A method and a device for controlling operational sequences in a vehicle in which at least one first processor is provided in at least one control device, which is used for the control of functions of the operational sequences of the vehicle, and at least one second processor of a vehicle-external portable technical unit as coprocessor is able to be connected to the at least one control device, using connection means and is used in addition to the at least one first processor for the control of functions of the operational sequences.