# both not functioning: driver door switches for trunk and fuel door operation (2004 W12)



## pdejong0 (May 16, 2011)

Greetings all... and any available suggestions would be appreciated please:

I've read through as many threads as I could find on this or related subjects, but I have not seen anyone report having both of these switches not working at the same time. Summarizing:
- both of these two door switches do not initiate their respective functions (trunk won't open and fuel filler door will not open when the switches are triggered)
- No VCDS fault codes reported related to these functions or components (no VCDS faults at all!)
- No other electrical problems to report... LH battery is in good shape (less than two years old), and I've used a battery maintainer, also.
- A technician checked all connections and everything is properly plugged in. All the fuses that power these items have power. When he checked these circuits with VCDS (output test on the control module), he says that pulling each of the switches does not trigger responses through VCDS. He believes that if there was a fault with either of the switches or with the wire harness, VCDS should provide a canbus code and a faulty switch.

The technician is now studying the wiring diagrams via the Bentley manual and will try to further diagnose the problem. While he is attempting this, I thought I would see what the collective wisdom of the forum might be able to provide to help find a solution.

Many thanks in advance,

Peter 

p.s. I do not think this is related, but the only other problem I've had recently was a "workshop... car too low" warning and eventually determined that the air suspension compressor ('compressor assembly air unit') under the trunk was bad. Fuse blown, and when fuse was replaced the compressor would operate for perhaps 15-20 seconds before it started making bad noises and then the fuse would blow again. Tried this three times and was satisfied the compressor motor had either starting shorting or otherwise gone bad. Replaced the compressor assembly ($958 part), and all is OK now... this cleared all air suspension related VCDS faults. Again, I do not think the driver door switch faults are related, but I thought I would share... just in case. The switch operation problem started a month or so prior to losing the air suspension compressor. Fun, fun, fun... ;-)


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## Paximus (Aug 26, 2011)

Hi Peter,

Those two switches are connected direct to the door controller, which is part of the power window motor assembly. The door controller feeds the switches' conditions over the CAN-bus to the Convenience Controller in the trunk shelf. In VCDS you can see that the door controller is a slave to the Convenience Controller.

For the tank flap release, the Convenience Controller feeds +12V to a relay which applies power to the motor. The trunk lid has its own slave controller which also communicates with the Convenience controller.

Ruling out wiring, relay or fuse problems for the moment, if VCDS does not sense either switch operation then either (a) both switches have had cola spilt on them sometime in the past and are truly not making contact or (b) perhaps there is some coding mis-set that tells the controllers that they don't exist, since the switch position is reported to VCDS by the Convenience Controller which must have the impression that they are not activated.

It could be worth recoding the Convenience Controller with the same code that is shown now, to perform a reset.

Chris


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## PowerDubs (Jul 22, 2001)

Does your dash look like this?


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## pdejong0 (May 16, 2011)

Paximus said:


> It could be worth recoding the Convenience Controller with the same code that is shown now, to perform a reset.
> Chris


Great education and input, Chris... Happy to report there has absolutely been no cola spill (are you kidding me?... allow cola by me or ANY others in my Phaeton... what an outrageous concept!), and I will try the recoding of the Convenience Controller. Will report back on this... thank you very much.

Peter


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## pdejong0 (May 16, 2011)

PowerDubs said:


> Does your dash look like this?
> [/IMG]


Very good / logical feedback, Josh... sorry, I definitely should have stated that I ruled this out from reading about this possibility in numerous other posts related to the trunk release via door switch. Not sure if the valet function also locks out the fuel filler door, too... but, either way, the Phaeton is definitely not in valet mode. Thanks anyway and any other ideas most welcome!

By the way... *I also should have noted that the trunk DOES release via the rear emblem trunk microswitch AND the key fob. The only way for me to currently release the fuel filler door is manually, as described in one of Michael's posts, by manually actuating the plunger of the actuator / motor that is normally supposed to open the fuel filler door.*

Peter


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## Paximus (Aug 26, 2011)

Josh's comment makes great sense.

Also, I doubt the garage techs are totally averse to sugar sodas, but I suspect they are very good at valeting!

Chris


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## mik15 (Dec 18, 2012)

i have the same issue with those 2 buttons, couldn't yet figure out a way to fix it, didn't really try that hard because i am not too bothered, however i would like them to work at some point! I had issues with the buttons on the driver's door and found out that the connector was loose and hoped that would also sort out all buttons on the door, but it didn't work on those 2, so the problem must be somewhere else!


