A method and system for measuring pressure in a pressure regulation unit of a motor vehicle braking system, without using pressure sensors and having a motor pump unit with an electric motor and a hydraulic pump. The steps include producing a relative motor characteristic diagram for a series of the units. The diagram includes the data of motor-rotational-speed-dependent parameters, intensity of the motor actuation, and parameters relating to the level of the motor load. Further steps include; determining individual motor characteristic variables, determining a current rotational-speed-dependent parameter of an individual motor during the operation of the pump, and calculating a pressure which is characteristic of the braking system, by means of the diagram parameter of the individual motor and the value of the current motor actuation which determines the intensity of the motor actuation, wherein the individual motor characteristic variables are taken into account.