A process and device for controlling the brake system of a motor vehicle with all-wheel drive are described. The process and the device include an electronic control unit which controls at least one coupling unit for engaging and disengaging an all-wheel drive, so that at least one wheel can be decoupled, from the drive. After stopping the motor vehicle, for example on a sloping roadway, a predefined brake pressure on at least one wheel of the motor vehicle is held either depending on or independently from the extent of brake pedal actuation. The brake pressure is held until a brake pressure reduction condition is present, such as during a brake pressure holding time. During that time, the brake pressure on at least the one wheel is reduced and the wheel is decoupled from the drive to detect slippage, while at least one other wheel remains pressurized with brake pressure.