Trunk latch problem
 

The second it gets cold out the trunk latch stops latching. the electronics work fine and the solenoid works fine it just doesnt actually latch and the trunk wont close sometimes. Im not sure if this is common.... any input?

I think pierreb has the exact same problem.

Have the same problem with mine ('07 S6).

Tried lubricating the latch, hoping problem was purely mechanical, but I found a new variant a few weeks ago - if the car is locked and I then open+ close the trunk, odds are MUCH higher the trunk will latch-then-unlatch on its own. This almost always occurs with (a) the advanced key in my pocket, (b) I'm closing the trunk from the left (drivers) side of the car, and (c) the car is starting out in a locked state.

Unlock the car, then return to close the trunk - voila!, the latching behavior is correct.

Which leads me to STRONGLY suspect this is due to a misfire of what I believe is the "protective" Advanced Key feature that won't let you close the trunk if (a sensor, I presume) believes the key is physically in the trunk, eg it falsely things the key is in there (vs in my pocket)

Hasn't bothered me enough to warrant it's own trip to the dealer...yet. Not sure how similar the circumstances are to what you're seeing?

Do an advanced search in the C6 section for "trunk latch", and you'll find a bunch of threads on it. I remember reading about the cold weather trunk latch issues a long time ago on the earlier C6 models. I think there was also a post by someone who figured out how to fix the problem by disassembling and modifying the latch mechanism.

I would say yes that its prob an advanced key issue but I dont have advanced key

Very interesting. This happened to me just the other night. I thought maybe I hit the trunk button with my tighter (getting tighter every week it seems, ugh) jeans, but I bet your explanation is it. I bet it thought I dropped the fob in the trunk!

Good call! I can't imagine I would have had the luck of hitting the trunk button JUST after I closed the trunk.

I lived through this problem a couple of years ago. Spraying the latch with silicone works for a a short period of time. The real problem is that the original latch design was defective and has since been redesigned. Audi replaced mine as a warranty claim a couple of years ago and with the redesigned latch I have had no problems.

it is deffinatly a defect in the latch. If you are under warrenty, you should have it replaced. Mine does the same thing only in cold weather. It had nothing to do with the the advanced key. I need to get mine replaced this year.

agree, nothing to do with advanced key - my 05 without that option had the same issue. I followed the advice here and sprayed a little silicone (alright, I was pissed, about 1/2 a can!), and never had the issue again. If under warranty, try to get the dealer to fix, but if not the solution is pretty simple!

If you're under warranty, take it to the dealer. Mine was giving me trouble last February- the dealer installed a new latch. They also mentioned it was a "documented issue with certain A6s"

-Mike