HELP! Active Body Control Drive carefully on
- Low pressure from the ABC pump
- Valve block malfunction
- ABC strut broken
- Leaking of one of the above
Usually this is bad (expensive) news.


The dealer discovered that the ABC pump was also bad and ordered me a new one. In my case, everything seemed fine with the ABC and there were no faults for either problem just an intermittent lack of acceleration related to the the overtemp issue.
I have to believe the dealer on this, because I am still covered under warranty and am not paying anything out of pocket.
Rob
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The dealer discovered that the ABC pump was also bad and ordered me a new one. In my case, everything seemed fine with the ABC and there were no faults for either problem just an intermittent lack of acceleration related to the the overtemp issue.
I have to believe the dealer on this, because I am still covered under warranty and am not paying anything out of pocket.
Rob
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I actually am picking the car up from the dealer tomorrow, so I can't speak to the success, but the dealer mentioned replacing an electric cooling pump and temperature sensor. He explained that the overtemp fault on the intercooler (which did not activate a check engine light) shuts down the boost and makes it feel like the car goes from accelerating hard to revving without power, simulating the transmission slipping. I am anxious to see if this fixes the problem. It only happened intermittently before and usually after I had passed a number of cars. So I can kind of believe the overtemp thing, but it hasn't been that hot in Colorado so if the pump or sensor was failing maybe this will be the solution. The problem with an intermittent fault is you never really know if it is solved. It may just happen later.
BTW, nice rides!
Rob
Thanks for the info. Please let me know how the car drives as these parts have been replaced. It is very hot in Trinidad (The Caribbean) so I believe that the heat is at my disadvantage. I also experience the part where I am not able to cross 90km/h but the rpm goes very high when I punch the gas. At times I would feel like a sudden "jerk" from the transmission and this is when my problem arises.
Yes, your symptoms sound the same as mine. I confess mine occurs when I am repeating full acceleration and it can generate the heat. I would just expect at an ambient temperature of 75 degrees F, MB would have the car running that way all day long. I will let you know if it seems to be fixed. (or even if not)
Rob
The coolant stops flowing and the intake charged air is no longer cooled, and once it reaches a certain temperature the ECU will disconnect the supercharger clutch and you will be driving a naturally aspirated 5.5L AMG car.
Nice to hear that the dealer is covering everything under warranty.
You may be right. And 3 hours ago, I would say you were definitely right, but something has happened since then. I left the dealership with my "repaired" car and 10 minutes into my 2 hour drive home, my "Coolant" (Get service; or whatever the words were) message came on. I turned around and the dealer asked me to give them a few minutes to see if there was air in the system or something else easy. An hour later they said my fan was not turning on and they didn't know why.
I am thinking this did not coincidentally happen in addition to the coolant pump. It is possible, I'll grant you that, but it would seem an inoperable fan may have also caused the overtemp fault. Again, there was no CEL for me, only stored codes for the dealer and the temp gauge crept, but not enough to cause me to do more than note it.
They may have reinstalled everything and messed up the connection to the fan somehow. The dealer was quick to replace the pump in agreement with your comment that they seem to all fail and they noted that the pump failed their checkout so I believe that it is still a likely cause.
Regardless, I now have a new coolant pump, a new ABC pump, and a new AC compressor pulley at no charge to me. My concern is that the dealer may be using a R&R strategy to fix my car vs. really knowing what is wrong. I will get a new fan out of it (according to them) and I am a big fan of them replacing everything under warranty, but when warranty time runs out and I need to have a repair done, I want to know that they know what is wrong and don't expect me to fund their R&R methods.
Rob
Rob
Benzino118,
I would have to say this is your problem as well. When you mentioned the sudden jerk of the transmission in addition to the rest, I knew we had the same problem. I failed to describe that part in my initial message, but I definitely noted it occurring when driving.
On a final note, the dealer had my car for about a week. They initially gave me a C300 4MATIC and then an ML320cdi. I wasn't a big fan of the C300, but liked the ML quite a bit. We have the R320 and that diesel pulls great in whatever they put it in and makes for an easy drive. Still, I lost perspective on how amazing the CL is. I missed that car so much. The driver from the dealership that dropped it off couldn't stop commenting on what a nice drive it was (2 hours from the dealership to my work). When I got in in to go back home, I quickly realized that while that Silver Star signifies some great machinery, the CL is just a cut above the rest. Phenomenal.
I am very happy that you have gotten back your car with it working properly. Thank you for helping me out with my problem. I will have the intercooler pump replaced. Any other parts I should change in addition to the pump? I see you have also changed the intercooler electric fan. Is it recommended that I change this as well?
regards
Yes, I saw the intercooler pump referred to as "coolant pump" as well on various paperwork. Also, when the intercooler fan faulted and sent a message, it said "coolant", not fan or intercooler. So they are consistent with the "coolant" portion of the message for the intercooler intake.
Maxwell79,
Sorry, I am not ignoring your post, but I don't have the answer.
Two days ago, I overshot a turning and reversed the rear end onto some uneven ground while the front wheels stayed on tarmac road surface. There was a sudden graunching noise like tyre rubbing on body and immediately as I drove forward the ABC warning light came up.
I stopped the car and applied some body weight to the rear end (hopefully) and guess what...the light extinguished and the car drove fine . The next day I started up and drove 100 miles before taking a break....when I restarted, the ABC warning light came back on. Once again some weight to the rear end and presto...back to normal. I set the body height up to max and then back to minimum and selected sport on the ABC and drove another 100 miles. When I came to start again, same old light....so I applied the same old body weight to the rear end and got the same old result....problem sorted.
It seems that each time I turn the engine off, the ABC warning light comes up....what's going on here?
I know for sure that the local MB dealership will say..." you need a new ????whatever and it'll cost at least £2000 to fix it".....they don't know and don't want to find the fault so they just do the old R & R and take your money. The car by the way has done 57,000 miles.
Could this be a rear end link broken or perhaps a solenoid or valve that has opened up too far and won't fully re-set? I'm betting it's something small on the rear end suspension assembly.
I would appreciate any constructive advice from anyone out there.
Thanks
Back there you have your rear axle valve block with pressure accumulator, 2 height sensors and the struts themselves.
You need to bring it to a mechanic that has the Mercedes Star Diagnostic system so he can check out the codes that the system is throwing out.
I'd highly advise you against continuing driving without getting this checked out... could cost you a lot more.







