maniekS500

Hello All,
From about 3 months I trying to find what is wrong with ABC suspension on my S500.
Mechanic replaced one hydraulic pipe (crack happened and I car was taken away on a carriage). From that time suspension is terrible hard. I fill every stone on the road, each small pothole generates vibrations and jumps of the car. I fill like struts are hard/pumped.

No any errors on dash and/or Star Diagnose. Fluid level all time is proper (no leaks).

Checked:
- car leveling - OK (when I leave car for one-two weeks it never loose leveling),
- lo/hi positions - works perfectly (fast, smooth about 8cm difference between Lo-Hi),
- rodeo tests - passed with no errors. The only observation during rodeo was that pressure never dropped below 178bar (max was 195). I expected that it will change in wide range (130-195bar ??).

Last Friday I replaced (DYI) both pressure accumulators (rear and front) + fluid was flushed and replaced to new. I bleed air from ABC system - no change, same behavior.

I am lost - during almost two years car was very comfortable, silent now I don't like back/gravel roads - noisy and 'jumping'.

I am looking for photos of front valve with pipes connected - maybe mechanic did something bad and connected them in wrong order ?

Additional question about HI mode - my car (from first day I have it - 2years) on HI mode always was/is like to much inflated ball - when I ride over speed bump -
it jumps with hard response.

Thank you for advice.
p.s. apologize for my Polish/English..

alx

Your English is just fine

During rodeo the abc pressure should fluctuate a lot. Pump should pump to about 195 bar and then as rodeo progresses pressure should drop to about 120 bars. Then rodeo should pause, pump should pump back up to 195 and proceed with rodeo. This should happen 2-3 times during rodeo.

If your pressure is not dropping your bypass valve is stuck close. Do not quote me as I have not had to deal with this problem, but I believe said valve is in the tandem pump. Please check location though...

Mike5215

WTF is rodeo? I thought that was a translation thing.

alx

It is a routine executed via das. It is used to circulate and bleed the abc fluid. It has also certain entertainment value

maniekS500

This is a rodeo :

maniekS500

Thank you for answer. I found this in PDF "AH32.50-P-0001-01N" : 'The ABC fluid-return circuit contains a distribution valve with a booster valve and a temperature sensor." As I remember mechanic changed 'short pipe close to pump' - on Saturday I will remove return flow pressure reservoir and will inspect this pipe. Maybe he did mistake and installed valve in opposite order or made too tin pipe...

xpl0sive

I did this to an SL65 I was looking at buying and the owner was very concerned and entertained at the same time lol

PeqpeK

Hi Maniek, have you figured out what it was? Mine started doing the same thing...I had an ABC pressure hose replaced (it blew) and after one month I noticed that the suspension is stiff, more like a 7series BMW

The Thomas J

See this is why I can't have STAR I would be driving down the street and making my hooptie hop. It's bad enough I terrorize people in the passenger seat by messing with there seat from my control panel. I can't be trusted with software that will make my car hop. No sir.

maniekS500

Still not sorted Last service found leaking rear left shock absorber - will replace both next month. Will let you know if it help.

Kevin Markussen

Hello
Any good news on this problem?
Mine has had it since i bought it.. I belive i got a low ABC pressure though, 75-120 on each strut?

DaveW68

This can be fixed using a pliers, gauze, 3 in 1 oil, 30 weight ball bearings and 10 qts of Quaker State anti-freeze.

PeqpeK

Mine got worse so after figuring out how the system works it looks like rear pressure accumulator/damper is shot. Ordered a new OEM and will see if that fixes the issue.

@Maniek, how's yours?

maniekS500

Last Friday I spend some time in garage with S500 and SD. I went thru all ABC checks/procedures (exc. rodeo) and is MUCH better. I found that one acceleration sensor at front changing its values (car is stopped, with no level changes). I ordered used one for $10 - tomorrow will replace it. The last what I will change are two rear shock absorbers - there is a company in PL - they replace old one with refurbished for $400 each.

I recommend all of you to setup leveling of the car (I used automatic setup), then went via changing elements procedure, then selected Sway ABC (option above Rodeo) and after that I did test drive and WOW ! Like previous - much, much quiet, softer.
Will update you after change acceleration sensor tomorrow.

alx

automatic level setup produces usually result in garbage leveling. best find a level surface and level car manually. take your time- even small changes on each corner will affect all 4 corners.

maniekS500

Can you tell how to do setup manually ?
On SD I seen only option to setup leveling automatically. Please advice /screen shoot ?

BTW. Today I made about 30km and hard suspension back again but for sure is was very soft for first 10-15 kilometers
Seems something went wrong when oil goes hot ?
Expect tomorrow for replace acceleration sensor maybe it helps ?

Thanks,
Mariusz

Jimweec

have u ever found what caused hard suspension

Jimweec

has anyone found out how to fix hard suspension on w221 S500mco Mercedes 2008

konigstiger

OP last reply was 2 years ago during diagnostic process seems as though acceleration sensor was malfunctioning. If you have not already done so, have someone pull fault codes using Xentry (MB diagnostics). See attachments noting sensor task, and MBUSA recall part info.