A control unit for an automatic transmission of a vehicle is provided. The vehicle includes a gear selection operating element which allows a user of the vehicle to set different drive positions of the transmission, but not individual gears, by actuating the gear selection operating element. The control unit is configured to determine that a drive position “L” has been set using the gear selection operating element, and in response thereto, the control unit is also configured to provide a graphical user interface on a screen of the vehicle. The user interface allows a manual gear shift of the transmission.