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Having an intermittent issue with air coming out of the left and right side vents in my 2004 CS.

Only front A/C unit installed. I do not have a durametric connection cable.

I have looked and looked but haven't really found any DIY regarding the replacement of the Servo Motors.

Assuming that it could be two things. Either the A/C controller or the Servo Motor Flap Actuator.

Since it works occasionally i am going to put my money on the Flap Actuator. Has anyone replaced one of these? I will gladly do a DIY write up if i can end up doing it myself.

It looks like i need to do the following…..

Removal of trim under dash.

Removal of the immobilizer.

Removal of the electrical system control unit.

Is it possible to change a flap actuator without having to remove the last two items?

Looks like there is 5 actuators. Which one controls the side vents?



Edited by seafeye
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I don't think so, I will double check later today. Yesterday driving the car air was coming from my left vent. The day before it wasn't. Maybe someone here has replaced the actuator and has the cliff notes on it.

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I changed most of the motors because of some cold/hot air issue and constant noise from the dash.

passenger side was easier, driver side especially the A and B were really tight. DIY possible but nasty. you need to remove the kessy unit and other control boxes.

Edited by royxaxa
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  • 1 year later...

I climbed in my 04 Cayenne this morning and turned on the heat to maximum.  Hot air blew from the passenger side and cold air from the drivers side vents.


I have been combing the forums today and all I can come up with is that the issue may be a "controller", "servo motors" or both.


Can anyone weigh in on this?  What is the "controller", what exactly are the "servo motors" called?


I cannot find descriptions, part numbers or DIY directions on changing them.  I would like to price them out to consider DIY but I am stuck.


someone help please... :eek:

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I'm gonna jump in this too as I've had no luck as my A/C flap actuator which defrosts the front windscreen does not direct air to the windscreen no more, when I press the windscreen defrost button I can hear the air going but is blocked and not going up toward the windscreen.


I think it would be a good idea to start a thread on a solution to these A/C flap actuators.

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I compiled a list of the VW part numbers for all 10 motors that are on the front.  Behind the dash, the HVAC system is the exact same as a Touareg and Q7.  I take no responsibility for the accuracy of this info. The reference numbers are to the Porsche parts catalog, the prices are from ECS Tuning (cheapest place I've found the parts at).  I think this covers the 2-zone and 4-zone, but am not sure on that.  From what I can tell, the whole dash needs to come out to get at all of them.  I don't have a problem taking off the lower pads and pulling the stereo, but if the upper dash needs to come out, I might think twice about doing this myself.  


Also - does anyone know why these fail?  Are they physically binding up somehow, or is it just the circuit boards that somehow go bad?  If they are physically binding up (which it sounds like they're doing), is there some type of lube we can put on them to keep that from happening?  It's $750 to replace all of them, $665 if you subtract the fresh air flap (which is really easy to replace).  That price sucks, but it's the labor to get back there that sucks even worse.  And, to do that multiple times to keep fixing these if you happen to just replace them as they fail will start to add up.  Would like to just go in and replace all of them if I could.  There are an additional 8 more in the back if you have 4-zone, but I'm pretty sure those are a lot easier to get at.




VW Part number, flap description, Porsche Reference Position Number, ECS Price


7L0-907-511-AB front, defroster vent flap (1) $69

7L0-907-511-AD front, center left vent flap (3) $69
7L0-907-511-AE front, left vent flap (2) $70
7L0-907-511-AK front, left mixing flap (7) $78
7L0-907-511-AJ front, left footwell flap (8) $92
7L0-907-511-AL front, right mixing flap (10) $78
7L0-907-511-AM front, right foot well flap (11) $69
7L0-907-511-AG front, right vent flap (15) $69
7L0-907-511-AH front, center right vent flap (16) $69
7L0-907-511-AQ fresh air flap (13) $86
Edited by wrinkledpants
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  • 3 months later...

This subject comes up every month with no practical solution, the expense and time to fix it is to great compared with the results . Unless you live in the Arctic, most of us with the problem just live with it. We have (3) 04 Cayennes in the family and all 3 have this intermittent problem.

