I saw a lots of great informations, figure I'll ask it here. Hope I come to the right place. :-)

My 2011 S550 (48000 miles) displays the yellow Airmatic "Malfunction" with an up pointing arrow after the car parked over night, sometimes, not always. This has been going on and off for over a year now, the dealer checked it 14 month ago, said "5111 Aromatic Pressure Sensor Implausible." and there's a "Loose connection". "Secured Connection and Fault Code Gone".
After a few months, it started to happen again.

Here're the 3 situations:

1) Both front suspensions are about 1"~1.5" lower than normal after parked for a while.
If the front doesn't lift up after engine starts, the "Malfunction" displays.
(But after a 10~20 minutes drive, AND restart the engine, it lifts up and "Malfunction" display off.)

2) Front is 1" lower after parked a while, but if the front suspension starts to lift up after engine started, there's no "Malfunction" display. (I step out the car and watch it lifts up)

3) Sometimes the front didn't drop down that 1" even over night, and no "Malfunction" will display after engine starts.

Here're two questions:

a) What could be wrong with the warning display? (Situation 1)

b) Does the front suspension supposed to lower about 1" after parked for a while? (Situation 2 & 3, which one is normal?)

Any help would be highly appreciated.

Best regards.

ps, sorry for the "Aromatic" by the automatic spelling correction.

Aromatic? Lol. That actually is an option on the w222. And an autocorrect brain fart feature on your posting device

Now on the airmatic (not to be mistaken with aromatic) issue- you have a leaky shock or valve body. If it goes down some times and not others I imagine it is a valve body but that is rare. It could be also a snesor that acts up on occasion.

If car is throwing errors it needs to be read

your car should not drop while it's sitting. this indicates a leak somewhere. Could be a leaking strut, valve body, line, etc. If you still have warranty, you need to get the dealer to diagnose it asap. This problem can get expensive in a hurry...

here's a good article for you to read

http://www.import-car.com/mercedes-b...c-suspensions/

Thank you guys for your advises, I had it checked by the dealer and it was the faulty valve block sends signal to the Airmatic control unit and makes it look like the control unit was at fault. Dealer had to put in a new control unit to test/read it, then switch back to my original unit after they replaced the valve block. At lest that's what the service adviser told me.
$520.65 parts and $328.88 labor.