MULTI-VOLTAGE CONTROL DEVICE FOR A MOTOR VEHICLE, MOTOR VEHICLE AND OPERATING METHOD FOR THE CONTROL DEVICE

The invention disclosure relates to a control device for a motor vehicle which comprises a first electrical terminal for receiving a first supply voltage of a first vehicle electrical system and a second electrical terminal for receiving a second supply voltage of a second vehicle electrical system, the second supply voltage being smaller than the first supply voltage, wherein an electrical ground terminal is provided for closing a common ground potential of the first and second vehicle electrical systems, and a switching device connected downstream of the first terminal is set up, depending on a voltage signal which is determined by a potential difference between the second terminal and the ground terminal, to block a current flow through the first terminal, wherein the switching device interrupts the current flow if the voltage signal indicates an interruption of an electrical connection between the ground terminal and the ground potential.