Hello guys i'm new here, just got my w216 and loving it but yesterday the seats air functions stopped working and this happens now 2-3 minutes after starting the car, scanner indicated leackage and the pump working correctly, i checked the tubes under the seats but they seem fine. Hope you guys can help and thanks in advance.

 

moved to W216 forum...

 

Problem most likely is failure of the air bladders in one or both seats. I had this failure while still under an aftermarket extended warranty. The warranty company pair over $6000 to fix both seats. The passenger seat cushion needed to be replaced at a cost of $5000.

 

Thanks mate this is what i thought, i detached the passenger seat from the system and now drivers seat works fine, so the leak must be from the passenger side. Hope to fix it soon

 

i have tried cancelling the passenger seat from the system and keeping the driver's one to check if the leak is from this side but problem persisted so i tried the same thing with driver's seat but same thing now i have hope that seats are fine (which is the costly part) and want to look into the tubes running to the pump but need help doing so!
Hope anyone can help with the procedure. Thanks

 

I have an 07 CL550 with leakage also. Found under both seats a air tube that is broken and blocked them both off. Looks like it can be a common issue. Under seat at the rear. Still havnt taken the seats out to see if I can repair it. My lower seat cushions do not inflate on the sides. My active seat back bolsters work for about 5 mins and shut down too. This is the pump detecting a leak and the system shutting it off. The seat bladders are the wear item here. I did read some service bulletins and only one seemed related and talked about a problem with transistors in the valve unit and a procedure flow to isolate the problem. I also read that if you remove the seat upholstery on the bottom seat cushion you can separate the air tubs and isolate the leaking bags. I havnt done it yet so dont be mad if this info is incorrect in any way.
When I get time to pull my seats out Im going to to diagnose witch bladders are leaking and simply block them off so the remainder of the system will operate. I like the active seat function and want it working full time. For those reading that dont know what that is, it is when you make a turn the opposite side left or right seat bolster inflates to hold you in the seat better. Its actually cool and secures you in the seat. Based on what happens when I inflate various bladders. The ones that dont work are the ones with leaks etc. For example I go into the command center and try to fill my lumbar support and it wont fill. Same with a few others too seems the only ones left that actually work are the seat back sides. So in short Ill block everything but those and get the system working with just the 2 sides. Once I know what it needs Ill go by the dealer and see if any of it is still available. Im sure it wont be cheap either since nothing on this car is. But what a car huh? I love it and if I can get it all perfect I will.