The invention relates to a method of a vehicle (1) with a control unit (10); and a communication system (20) with a communication control device (21) and a transceiver (22). The transceiver (22) is designed for Ultra-High-Frequency, UHF, communication with a vehicle key (2). The invention furthermore relates to a vehicle (1) designed to carry out this method, a vehicle key (2), and a system consisting of such a vehicle (1) and such a vehicle key (2). It is provided that the method comprises transmitting (101) a first message (111) by the control unit (10) to the communication control device (20) and adjusting (102) a UHF transmission power of the transceiver (22) based on the first message (111) by the communication control device (21). Further method steps comprise sending (103) a second message (112) by the control unit (10) to the communication control device (21), controlling (104) the transceiver (22) by the communication control device (21) in order to send a data packet (114) based on the second message (112) to the vehicle key (2) with the adjusted UHF transmission power, wherein, if the second message (112) comprises data relating to a service function for the vehicle (1), the communication control device adjusts the UHF transmission power as a first predetermined UHF transmission power.
