I have been having an intermittent power seat adjustment issue. Did quite a bit of searching here and elsewhere and mostly found dead or unanswered threads plus a few "I replaced the switch but it didn't fix the problem". However the problem seems to be common.

So I decided to dig in myself in hopes of fixing the problem and possibly posting my findings to the community.

Symptoms: Random inoperable seat adjustment...sometimes it will recline, but not come forward, sometimes 2 of the 3 adjustments won't work, other times all of them will stop working or make very quiet "stepping" movements. Most of the time it just works fine. It seems the worst when the detailers move the seat around alot.

I started by removing the seat switch:
-Raise seat to it's highest "up" position (that is if it's working)
-This helps you see the two tiny #1 Phillips screws.
-Remove them
-Remove the entire switch by gently lifting the switch away from the seat to release the two top hooks. The cable will still be attached but there is some extra working length built in. If you are just replacing the switch (which I just might have to do at the end of this experiment) stay tuned because the cable routing looks like a b-tch.
-The "switch" (which we find out later is actually 8 switches) has a back cover.
-Gently pry off this cover, it has 12 or so little finger catches. See picture, the cover is the flat black piece.


-Cut the ty-wrap that holds the cable to the switch body.
-The circuit board can now be lifted out and from the switch cover.
-See picture of circuit board, still attached to the seat.


Findings: The seat "switch" is really eight little switches soldered to the circuit board. In this configuration you can actually cycle the switches and everything seems to work a little "better" meaning I can move the seat around. Usually.

I was pumped, and then dissapointed, thinking that the plastic toggles that cover the switches had just worn out. Wrong. Seems the circuit board, all on its own, has the same problems...sometimes one but not all work, sometimes none work.

Conclusion so far: It's not the switches or the switch cover. It must be the cable or a loose ground...so no need to actually open up your switch...meaning the DIY just got alot simpler. But....

If you are just plain curious it's pretty easy to take this thing apart, but getting it back togther requires that you duct-tape all of the plastic toggle switches in the "center" position in order to get the male switch tips to slide into the female toggles.

On to checking the connections...

With the seat raised to full up remove the front plastic cover underneath the seat. You will see a plug buss-bar for all of the seat connectors. I just verified that they are all seated, thinking that the seat motion might be making one of the connections loose. No joy, problem still persists.

Leaves me with either a broken wire inside the switch harness or a broken ground wire somewhere under the seat. Moving the seat seems to make the problem appear as well as disappear. I do know Porsche issued a TSB on a cable pinching issue. I saw a small thumbnail of the document, but for some reason my browser won't let me open it.

Next Steps: Remove the entire switch cable, unwrap electrical tape and look for a cut wire. If that's not it remove the seat entirely and look for broken ground wires.

Stay tuned.

 

Have you used a millimeter to confirm power at the switch? This way you know which side to look at.

 

Same car. Same problem sort of. My seat is all the way forward. Seat moves in all directions except back. Seems like it wants to. It travels back and forth about 1/2 inch. This is the first time I have had this problem. Have you had any luck finding more info, or finally resolving it.