[Joe@TopGearSolutions]

Originally Posted by ChrisCharcoalE92

Bump


I just got this same issue yesterday on my 08 e92 well out of warranty lol...theres a tiny panel thst popped out under the drivers side pretty much above where your left leg sits...no idea what its for, so i shoved it back in and now my radio will not work and its driving me nuts...when i start i see the sos error then my idrive freezes up and i cant move or use it...did i do something when i shoved that tiny panel back in? I was thinking of unscrewing the whole panel and taking a look if anything is disconnected...did the op or anyone find a fix for this? I rather not bring to bmw n have them bang me over the head to fix this but its hard to drive without a radio or music

That's most likely the fiber optic MOST loop maintenance connector. There should be a fiber optic line that drops down and connects to that panel. If it's unplugged, the fiber optic signal is broken, therefore your radio won't work.

There is a way to disable the SOS portion so that error goes away, but that won't fix your INOP radio.

[ChrisJadesFireF82]

Originally Posted by Joe@TopGearSolutions

That's most likely the fiber optic MOST loop maintenance connector. There should be a fiber optic line that drops down and connects to that panel. If it's unplugged, the fiber optic signal is broken, therefore your radio won't work.

There is a way to disable the SOS portion so that error goes away, but that won't fix your INOP radio.

Thank you for the info. Do you know how to fix this? Or is there a threat that details this? I definitely think this is my issue bc it was fine prior. Thanks for the help!

[hz_diesel]

Originally Posted by ChrisCharcoalE92

Thank you for the info. Do you know how to fix this? Or is there a threat that details this? I definitely think this is my issue bc it was fine prior. Thanks for the help!

Same issue. Trying to figure it out, following this thread.

[Joe@TopGearSolutions]

Originally Posted by ChrisCharcoalE92

Thank you for the info. Do you know how to fix this? Or is there a threat that details this? I definitely think this is my issue bc it was fine prior. Thanks for the help!

As long as the fiber optic wire is still intact and not damaged, make sure it's plugged into the termination adapter that's attached to the panel that dropped down as pictured below.

If the fiber optic wire is damaged due to that panel coming down, then you have bigger issues

[Joe@TopGearSolutions]

Originally Posted by hz_diesel

Same issue. Trying to figure it out, following this thread.

Do you just have the SOS error, or are you without a stereo as well?

[hz_diesel]

Originally Posted by Joe@TopGearSolutions

Do you just have the SOS error, or are you without a stereo as well?

I am without any sound at all. CIC is functioning, optic cable light can be seen in the rear. I bought a new combox but it won't show up when I try to code it using rheingold. I also know sound comes back when I do the mostbus bypass so I am pretty stumped.

[Joe@TopGearSolutions]

Originally Posted by hz_diesel

I am without any sound at all. CIC is functioning, optic cable light can be seen in the rear. I bought a new combox but it won't show up when I try to code it using rheingold. I also know sound comes back when I do the mostbus bypass so I am pretty stumped.

Replacement or retrofit combox?

[hz_diesel]

Originally Posted by Joe@TopGearSolutions

Replacement or retrofit combox?

Replacement, I thought the replacement was bad and the sent me a second one which also didn't work.

[Joe@TopGearSolutions]

Originally Posted by hz_diesel

Replacement, I thought the replacement was bad and the sent me a second one which also didn't work.

Make sure it's not a BN2020, which is for F series.

[hz_diesel]

Originally Posted by Joe@TopGearSolutions

Make sure it's not a BN2020, which is for F series.

Yeah I checked that that part numbers are identical. So I'm bewildered

[ChrisJadesFireF82]

Originally Posted by Joe@TopGearSolutions

As long as the fiber optic wire is still intact and not damaged, make sure it's plugged into the termination adapter that's attached to the panel that dropped down as pictured below.

If the fiber optic wire is damaged due to that panel coming down, then you have bigger issues

Is there more diy topics on this...i like to think im pretty savy tech wise and fix most small things myself but im at a loss here with half you said lol

[Joe@TopGearSolutions]

Originally Posted by ChrisCharcoalE92

Is there more diy topics on this...i like to think im pretty savy tech wise and fix most small things myself but im at a loss here with half you said lol

See if this info further assists... I know it talks more about changing amps, but it still explains the MOST pretty well.

http://www.e90post.com/forums/showpo...69&postcount=1

[ChrisJadesFireF82]

Originally Posted by Joe@TopGearSolutions

See if this info further assists... I know it talks more about changing amps, but it still explains the MOST pretty well.

http://www.e90post.com/forums/showpo...69&postcount=1

Got it, pretty straight forward...Now my question is if I destroyed this unit how can I replace it so I can get everything up and running again it is miserable driving without a radio when you drive as much as I do

[ctuna]

This may be redundent info at this point.
Yeah one is for the E65 but it has some basic
tech info about the most system.

