Abstract: A motor vehicle control system for a motor vehicle with a hybrid drive, with first control units, namely, at least one engine control unit associated with an internal combustion engine of the hybrid drive and a first diagnostic control unit, which send and receive diagnostic data and/or program data by way of a first data bus, and second control units, namely, at least one hybrid control unit associated with an electric machine of the hybrid drive and a second diagnostic control unit, which send and receive diagnostic data and/or program data by way of a second data bus. The hybrid control unit is connected to the first and second data buses and sends and receives diagnostic and/or program data via the buses, and the hybrid control unit converts protocols and/or contents of the diagnostic and/or program data bi-directionally between the first data bus and the second data bus.