Control apparatus (5; 6; 7; 8; 10) for a vehicle, having: - interfaces (5a, 5b) for connecting to two independently redundant communication networks (KN1, KN2) that are each galvanically isolated from one another, wherein, in the event of a failure of a first communication network, messages are able be transmitted to and from the control apparatus (5; 6; 7; 8; 10) by way of a second communication network, and vice versa, wherein a failure of a connected communication network (KN1, KN2) is not able to adversely affect the functioning of the control apparatus (5; 6; 7; 8; 10); and - interfaces (5c, 5d) for supplying electrical power to the control apparatus (5; 6; 7; 8; 10) by way of two independently redundant low-voltage networks (NN1, NN2) that are each galvanically isolated from one another, wherein, in the event of a fault in a first low-voltage network, electrical power is able to be supplied to the control apparatus (5; 6; 7; 8; 10) by way of a second low-voltage network, and vice versa, wherein the control apparatus (5; 6; 7; 8; 10) comprises a diagnostic module, wherein the diagnostic module performs a preventative diagnosis of all the lines of all the networks of the vehicle in cooperation with battery management systems of the vehicle and electrical loads and generators of the vehicle are consequently able to be selectively switched depending on diagnostic information, which is transmitted by way of the interfaces (5a, 5b; 6a, 6b; 7a, 7b; 8a, 8b; 10a, 10b) and concerns the networks (KN1, KN2, NN1, NN2), wherein a minimum functionality for safety-relevant systems of the vehicle is maintained by the selective switching of the loads. - interfaces (5a, 5b) for connecting to two independently redundant communication networks (KN1, KN2) that are each galvanically isolated from one another, wherein, in the event of a failure of a first communication network, messages are able be transmitted to and from the control apparatus (5; 6; 7; 8; 10) by way of a second communication network, and vice versa, wherein a failure of a connected communication network (KN1, KN2) is not able to adversely affect the functioning of the control apparatus (5; 6; 7; 8; 10); and - interfaces (5c, 5d) for supplying electrical power to the control apparatus (5; 6; 7; 8; 10) by way of two independently redundant low-voltage networks (NN1, NN2) that are each galvanically isolated from one another, wherein, in the event of a fault in a first low-voltage network, electrical power is able to be supplied to the control apparatus (5; 6; 7; 8; 10) by way of a second low-voltage network, and vice versa, wherein the control apparatus (5; 6; 7; 8; 10) comprises a diagnostic module, wherein the diagnostic module performs a preventative diagnosis of all the lines of all the networks of the vehicle in cooperation with battery management systems of the vehicle and electrical loads and generators of the vehicle are consequently able to be selectively switched depending on diagnostic information, which is transmitted by way of the interfaces (5a, 5b; 6a, 6b; 7a, 7b; 8a, 8b; 10a, 10b) and concerns the networks (KN1, KN2, NN1, NN2), wherein a minimum functionality for safety-relevant systems of the vehicle is maintained by the selective switching of the loads.