I have a 2008 535I. The head units AM / FM had quit working the USB and Aux were working. I replaced it with one I found on the Internet (same numbers same Head unit) Now the radio works (AM- FM ) It shows the AUX on the screen not the USB. None work. Any Suggestions?
Thanks

 

Check all connectors to make sure this is not the problem. Then you need to code your new replacement HU to your car specs. Find somebody that has interface cable and knowledge in Regional subforums. Alternately head up to your dealer.