The side rest adjustments does not work 90% of the times. The active drive adjustments i've only gotten to work once so far. Finally the lumbar adjustments work like 70% of times and seem to deflate on it's own after extended periods of driving. Massage and other features seem to be working fine. Any ideas what could be wrong b4 I resort to the dealer? BTW this is the driver's seat of a w221.

Thanks in advance,
Rasheed

 

I just brought my 2009 S550 in yesterday for the same issue and a few others. The driver side rests will not hold air and deflate immediately after attempting to inflate them. The dynamic seat function also does not work due to this as well as the seat bolsters and lumbar.

The setting on the COMAND goes from 20 down to 0 by itself and then I cannot attempt to inflate the seat again unless I turn the car off and back on. Not sure if it's the seat or the COMAND software, but if your car is under warranty you should certainly bring it in to have it corrected.

 

Dealer called me today to let me know that the driver's seat in my 2009 S550 has a hole in one of the pneumatic cushions and they will be replacing it. Not sure if you have the same issue but you should have it checked. Would be interesting to know if this is a systemic or isolated issue.