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Wierd problem with ADS

3K views 7 replies 3 participants last post by  Anders Christian Jensen 
#1 ·
Hi guys im having a bit of trouble with my E420.

When the room temperature in the cabin gets above 20C i get an "Adaptive damping" message and the system goes into failsafe and becomes unpleasantly hard.

What components inside the cabin can cause this kind of behavior?

Another issue i have is that if i lift the rear wheels off the ground and put it back down again the car settles at a perfect lowered avantgarde ride height but when i have driven if for 30km or more the rear end lifts up and is about 30mm too high.

Any help is appreciated
 
#2 ·
hello:)

I do not think it has really anything to do with the cabin temperature. How did you come to such an observation ?

I think your problem is more likely due to a response to an electrical malfunction. One possibility is voltage on the ADS control unit goes down below threshold. When this occurs, the ADS unit defaults to the firmest setting for the shock absorbers damping forces.

The second possibility is inadequate oil level in the ADS oil reservoir. It needs to be between max and min. If inadequate, it will cause the warning lamp to come on.

Address the warning problem first. If the leveling issue still not resolved, get the car system checked for codes. The ADS controller can be reached through the 38 pin port with a scanner like MB SDS, Snap ON etc.
 
#4 ·
The only thing that are directly related to the ADS are the stop lamp switch and the steering angle sensor. It is possible that you may have a bad / intermittent connection of the steering angle sensor (mounted on the steering column) at the clock spring (the rotating connector, as you rotate the steering wheel). How it is affected by cabin temperature is beyond me.

I do not think you can reach a definite conclusion based on outside / inside temperature. My suggestion is to get the car scanned by a dealer or an independent shop through the 38 pin connector. They can access the controller and find out what the faulty component is..
 
#5 ·
I have been leaning towards the sas for some time because if the failure has been there when the car was parked the error message would come up when i start it again only to disappear when the steering wheel is turned.

Im currently waiting for a 38pin adapter to my obd scanner hopefully that will allow me to access the ads module.

I have uploaded 2 photos of the rideheight just to show how much it differs.

If i lift the backwheels off the ground with a jack and put it down again it will set at the low height.

When i drive the car it rises slowly and after a few days its like an offroader.
 

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#6 ·
The ADS is accessed through pin 11 of the 38 pin connector. Only few professional scanners can access the whole modules including the ADS. The 38 pin adapters sold online typically have 3 wires, power, ground, and connection to the ECM. So you will be able to get the Engine codes with your OBD scanner, but I doubt it will access the ADS. I am sure the MB Star (SDS) scanner from a dealer or an independent workshop should be able to read the codes. through HHT simulator function.

For rear raise issue, it may be related to the cause of the warning. What happens when you press the ADS switch to lower the level to normal ?
 
#7 ·
Wow, you have a really rare option...I want active suspension on my car too! Where are you located? We dont have 1996 E420 here in the US.

Anyway, the principle is the same as the SLS on older W201, ADS in W140 and SLS in W124/W210 wagons.

Check the rear level rod linkage -- it should be connected to the rear swaybar by a rod of some kind. Usually it's non adjustable, but some owners swap the rod linkage with an adjustable one that has a nut you unscrew to lengthen/shrink the rod length, then tighten it. It's possible the little nut is a little loose and the rod extends when subjected to road vibrations.
 
#8 ·
I live in Denmark

I have been under the car to check the valve for the sls and it looks a bit corroded so i decided not to play with it until i have time to fix it if i break it.

Also the car has developed a leak at the front so i might have multible failures on the system.

Im afraid that it at some point have had the wrong fluids.

I hope its not to bad though.
 
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