SOS error and no sound

RAYK47 · Post by **RAYK47** » Mon Dec 04, 2023 9:18 am

Hi, 2009 35i owner

Started the car this morning and there was an SOS error showing up. Didn't seem a major issue I til I then noticed the screen didn't pop up and I have no audio at all. No radio, CD or even PDC audio.

Could these be related?

It worked OK yesterday.

Thanks in advance.

B21 · Post by **B21** » Mon Dec 04, 2023 9:54 am

Could be a fault with the unit,,which is no irrelevant as they’ve switch off the technology it use, or the MOST optical bus…

I have a similar intermittent problem losing audio and the screen not working..mine happens after a few minutes then re-boots after about 5-10 minutes then repeats..

Have you left it on for an e tended period?

Mine happens when it’s cold n damp..

There is a suspicion in my case that it may be due to a failing CIC hard disc which I’m going to address with a fresh disc this winter…

RAYK47 · Post by **RAYK47** » Mon Dec 04, 2023 10:35 am

Thanks B21

Drove 1.5hrs to the office this morning and there was no life at all.

AnubisZed did install an MMI box a few weeks ago, but that is the only change that could affect the MOST bus.

enuff_zed · Post by **enuff_zed** » Mon Dec 04, 2023 10:44 am

RAYK47 wrote: ↑Mon Dec 04, 2023 10:35 am Thanks B21

Drove 1.5hrs to the office this morning and there was no life at all.

AnubisZed did install an MMI box a few weeks ago, but that is the only change that could affect the MOST bus.

Whilst I have no doubt of AnubisZed’s abilities, I will go back to my old mantra. If you do something to your car then something possibly connected goes wrong then you should firstly eliminate the work done as the cause.

B21 · Post by **B21** » Mon Dec 04, 2023 12:10 pm

If it was a MMI box with MOST then its possible..usually you get a 'no audio' message on the idrive as part of that..but..

The MOST connectors can pop out or the line damaged..

Needs a diagnostic tool..probably an expensive one that does MOST..most cab't do MOST!

RAYK47 · Post by **RAYK47** » Mon Dec 04, 2023 12:58 pm

Thanks all

I do have a basic BT diag but it certainly is not a decent one.

Regarding the SOS error, can this be coded out using bimmercode? I don't really need to see this error as I assume it is just regarding BMW services that I do not even have.

enuff_zed · Post by **enuff_zed** » Mon Dec 04, 2023 1:27 pm

RAYK47 wrote: ↑Mon Dec 04, 2023 12:58 pm Thanks all

I do have a basic BT diag but it certainly is not a decent one.

Regarding the SOS error, can this be coded out using bimmercode? I don't really need to see this error as I assume it is just regarding BMW services that I do not even have.

As it only appeared very recently it is not likely to be just because you don't have the service.
It will be linked to the no sound problem etc.
Pointless trying to code out a single symptom when the underlying fault is still there.

B21 · Post by **B21** » Mon Dec 04, 2023 2:26 pm

RAYK47 wrote: ↑Mon Dec 04, 2023 12:58 pm Thanks all

I do have a basic BT diag but it certainly is not a decent one.

Regarding the SOS error, can this be coded out using bimmercode? I don't really need to see this error as I assume it is just regarding BMW services that I do not even have.

I think you will need a tool liek ISTA or Protool that can remove components form the VO (vehicle order) ad the associated sub systems

If the MOST bus goes down then all sorts of s**t happens!

RAYK47 · Post by **RAYK47** » Mon Dec 04, 2023 2:54 pm

Yeah I think you are right, it seems SOS also uses the MOST bus so it all seems to be linked.

I have contacted AnubisZed and he has advised that there may be an issue with the box itself. My first port of call is to Mr12Volt to see what they suggest.

B21 · Post by **B21** » Mon Dec 04, 2023 3:26 pm

RAYK47 wrote: ↑Mon Dec 04, 2023 2:54 pm Yeah I think you are right, it seems SOS also uses the MOST bus so it all seems to be linked.

I have contacted AnubisZed and he has advised that there may be an issue with the box itself. My first port of call is to Mr12Volt to see what they suggest.

