MOTOR VEHICLE CONTROL UNIT WITH REDUNDANT POWER SUPPLY, AND CORRESPONDING MOTOR VEHICLE

A control unit for a motor vehicle, having a supply connection for receiving a supply voltage from a supply line needing to be secured against a reaction from the control unit, wherein to protect against the reaction there is provision in a current path of the supply connection for a unidirectional first blocking element, and a diagnostic circuit is configured to check the blocking effect thereof by a predetermined diagnostic routine. An additional, second unidirectional blocking element is connected in series with the blocking element in the current path of the supply connection, wherein the first and the second blocking element each provide for a unidirectional flow of current to the device circuit, and the diagnostic circuit is configured to use the diagnostic routine to also check the blocking effect of the second blocking element.