[ctuna]

Logic 7 systems from BMW are not simple .
Because they use the MOST fiber optic system.
There is very little that is compatible with it, and what is
is expensive and kind of exotic.

This subject has already been hashed to death over and
over that why there is an audio up grade sticky .(in the stickys
at the top of this sub forum)


BMW stereo types
http://www.e90post.com/forums/showthread.php?t=352586
http://www.e90post.com/forums/attach...2&d=1266451970
http://www.e90post.com/forums/attach...2&d=1260829447
http://www.e90post.com/forums/showthread.php?t=343673
http://www.e90post.com/forums/showthread.php?t=138949
http://www.e90post.com/forums/attach...1&d=1209780605
http://www.e90post.com/forums/attach...1&d=1209780865
http://www.e90post.com/forums/showthread.php?t=641323
http://bmwcoders.com/forum/3-er-8/bm...1-e92-e93-291/
http://technicpnp.com/menuDiagrams/d...e90_92_93.html
http://www.musicarnw.com/page-2/
http://www.e90post.com/forums/attach...3&d=1169133185
http://www.e90post.com/forums/attach...4&d=1278871872

Your genius at the BMW place is more likely an idiot.
The most common problem with these is the amp getting drowned due to water leaks. Second most common problem is the TCU or the Sat module goes out.

Also the head unit's are programmed for the sound system
in the car unless it came from another car that was programmed for Logic 7 it won't work in your car unless it is.
There are two other sound systems it could be programmed
for.

Logic 7
http://www.bmwgm5.com/Logic7_6941681.htm
http://www.bmwlogicseven.com/?p=3837
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

The logic 7 is a 9 channel amp .
to run something else the head unit has to be reprogrammed to run analog signals and harness that supports them installed or there is now a fiberoptic to analog converther made by Avin

I would fix the amp at the places mentioned in the links
if that is the problem. After the leak is fixed.