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Discussion Starter #1
Hi,

I have got a problem in my SL500 with ABC suspension. If I leave vehicle suspension in raised position (2nd level) in parking (because of frieze or any other obstacle), after some time, it looses level on passenger side lengthwise, eg. driver side is still raised, while passenger has drooped to "0" level. It happens quickly sometimes (passenger side looses level in ~2-3 sec.), and sometimes slower (not noticeable, or at least I am not patient enough to wait and see).

I think this is malfunction, the vehicle should be standing in the pumped-up position no matter what, right? :confused:

Any ideas? Dealer mentioned something like valves, but was not specific enough neither on culprit, nor on the price-to-fix. I will be going to interrogate personally after some time, because on phone they are useless :-\
 

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something must be leaking leaking

I park mine in the max raised position for weeks at a time and it does not go down as you mentioned...you must have a leak somewhere...I hope you have a warranty but if not hang on to your hat because the suspension fluid and struts of the SL ABC is expensive...do you see any fluid on the ground? I ask because I blew a rear strut and I first noticed the fluid on the ground...
 

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Discussion Starter #3
I park mine in the max raised position for weeks at a time and it does not go down as you mentioned...you must have a leak somewhere...I hope you have a warranty but if not hang on to your hat because the suspension fluid and struts of the SL ABC is expensive...do you see any fluid on the ground? I ask because I blew a rear strut and I first noticed the fluid on the ground...
There is no leak for sure. Rear struts where exchanged just after I purchased the car (the price was ouch! ;-), as one was dead, the other was ready to die. Front is OK.

I did not topped ABC fluid, as it was not necessary. The dealer did not recommended to change the fluid, as there was no real reason for that.
 

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Let us know

Let us know what the ABC service fix turns out to be.
I am not a mechanic but I was thinking if there are no leaks then could there be air in the system and after time it allows the pressure to reduce and causes the problem your having? Anyway I'll want to know your solution.
 

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Let us know what the ABC service fix turns out to be.
I am not a mechanic but I was thinking if there are no leaks then could there be air in the system and after time it allows the pressure to reduce and causes the problem your having? Anyway I'll want to know your solution.
If I will have any useful info, I will post it here.
 

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needs a new pump for sure
Impossible. When the engine is shutoff the pump is isolated from the struts' hydraulic circuits. Further, if the pump were bad the system pressure sensor would trigger a low pressure fault and light-up the red malfunction display in the cluster.

This problem is something I have looked into before. If I remember correctly the cause is likely a defective valve block or strut or contaminants in the hydraulic fluid. The contaminants can be removed by filtering the fluid.

I would suggest living with this "feature" of your car or taking it to a shop equipped with Star Diagnosis (SDS). If you have technical skills, then you might consider buying your own SDS for about $900.
 

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Discussion Starter #9
Impossible. When the engine is shutoff the pump is isolated from the struts' hydraulic circuits. Further, if the pump were bad the system pressure sensor would trigger a low pressure fault and light-up the red malfunction display in the cluster.

This problem is something I have looked into before. If I remember correctly the cause is likely a defective valve block or strut or contaminants in the hydraulic fluid. The contaminants can be removed by filtering the fluid.

I would suggest living with this "feature" of your car or taking it to a shop equipped with Star Diagnosis (SDS). If you have technical skills, then you might consider buying your own SDS for about $900.
Thanks for ideas. This "feature" requires to modify my behaviour ;-). That is possible, but if it is fixable for reasonable money, I would do that instead. I had been to the workshop with SDS several times, a few times for several other problems, they did not find any related problem. After I bought the car, I have asked to change all the fluids immediately, but the shop did not recommend to change ABC fluid (it is for suspension and power steering, just different pressure circuits), as from their POV, it was unnecessary.

P.S. There was recall for these cars in USA, due to problems with the ABC pump, and this recall was carried to this vehicle.

Anyway, thanks all of you for the input, I will post later with any valuable information.
 

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been there done that...

step 1: ABC fluid flush and filter change...they should have doen this after strut replacement, or at least a top off

step 2: load test, and rodeo ... customer observation period thereafter...

step 3: faulty valve block (front, rear, or both)... replace...

if it's the pump error will occur while driving; at rest pump is not active; leak or valve block could be your likely culprit.

Sl500 in the past, Sl55 now - ABC has always been a sore topic, especially ABC gen one...
 

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The problem might be the ABC Valves. There are two (Front and Back). The bad news those valves are about 1500 a piece. The reason I know is mine were both replaced in March. Eventually you will receive a message indicating ABC fault take in to dealership if you keep on driving your SL. The fix also requires a suspension flush which requires P\S fluid Pentosin 1 and a filter you can also try flushing the system to make sure there is no debris in the system.
 

