E93 M3 - No audio/bluetooth, voice, etc sos failure
I just found out why my audio, sos, bluetooth and beeps were not working on my e93 m3. I unplugged an optical ipod cable from my glove box a few weeks ago. all audio went out - 3 weeks of driving without phone, nav audio or radio was killing me.
Playing around in the car today i disconnected battery, hard reset on the MOST-Bus - no luck!!!
I found out that it stopped working because it was not grounded to the chassis properly.
Figured this out when the MOST-BUS box touched the metal part of the car near the fuse box in the glove compartment. all of a sudden i hear loud music and see a spark from the MOST-Bus box.
took it to Calabasas BMW 3 weeks ago, the service guy told me that since the car had done 53k, my warranty had expired and it would cost aprox. $1200-2000 to diagnose and fix.
Fixed it myself. - try to make sure it is grounded properly if you have the same issue.