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  • 9 months later...
  • 3 weeks later...

I am with you on this. 03 Cayenne S. Left side drive (US). Have heat on drivers side but only cold on passenger. Is there seriously no one that has info on what to do, where these parts are or how to get to them? I will do a complete write up with pics if I can get some info to get me started. Anyone???

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Here is the picture image to go with my part numbers I've listed above.  From what I've heard - you can reach all of these from the lower side if you don't mind working in confined spaces with some scratched up hands.  


You can download the Porsche PET catalog for the 955 from Porsche themselves, FYI.  




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Thanks for this diagram. I have removed the glove box and can see some of the parts on the right side of the pic. Do I need to pull the stereo/nav/heating and ac controls out to be able to access this? Or does the whole center dash pull out somehow? This is a U.S. left hand drive model 955 S. Thanks,

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  • 2 weeks later...

I have just replaced a few in my car (RHD) but the procedure should be the same for you.

See my post http://www.renntech.org/forums/topic/44003-air-cond-blowing-cold-on-right-hot-on-left/

It is motor #10 right hand temperature mixing flap motor you need to change.

You should be able to to change yours without taking the whole dash out though.

If you're up to it bite the bullet and pull the dash and fix them all.

I had to fix the defrost flap motor and you can only get to that by removing the dash.

Good luck!

Edited by darrinsmith
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Thanks for the info and link. Do I need to have a durametric to reset the servos or "prepare" this for disassembly? Also you mention a repair manual. where can i get one to help me out on this. I am having a few problems on getting some parts removed.. like the temp control module above the ash tray. I see some repair manual downloads on the internet but I don't know if it is a scam. I also need to dig into a heated seat and steering wheel issue while its apart.. Any help is very appreciated!

Also , its LHD.

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No you won't need the durametric to set the servo's for disassembly as the software can't do it anyhow.

I really do recommend you buy the software if you want to work on your car.

It's really helpful to know which servo's are actually broken, as you can test them all, plus the blower motor etc with it.

Plus you can trouble shoot all the other gremlins in the cayenne's

As far as the manuals go, if you ask "porschelibrarian" on this forum he can get you a copy, they are LHD versions so will suit you car just fine.

To get to the lower servo's you need to remove the A/C controller, ashtray and PCM, then remove the "carrier" and then the surround.

It really helps to have the manual



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  • 5 months later...

Hi All,


I'm new here, but found this thread very helpful.  I thought I would sign-up and share my experience.


My 2009 Cayenne V6 (left hand drive) has been blowing cold air on the driver side and warm air on the passenger side for the past 2 years. All passenger side vents (center right, far right near the door, and rear center right) would blow the same warm air not matter what.  With summer coming up, I thought I better revisit this issue.


After reading a bunch of forums on this issue, I came to the conclusion that  -

1) I have the 2 zone A/C system (meaning I have less flap motors than the 4 zone)

2) it seemed to me that the front, right mixing flap was the issue.


I began by taking off the lower passenger panel - its 1 screw and the glove box and a piece of triangular trim on the passenger side of the centre console (it just pops off). Once those were off, I could see 2 flap motors. One was right where the lower panel was and easily accessible - it was attached to a white plastic arm that it moved back and forth. I turned the car on and played with all the A/C setting and could see that that motor was working - it moved the white plastic arm back and forth.... (note, when I turned on the car, there were a bunch of dash warnings including low oil pressure - they went away once everything was back together)

The other motor I could see was not as accessible. It was more towards the center and higher up. It was to the right side of the nav screen, inside the dash... I could only assume that had to be the front, right mixing flap.


I decided to take a shot and changing it. I ordered:

  1)  7L0-907-511-AL front, right mixing flap (10) - from Volkswagen. This is the equivalent Touareg part.

