You don't have an ipod interface, do you? I had one go bad and it did exactly like what you are experiencing (but it was on my wife's 2002 M3).

__________________
Kirk
Las Vegas
2016 X5 40e Mineral White/Black Dakota Leather, ZLL, ZCW, ZDA, ZDB, ZPP, multi contour seats, rear side window shades, HK stereo
2011 E90M3, 6-speed manual