A device for generating a sensor signal suitable for an in-operation test of a signal path from a sensor cell to an evaluation location. The sensor cell provides a sensor cell output signal depending on a physical magnitude to be detected which is changed in a changer for changing the sensor cell output signal according to a predetermined change regulation based on a test signal in order to obtain the sensor signal. A signal derived from the sensor signal is detected by a device for an in-operation test of the signal path and is evaluated.