w220 airmatic question

bonchester

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Apologies if this has been covered before - can anyone tell me what psi/ bar is normally in the suspension struts . The car is at the correct level,the voltages are within the correct range,it will raise on start up and the button ,it doesnt sag but when i use my icarsoft pro, to have a look, it shows that there is no reading of pressure in the struts or the resevoir. No fault codes show. Any ideas please?
 

malcolm E53 AMG

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What’s the issue your trying to solve with the airmatic system is it loosing pressure or have you got an issue with the icarsoft pro?
 
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bonchester

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What’s the issue your trying to solve with the airmatic system is it loosing pressure or have you got an issue with the icarsoft pro?
no problem with the icarsoft or indeed with star,its just that i cant understand why it reads that the pressure in the struts and the resevoir is zero. The car stands correctly. If indeed there was no pressure would the car not drop? i keep measuring from the hub centre to wheel arch and it remains constant.
 

Snake Charmer

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I have an iCarsoft CR Max and the rear air suspension test comes up with pressures in Bar, up to 20 if I remember, so around 300psi.

I think there is a software glitch on my iCarsoft CR Max as if I run the compressor test procedure I get a failure unless I ignore starting the compressor 40 second run after the 20 second air spring solenoid operation/deflation. The software starts the compressor automatically after the 20 second deflation and pressing yes starts the 40 second timer resulting in a fail. If left running without starting the timer, the pressure rises lifting the rear quite high and gives a pass, shutting down the compressor and immediately lowering the suspension back to normal ride height.
 
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bonchester

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Could the airmatic pressure sensor which measures system pressure be at fault?
 

mioba

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Such a fault would show on a reader esp star, which you used already
 
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bonchester

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Still an ongoing saga. The car has been sorned for a while now and it has dropped too low to drive. I have had a mechanic with an autel diagnostic tool ( the very expensive one) help me out. The scan shows no faults and we have raised the car to the correct height through the autel, however it shows that there is no pressure in the resevoir or the struts! It also shows that the compresor interlock is off, what does that mean? We tried and failed to fill the resevoir. Everything seems to work with raising the car using the autel apart from the lack of pressure in the resevoir. Leaving the car for a few hours and it drops about 2.5 cms and wont rise once started. Can anyone help please ?
 

malcolm E53 AMG

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It’s worth disconnecting the pump and testing the pressure it provides if the pump piston Is worn there is no chance of the reservoir getting up to pressure, the system works on 6-10bar and the reservoir holds 13-16 bar, but if the pump is weak you won’t attain these figures. It may be that you have a leak somewhere but you need to make sure the pump is good first
 
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bonchester

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It’s worth disconnecting the pump and testing the pressure it provides if the pump piston Is worn there is no chance of the reservoir getting up to pressure, the system works on 6-10bar and the reservoir holds 13-16 bar, but if the pump is weak you won’t attain these figures. It may be that you have a leak somewhere but you need to make sure the pump is good first
Thanks for your reply. I still do get why it can be forced to rise and therefore the pump is strong enough? What is compressor interlock? Autel shows no faults at all. To force the car to rise does the valve block only allow air to the 4 corners and in my case not to the resevoir hence no pressure? The pump is not old at all. When forcing the car to rise we did the automatic ride height and levelling and got it to 1 mml difference, also measured with tape from hub centre to wheel arch . What am I missing apart from pulled out hair!
 

malcolm E53 AMG

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Try this reset procedure:


My next move would be to test the valve block they have a reputation for failing on the W220 due to rust
 
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