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Check the buttons above the center console. If one of them says "ABC" and has a single red LED illuminated after it is pushed, you have Active Body Control. If instead it has a strut-type symbol with curved arrows on either side, and 2 LEDs, then you have Airmatic. Airmatic is the more common suspension. See more at how can i find out if i have Active Body Control or not - MBWorld.org Forums

Also you can look at the front strut mounts. An Airmatic system will look like the photos at post #18, http://forums.mbworld.org/forums/s-class-w220/243997-air-matic-failed.html (with the 2 different Airmatic tops - note that the contributor labeled them "old" and "new" based on when they were installed in his car, but in actuality they are reversed; the new style has the mastic); and there is a photo of a Hella relay there as well. See http://www.benzworld.org/forums/w220-s-class/1492060-whats-suspension-2001-s500-sport.html for a photo of an ABC strut top (which, when you get to the end of the discussion, it was).

If you have ABC, there has been a recall to replace a stainless steel pressure line that has been subject to failure. If you have Airmatic, you will want to read the rest.

Likely Airmatic problem areas are listed at post #6 at http://www.benzworld.org/forums/w220-s-class/1329314-s-class-airmatic-woes-yes-again.html and there are some things to watch for at Airmatic Questions!! - MBWorld.org Forums

If your front struts are leaking at the upper seal, there is a repair kit - around $550 parts & labor for both sides. If any struts need replacement, Arnott Industries has a more durable strut - new or remanufactured - at 1/2 to 1/4 the cost of OE. They recently began offering struts for 4matics, and plan to follow with ABC hydraulic struts as well. See http://www.benzworld.org/forums/arnott-inc/

You will want to check your Airmatic relay, and if it is not Hella brand, replace it. AutohausAZ has had the lowest price recently; see Your Parts Search Returned 2 Part(s) - you'd need the 4 prong relay. The relay goes in position "O" in the right hand fuse panel in the engine compartment.

A bad relay can either cause the Airmatc pump not to run, or can keep it running when it shouldn't and burn the pump out. The Siemens relay has been problematic that way.

The string at http://www.benzworld.org/forums/w220-s-class/1491879-airmatic-problems-comp-runs-but-no.html has good info on a pressure line that could come off of the pump, and also toward the end, info on the valve block location. I haven't bookmarked anything on pump replacement and costs, but new pumps seem to run from $300 to $600 depending on where you get them. I'd try AutohausAZ first if you need one.

There are a ton of Airmatic writeups that will give you tons of information - so if you need more, I'll leave you to search.

 

If its ABC it is normal for it to drop over a few hours. as soon as you start it will raise, just dont slam into drive or reverse the moment you turn the key or you will get a car too low warning.


but, check your fluid level. if its low then suspect a leak. If you need to top it up you MUST use the MB fluid and make sure the area is as clean as a operating theater before topping up.

 

what if i dont have hella relay and my car is working fine and no drop in the suspension even after a week parked in the driveway ! do i still need to change it !

 

ermm....no

if it aint broke, dont fix it

 

I would say yes, go ahead and upgrade your relay. It can help to prevent against FUTURE issues. The relays super cheap and it will keep you from risking burning up your pump. Its just stupid not to.

On the other hand OP, I'd be willing to bet your '00 S500 is airmatic, I haven't seen any with ABC in that MY.

 

thanks guys for all the help I found that the relay was bad replaced and all is well

 

what relay is it and were is it located

 

can someone tell me where is that relay i think i have same problem

 

Thoroughly discussed in the W220 S-Class Encyclopedia sticky and also shown in your fuse diagram.

 

Hello,

A good writeup indeed.

I have SDS and I wanted to learn some thing more.

I am trying to find out what should the pressure be ( in bars) for a healthy pump ?

I am looking for more information in the Control Module Adaptations; those degrees look daunting at best and I want to understand all aspects before changing any one of those.

Does any one have WIS sheets with above data ?

Thanks and regards

 

If you run the Airmatic diagnostics on the Star Diagnostic System, it will tell you the specific pressure requirements for your VIN, and whether the compressor reaches that pressure within the specified time.

 

Hello how do you run the airmatic diagnostic on the star sydtem.? Is this something done st the dealership? I suspect an issue with my airmatic system.

 

Hello how do you run the airmatic diagnostic on the star sydtem.?

Well, first you need to purchase a Star Diagnosis System (SDS) of your own. This can be had for as little as $300, but the setup I would choose would come to around $400: "C3 multiplexer" with cables and all software pre-installed on an internal hard drive and an old Dell or IBM laptop purchased separately to receive the hard drive. There are countless sellers offering SDS on alibaba.com, and there are occasionally reasonably-priced auctions on eBay.

Also, you've been posting about actuations, sensor values, and fault codes associated with your climate control. SDS provides easy access to all of this information and presents it an easily-read tabular form.