The present invention claims a method for controlling an automatic gear shift of a vehicle, a control device in which such a method runs, and a vehicle with such a control device. It is provided that for controlling the automatic shift, an efficient mode is provided in which, depending on the environmental and/or operating parameters, the gear shift or the transmission ratio of the gear shift is selected in such a way that substantially energy-optimal propulsion of the vehicle is enabled. It is irrelevant whether the energy expended for the propulsion comes from a motor and/or a mechanically applied force such as, for example, the pedaling force of a cyclist. The core of the invention consists in that the control of the gear shift, depending on a security signal which represents the securing of the vehicle against unauthorized movement or theft, continues the further operation of the gear shift instead of in the efficient mode in an inefficient mode.
