CL500 ABC light flashes red on hitting bumps

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Uav Pilot

Member
Joined
Aug 19, 2014
Messages
44
Location
East Sussex
Car
CL 500
So I recently bought a CL500 without knowing any of the related issues to look out for such as the ABC system, the car looked and felt great so I bought it but after driving for several days I heard the computer beep at me after hitting bumps but nothing was ever displayed on the dash or at least it was that quick that by the time I looked it was gone until one day I happened to look at the dash at the same time as I hit a bump and saw ABC drive carefully displayed in red for a split second. Anyway I took the car to my local official Mercedes garage expecting they would be the best to diagnose the fault?? the next day they phoned me after completing a full check of the car and told me that the suspension is in perfect working order but the car needed a brake caliper so I told them to fix it for me ( £944 ) after the weekend I picked up the car and drove it home and noticed the same issue it went in with! naturally I was a bit ****** off and took the car back... A couple of days later I was told that it needed a new ABC / power steering pump and it would cost £1900 after getting a lift up there and expressing my disappointment with the original diagnosis a day later I managed to knock this price down to £1200 and was told it would be ready the following day. 4 days later I am phoned and told they have replaced the pump and the problem is still there!! So personally I feel that I shoudn`t pay for the pump as it would appear that there was nothing wrong with the original? another day has passed now and have not been informed of the progress and whether it has been fixed! If anyone has any ideas on here on what the issue may be? perhaps I can tell Mercedes what the issue is!
All together I am not a happy bunny and will be going down there today to express my thoughts in no uncertain terms and will expect not to pay for the unnecessary work carried out, after all this is MERCEDES and not some back street garage? Rant over... Any ideas will be greatly received.
 
That sounds like an accumulator problem to me. You hit a bump, accumulators are supposed to absorb the rising pressure in the system and not pass it on as it will otherwise blow a hydraulic pipe somewhere.

Be prepared that overwhelming majority of Mercedes certified mechanics are clueless about ABC issues and simply find it easier to replace everything they can - at your expense. Also in the future ask Mercedes for factory rebuilt ABC components - they will be cheaper.
 
Lexman8 thanks for the info, it looks a very interesting read..
Alx I originally thought it may be the accumulators after reading several forums but thought it better to leave it for Mercedes to diagnose the fault rather than me guessing? as I assumed they would be fully trained and have the correct equipment to sort the issue, obviously I was wrong. I just received a call from them to tell me the mechanic is on a training course today so isn`t working on the car and will start again tomorrow running more diagnostic tests.. Been over two weeks now since I took it in and told everything is in perfect working order. It would appear they have no idea as to what is wrong and will replace everything until the light stops flashing up. One thing it will not be is at my expense! The whole experience has pi**ed me off from the day I picked it up after they replaced my brake caliper, no returning of phone calls, backtracking on what they have told me, my sunglasses gone missing from the vehicle ( Probably from the contract cleaners? ) 10 days and counting since the original inspection and replacement of caliper. If they diagnose a real problem and fix it I am happy to pay and have done but not have them costing me time and money because they are incompetent. I expected a highly professional service for the price they ask and its just not what I got, in future I will take it to an independent specialist on a good recommendation
 
I'm afraid that changing a part and hoping it solves the problem is all too common with MB dealers.

This is partly down to MB's diagnostic system (STAR) being unable to recognise many of the problems with ABC such as issues with accumulators, the dampener, valve blocks, etc. It needs on an experienced mechanic to think the problem through but there are probably only 2 or 3 thousand cars in the UK with ABC so most mechanics seldom see it. Also, many owners will avoid the main dealers because of the costs involved.

You might want to find a good MB indy who can look after your car. The indy I use charges £55 an hour while the local MB dealer charges double that.

Good luck getting it fixed.
 
Does it definitely come up in red, this normally indicates low pressure (pump gone or a fluid leak).

Ive heard of it coming up in blue when you hit a bump and this would be the accumulators? (I could be wrong but I have done ALOT of ABC work on my own car and read alot of threads on ABC so I could have confused myself lol).
 
Ok so after reading the info Lexman8 passed on to me, I confidently went into Mercedes today and asked for the workshop manager and the appointed guy that was dealing with my car and explained what I KNOW is the problem and why and even gave them the part numbers of what was needed and told them to stop all the messing around and guessing what it could be and get on with it asap.. After looking at each other confused and thinking who the hell is this guy? they said they would look into it.. After several hours they phoned back and said that my diagnosis was correct ( The accumulators ) and they would remove the pump and replace it with the old one and get the car back to me as a priority. Of course this would entail the 6 hours already used to fit it and another 6 hours to put the old one back and they would be left with a used pump, so I have suggested they leave it on there and give me it for as little as possible.. Of course plenty of messing me around and wasting my time has gone on before today, including the theft of my Ray Bans and effectively I see that they owe me for not contacting head office in regards to all the nonsense and in fact twice telling them that there was a problem with the suspension, the first time after paying for two hours labour for diagnosis I was told it is in perfect order until I demanded it was not in perfect order the second time I am told it was the pump and now I have yet again corrected them and notified them on what should be done. So unless they want me to take the whole matter further they had better look after me. And I think after this morning and them looking a little silly after me the customer who is not a professional Mercedes technician explaining what is the problem and why? I think they will. I will be sure to report back here with the end result?
 
