Aquadancer

New member here... hoping to get some help from the MMI expert on this board.

I have a 06 A8 with approx. 40k miles on it. It has developed a very annoying MMI problem. The system will shut down at random and typically not restart for a while. I hear a ping in the speakers, the screen goes blank, and all MMI functions stop working. When I press one of the MMI buttons, Audi logo screen will show up for 10-15 sec and everything goes blank again. Sometimes soft reset will bring it back to life, sometimes not.

My dealer replace the MMI controller once but it didn't help. They now had the car for the last week but cannot diagnose and there are apparently no codes.

Any similar experiences / suggested fixes?

Thanks in advance

Rowlie

I had the same problem a couple of years ago and it turned out to be a sticky button. (The "car" button in my case). I exercised the button a few times and haven't had a problem since. I hope yours is that simple as well.

Aquadancer

Unfortunately it is not sticky buttons. Been checked and cleaned just in case.

New info from dealer is this: GFF shows "faults in 07 and 19 for optical data bus open circuit". Also says that it "passed ringbreak everytime".

AoA wants them to continue to drive the car with the scan tool until they duplicate the problem and perform ringbreak diagnostics during the shut down before they replace any other MMI component.

Dealer has been at this for over a week now... cannot figure it out.

Can someone help translate this stuff? What should I be asking them to do?

MP4.2+6.0

The usual starting point is what rev. MMI do you have if it isn't an obvious h/w problem. But since you are at the dealer and it sounds like you may have a (not too common) h/w issue, I would think they would have thought through that.

With what you have mentioned so far, it sounds like they are looking at the optical ring. As it sounds, it is core car equipment configured in a network using an optical backbone. It is a ring rather than star configuration, so everything along the ring needs to pass data successfully, plus function itself. The ring itself could be compromised (unlikely unless someone was working inside dash or maybe with upholstery and physically moving cable type bundles), or more likely the control boxes or the optical couplings/plugs/transmitters receivers at the boxes (part of the boxes of course). Among the obvious things on the ring in the strereo and MMI area are the MMI screen, the CD changer, any AMI unit, sat unit, core radio unit, etc. Lots of other things feed into it too that you see in the display. A comprehensive VAG scan of all the control units might tell them if others have faulty codes; again something I would thing an good service tech would do pretty early.

First questions I would have are what has been fooled with on the car before; usually the most likely source of a downstream problem, especially if it could be a problem with the optical transmission. Thus, has AMI been retrofit, has the changer been replaced, or the display screen, or the tuner, or any sat radio box. You already mentioned they changed the MMI brain itself, and even that replaced part or its couplings could be suspect.

audirocks1

I had a similar issue with my 05, it turned out not to be a sticky button, but sand that had gotten in between them. My dog loved to stand on the arm rest when returning from the beach. Replaced under warranty the first time, they split with me the second time - after that, I had a long chat with the dog and has not happened again.

MP4.2+6.0

picked mine up from a shop for some minor body stuff. They detailed the interior, and got a piece of cleaning rag lint stuck in a button. Set up the same on-off dance until I saw it, pulled it out, and it cured up right away.

Aquadancer

Dealer claims that the root cause was the amplifier. Replaced amp and MMI control module. Seems to be all good for now.

Colemanator

I have this same problem with my 2006 A8, but only on long trips. It may be related to the amplifier. My fix has simply been to open the rear trunk and remove the cover panel for the amplifier. Then simply unplug the fiber optics plug on top of the amplifies and then plug it back in. It seems to effectively reset the system and works every time my MMI shuts down which is very infrequently, maybe about once a year.

ltooz_a6_a8_q7

Had the same problem while doing the back up camera retrofit, unplugged and plugged back all the optical cables... worked ever since. If the MMI doesn't response to anything - it's the optical bus - daisy chained - 1 broken link - the whole chain dies. Simple fix - buy a plug - start plugging 1 device at a time to find out which one causes the problem.


Cheers,

Louis

Teamelevation

BUMP