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## pdejong0 (May 16, 2011)

Summarizing / updating:

- 2004 W12 Phaeton has two driver door switches that will not initiate their intended functions: 1) trunk opening, and 2) fuel door opening.
- Motorized trunk lid operates normally via rear emblem microswitch, key FOB, and trunk close button inside trunk lid.
- Phaeton is NOT in valet mode (sorry for not noting this originally, Josh)
- Resetting the Convenience Controller did not resolve the issue, and no drinks were spilled into the switches (thanks for the suggestions, Chris)
- We've got at least one other Phaeton with the same symptoms.
- Other ideas or suggestions would be greatly appreciated! 

Thanks again,

Peter


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## PowerDubs (Jul 22, 2001)

Do the buttons light up at night when the rest of the cabin lights do?


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## pdejong0 (May 16, 2011)

PowerDubs said:


> Do the buttons light up at night when the rest of the cabin lights do?


Confirmed... the lights on these two switches are illuminated when the rest of the cabin lights are lit. Thanks for your continued thoughts and ideas, Josh.

Peter


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## Paximus (Aug 26, 2011)

Hi Peter,

Will you be able to post a full scan?

Chris


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## pdejong0 (May 16, 2011)

Paximus said:


> Hi Peter,
> 
> Will you be able to post a full scan?
> 
> Chris


Not right away, Chris... She's with the technician (certified on W12 Phaetons). The last scan had no faults other than the suspension issues (low height and compressor related). 

Peter


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## toaph (Nov 27, 2012)

So how does one open the fuel filler flap if the drivers door button isn't working? Right before I left for my big road trip the trunk button failed. I can still use the key so I'm okay there. But then I experienced the same thing where a winter car wash froze the filler flap shut. I was able to pry it open with just my fingertips, but it was enough to make me uneasy. Now I read this thread and I'm paranoid the filler flap door button will fail too. I'm still 1400 miles from home. I could live without the stuff in the trunk but I'm going to need a few more tanks of gas to get home.


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## pdejong0 (May 16, 2011)

toaph said:


> So how does one open the fuel filler flap if the drivers door button isn't working?


http://forums.vwvortex.com/showthre...-(if-it-is-frozen-closed)&highlight=fuel+door


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## toaph (Nov 27, 2012)

Ouch! When mik15 said that he wasn't too bothered by the button not working I thought there was an easier way.


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## pdejong0 (May 16, 2011)

toaph said:


> Ouch! When mik15 said that he wasn't too bothered by the button not working I thought there was an easier way.


It's not really that tough... the panel covering the right battery (which includes the small netted cargo storage area for the red medical kit) pops off, attached by spring loaded clips... very easy. The actuation of the fuel door "plunger", at the top of the motor assembly, is also quite easy... especially after you do it for the first time. I use needle-nosed pliers, but you might even be able to do it by hand... sadly, it seems that my hands are too big for this job.

IN THE MEAN TIME... I am still hoping that SOMEBODY can please provide the REAL FIX for this issue, as I am tired of following this "work around" every time I need gas or wish to open the trunk from inside the passenger cabin. Somebody else has got to have had this same set of symptoms and knows the REAL FIX! Come on team... share the answer! ;-)

Thanks again,

Peter


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## mik15 (Dec 18, 2012)

just to confirm, those 2 buttons are illuminated but aren't operable! Regarding the fuel door, mine doesn't lock anymore, i assume the previous owner broke the pin that holds it locked because he couldn't open it anymore due to buttons failure, therefore i need to open it from outside sticking a credit card or with my bare hands! 

On the other hand i have other few buttons that do work, but aren't illuminated  ! Clearly the Phaeton has a mind of its own! Sometimes it shuts off/opens the sunshade with no reason whatsoever, all of the sudden, i couldn't set a pattern why is doing it  !


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## jkuisma (Nov 23, 2009)

> IN THE MEAN TIME... I am still hoping that SOMEBODY can please provide the REAL FIX for this issue


I had missed your post previously but I would be a lot of money on this: your problem is with the door switch unit/assembly. I had exactly the same issue but it was with the child lock buttons.

