a method for controlling a motor vehicle electrohydraulic braking system . the method being activatable in a “ brake - by - wire ” operating mode , having a pressure supply device , which can be activated by an electronic control and a regulation unit , can be connected to a hydraulically actuatable wheel brake . wherein the pressure supply device is formed by a cylinder - piston assembly . the piston can be actuated by an electromechanical actuator , the control unit carries out the steps of determining a pressure target value for the pressure supply device , performing a pressure control operation or an actuator position control operation on the pressure supply device in accordance with the magnitude of the pressure target value .