AC Control Reset
 

Courtesy of Benzworld. Worked 1st time on my S500L.
1) Set the car in park and turn on the engine, hold the rest and particle filter buttons down together for about 5 seconds (The screen will show searching)
2) This screen gives you the fault codes. If you're curious, scroll up and down to see them using the temp up and down switch.
3) Pop out the left auto vent button and right auto vent button.
4) Now press the the left button in, and then the right one. The system will reset.
5) Turn the car off, wait a minute, then turn it back on again. If you don't have any further problems, the light should stay off. (If it comes back on again, you have more things to do)

Dear PorschePlus,

Thank you for the highly informative description on how to reset the AC Control Rest feature. Worked like a charm for me, as my S55K went into AC off Mode today for the 1st time in it's life. She also spends most of her days In-house.

Incidentally, the entire 4 zone Climate Control cooling system aswell as all four of my seats seem to blow out cool air @ a much rapid rate.

Many Kind Regards,

Sher S Judge - Johannesburg Houghton - South Africa.

THANK YOU SIR !

It worked on my 2001 s350 too. The thing that you should keep in mind is, before you hitting two button simultaneously, please turn the air conditioning on too. No matter what it is working properly or not. Thanks again