The fault is not with the individual switches themselves. Actually, there are no individual switches but the switch assembly has a single printed circuit board, on which all the switch contacts are printed on.

The individual switches are so-called resistor switches. This helps to rationalize the number of wires needed to couple the switch assy with the door control unit. In a resistor switch setup, several switches (in your case two) are connected to a single signal wire in parallel. Each switch has a resistor in series. The control unit can read the position of several switches by measuring the total resistance on a single wire. Blah blah, I don't need to get into more detail here. What this means in practice, is that a single failed conductor will render two switches inoperable.

I got fed up with my inoperative child lock buttons and I took the door switch assy apart. It has a bit stupid design. Any water dropping on the door handle (from an open window, from a door opened when it is raining) will find its way inside the switch assy and directly on the printed circuit board. In my unit, there were obvious traces of water infiltration. The individual conductors on the circuit board are really tiny (remember that the switches switch no current - they are for signalling only). I could not see anything obviously wrong with the conductors visually, but by measuring each conductor for the malfunc switches it was obvious that there was one which was corroded and no longer made contact. Soldering a "jump wire" was a 5-min job and the switch assy was very easy to put back together. Worked like a champ.

As I said, I would bet my money on this. Good luck!

Jouko


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## pdejong0 (May 16, 2011)

jkuisma said:


> As I said, I would bet my money on this. Good luck!
> 
> Jouko


Very interesting Jouko... thank you, and I will definitely look into this possibility! More later!

Peter


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## pdejong0 (May 16, 2011)

Jouko wins his bet! After removing the door switch cluster, it was clear that the printed circuit board had seen some water (or some kind of fluid) damage at some point in time. Based upon the corrosion, it did not look to be recent. While some PCB cleaning allowed partial / sporadic operation of both the trunk and fuel filler door, there was enough general corrosion that replacement of the entire cluster of switches was warranted. $106.87 on 1stVWparts.com for the left door switch cluster. Thanks for the feedback and recommendations!

Peter


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## PowerDubs (Jul 22, 2001)

*both not functioning: driver door switches for trunk and fuel door operation (2*

Check parts.com as they are usually cheaper.

Glad you found a solution.


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## Paximus (Aug 26, 2011)

> Jouko wins his bet!


So no cola down there then? 

Chris


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## Paldi (Sep 4, 2004)

Care to donate your old part to science?

I'm trying to do a switch move and arm rest swap on my Phaeton to 1. bring the window switches closer and 2. make it easier to close the door! 

I need window and trunk/gas flap switches to give to the guy who is going to fit the parts together!









How it looks stock...









RHD (English) passenger panel with door pull assembly Photo-shop-fitted to my USA LHD driver door. That's the plan!


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## PanEuropean (Nov 3, 2001)

Peter:

You can narrow down the "path of influence" for troubleshooting purposes by using the "Measured Value Blocks" feature of VAG-COM (VCDS) to determine whether or not the two switches are responding to physical movement when you lift either of the switches. By this I mean you can determine whether or not the switches are passing a signal to the controller indicating that the switches have been operated (lifted) or not.

Doing this will enable you to isolate the cause of the problem to the switch assembly itself (or perhaps its connection to the car's wiring harness) if you don't see a response to switch movement in Measured Value Blocks, or; it will rule out any fault with the switch assembly and wiring to the switch assembly if you do see a response when you lift a switch.

I can't recall (from memory) which controller's MVBs you need to look at to see if these two switches are responding to movement - my first guess would be controller 46 (central convenience), if you don't find the MVBs there, perhaps try controller 09 (central electrical).

Michael


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## n968412L (Apr 23, 2009)

pdejong0 said:


> some water (or some kind of fluid)


Has to be cola!

But very glad it's sorted!

Regards
M


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## pdejong0 (May 16, 2011)

Paldi said:


> Care to donate your old part to science?


Would be happy to help, but please take a look at the condition of this part... it's really in bad shape..

https://www.dropbox.com/s/e6lniw1beba3vlz/2013-02-25_1616.jpg?dl=0


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## Paldi (Sep 4, 2004)

Ah... my interest is in the switches themselves and the black surround that holds them. I don't care at all about the circuit board. I need a "pattern" to help the guy cut the leather on the armrest and form a fitting to hold the switches in place.


