[turbosnow]

So, I bought this great e93 at a steal, partially because there was no audio, due to a rear strut mount failure that severed the fiber optics going into the trunk. I stripped a MOST bus harness out of a junkyard for $20 and painfully wired it in to the existing repaired copper harness. After replacing a number or fuses as well, I now no longer get the dreaded SOS alert issues and have alert sounds (yay) and the bluetooth phone works. However, to my great disappointment, I cannot select any sources for audio in idrive, they are all greyed out, except for CD/DVD, I’m searching my house for audio CDs but to no avail. The USB and aux connections do not seem to work, nor do AM or FM radio. Any thoughts, this is a pretty unusual circumstance.

[ctuna]

Depending on the year of the car the USB will be handled by a Mulf 2 module
in the trunk or a Combox on the later years.

If you have a TCU for SOS the Mulf 2 module will be underneath it.
If you have a combox it handles both.

You should find out which options the car came with .
Run Mdecoder. com on the Vin look at the options in the 6 hundred range
6LF is the the USB option.

If you have a used car you don't know what has done to it.
Both Aux and USB come from the modules I mentioned if you have 6LF option.



You didn't say if you have Pro Radio or Idrive.
Or even if the Head Unit is stock.
If you have tuning on the Radio function but no sound the antenna's could be bad.

Or you might have a bad head unit.

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/attach...1&d=1209780865
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...1&d=1209780605
http://www.e90post.com/forums/showthread.php?t=641323
http://www.e90post.com/forums/attach...4&d=1278871872
http://www.e90post.com/forums/showthread.php?t=343673
https://www.bimmerfest.com/threads/e...n-752.1275694/
base system wiring pre/post 3/09
https://www.google.com/url?sa=t&rct=...tDpLJPcGkw_ui_
Base System Guide
http://www.e90post.com/forums/attach...5&d=1493273253

Logic 7
https://www.e90post.com/forums/showthread.php?t=1056432
https://www.bavlogic.com/?p=3729
https://www.bavlogic.com/?tag=loop
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/
Diagnostic Manuals Inpa/Ista D
https://bimmerprofs.com/diagnostics-inpa-part-1/
https://www.google.com/url?sa=t&rct=...7x8H3pN8h1fMuF
https://carmod.ru/files/icom/istad_en.pdf
https://www.e90post.com/forums/showthread.php?t=1681573
https://www.bimmerforums.com/forum/s...-P-actually-do
primary links
https://www.bimmerfest.com/forums/at...9&d=1539905743
https://www.e90post.com/forums/showthread.php?t=1681573
https://www.bimmerfest.com/forums/at...1&d=1590283589
https://www.nathansbmwworkshop.com/b...or-dean-videos

[turbosnow]

Thank you! I have the TCU and the MULF. It’s strange that bluetooth works but USB and aux do not. I have idrive.

[ctuna]

with Mulf 2 the aux and the usb come from the that unit option 6LF as
long as you have the OEM head unit either I drive or pro radio .

[turbosnow]

Gotcha, so it’s probably bad MULF, which I was suspecting. I think I can grab one either from
The junkyard or from ebay.

[turbosnow]

I looped everything on the MOST except for the TCU and the MULF. The system behaves exactly the same, also telling is that the USB is not even providing 5v power, which I’m guessing is tied to the MULF, I’m going to to looking for a replacement MULF. I don’t really care about the radio or SOS system which I don’t have active. I’ll check fuses again, and plug the MULF back in for giggles, but it seems likely that this is the issue.

[turbosnow]

Looped the MULF too, same effect.

[ctuna]

If you loop it takes it offline , turns it off , makes it a dead parrot.
The same as anything else you bypass if that's what your saying.

[turbosnow]

Yep, that's the behavior I expected, I just wanted to see what items might be bad, it seems like everything other than the amp and the TCU driven bluetooth is non-functional. I'm going to try the CD player when I can grab some CDs, and bring the car back online, it's currently without battery power as I got stuck during a steering wheel swap due to not having the right harness, and I'm unwilling to fight with the airbag again until I get the right one.

[turbosnow]

sorry for the hiatus, life got in the way. I tried a different MULF with the same results, the CD and DVD player work, so I burned some DVDs with MP3s and at least can listen to music, my goal is to install an upgraded android screen with apple car play etc. To do this I understand that I need working Aux in audio, which I currently don't. I'm thinking of pulling the trigger on a new CCC head unit, as it doesn't make sense that bluetooth phone, alerts and the built in optical drives all make sound, but none of the other options on the head unit work, I can't select anything other than CD. Nav works as well, although I don't really care, since any of the apps on my phone are infinitely better at navigation.

[ctuna]

With a Mulf 2 Hi and the 6LF option PROGRAMMED correctly the Aux
and the USB come from the Mulf 2 Hi .
Both the head unit and the Mulf must be programmed for 6LF.
And the wiring must be correct for it.

http://www.e90post.com/forums/showthread.php?t=1181654

Cars made after after 2009 may not have prewiring for options.
USB and mulf was not an option till 2007

[turbosnow]

So my car is listed as having S6FL USB/Audio Interface , I haven't tried looping the TCU and seeing if the bluetooth still works, but I could do that. I'm suspecting the head unit since I can't select any audio sources from the idrive screen other than CD/DVD, which both work. The bluetooth phone also works as previously mentioned. I ebayed a new head unit with the same part number and I'm going to have to get comfortable with using NCSexpert anyway, I have the cable and a computer set up already, but so far have only used INPA.

[turbosnow]

so I replaced the headunit, when I put it in prior to coding, I could see the aux input and select it. I default coded the new headunit, got CD/DVD working, but I still have the same damn issue with not being able to select any sources except CD/DVD. I tried coding out the sattelite radio, and the option disappeared, but now I still cannot select FM, AM or AUX in. I don't understand why this is still an issue unless there's some bad copper wiring, or the MOST bus isn't done right, the amp works and the TCU/Bluetooth work, so I'm a bit mystified, if the MOST loop was not working, I would think that nothing would work. I guess I can go back to the original headunit, as it appears that it works just fine. I do have a couple of MOSTGW errors in INPA, but can't figure out what they mean. Could the issue be that the most bus is not wired in the correct order? To me, it seems like it wouldn't matter at all as long as the fibers can transmit light and the electronics or the loop is repeating the light properly.

[ctuna]

Just to be sure if you have idrive and there is sound the Most loop is intact.(For logic 7)
(Except for any modules you have bypassed with a jumper. )
This is based on having the Logic 7 amp which is connected to the Most Bus.



If you have the Hi Fi system the amp is Analog and the sound will work without
any interaction with the Most Bus.

[turbosnow]

I definitely have logic 7 and the MOST bus is functional. I’m wondering if there’s an issue with some
Copper wires that weren’t spliced right, or if something is hosed in the coding.

[ctuna]

There are additional cables for all the modules .
The Wire harness for those may vary by year.

First year in 06 only supported TCU and Sat after
that the Mulf was added.
After that the combox replaced both the Mulf and TCU.

I would think the Radio would work if you have a working antenna connection
and the Radio Frequency for your country is selected.

[turbosnow]

It may be the antenna is messed up which could be causing the radio issue. Nothing is selectable other than CD/DVD which is the strange part, but there’s still audio from that. I’m about to give up and just burn more MP3 dvds, and sell the android unit I grabbed for it awhile back. This car is about to get sidelined for the winter anyway as it’s too nice to drive then.