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It is the ABC Valves just had them replaced in my 2003 sl500. The valves are about 1500 a piece. There are two one in the front and rear. You can keep on driving but you will eventually get a category 2 warning (ABC visit work shop) it will happen after 45 minutes of driving. The fix is to flush the system of foreign objects and to put on the rodeo. Your Sl is dropping lengthwise because the valves are not closing.
 

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Discussion Starter #13
It is the ABC Valves just had them replaced in my 2003 sl500. The valves are about 1500 a piece. There are two one in the front and rear. You can keep on driving but you will eventually get a category 2 warning (ABC visit work shop) it will happen after 45 minutes of driving. The fix is to flush the system of foreign objects and to put on the rodeo. Your Sl is dropping lengthwise because the valves are not closing.
I have never had any ABC warning message, or the DTC stored in the memory. I did not understand your idea - does both the replacement of the valve, o flush+rodeo is necessary to solve the problem? Or was valve replacement optional and only flush+rodeo necessary?

And what exactly rodeo means - going with suspension up/down multiple times in the row? For how

It seems a bit overkill to change 3000 $ worth of valves every 5-6 years.
 

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You have a height control switches under the front wheel arch, that would be where I would check.

This could also be a SAM problem, in conjunction with the above where the SAM cannot communicate with the ABC. I would check for any corrosion under the contacts of the passenger side SAM.
When a SAM goes down,it does not know what the car has got, when you start up it may find the lost signal and be OK when it is running, you turn off and it loses it.
Certainly nothing to do with the struts or pump

http://i107.photobucket.com/albums/m309/television_02/DSC00139.jpg
 

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Discussion Starter #15
Hi,

Thanks for ideas! A few questions in-line bellow

You have a height control switches under the front wheel arch, that would be where I would check.
Maybe you have some reference of the procedure. I get the idea, but it would be nice to stick to some good manual.

This could also be a SAM problem, in conjunction with the above where the SAM cannot communicate with the ABC. I would check for any corrosion under the contacts of the passenger side SAM.
Wouldn't that store some DTC/errors in the CPU's? I have found none, when checking with the Command Headunit diagnostics mode, both normal (user) DTC and the internal list.

When a SAM goes down,it does not know what the car has got, when you start up it may find the lost signal and be OK when it is running, you turn off and it loses it.
Certainly nothing to do with the struts or pump

http://i107.photobucket.com/albums/m309/television_02/DSC00139.jpg
Perhaps. But the car looses level lengthwise, not as a whole. If I understand correctly, ABC valves are actuated by some electric actuators, and if something bad happens, like bad connection, or some shorting, valves might open or close unexpectedly?

P.S. Maybe also you have reference how should I get to passenger SAM?

In any case thanks!
 

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The Comand will tell you nothing about the car at all,It must be plugged into STAR

I can send you a paper on the SAM and checking that, its in the little fuse box by the battery. but STAR will tell you what is wrong
 

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The Comand will tell you nothing about the car at all,It must be plugged into STAR

I can send you a paper on the SAM and checking that, its in the little fuse box by the battery. but STAR will tell you what is wrong
Won't this: Mercedes COMAND Diagnostic (Service) Mode be of help?

Regarding the SAM white-paper - that would be nice. Thanks in advance
 

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Won't this: Mercedes COMAND Diagnostic (Service) Mode be of help?

Regarding the SAM white-paper - that would be nice. Thanks in advance
Listen to what TV is saying here, the Command thing will not help you. Only Star diagnostics are of use on this, I will also add that the W220 range had problems with the ABC control units, maybe does not apply in your cars case but with star all can be tested. Especially the SAM's (Signal acquasition module)
 

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I also note that you asked about the RODEO test. This test is carried out using Star and the star computer will take control of your ABC control unit. During this test the car will be rocked front to rear and side to side and also in a circular movement.

This ensures all the valves/accumulators/struts/pump etc etc are all working normally and will be a prelim to flushing the fluid from the system prior to putting new fluid in.

Flushing the system is the first immediate action to be carried out in any ABC problem as it can alleviate the need for costly repairs. :thumbsup: Hope this helps and listen to TV thanks.
 

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You did not mention if the car drops after you turn the car off or while the car is on. It appears to be normal after you turn the car off for the car to drop abit Although it does not happen to all car immediately. I talked to serveral dealers and their specs appear to be a drop of no more then two inches when the car is turned off. The key is that when you turn the car on, the ABC system levels all four sides. That is why the dealers cannot find the problem. If you push the dealer to fix something that may not be broken, they may breake it trying to fix it. I feel your pain. My front right side drops about half an inch when I turn my car off. I had it check at three different dealers. I'm not sure how I'm going to handle this becuase it is a beautiful car, but when you own it and you learn about the car, my god, the cost of the roof, ABC system, and the shocks. Good luck.
 
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