  2) this ratcheting screwdriver tool: http://www.amazon.com/03044A-4-Drive-Mini-size-Ratcheting-Screwdriver/dp/B000XYOUS6/ref=sr_1_1?ie=UTF8&qid=1464195744&sr=8-1&keywords=Neiko+03044A+1%2F4-Drive+Mini-Size


The flap motor only has 3 screws.. they were tough to get out. It took me about 1-1.5 hours to unscrew those 3 screws... most of the time was spent finding the right position to unscrew the screws.... and there was not a lot of room to turn the ratcheting screwdriver (a regular screwdriver would 100% not work). So once I would get the torx bit to connect with the screw..I had to unscrew very slow (shallow turns) and often drop the screwdriver.  Annoying... and frustrating.. but keep at it.


Getting the new motor back in was a bit easier and I had figured out the best position to deal with each of the 3 screws. Make sure the motor connect properly to the white piece that it controls. putting the new motor in was probably about 30min max.


I put back the trim piece, glove box and lower panel and turned one the car... and cold air was blowing out of all vents!


Glad that is dealt with!.. I almost have no problems with my Cayenne now...  I suspect the rear hatch struts are due to fail next!





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  • 3 months later...

Bringing up an old thread as I think I may have something to offer. I've been searching for info on this problem for the past week and currently have my dash ripped apart - which is amazingly simpler than I expected. If anyone has questions about pulling it apart, feel free to inquire. 

Anyways, I have not come across anyone offering a reason for what is wrong with the actuators, so after I had my footwell actuator free, I let it dangle (while electrically connected) and fired up the truck (didn't fire up the first time because the KESSY unit was disconnected). I could see the actuator was buzzing away, but the arm wouldn't move. After taking it apart (see photo) and manually spinning the worm gears by hand, I verified that nothing was seized and I already knew the motor seemed to be working from the buzzing. I then reconnected the actuator without the cover in place and I could see that the worm gear coming directly out of the motor was spinning, but not engaging with the straight gear below it (top right corner of the photo). After pushing down on the worm gear a bit it engaged well and everything was working again. 


I have only had the Cayenne for several months and I could hear the actuators acting up on the test drive. The seller played dumb saying he had never heard it before (can't know for sure if that was the truth), but I suspect that over time the motor may burn itself out cause it keeps trying to open or close the arm. If that is the case, if you don't fix it soon, it may need to be replaced, but I plan to put mine back in the car and save the $150 for a new one.

hvac actuator.jpg

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I bought a set of actuators off a 2008 before I dug into the left side.  Four days later after replacing five of them, my air and heat all work on the left side, but my left arm doesn't.  Two sessions of physio for a mildly compressed neck vertebrae and things are improving.  


Anyway, I learned a few things:


1. The 2008 actuators (below) seem better engineered than the '04s, seen above.  So I switched them all on my LHD '04 S.  When I removed the originals, one actuator, "D", the one closest to the driver's seat on the bottom plate, had its plastic shaft broken off.  This might have accounted for the annoying and constant clicking which persisted on the left (if the heat setting was anything but LO) after I'd fixed the click on the right in an earlier adventure.


2.  Don't disconnect the KESSY.  It can rattle around under the gas pedal until the job is finished.  The instruction in the manual to remove the plastic housing over heater pipes on the driver's side -- that's a cruel practical joke.  Ignore it.


3.  I connected hose-clamping vice grips to the little ratchet and the T20 bit.  Along with a long T20 screwdriver, that worked to get the two plates out, but then the problem came up in getting the screws back in.  Eventually I learned to dip the bit in Gorilla Glue (woodworking variety), push the screw on firmly, and then cook it into place with wooden matches.  These welds held well enough to start the screws, especially with leverage from a small paint-stirring stick.  The brittle glue broke free easily after the screws had started in their holes.


4.  Do not under any conditions neglect to attach the wiring harness to D before you push the lower plate into position.


5.  Setting the arms for installation is tedious, but easy.  With a small 12V supply, the pinout is 1,2 to move the arm one way, and 2,1 for the other.  1,2 are off by themselves. Line the arms up with the diagram on your computer screen.  Grease them.  The old ones on my car had hardened grease impeding their operation.


6.  This was a hellish job, but it's great to have the climate control working.  Winter is coming.






20160924_095101-4 copy.jpg





Edited by Rod Croskery
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