In the early car builds you got a TCU to do bluetooth phone and
SOS and a Mulf 2 Hi to do USB.
Mulf is under the TCU.
If you have an SOS error with Logic 7 most people report there is no
audio as the Logic 7 amp is part of the Most Loop and if anything is
disrupted on it nothing works.
There is no support for SOS anymore and the Mulf 2 Hi will support
bluetooth phone. You need to reprogram the Mulf to turn on
its bluetooth function and repin the Mulf connector for the Microrphone.
And also program out the TCU SOS function and remove the tcU.
First thing look at the TCU to see if there is a Most bypass loop there that
is the only way you could have audio with Logic 7 and SOS error.
Logic 7
https://www.e90post.com/forums/showthread.php?t=1056432
http://www.bmwlogicseven.com/?p=3837
http://www.bmwgm5.com/
https://www.e90post.com/forums/showt...5#post24455335
http://www.e90post.com/forums/attach...2&d=1260829447
http://www.google.fr/url?sa=t&rct=j&...slMu2A&cad=rjt
https://www.bmwgm5.com/Logic7_E90_91_92_93.htm
http://www.bimmerfest.com/forums/sho...d.php?t=982666
http://www.e90post.com/forums/attach...1&d=1209780605
Most
http://www.e90post.com/forums/showthread.php?t=727663
http://www.e90post.com/forums/showthread.php?t=347222
https://www.google.com/search?q=BMW+...VCkMqy2aCK09M:
http://www.1addicts.com/forums/showt...php?p=19256760
https://www.teacremotes.com/bmwgm5/
http://www.e90post.com/forums/showthread.php?t=1181654
This last one is pertinent to your situation.