[N54sk8r]

I'm having an extremely hard time reading and understanding Bmw Most , fiber optic wires and how the radio and amplifier work in my 2008 335i . A few months ago my cheap coil over suspension decided to break through the trunk severing the harness going to the HiFi amplifier and the following day the same happened to the right rear harness . The following has happened since the incident. 1. I immediately received the SOS / phone indication on the gauge cluster message center . 2 I no longer have sound . 3. I no longer have comfort access or the ability to open my or start the car without having to put my key in the slot .

After finally repairing my suspension with new Fortune 500's I went to a local audio shop for insight into repairing the wiring and replacing the factory amp with an after market amp . The shop had shown me their 09 e90 335i sport with every oem Bmw performance accessory under the sun including performance steering wheel and IDrive with a aftermarket Nertz amp and some other audio stuff that I didn't care about . MY POINT IS they showed that an aftermarket amp could be installed utilizing the oem head unit . Which was the purpose of my visit . I had told them about my damage and they were willing to work on the car by repairing my harness and installing some JL 400 w amp but they did warn me that this would not guarantee the return of sound in my car .

The process was completed in 4 hours which they called and told me that it the fiber optic cable was damaged and that I needed a radio . Which he than began to show me single din head units with flashy lights and displays which I would have bought in my youth . I asked why cant I just buy a new factory head unit and he said that if I did I would have to undo every thing that was just installed ,purchase a working factory amp and have it coded by Bmw and than have a new fiber optic cable ran and once this was done than re install the amp they put in .
any idea of what else I can try to regain music and sound back in my car . I completely understand that you should never cut wires in these cars but my old suspension kind of chose to do that .

I'm sorry for the long read but after writing to bav sound and trying to search this form for post it seems like my situation is close to and far from any I've found here . I have pics of damage once I figure out how to put them on here

[ctuna]

First you need to know which system you started out with
for sure. I thought that the US 335 08's still had L7 as a standard .
If you have L7 the amplifier is part of the most loop and only
will work with the BMW idrive or pro head unit as (pretty much) as that's
the only one that transmits via the bmw fiberoptic system. If you
have Hi Fi the fiberoptics don't go to the hi fi amp.
don't know why your Comfort access stopped as unless power was
cut to the whole dashboard area.
If you had a cdc changer in the trunk area that uses the most bus and
could be cut which would break the most bus loop even if you didn't have
L7.

A broken fiber optic cable wouldn't cause the radio to go bad as light doesn't
short out. You would just replace the cable.

L7 system = l7 amp which means fiberoptic connection between the
amp and head unit. Only the dynavin n6 head unit comes with and adapter
that will allow it to play with a BMW l7 amp opticly.
Mobridge makes a fiberoptic to analog preamp that allows
aftermarket amps to work with the L7 programmed head unit.
Hi Fi system has analog connection between the head unit and amp
aftermarket amps will work with it.
The SOS system takes control of the sound system when in operation
so it can stop sound if its not working properly in either the L7 or Hi Fi system.
The SOS error you got a first suggests you have the L7 system.
The Head unit in the L7 can be reprogrammed to the Hi Fi outputs
I don't know if the analog outputs from the head unit are wired to the trunk
in an L7 system.

The systems in these cars are integrated with the rest of the car and
most stereo shops don't understand how to deal with them effectively or
at all.

The sound system has nothing to do with the Head Unit or Idrive except
in the ampless 2010 early 2011.

Do you have a picture of the amp that came out if was silver its L7 if its
black its Hi Fi for years before 2010.


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/showthread.php?t=641323
http://bmwcoders.com/forum/3-er-8/bm...1-e92-e93-291/
http://www.e90post.com/forums/attach...1&d=1209780865
http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja
http://www.musicarnw.com/page-2/
http://www.e90post.com/forums/attach...4&d=1278871872

Is that Hamstead in the US(Maryland) or some place else
as standard options vary form country to country.

If you are in the UK you might try

http://www.e90post.com/forums/showthread.php?t=704363

http://www.monsteraudiodesign.co.uk/

[N54sk8r]

Thanks for the info !! I'm from Hampstead, Maryland. The amp after picking it up just now says L7 on the side ( I'm an idiot ) .

I've actually been researching the Dynavin unit unit for a candidate for replacement of my factory HU if I can't find any other solution. I have seen the Mobridge device and I'm trying to figure out if this is what I need to keep it oem .

As far as the Dynavin unit is concerned I saw that it has Usb for IPod / Apple products but what if you have the Usb Aux ports in the center armrest counsel? Are they no longer needed

[ctuna]

If you had L7 its obvious the shop you took it to are Hosers.
Your most loop is now broken that is probably why you are getting
the SOS error. And that is a L7 amp.

Your factory Head Unit or Idrive is progammed to use the optical output
of the head unit and it also is connected to the TCU phone unit under the trunk floor that runs your bluetooth , Sos and maybe your usb ipod connection it disconnected.

I would back out of everything they did if I could.
You had a 9 channel amp the amp probably wasn't even bad.


If you want to keep the OEM HeadUnit but change to aftermarket amps and
speaker there are two options . Either you buy the mobridge DA-2 or you reprogram the output of the radio to Hi Fi low level analog signals and connect them to the amp they supplied. Then this come backs to how they connected
the aftermarket amp.
Then you have to close the most loop to get rid of the SOS error.

If the system they showed you started out with Hi Fi there is no problem adding
aftermarket amps and it's actually and improvement but with
the L7 system its a big problem because to the fiber optics and L7 system is already pretty decent.

If you decide to change the head unit hang on to the old one you may need
to reinstall it to get software updated and or repairs if you take the car to BMW.

the upper east coast shop the understands these system or maybe
can help you find someone closer is

http://unexpectedcreations.com/

On the comfort access problem
See the second document

electical e90 pdf
http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU

There is a ca module and antenna connection running on the right side of the
car near the rear wheel well. look at around page 42 on in the second pdf.

I think the dynavin has usb outputs in the back you can use a cable to run it
anyplace you want to . But to further confuse the issue you could run aftermarket amps from that head unit with analog connections. If you want