I don't think the Accumalator will trigger an ABC warning. The Accumulators are just spheres filled with nitrogen. In my experience I have never known an Accumulator to be solely responsible for an actual error to be set. The front pulsation damper has a pressure sensor but this will still function even after the accumulator has failed. I hope your right but in my experience I think you will have to look at getting the actual error codes when the ABC warning happens next and also do a pressure test on the pump (old one as this what's fitted now). The pressure should be 180-200bar, anything less than this is a problem.

What was the actual error code ?
Pump pressure ?
Rodeo test results ?

Hope this helps, it's never easy reading but ABC is a nightmare. (A-B***dy-C**t)
 
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Red warnings are normally down to lack of pressure.
 
It was a low pressure warning due to the accumulators or one of being worn or failing which led them to replace the pump... They have concurred with my diagnosis and offered me the new replacement pump and all three accumulators and all labour and sundries for £1200 which I agreed to as it would probably cost at least more than double that normally. Anyhow I paid that today and no more than 100 yards down the road the ABS kicked in on the front left wheel without me even touching the brakes and nearly pulled me into a lamppost! needless to say I took it straight back with smoke coming from my ears and swearing profusely, even the Mercedes guy dealing with me started swearing at the mechanics in their absence as he was yet again made to look stupid after assuring me everything was good and they accepted the blame for misdiagnosing the fault and had charged me less than the parts came to. The saga will continue Monday when the mechanic comes back to work... At this rate they will be paying me to fix the car before much longer.
 
That's very reasonable. Shame about the ABS issue now.

How old is the car?

Its a 2000 I looked at many CL`s up to 2004 but this was actually the best condition although not as new.. I usually believe that if the car is in good condition it has been looked after rather than abused so the age is not important especially as it now has private plates?
It is a shame about the ABS issue, I expect they damaged something when taking off one of the front hubs? I have already told them that the B service is due in the next few months and I will need looking after on that and in return I will forget this latest episode. To be fair it has been a bit of a carry on and a pain but I have two cars so still have transport... In the long run I would rather deal with a little stress than the open wallet surgery that I originally expected to deal with.
 
Any confidence level must be surely very low on them 'fixing' the issue ... If I was you I would quickly get the car into recognised reputable MB local indie, you will need to negotiate what you have paid the 'stealer' for work carried out refund etc

If you post your area I am sure forum members will advise indie...
 
Any confidence level must be surely very low on them 'fixing' the issue ... If I was you I would quickly get the car into recognised reputable MB local indie, you will need to negotiate what you have paid the 'stealer' for work carried out refund etc

If you post your area I am sure forum members will advise indie...

Well I reckon they should be able to carry out general repairs? I think it was just the ABC system that they couldn`t get their heads arounds? they are probably used to doing what the computer says rather than using their heads.. But a good Indy recommendation would be good for the Surrey area.
 
Well I reckon they should be able to carry out general repairs? I think it was just the ABC system that they couldn`t get their heads arounds? they are probably used to doing what the computer says rather than using their heads.. But a good Indy recommendation would be good for the Surrey area.

I would contact SS Motors near Weybridge, I know they are experts on the R129 adaptive damping system (ADS).

They've had several recommendations on here (apart from mine).
 
hmmm...I think a quick general search on the forum would answer your questions on overall 'stealer' service / repair performance:rolleyes:...most on here use the good indies:thumb:

Well I reckon they should be able to carry out general repairs? I think it was just the ABC system that they couldn`t get their heads arounds? they are probably used to doing what the computer says rather than using their heads.. But a good Indy recommendation would be good for the Surrey area.
 
Also get the dealer to check that these recalls have been done, see pics.

The one for the brakes is actually to replace an ABC line according to my local dealer. For some reason it was never applied to my car but it was done free of charge despite the recall being 8 years old.

They weren't too happy doing it in the end because what was supposed to take 3 hours ended up taking a whole day. Perhaps because whoever did it had never done it before?
 

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Ok I finally got her back today.. With new ABC pump three new accumulators new fluid, filter etc and new steering angle sensor £1200 for what should be around £4000 of work. Also my next B service at a reduced price! Not sure that I would have received the same treatment if I hadn`t done my homework and shouted at them so much? and made sure the head technician got a bollocking after damaging the steering angle sensor and giving me back the car unsafe to drive. All in all I think I had a result and worth a bit of grief but my confidence in Mercedes main dealers is very much different from my initial expectations.... I feel if I was in Germany perhaps I would have received the legendary Mercedes service that was expected?
 
She definitely feels much smoother on the road than before.. Don`t notice the bumps as much, enjoying driving her again.
 

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