Hello. This post goes out specifically to guys who know their way around the suspension system in our vehicles (2011 4.4tdv8) and perhaps even had an issue like mine and understand how individual parts of the system operate. I am having a problem with the suspension. Found out two days ago that the wheel well was filled with water. The compressor was virtually flooded. Yet the car worked fine (the water must have been there for like months) and suddenly BOING 'suspension fault'. I immediately began drying the well. The compressor kept slurping like crazy but it did start working. I cycled the air ride several times to vent the system and went to bed. The next day i finished cleaning the well and started the engine- BOING air 'suspension fault'. This time I dropped the vehicle to access mode to vent it again stupidly not leaving any air for emergency drives and ever since it has been in this mode irrespective of the height setting. When you drive above 40kmh the system wants up but it cannot and the central display very rapidly interchanges between access and normal. The above I totally understand- the system is confused getting implausible information. I have been looking for the problem for like 2 days now only to find that one of the wires leading to the air compressor solenoid valve block was rusted and snapped. Alright I say we have the culprit! I reattached the wire and....... BOING suspension fault again. BTW, I disassembled the compressor dried out the desiccant and refitted it in the vehicle
The symptoms: The vehicle starts I set the height, shut the door and the compressor starts to work, builds the pressure and stops.The vehicle does not rise. The most probable cause is that there is some short circuit in the system due to water ingress. What I need is a crash course in what does what in the system. My understanding is that one of the valves is not opening and does not feed compressed air to the system, when the pressure exceeds the limit it stops and the fault comes on. I seriously suspect the rear solenoid valve block (the one attached to the compressor, the one with the snapped wire). There are three lines - two green and one black. I need to know what it does. The solenoid is dead (0.34v or something), even though I reattached the wire. Should it be dead when the compressor starts? Maybe it is not supposed to be active when the pumping begins, I dont know, but I need to know this before I go any further. Any help appreciated.

I'll comment what I can, my old 322 was drowned in a Welsh river with water up to just below the seat base, the whole boot was under water.... The compressor carried on working and put a lot of water into the suspension... the faults that came up were many and they are all hard faults... This means you have to fix the fault then use a diagnostic tool to clear the faults, they will not clear on their own or by disconnecting the battery... it took multiple goes to fill the suspension with air, then vent it to remove all the air, then dry out the crystals and start again until they remain dry, all the while having to use a diagnostic tool to clear faults and vent the system... It took a lot but it did work and sorted the system out....

I can't comment on rusted wires as the car was not under water long enough to rust anything, I guess you will have to check, clean and repair any faulty wiring but you do need a diagnostic tool to clear faults...

Good Luck... Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Thanks, I think I need to add that it throws C1A20 (buildig pressure too slow) but IMHO it is not the case. The compressor does not die overnight. It worked right after the flooding. I suspect a valve being stuck open/closed (i dont know) or no voltage supply to the solenoid

AN UPDATE! For posterity: I kept looking for the problem in all sections of the vehicle slowly forgetting that I flooded the wheel well and most likely I should have been looking in that particular spot. Denial is not just a river in Egypt, C1A20 (slow pressure buildup) turned out to be the right trail. I eventually disassembled the entire compressor unit and found out the plate valve on the compression side of the piston broke off, probably due to the presence of water, which is not as compressible as air. I renewed the entire piston assembly incl. the 4 rings (the valve is pressed into the piston and cannot be replaced). Now the suspension works perfectly. I also found out that my compressor before the repair was on its last legs anyway and the water only accelerated what was inevitable. The height change is like 10 times quicker than before. For those who do not believe I say it is an easy job except one tricky thing with removing the piston and pressing it back onto the electric motor. A hydraulic press would come in handy. Other than that I made all the repair on my office desk with a few tools really. Good luck to those who are not afraid.....