pressure generator, wherein a control valve which is pressured-controlled at the output side is arranged in the bypass fluid path.