04 TT door mirrors misbehaving

[NT_996]

Have programmed seat and mirrors for both my wife and myself; memory setting 1 for her, memory setting 2 for me.

Everything worked perfectly each time either setting was recalled, for many, many months (we've had the Cayenne for nearly 2 years).

Now, occasionally, on engaging reverse gear the door mirrors are adjusting themselves UPWARD, which because I have set the passenger mirror to drop to view the curb in reverse, means the driver's mirror is skyward, while the passenger mirror is set normal (it should be pointing toward the curb).

I've reprogrammed both settings numerous times, which seems to cause it to behave for a while, but then it reverts to its bad behaviour.

Problem is, it's intermittent, and I can't provoke it to happen, so the above sequence of events is from memory, and it could be slightly different, but it's definitely linked to engaging reverse gear, as I said, the driver's mirror ends up too high, which means I have to adjust both mirrors down, and then adjust the passenger mirror again independently...and then reprogramme and save the setting.

Any ideas or comments welcomed!

[wvicary]

A weak battery can cause many odd effects on these vehicle so have that checked first then the system checked for fault codes.

[bigbuzuki]

There are position potentiometers on the servo loop for the mirrors.

With time they wear and may not be reliable when it comes to transmitting feedback position information to the control units.

In short the motor assemblies which contain the feedback pots will need replacing.

[NT_996]

Thanks wvicary - I did wonder about the battery having read of the issues there have had with the mirrors.

Thanks bigbuzuki - I tend to lean toward this as the most probable scenario, but think I might start with a new battery, after all, it is still the original from what I can tell (8 years!) so must be due to be replaced by now.

[NT_996]

Ok, so something else has now happended:

I can't adjust either mirror...twiddling the knob, nothing...

But, both are still heated, both still fold in using the knob, and both still auto adjust with the custom settings (seat/mirror positions 1,2 & 3).

What the heck is going on??

Anyone still reckon this could be the battery??

Edited October 29, 2012 by NT_996

[NT_996]

Have had the battery tested (its a Varta too so not the original battery so it has been replaced since new but not sure how long ago).

It recorded 11.99v and start capacity was 92%.

So does anyone have any ideas what might be wrong with my mirrors?

[gasguzzlingV8]

NT_996

I dont think its your battery. I have a new battery, and my mirrors still play up. I think its the switch on the drivers door, when adjusting my drivers mirror, my passenger mirror is moving at the same time. annoying, it doesn't happen all the time, but sometimes.

it also sometimes doesn't matter where which position the switch is in when reversing into the garage, the passenger mirror still dips, even when the switch is set for to the drivers door adjustment only.

I've seen procedures for reset of the cars electronic memories, you could try these, or disconnecting the battery for 15 minutes. for me, its just one of those things, I will get round to replacing that switch eventually, I put it down to a car stuffed with electronic gadgets, some are going to play up from time to time!

Regards

Chris