Hello friends,

I have an W220 year 2000 that I have owned since 2009.

Few days ago I noticed the right side of the car is 1.5" lower than the left side.

The car drives fine but the tire rubs against the wheel housing when I go over a bump ay high speed.

The suspensions don't deflate or inflate. Even if I don't turn the car on for 2 weeks, the height stays the same and it also does not go up when I turn the car on.

At first I thought the problem is with the air struts but then I thought if they leak air, they should go lower over time but they stay at the same height.

So my next guess is that the compressor does not work.

I checked all the fuses and relays and they are fine, so the problem is probably with the compressor itself.

Do any of you folks have any advice on this ?

The car has been driving like this for 3 years so is it possible that the air struts hold air for 3 years and don't go lower if the compressor is bad?

I would appreciate if any of you guys can give me some suggestions and lead me to the right direction.

I don't want to change the airstruts if the problem is with the compressor.

How to check to make sure the compressor is functional and it does turn on ?

Thanks

 

As answered in the other Forum, I suspect the right-hand height sensor, it linkage or its mounting.

 

Thank you very much Wally.
I looked at the sensor and the mechanism it is attached to the upper control arm and they look intact.
How do I know whether the sensor, the mount or the linkage has problems ?
Since both the front and rear of the car is 1.5" lower in the right side, what is the possibility that both sensors for the front and rear are faulty to set the car exactly 1.5" lower for both front and rear ?
And assuming the problem is with the sensor, how can I adjust it so it brings the car 1.5" higher again?
Thanks again for your response.

 

Would suggest to scan for faults. On rear there is only one sensor and it's on center of car. Basically if on front sensor or sensor arm fail, the rear also will drop.

 

Thank you for your response, suf3r.
I have a simple ELM 327 Bluetooth OBD2 scanner which does not show any fault code.
I get airmatic warning sometimes on the instrument cluster, but not every time I drive the car.

Let's start with the compressor. How can I confirm that the compressor is actually even working ? How can I test it ?

And how to test the rid height sensor ? So far I have tested the 3 fuses and the relay and they are all good.
But I don't know how to force the compressor to turn on or how to check whether it is working or not.

 

To test it properly you will need STAR diagnostic tool, suggesting to search in your area, maybe somene has it and then properly scan for faults. Very good read is here: https://w220.wiki/Airmatic
Video is in another language, but should apply to MB also i think:
To test compressor:

 

Thank you very much Suf3r,
The wiki link was very helpful. I learned a lot about the AirMatic system.
OK, let me see if I can find a shop that has STAR diagnostic tool.
I appreciate the time you spent to send me these links.

Is there an affordable STAR scanner on Amazon that also works for other cars, so I just buy one to use for future ?
I have a BMW E66 too and it will be nice to have an affordable scanner that can work on both cars.
The ELM327 bluetooth scanner I have is basic and can't read specific codes for BMW and Mercedes.

 

STAR is only for MB. I would suggest to into this price range 300-500 dollars/euros. That way you would be able to scan your cars and probably make some coding to control units.

 

If your problem is just that one side of the car is continually lower than the other, the compressor is not your problem.

 

ride height is set wrong

you need some way of adjusting all of this to make it sit right.

If I were you, I would make sure the height of the suspension is set correctly with a diagnostic tool. it asks for inclination level and other parameters that are found on forum to eyeball it. you can always lift each side individually too

scan tools let you test every. single. part of the airmatic. you can do a leak down test for the valveblock, compressor to reservoir, ect everything can be measured and tested and adjusted down to the 1/10th of a degree
edit: I have ways of doing all of this and am still learning. but if you are low and not leaking your ride height is not set right . INITIAL RIGHT HEIGHT calibration has to be done after strut change in my experience!

 

I have changed numerous struts, and have never had to reset initial ride height.

 

Foxwell nt510 or nt530 has Mercedes specific software available it’s about $150 and will have much better Mercedes and bmw scanning ability

but you can’t set ride height with it , you need star diagnostic laptop for that

 

How to check to make sure the compressor is functional.

 

Hello, check few posts above, in video you can clearly see how to test it.

 

If you're still looking for a Mercedes scanner I highly recommend this one. It's bidirectional and It's the closest thing to DAS on a budget that I have found. Did suspension adjustments including romess settings with ease. You can read up on everything it can do on the web site.

2023 LAUNCH X431 Fit for Benz Sprinter Full System OBD2 Scanner,Bi-Directional Diagnostic Scan Tool,Full Reset Function Code Reader,ECU Coding,Camshaft &Crankshaft Relearn,AUTOVIN,Lifetime Free Update https://a.co/d/fN8uBkT

 

Hello folks,

Thank you all very much for your responses and for your willingness to help.
This is what I love about these forums, that people help each-other so we all learn something and also save money by not going to the dealer and by repairing our cars ourselves.

