A method a method of accessing a device in a communications network in a motor vehicle via an external device (1) is described, a software element being transmitted to the external device in the case of authorized access to a device in the communications network to permit control of the device in the communications network by the external device. A gateway checks on whether access is possible, either checking directly with the device requested or via the system manager. Security in communication between the external device and the device to be controlled is achieved by an additional encryption and/or a specified validity period of the software element transcribed to the external device. If there is no software element for a device to be controlled, such a software element is created by using a control module and data stored in the device. A bus system, preferably according to IEEE 1394, is used as the communications network. This method increases security while at the same time using a less complex gateway.