hi guys
i had the usual suspension MIL lamp message ,c2303 reservoir plausibility error, had this for sometime now, so removed compressor usual 1 bolt totally seized in !!
sorted that, fitted new piston ring , bore has few lines at top of bore but couldent feel like scratches, rebuilt carefuly including new dryer material (*****) to dryer unit,
took for a drive car felt better soaking up the bumps. then on way home same message on dash !.. i did a live data recording on my thinkcar 2
the pressure steady at a little over 10 bar, vent valve shut on compressor, then vent opens like open shut quickly pressure at 3.3 bar ????
compressor doesent cut in ,so alarm on dash again...my thoughts are if compressor is pushing good pressures the piston must be efficient,
and why doesent the pressure sensor tell the pump to start ? i know there is a suspension controller box on x358 is there one on the x350 ??
or is relay getting hot ? ive had relay problems fuel pumps on fords lots of times, is this a similar fault ?
info on fuses and relays + the control box position would be good , thanks

 

I would try to solve the actual problem and that is the sudden pressure drop from 10 bar working pressure to 3 bar in the pressure accumulator.
The cause may be a leak or a malfunction of the relief valve.

Like the X358, the X350 also has a control unit behind the rear seat back on the bulkhead to the trunk.
The control unit has a programmed overheating protection for the compressor and ensures that it is switched off after a maximum of 2 minutes of running time. In addition, the compressor is only switched on in normal operation from 25 mph upwards if the pressure in the accumulator has dropped too far.

The compressor is not designed to compensate leaks in the system over the long term.
Fritz

 

Once the light goes on, the system WILL NOT activate the compressor. To run it again you have to stop the car and shut it off.

During the compressor rebuild, if you didn't go all the way to the other end of the compressor body and clean up that vent valve, you'll probably find that it's rusted and possibly sticking open once activated. The Bagpipe Andy kit is only the piston ring and the hardware, but you did the dryer as well. I just think you didn't go far enough, and you'd have found that release valve in less than stellar condition.

 

I have been reading this forum for a long time and have never had a fault

on the air suspension system however two faults that I remember being

reported are:

Bad connection on plug/socket on control unit behind back seat

The solenoid valves on the manifold in the boot can leak across

from one section to another not just to atmosphere.

The above do not seem very relevant but you never know.

BTW the only way to prove the manifold was leaking was to replace it

 

thanks flatsix Fritz, all makes sense i found the page for info on control unit being behind seat does the seat have to be removed for access ?, interestingly the pump wasnt showing running at the time i had live data on the chosen items showed over 10 bar but ive seen 15 bar mentioned so could be that, ime convinced theres another reason ie the control unit ? the relay ? but i did consider needing a new compressor at time of rebuild as bore had a bit of wear and did the ring have to bed in, i normally repair items if possible .. ile look up relay position today and swap it out..
thanks for the help .

 

thanks for info wfooshee ,, is it possible to remove vent valve with compressor in situ ? i actually forgot to look at it as i didnt feel well on the day of rebuild and install.. and ime thinking the same about that as well, on first run of the compressor after install and started engine comp cut in & the valve blew once big hiss, and must have closed ? as no mil lamp but car stationary.. videos of the process dont mention the relief valve but obvious the seat etc cold be grubby and would fail

 

Can't get to it in the car, I don't think.

Also, the seat does have to come out to access the air suspension module, but I seriously doubt your problem is the module. I think you're assuming something is wrong with the module because it stops running the compressor, but like i said previously, once the fault light goes on, it will not run the compressor again, by design, until the car is shut off and restarted. Basically it's programmed to give up at the point of showing the fault, rather than keep trying to fix it.

As for removing the seat, you'll need to find a thread outlining that, as you'll never get it just by exploring.

 

car stood unused for 4.5 days when ignition turned on had low suspension warning and car looked slight low, i started car and walked to n-s-front compressor running, then comp stopped & solenoid opened for maybe 1 - 2 seconds and closed no air coming from the small outlet from solenoid .. suspension height normal.... ile take car for a run and see what i get on dash, unfortunately my diagnostic dongle needs a fee paid so ile sort that and again do the same leave it to sit etc... ime thinking a small leak now i did a low pressure compressed air test on the rebuilt compressor before fitting with leak finder around joints but didnt see anything. again thanks for the replys