Well, I can't find any more details about ADS - PeachParts Mercedes-Benz Forum

pcmaher · #1 02-24-2005, 08:39 AM

I've been searching high and low for detailed info on how the ADS system (Adaptive Damping System) works. I've found general descriptions on how it operates, but there is just nothing specific out there on the web. Unfortunately for me, I'm getting no responses to my previous posts. I'm starting to suspect that there is no one on the forum that has details of this system. I'm sure I would've gotten responses otherwise. Do any of you subscribe to a MB magazine of some sort? Do these publications get into the technical details of complex systems? I'm trying to find info on how to test the damping valves for proper functioning, as well as the specifics of the signals generated by the system that are sent to the valves. I am also trying to find out how to check condition of the front shocks. In the "old days", one simply pushed down on the corners of the car, started the car bouncing, and watched how quickly the shocks stabilized the car. If it bounced too many times, it was time to change the shocks. I don't want to buy new shocks ($625 each is cheapest I found) if I don't need them. I'm still not happy with the ride of the car. Some days the car rides smooth, other days it's too firm. Pressure reservoirs (accumulators) were changed last year. Does anyone have any ideas, or possibly a technical contact I can ask? I appreciate any leads I can get.

dkveuro · #2 02-24-2005, 09:51 PM

Simple 'Google' search turned up this on ....www.carlist.com.
There are other search engines too.
You might find that a SAE paper has been writen on ADS.
Need to go to SAE and do a search.

[QUOTE]Adaptive Damping System (ADS)

The standard-specification AIRMATIC suspension system of the Mercedes S-Class combines pneumatic suspension with an Adaptive Damping System (ADS), which adjusts the front and rear shock absorber forces to the current payload, the condition of the road surface and driving style.

A steering angle sensor, three acceleration sensors on the car body, the ABS speed sensor and the brake pedal sensor constantly measure the lateral and longitudinal acceleration of the body. From this data, the ADS control unit calculates the optimal damper setting for each individual wheel and transmits the relevant signals with split-second speed to special valves on the gas-pressure shock absorbers.

These valves are able to switch between four different damping characteristics. Using a selector on the instrument panel, the driver can also switch between a standard mode or a tauter, more sporty mode. This adjusts the thresholds at which the different damping characteristics are activated. In sporty mode, the firmest characteristic is selected earlier, while in comfort mode the softest characteristic remains activated for longer.[UNQUOTE]

leejxxxxx · #3 02-24-2005, 10:02 PM

Quote:

Originally Posted by pcmaher

I've been searching high and low for detailed info on how the ADS system (Adaptive Damping System) works. I've found general descriptions on how it operates, but there is just nothing specific out there on the web. Unfortunately for me, I'm getting no responses to my previous posts. I'm starting to suspect that there is no one on the forum that has details of this system. I'm sure I would've gotten responses otherwise. Do any of you subscribe to a MB magazine of some sort? Do these publications get into the technical details of complex systems? I'm trying to find info on how to test the damping valves for proper functioning, as well as the specifics of the signals generated by the system that are sent to the valves. I am also trying to find out how to check condition of the front shocks. In the "old days", one simply pushed down on the corners of the car, started the car bouncing, and watched how quickly the shocks stabilized the car. If it bounced too many times, it was time to change the shocks. I don't want to buy new shocks ($625 each is cheapest I found) if I don't need them. I'm still not happy with the ride of the car. Some days the car rides smooth, other days it's too firm. Pressure reservoirs (accumulators) were changed last year. Does anyone have any ideas, or possibly a technical contact I can ask? I appreciate any leads I can get.

As far as I know, your car doesn't have regular shocks. They're hydropnumatic with the damping action via the accumulators so unless they leak, there's nothing wrong with them.

I had a problem in the heat where if I ran the car, shut it off and then started it within a half hour the ADS fault light would go on. It never went into limp home mode and it always went off the next day but it still bothers me. The dealer couldn't ever find anything and it hasn't happened since it has been cold.

pcmaher · #4 02-25-2005, 08:48 AM

Thanks dkveuro. I did come across that webpage early in my search. What I'm looking for are specific details, like what the signal voltages are for the different levels of damping.

leejxxxxx, you are correct. This car does not have regular shocks. The rear shocks work with accumulators and seperate damping valves. The fronts do not use accumulators, and the damping valves are integral to the shock. I too had a problem with my ADS system last year. In hot weather, the ADS warning lamp would come on as soon as I turned the steering wheel, and the ride defaulted to firm. It didn't happen in colder weather. Pulling codes indicated it was a faulty steering angle sensor. I changed that and haven't had a problem since.

I'm not getting any codes now from my car, but it just rides too firm. From the comments I see on this and other boards, the car should ride smoother.

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