Something to keep in the back of your mind. My A/C stopped working, 2008 Cayenne S, and after some frustration and a lot of reading, it turned out to be my key FOB. Yes the key has a memory, so if you use the economy setting, it turns off the A/C compressor. Every time I dropped the car off because the A/C wasn't working, I left my wife's key with it and she doesn't use the economy setting, so the A/C worked fine for the garage. I guess the economy setting really isn't very economical for me and very generous to the garage.