Star211

Have a periodical issue. Sometimes when driving, seat suddenly deflates by itself and none of the buttons for lumbar or dynamic/pulse work on either passenger or driver simultaneously. Have to turn of car and take out key and start again and then its fine.
Anyone experienced this before?

should specify that neither dynamic or pulse has been active when this has happened. Only standard side support.

sjc246

Probably a leak. You should try to find it asap because if not, the PSE pump will wear out or melt sooner or later. Everything stops working because the car is automatically disabling the pump to prevent overheating, but eventually you will do damage.

Star211

Well, still have the problem. Can not find any leak. The pump will run for a few seconds and then stop, seem to work as it should. However after some driving, the seats turn off, no reaction from the buttons on the seat. Have to restart the car. Has anyone experienced this?

Ls1toAMG

I would say you have a leak somewhere. It will shut down for safety. More than likely it's a bad blatter in the seat

One member that may know about this is bbirdwell he is extremely knowledgeable on this platform

Star211

You may be correct, but it seems it may be a control module? I get this fault only on left lateral support air cusion for driver seat... any inputs appreciated

Star211

Did a manual test as well, pressure actually increased from 285 hpa to over 300, wich is max. So far it serm it is a valve leaking. For info to others, not always air cushion even though fault code indicate it.

7Krys

Hello,
I have the same problem with my CLS 55. The air pump is new and was replaced at the dealership.
Batteries seem in good condition but I suspect a leak in the system.
Did you resolve your problem? I'm taking my car to MB tomorrow for that.

Star211

I have not fixed the problem yet, however, I strongly suspect the valve box in the seat back because pressure increases in the air cushion. But due to the price of a new valve block, I have not yet replaced it. The part seems to have been updated as it has a new part number.
Please let me know what your problem is...