B&O Tweeter - Rise & Retract Signal
 

My nearside tweeter seems to have a mind of it's own.

When I unlock the car, it rises. Sometimes all the way, sometimes part way. When the MMI is turned on, it then goes through a full cycle of movement. If unlocking left it open, it will be closed. If it was open a quarter way, it will fully open, then retract a quarter.

The mechanism itself seems OK (although it does stop briefly, which tells me it's got a broken tooth) but it's getting a signal from somewhere that tells it to rise and retract.

Where does the signal come from? What controls it? Any suggestions to a fix?

The actual signal would come from MMI.
Have you scanned it for faults Tony?

Yes, I've scanned it but it only shows a mechanical fault on the tweeter. I think that may be caused by me holding down the tweeter to get it to reset itself.

Not sure if holding it down was a good idea unless that's what manual says.
I don't think it's anything to do with signal so your next step is to remove it, strip it and investigate. It will be most likely a small toothed wheel like on MMI screens which fail too.

Seems like a new tweeter from this post depends on how many tooth you have broken, if it's only one then repositioning the broken gear can solve the problem.

http://www.audiworld.com/forums/a8-s...n-but-2882401/

My guess (based on nothing!) is that with a broken tooth the system is uncertain of its position and so tries to re-set it to the correct position for the system state when, for instance, opening the door, switching on MMI etc.

Thanks guys. Hmm... The broken tooth theory sounds like a viable option.

I did remove the tweeter to take a look and it is only the one, but because it's in the middle of the travel, I can't imagine I'll be able to shift it to anywhere it isn't used at all.

I found that thread and the more recent one on AudiWorld and a member on there provided a link to a place in USA that sells the tweeter cheaper than it's available here in the UK. If all else fails, I'll order one when I'm next there.

Don't you think it's strange that it rises on unlock though? David, I think your guess may just be right and if it is, at least it means the problem is limited to just one component.

Unfortunately there isn't much room for discount on this item in UK, I can get it for something like 250-290 which a bit silly to be honest.
But, I know my supplier stocks A8's B&O systems so I will check with them on Monday. It's the left one you are after isn't it??
This is the part number I will be enquiring about.
4E0 035 361 13S-Black B&O trim

Yes, it's the left one. My interior is Silver/Platinum, but it makes not difference to that part, because the cover is removable. Thanks Marcin! I didn't expect that! +++

Morning Tony
Sorry mate, they have sold both tweeters same day they got it.
I've asked both suppliers to keep an eye for the left one for me.