ted8porch

The A/C and heat both work, but the vent controls don't seem to work. The defrost function doesn't work at all, so the vent selection controls are not working. This car uses electric servo's for flap control.
I can't seem to find any info on this system, like a parts diagram or anything. There is a control unit, not sure where that is located? I want to start with the defrost servo, since I know that doesn't work. Not even sure how many servo motors there are.

Is there any info available for replacing the vent servo control motors?

Pelican has instructions for replacing the temp control servos, but those seem to work.

Thanks

phatz

Have you seen
https://rennlist.com/forums/cayenne-...nt-servos.html

hatchetf15

OP - Also check a post on Renntech…search “A/C Flap Actuator”. Good luck.



HVAC box ghost in background

ted8porch

I ordered a set of slightly used servo motors, assume number 1 isn't working. I assume, the the bracket with 1, 2, and 3 is on the left side of the assembly.

Wish there was more instructions available, but maybe it won't be to difficult. In a few days it will be warmer and I will then have the batch of used servos. Maybe it's fairly easy to access the problem, will find out.

Not sure if the defrost flap control is the only defect, will have to see if there are any codes. I assume the controls work, when the defrost is selected, it sounds like a second fan turns on at high speed, but nothing comes out of the defrost vents.

This is a 2008 GTS, so it maybe has the updated servo motors?

Harry Apps

You can download (free) the correct parts list (PET) for your car at: Porsche Classic Genuine Parts Catalog - Porsche USA. Then use the page numbers above to trace your servos.

ted8porch

Thanks, a parts diagram should be handy for future work.

Back when I had a 928 I bought the factory service manual, all 9 binders, but the price of that seems to have gone up. So I don't have much for tech manual for the cayenne.

TED

Klaird928

Do any of the servos work? You can watch them move while laying in the floor looking up. You have to remove the console side panels, the lower dash covers and a computer module or two. It is possible to change out the servos, but it is really difficult to get the top ones. If I recall the servos are all a little different. Before you replace it you should unplug the existing one and plug in the new one before trying to replace it just to make there is no other reason the servo is not working.

Each servo is held on by two torx screws and a blue electrical connector.

ted8porch

Thanks for the pictures, yes the plan is to plug in and test the used replacement prior to installing. I think I got a really good deal on a set of used servo motors. Without really knowing what the issue is, didn't feel like buying a new one, they are not exactly cheap. Once I figure it out, I might then get a new one.

theprf

My defrost flap servo is defunct, I can hear it cycling continuously and it shows an error in PIWIS.
I looked up under there.... does not look easy to get at. So it's still defunct. I do wish I could close the defroster and get the heat to the footwells.