[ChrisJadesFireF82]

Hi guys, just providing an update and maybe can help you

I fixed it! Turns out my satellite radio went and my optical signal was not being returned from it...so i bought the MOST bypass on amazon (cost $15 on amazon) and used it to bypass the satellite radio all together...originally thought it was the little optical sensor that popped out below my steerling wheel but i replaced it with the unit i bought and it did not fix...so i went in my trunk removed the cover and checked the sensor on my satellite radio and plugged in the loop bypass and when i turned on my car everything worked as normal! (Except my sattelite but i dont even use it anymore so i dont care)...i had to cut up the plastic housing of the bypass i bought to fit but it worked nonetheless...also threw on some electrical tape to keep it in place, i later ran it along the side of the TCU so the cover would not touch it...pics below

[juleshue]

Originally Posted by Joe@TopGearSolutions

That's most likely the fiber optic MOST loop maintenance connector. There should be a fiber optic line that drops down and connects to that panel. If it's unplugged, the fiber optic signal is broken, therefore your radio won't work.

There is a way to disable the SOS portion so that error goes away, but that won't fix your INOP radio.

I recently picked up an '08 335i and have the SOS malfunction. I've tested the modules from the AMP -> Bluetooth Module -> Satellite Radio and appears I can get a signal up to the Satellite radio module (connector unplugged, red optical light present)


Once the Sat Radio is plugged in, there is no optical red light at the final termination under the dash. Thinking its the sat radio module that's the problem as most cases are, I used a bypass loop on the connector to bypass the module. Same thing, no light at the final termination under the dash.


I thought maybe the MOST bypass loop is faulty, plugged it into the Amp's connector and found that the signal is still present at the Bluetooth module as well as the sat radio connector.

At this point I'm completely lost, checking multiple forums, videos, posts, even going to E90/2/3 facebook groups.

Checked the MOST BUS behind the driverside rear bolster and nothing looked tampered with.

[minifridge1138]

This issue just happened to me this evening in my 2007 335i. I started listening to music through the AUX cable when suddenly i lost all sound, bluetooth connectivity, radio, and got a "SOS Call System Malfunction" message in iDrive.

I understand that the MOST system uses fiber optics and is supposed to be a closed loop. So either a cable is broken or a module/component in the loop is dead.

I'm happy to troubleshoot it myself, but I don't know where to start. Literally. Where should I start disconnecting a cable to test it? Is there a wiring harness under the dash? Is there a line that runs from under the dash to the trunk?

Anyone know of a good wiring diagram that can show me what runs from where to where?

Thanks!

[opjose]

Look for Ctuna's posts on the car radios here.

He often posts a list of links that include wiring diagram PDFs that include the Most loop.

[ctuna]

Optical jumpers are cheap on amazon and ebay.

[ctuna]

Optical jumpers are cheap on amazon and ebay.

https://www.e90post.com/forums/showthread.php?t=1673885

read the second entry with all the links.

[agustincuenca]

Originally Posted by juleshue

I recently picked up an '08 335i and have the SOS malfunction. I've tested the modules from the AMP -> Bluetooth Module -> Satellite Radio and appears I can get a signal up to the Satellite radio module (connector unplugged, red optical light present)


Once the Sat Radio is plugged in, there is no optical red light at the final termination under the dash. Thinking its the sat radio module that's the problem as most cases are, I used a bypass loop on the connector to bypass the module. Same thing, no light at the final termination under the dash.


I thought maybe the MOST bypass loop is faulty, plugged it into the Amp's connector and found that the signal is still present at the Bluetooth module as well as the sat radio connector.

At this point I'm completely lost, checking multiple forums, videos, posts, even going to E90/2/3 facebook groups.

Checked the MOST BUS behind the driverside rear bolster and nothing looked tampered with.

did you ever figure this one out? I'm still dead on the water, multiple jumpers, even bought an amp and still no audio