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## jkuisma (Nov 23, 2009)

Glad to hear you got it sorted out, Peter! I was not spot-on this time as your corrosion seems to be quite severe and involved both buttons. My switch assy was otherwise intact, just needed one jump wire. Good to know that the part is relatively affordable anyway.

BR Jouko


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## pdejong0 (May 16, 2011)

Paldi said:


> Ah... my interest is in the switches themselves and the black surround that holds them. I don't care at all about the circuit board. I need a "pattern" to help the guy cut the leather on the armrest and form a fitting to hold the switches in place.


OK, and happy to help in this case. I'm a big fan of science. ;-) Will PM you for a shipping address.

Peter


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## pdejong0 (May 16, 2011)

PanEuropean said:


> You can narrow down the "path of influence" for troubleshooting purposes by using the "Measured Value Blocks" feature of VAG-COM (VCDS) to determine whether or not the two switches are responding to physical movement when you lift either of the switches.


Thank you, Michael. Back in the original post, I tried to communicate that this had been done... and that the switch operations were not being detected by VCDS... however, my terminology was poor. Thanks, as always, for the education here!

Peter


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## Paldi (Sep 4, 2004)

Thanks Peter! 

I'll let you'all know how it goes.

If anyone takes their USA spec driver side interior door panel off, I'd like to know if there's a place for the bolt securing the top of door pull to screw into.


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## Silky6053 (Dec 3, 2012)

Hi Guys

Last week I discovered my fuel filler door wouldn't open. I managed to release it by pulling the actuator near the rear battery and was able to refuel.

I've done a VCDS scan and there are no faults shown. I suspect it is the fuel filler actuator switch in the drivers door. Reading this and other threads people have repaired or replaced the circuit board under the switch.

My question is : How do you remove the switch assembly from the door. I've prised and prodded but I cannot get it to loosen. Does the door card have to come off? Or can it be done without.

Any assistance will be greatly appreciated.

Thanks

Glynn


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## Paximus (Aug 26, 2011)

Hi Glynn,

Did you manage to check the status of the door switch using VCDS? MVB 024 in the central convenience controller at address 46 should show its status (if I understand Michael's text properly):

024,0,Requests related to rear window heater and gas tank flap
024,1,Rear window defrost, button depressed,Possible display: yes/no
024,2,Rear window heat, relay stage 1,Possible display: yes/no
024,3,Rear window heat, relay stage 2,Possible display: off/on
*024,4,Gas tank flap open, button lifted,Possible display: yes/no*

Chris


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## Silky6053 (Dec 3, 2012)

Thanks Chris

I read and re-read Michael's text, but being a simple Manchester boy, I didn't entirely understand.

My use of VCDS has been to do auto scans and the odd adaptation to change behaviors, but I'm no expert.

I'll have a further delve with VCDS tomorrow and see where I get to.

I thought, that if the switch assembly came out relatively easily, I could do a physical check of the circuit board. I suspect there may have been water ingress, but other than the fuel switch, other switches in the assembly are fine.

Thanks

Glynn


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## pdejong0 (May 16, 2011)

Silky6053 said:


> My question is : How do you remove the switch assembly from the door. I've prised and prodded but I cannot get it to loosen. Does the door card have to come off? Or can it be done without.


Hi Glynn,

See this thread about accessing the front driver (and passenger) door interior for a speaker wire repair. The same interior door panel removal and assembly procedure applies for accessing the driver door switch cluster. 

http://forums.vwvortex.com/showthread.php?4564768

It looks complicated, but it really doesn't take much expertise or time. Hope this helps you to get your issue resolved.

All the best,

Peter


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## Silky6053 (Dec 3, 2012)

Thanks Peter

I'll have a look tomorrow (in UK weather dependent!). Been to the US many times and have family in Boston. Hope to do a tour of the deep south next year.

Thanks

Glynn


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## pdejong0 (May 16, 2011)

Silky6053 said:


> I'll have a look tomorrow (in UK weather dependent!).


Good luck, Glynn. FYI, and since the link to the original photo is broken, here is what my defective switch cluster circuit board looked like:

https://www.dropbox.com/s/e6lniw1beba3vlz/2013-02-25_1616.jpg

All the best,

Peter


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## Paximus (Aug 26, 2011)

> the link to the original photo is broken


Hi Peter,

Which link was broken? Perhaps I can fix it.

