When you say nothing, do you mean it won't connect by blue tooth or there is nothing on the screen where the options to telephone and/or nav appear? If it is the latter, I have that problem at the moment. It is (hopefully) now resolved. Basically, it was (hopefully was) intermittent in that sometimes when you turned the ignition on, the screen was blank and other times it would come back on. So, the conclusion to all that is, get the dealer to disconnect the lot and then reconnect it.