Patent ID: 7992947

Claim:
A method for activating a two-stage switching valve including a first stage having a smaller flow cross section and a second stage having a larger flow cross section, the switching valve being situated between a main brake cylinder and a hydraulic pump in a hydraulic brake system, the method comprising: activating the switching valve in a first phase by a control signal having a small amplitude to first open only the first stage of the switching valve for a predetermined period of time; and activating the switching valve in a second phase by the control signal having a higher amplitude; determining a differential pressure prevailing at the switching valve; performing the activating in the first phase and the second phase only within a predetermined pressure range; and determining if an admission pressure lies within a predetermined pressure range., wherein the control signal is temperature-compensated and voltage-compensated; wherein the pressure range lies between at least 5 bar and 35 bar, and wherein the control signal has a magnitude in the first phase such that the first stage of the switching valve is open for at least 10 ms before the second stage opens.