Chris


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## pdejong0 (May 16, 2011)

I think the problem was at my end, Chris... removing the photo file from my Dropbox share folder by mistake.


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## Silky6053 (Dec 3, 2012)

Hi Guys

Did the VCDS block thing and it showed the switch wasn't actuating. Thanks Chris.

Got the door panel off. Thanks Peter.

Problem now is how to remove the switch assembly from the door card. Took some pics.

http://gofile.me/6iNam/0Gsaf8vn


The switch circuit seems well covered. Any ideas how to extricate it please?

Thanks 

Glynn


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## ravenflies (Oct 31, 2013)

This is what ElsaWin shows:









/Lennart


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## Silky6053 (Dec 3, 2012)

Thanks Ravenflies

I'll have a look tomorrow.

Glynn


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## pdejong0 (May 16, 2011)

Glynn,

Now that you are that deep into it, all you need to do is a bit of gentle prying and coaxing to get the smaller sub-assemblies apart and reassembled. If I could do it, I guarantee that you can (!). Sorry I cannot recall the details at this time, but I think you will find a way if you look at the assembly carefully and determine what is possible and what is not. 

Josh may be able to chime in, as he has probably performed this operation more than any of us.... see this thread: 

http://forums.vwvortex.com/showthread.php?6740571-My-W12

BTW, if you'd rather go used vs. new, I see there are about a half dozen used switches available on your side of the pond via eBay... most in Germany. Here is an example:

http://www.ebay.co.uk/itm/window-lifter-switch-front-left-VW-Phaeton-3D2-3D1959857B-/281725190679

Best wishes,

Peter


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## Silky6053 (Dec 3, 2012)

Thanks Ravenflies and Peter.

Took the switch assembly out today and then took the assembly apart. Expected to find some damage, but the circuit board was clean with no obvious water damage. Cleaned all switch surfaces and re-assembled. Still doesn't work!

Recoded convenience controller 46. No joy.

Now ordered used switch assembly from Ebay. At £17 it won't break the bank but will come from Germany.

If that doesn't work I'm at a loss.

Thanks for everyone's help.

Glynn


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## Silky6053 (Dec 3, 2012)

Al now working with replaced switch assembly. £17 plus postage well spent. Having re-assembled the switch and door card I disassembled the errant switch assembly. Just to satisfy myself there was something wrong.
Using a magnifying glass I traced the circuit from the fuel door switch to the pin outs to the block connector. The two output pins for the fuel door had arced and weren't switching. A continuity check confirmed this. A quick scratch with a small screwdriver and a clean and the switch was brought back to life. Should have found this first time but was actually concentrating on the switch end. Hey ho. Now I've got a spare.

Thanks for group's assistance.

Glynn


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## pdejong0 (May 16, 2011)

Congrats, Glynn... every day is an opportunity for learning. With a Phaeton, maybe every hour... ;-)

All the best,

Peter


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## ravenflies (Oct 31, 2013)

Good News!  Always good to see a problem in a thread marked as solved. :beer:

/Lennart


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## Silky6053 (Dec 3, 2012)

Anglo / American / Swedish co-operation. You can't beat it!

Thanks again

Glynn


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## searay240 (Mar 21, 2016)

Guys sorry to drag up an old thread, however, I'm having the same problem as described by Peter with my daughter's Cayenne:
Both door switches do not initiate their respective functions (trunk won't open and fuel filler door will not open when the switches are triggered) with all of the same symptoms.

I've taken both apart and both had significant corrosion. I replaced one with new and did not replace the other (yet). With that said, the new switch still does not work. 
Is this a matter of both switches must be in good working order top complete the circuit or could it be the comfort control systems still may require resetting?
Thanks
Rich


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## Paximus (Aug 26, 2011)

Hi Rich,

In the Phaeton, it is the printed circuit board holding the switches that can corrode if damaged by a soda drink spillage, for example. This is known to stop the switches working, even if they are good.

You might have some luck using a VCDS scanner to try and see what faults remain. Although the Cayenne uses some of the same controllers as the Phaeton and Touareg, Ross-Tech don't actually support its use. I would guess it might communicate in this instance though.

The MVBs (Measured Value Blocks) in VCDS tell you in real-time what the switch states are (as seen by the controller), so it's immediately obvious if the controller is getting the correct signals from the switches. That is, if the MVB labels are not too different between the car versions.

Chris


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