Odd reverse dip mirror behaviour
 

Can anyone explain this and point to a fix?

I rarely use the auto-dipping nearside mirror function, but today noticed it wasn't working properly. This was first seen while the garage were using the spare key which isn't programmed to any memory button. But it's the same on the normal key.

On selecting reverse it dips, but doesn't return to normal. Reverse again it dips further, and so on.
The normal adjustments all work, up down left and right. So I can just put it back. :Confused:

Any thoughts?

My D2 did that too... you'd have to manually put it back after dipping sometimes..

There was some suggestion removing the mirror glass and cleaning some contacts can influence behaviour of the dipping function.

Mine had a meltdown after the new mirror bodies were fitted, but some perseverance with setting it back to normal and reinstating the memory setting seemed to sort it and it's never happened again.

If you stick it in reverse it should dip with the mirror control set to L, and either moving out of R or moving the mirror adjuster to off or R should also see it return to the original position.

You always see mirror modules for sale, but not sure I've ever known one actually fail?! You'd expect a fault code if it did....

Yes, I know how it is "supposed" to work, but does anyone know what the actual mechanism is?

If, for example, it's a separate set of contacts inside the mirror mechanism, that could be susceptible to damp/dirt.
Or is it just a timer spinning the relevant motor for set time? That seems unlikely though.

I don't use mine much, usually turning the control to the central position when "unfurling", but it has always worked before today. Pretty cold and damp out.....

Mine occasionally does this, or 'forgets' to move back up.

I get the impression it calculates the mirror's position through a simple timing procedure, rather than some sort of feedback arrangement, since it doesn't seem to be aware of the absolute angle of the mirror.

At least that's the way it seems because I find that I can 'resynchronise' things by moving the mirror back up then, using the memory seats button, store the new mirror position by over-writing the appropriate memory. After doing that, it usually works perfectly again for a while. I haven't confirmed the cause, if any, but I suspect it could be getting nudged at the drive-through car wash.

I cant comment on the D2 but i serviced a 2009 A8 the other week which had limited mirror movement, so i removed the glass, removed the unit which controls angle, a good old blast of WD40 and reinstalled and all good.

This morning it's working perfectly. :Confused:

Mine does just the same. Sometimes it's fine but occasionally it malfunctions as yours does. But I hardly ever use it, so it's not really an issue.

I'm surprised the "OCD Crew" haven't been all over this Mark :)

Glad it's working as normal HP, I found a 2012 thread about the same problem but you'd made several comments on the issue so guessed you were well aware of it

mine does it as well, but like Jim I ignore it, looks like it becomes a feature as they get older:(