So, I managed to read the codes. The scanner is not bi-directional, so I can't set or adjust anything, but at least I have the codes now.
Before I continue with the codes, which of these bi-directional models is the best for these type of work ? LAUNCH X431, Foxwell NT510 or NT530 ?

You can find X431 for Benz and BMW for $110 on eBay.
I like X431 because the screen is bigger, is touch screen and is high resolution, but I don't know if Foxwell in general does a better job compare to LAUNCH X431.

Now, here are the SUSPENSION codes and DATA :

C1026-032
Historic. Fault in CAN communication with control unit N4 7-5 ( ESP, SPS [PML] and BAS control unit )
C1026-064
Historic. Fault in CAN communication with control unit N8 0 ( Steering Column Module )
C1517-001
Historic. Critical Vehicle level at front axle. Pay attention to STIP AF32.22-P-4040AU!
C1517-002
Historic. Critical Vehicle level at rear axle
C1517-032
Historic. Stabilizing times when emptying or filling are too large.
C1013
Historic. Terminal 30 under voltage

Data :

Terminal 30 is 11.6V
Terminal 87 is OFF

Signal 1 of component B22/8 ( Left front level sensor ) is 2.27V
Signal 2 of component B22/8 ( Left front level sensor ) is 2.76V
Signal 1 of component B22/9 ( Right front level sensor ) is 2.31V
Signal 2 of component B22/9 ( Right front level sensor ) is 2.73V
Signal 1 of component B22/3 ( Rear axle level sensor ) is 2.24V
Signal 2 of component B22/3 ( Rear axle level sensor ) is 2.8V

Left front vehicle level is 9 mm
Right front vehicle level is -26 mm
Rear vehicle level is 0 mm

B24/3 ( Left front body acceleration sensor ) = 2451 mV
B24/4 ( Right front body acceleration sensor ) = 2510 mV
B24/6 ( Right rear body acceleration sensor ) = 2412 mV

B7 ( Air-Matic pressure sensor ) is 4.53 bar ( For all components )
Lock position is OFF

And here are my own measurement today from bottom of edge of the wheel housing to the center of Benz logo :

Front Left = 401 mm & Front Right = 352 mm
Rear Left = 402 mm & Rear Right = 361 mm

These values change every time I move the car.
For example last week they were :

Front Left = 411 mm & Front Right = 377 mm
Rear Left = 394 mm & Rear Right = 369 mm

Would you please let me know what do you think the problem is, after looking at all these codes, data and measurements ?
Thank you again for all your replies.

 

Try the launch x431

 

is this car squatting to the ground or laying on the ground? sounds like the compressor isnt click on?

 

It is drivable but the rear tire rubs against the wheel housing when I go over a bump.
When I drive it, the right side seems to come up a little bit, which probably means the compressor works, but I don't understand why it does not bring the right side as high as the left side.
Even if the right struts are old and leaking air, when the compressor pumps air into them, they should still come up to the same level as left side, but they don't.
That is why I asked for help from people on this forum because I don't really know whether the problem is the leaking and old struts in the right side or the ride-height sensor or something else.
After I park the car, the right side does NOT drop, which means it is not leaking that bad.
If I don't turn the car on for even 2 weeks, it stays the same way, right side around 1.5" lower than the left side, but it does not drop to the ground.

 

A leaking strut does not "drop to the ground" on the W220.
The compressor can not pump up a strut with a serious leak.
A W220 can be driven with a blown rear strut, but will be too low.

It sounds as if you have a failed strut air spring.

 

if the rubber peels from the strut it will not inflate at all. will be slammed. leaking is different than blown out though. if compressor is kicking on more than a couple times when you drive, distinctly, you have a leak.

 

we need a sticky thread for
"I Have Air Suspension and it ____-." top 10 tips

haha

 

Thank you for your replies.
So, based on what I explained, and based on the data I read from the car and the measurements I gave you, do you think the problem is with the rear strut, front strut, or both ?

 

when you jack the car up (on the side that lowers even a little bit), does it hiss? i noticed if you jack car up it puts pressure on top strut hat and it show where leak is if from strut

also, I didnt read everything in detail but you didn't change the strut did you? why not change it and see. it is an automatic system

a nice rebuilt one is 100 bucks on ebay, their quality has really, really improved

 

I changed the front strut on the driver side about 3 years ago but now I have this problem with the passenger side.
The struts are original, from 23 years ago, so I am sure it is time to change them. But I wanted to make sure the problem is with the struts, not the compressor or valve block or hoses and ride height sensors, etc.
Yes, the struts are inexpensive on eBay but it is labor intensive to change them, especially the rear ones. So I wanted to get advice from you guys before I do it because the problem could be with something else, not the struts.