Both heated seats won't turn on sometimes. Then they begin to work for a while but then turn off, they go back on without pressing the button.
If I press the air condition button I can get then to turn back on.
Anyone have a problem like this before?

 

There is a module under the seat and in the driver's side door, at least for the adaptive sport seats. I have had to have both replaced, due to water leakage or other, unknown issues. Strange things can happen with module problems, sometimes in unrelated systems.

Intermittent electrical problems may be hard to track down.The car may need to be plugged into the dealer's PIWIS for diagnosis. Expect charges for finding the defective part and replacing it to be up to several hundred dollars.

 

I know the heated seats will automatically turn off when the interior reaches a certain temperature. So if you try to turn the heated seats on when your car is a certain cabin temperature the button will light up, but immediately go out.

 

When they shut off, I pressed the button and they would not turn back on. When I tried later they went on. At certain times when they shut off they turned back on without pressing the buttons again. It is very strange.

 

At that point they have reached that maximum temperature that Porsche allows the heated seats to get. They will then shut off until they have reached the allowable temperature to turn back on without pressing the button. Hope this helps, I know a lot of Cayenne owners have complained about this issue but Porsche says it's normal.

 

This is NOT true in my '06 997 and my wife's '05 Boxster. Once I turn on the seats they stay on until I turn them off or take the key out of the ignition. Maybe this is a later year "feature"?

Sounds like something is wrong.

Matt

 

Try unplugging your battery to reset the module, better yet if the battery is 4+ years old, change it. Might be a voltage fluctuation issue.

 

My 2007 997 s is doing this intermittent issue as well. Any resolution? Don't think it's from reaching a temp as it does it if I try without ever using them. Seems to not work after long drives, over an hour or so. Then is intermittent.

 

My heated seat problem cured itself, not sure how.