ADS issue (W 251)

Jan Grenner

New Registration
Jan 23, 2018
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Your Mercedes
W251 (R-Class) / 2007 / 320 CDI
I have an ADS switch in my R 320 CDI (sport/comfort), which lights up but does not seem to change anything. I would describe the suspension as always too stiff ( I own this car since a few weeks and I have no comparison what it should feel like).
The airmatic is working fine, I had just had it repaired as the compressor seemed to work too much and there was a leak somewhere that has been closed. I DON‘T have that common issue of the car losing height overnight or being out of balance. It is just that seemingly non-reacting suspension mode switch.
Can someone point me to some possible sources of the issue that I can relay to my mechanic?
Thank you very much!


(excuse my English)


Senior Member
Jul 29, 2014
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Your Mercedes
the suspension can lock you out if the compressor stops or a leak is detected and it just maintains the ride height and suspension setting it was at when it went into this safety mode... I think if the way the car is sitting is OK it can stay like this without throwing a light on the dash

pretty sure mine was like this for more than 6 months.... before I loaded the car with a heavy load and it started to play up.... once I had a new compressor the change of both height and firmness on the suspension was back to normal

did the person working on the car have decent diagnostics kit?
Specialist in parts for W140 and R129 Mercedes-Benz models.
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