Telephone manufacturers implement the Bluetooth standard in different ways. As implementation of the Bluetooth standard differs between mobile devices and may change during the product life cycle of a model, limitations of function may occur in the vehicle for which the BMW Group is not responsible. In addition to the software status of a mobile device, the following factors may have an additional influence on compatibility: - hardware version of the mobile device – configuration of the mobile device (e.g. size of phonebook, power-saving mode) – operating status of the mobile device (e.g. battery charge, length of operation, degree of usage ...) – network and SIM card. For this reason, sporadic impairment of functions cannot be ruled out, even in the case of mobile devices which otherwise function reliably.