2015 C400 4Matic

Been searching but most the problems I’ve found don’t match mine so here it goes. Last month I had my right rear airbag replaced by Mercedes. It was leaking for a bit prior to getting the repair done for a bit. Got it fixed all seemed fine.

Just recently, about a month later, I went out to my car in the morning and it seemed fine, but it was dark so might have been already low. Pulled out, got around the corner, and got the STOP, CAR TOO LOW message, managed to limp home doing 10km/hr. Car will not rise at all.

Suspected the compressor, but it runs when car is started, vehicle says “Vehicle rising” compressor runs but no lift, then stops and I the get the STOP, car too low message. Have the vehicle now up on blocks/stands to diagnose. Can’t be put onto flat easily, the wheel wells were touching and the car doesn’t want to roll.

Having all four corners drop and no action whatsoever makes me suspect it’s not a single strut/airbag, but I could be wrong of course. I am trying to learn as much as possible online but most people have one side/end drop or all drops overnight but inflates when started.

When I pulled the harness from the compressor I noticed a bit of corrosion in there. The compressor still ran, but could bad wiring prevent the compressor from producing enough pressure to even lift the car a tiny bit?
Relay and fuse seem fine as the compressor seemingly is cutting in and out properly.

Level sensors seem fine and car does recognize it’s too low, so don’t suspect them. Lines seem fine and don’t hear any hissing.

Should I suspect the valve block? The system not lifting even a bit and the way it happened all of a sudden and not gradually, seems to be a big disruption somewhere could it be just not opening valves to the air lines?

Any help or suggestions would be greatly appreciated. I understand that I may need a mobile mechanic to properly diagnose it but I also know Airmatic isn’t impossible to learn and repair to save thousands. Thanks for any help.

 

If you are keeping your ride for years to come, my advice is to switch out the airmatic for regular shocks and springs.

If you are keen on keeping her, as you said since all 4 corners drops in height at similar level, we can deduct the air hose isn't ruptured there but possible just single main supply hose from the compressor which you saw corrosion around the housing. Price out a some new hose fittings for the compressor.

 

Though I don’t have a lot of experience with Airmatic (not even mine for that matter), I’ve many years with using air suspension in VIP platforms. In shelf-bought systems, such as Airlift, Airrunner, etc., air usually goes from compressor to tank, tank to manifold, manifold to bags. From what it sounds like, your manifold is leaking air.