Hello,

I'm experiencing a very stiff ride with my 2014 CLS 550 equipped with Airmatic suspension, it typically starts after about 10-15 mins of driving. I only take my car out during the weekends (I live in NYC), so it sits in the garage usually for a week at a time not being driven.
I bought the car back in February at a Mercedes dealership in MI, the car has now about 65K miles on the clock, no warning message or lights on the dash. I have also searched for codes with my , but nothing comes up. I realize that this OBD2 scanner might not be able to access the Airmatic module or any other applicable module related to this issue.

Observations:
- Stiff ride typically starts after 10-15 mins of driving. No shock absorption at all, especially in the rear. Even the mildest imperfection on the road can clearly be felt in the car.
- Ride can be bouncy on uneven road surfaces
- Car does not ride low, not even after a week of not driving the car, meaning this is not related to a leak from my understanding
- I can shift between Comfort and sport, although I do not feel any difference between these to modes
- Main and Aux battery are brand new
- I've checked tire pressure, all within range

Considerations:
- Could this be a faulty ADS solenoid (level control valve) in one of the air struts? Source
- Faulty ride height sensor?
- Faulty airmatic module?
- I've read you could reset the ADS module by turning the steering wheel lock to lock, this didn't have any affect.
- Seems like an emergency ride mode

Now I'm not expecting anyone here to provide an exact answer what the issue is but I'm curious what you guys think I should check out before either taking it to the dealership or some Mercedes Airmatic specialist. Here's a photo of the car, for you check if the ride height here makes sense (in comfort mode). Car is equipped with OEM CLS 63 AMG 19" wheels.



Thanks.

 

While I'm certainly no expert, the symptoms you're experiencing do point to a bad ADS solenoid, likely in the rear.

 

Thanks DigitalDisaster - do you know if just one ADS solenoid has gone bad if it would affect any of the other ADS solenoid's or any other part of the airmatic/ADS systems/modules?

 

I don't much about it, but from what I've read it's usually a single unit that fails, but they describe an overall harsh ride that sounds like it would involve more than a single strut. Hopefully, somebody who's personally dealt with this issue will see this thread.
Do you have a trustworthy Mercedes shop (that is not a dealer) that can diagnose it for you?

 

I would suggest having someone pull codes using Xentry (MB diagnostics) see attachments to better understand your suspension system. In the mean time if you're feeling ambitious you can visually check connections to all accessible sensors, valves, etc.

 

Thanks guys - I've spoke with a AMG / Mercedes specialist in Queens, NY and he mentioned that if one ADS valve fails the entire system will go into a sport/emergency stiffness mode. I'm planning to bring the car by in a couple of weeks for a diagnosis. Will report back once I know more.

 

I bet that's it. Hopefully, it won't be too outrageously expensive.
BTW, you have good taste in cars

 

Any update? What was the problem?