Its a pain but the simple method of proving it is to join the input / output MOST connector with a bridge connector...if everything comes alive then...

MOST is a ring topology so any break..anywhere and all the s**t hanging off it goes down...

RAYK47 · Post by **RAYK47** » Mon Dec 04, 2023 4:05 pm

Strangely I just tried it and it was fine, no SOS error and screen word perfect. Definitely all related then.

Might be an intermittent issue by the sound of it. This seems to point to the box being dodgy rather than any cabling.

See what Mr12Volt come back with.

B21 · Post by **B21** » Mon Dec 04, 2023 4:21 pm

RAYK47 wrote: ↑Mon Dec 04, 2023 4:05 pm Strangely I just tried it and it was fine, no SOS error and screen word perfect. Definitely all related then.

Might be an intermittent issue by the sound of it. This seems to point to the box being dodgy rather than any cabling.

See what Mr12Volt come back with.

Personally I think the issue is elsewhere but..

I did have a dodgy Mr 12 Volt but mine was video glitching when warm..

AnubisZed · Post by **AnubisZed** » Tue Dec 05, 2023 2:53 pm

For anyone else reading this, as I've spoken to Ray on this.....

There are potentially two ways this could go,
1) The MMI box has a fault (possibly an intermittent one). If this is the case, and because the MOST goes to the box, then it'll stop the MOST signal continuing along it's path, thus all items connected to the MOST won't work as they should.
2) There is a connection issue with the MOST circuit somewhere (maybe the MMI connector or the new fibre optic jumper that was fitted). Again this would take down the full circuit.

As SOS is from the Telematrics unit (either Combox or MULF) then this signal is part of the MOST.
No Audio, again this is part of the MOST, but only if it has the full 13 speaker setup (The 6 and 11 speaker systems don't use MOST) so no audio and no PDC (can't remember if Rays car had the 13 speaker setup).
iDrive not working though, he mentioned to me about the screen not going up, although the headunit is connected to the MOST, it powers itself for functions and controls the screen via canbus, so I'm not sure on this.

As for SOS being coded out, yes this can be done. It certainly can be done in BMW Tools (NCSExpert, NCSDummy), I'm not sure about other coding tools though. It is a bit of a long-winded process as you have to make sure it's fully removed from a few components and not just removing 612 from the VO, but actually from within the fsw.psw file, and I don't know if the likes of Bimmercode will do this.

Of course this may have nothing to do with the new MMI box or the associated MOST connection at all, it could simply be a coincidence but to be honest I think it is something to do with it.

B21 · Post by **B21** » Tue Dec 05, 2023 3:31 pm

Thnx for the write up..

I'm still getting occasionally an idrive screen close and loss of all functions nav, audio etc..then after 5 minutes re-boot..then 2 or 3 minutes later shut down and repeat, usually for about an hour before it is stable..one day a few weeks ago this went on for about 5-6 hours.

Its suggested in my case its the CIC hard drive failing so I've got a new SSD and I'm going to install that shortly...

Mine is the 677 system, 15 speakers..

You can in Protool remove the entries from the various subsytems like ISTA. had to do this when I deleted adaptive dampers..but I still had to remove the EDC ECU as well as it still generated errors even though I had 'removed it'

RAYK47 · Post by **RAYK47** » Tue Dec 05, 2023 11:47 pm

So a quick update from me.

AnubisZed has been very helpful as always.

On the way to work the screen did not pop up and there was no audio at all, even PDC. SOS error was visible. Tried switching off the car etc to see if it would reset but nothing changed for the 1h 20mins journey.

However when I left work the screen popped up and everything was working normally, the SOS error was no longer present. There were no issues encountered at all during the 1h 40mins drive home.

I also have the 677 stereo but I have never counted the speakers (unless all 677 are the same).

Mr12Volt have not been much use, I get one response every few hours and they have suggested: -
1) check all connections
2) disconnect power to the box, switch off car for at least 30mins
3) Disconnect all cables and see if there is audio from the radio

Obviously I can't really do any of those tests during the week so they will have to wait until I get a free weekend.

I am certain they are related so coding out the SOS error is no longer something I think is worth doing.

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