A gateway device for controlling an air-conditioning device of a vehicle, a vehicle having such a gateway device and a method for starting up an air-conditioning device in a vehicle. The gateway device includes at least one plug-in contact for connecting the gateway device to an air-conditioning device and/or to a vehicle component, a reception unit for receiving configuration data for selecting a plug configuration of the gateway device, a configuration circuit associated with the plug-in contact, that is designed to take configuration data as a basis for changing between at least one first switching state of the plug-in contact, in which the plug-in contact is designed to perform a first function, and at least one second switching state of the plug-in contact, in which the plug-in contact is designed to perform a second function.