Method for measuring pressure in a pressure regulation unit of a motor vehicle braking system, and a motor vehicle braking system in which the method is implemented

A pressure regulation unit in a motor vehicle braking system comprising an electronic regulator and a pump motor which is actuated by means of a PWM stage and is connected to a hydraulic pump, wherein means for sampling the motor voltage are present, comprising in that the electronic regulator carries out a pressure measuring method of producing a relative motor characteristic diagram for a series of the pressure regulation unit or of the motor pump unit or of the motor before the manufacture of an individual of the pressure regulation unit or of the motor pump unit or of the motor which diagram includes at least the data of motor-rotational-speed-dependent parameters (n/n0), and intensity of the motor actuation (DC) and parameters relating to the level of the motor load (PG),

• determining individual motor characteristic variables (N_MAX, N_200, U2N) after or during the fabrication of the motor pump unit or of the motor,
• determining a current rotational-speed-dependent parameter of an individual motor (Nact) during the operation of the pump, and
• calculating a pressure (PTHZ), which is characteristic of the braking system, by means of the motor characteristic diagram and the motor-rotational-speed-dependent parameter of the individual motor (nact) and the value of the current motor actuation (DC) which determines the intensity of the motor actuation, wherein the individual motor characteristic variables are taken into account.