Every single time I work on an ABC car and have to test or bleed the system I get interrupted by no fewer than five people exclaiming it’s the coolest thing they’ve ever seen and asking how it’s doing that and “how much it cost to have thoze bagz put in, yo?”, thinking it’s an aftermarket system (it’s not). These questions come from salesmen, porters, customers, apprentice techs, service advisors, managers, and everyone else you can think of.

Now, I’m a car guy, and I like helping people and answering questions and chatting about cars, like most of us here on oppo. But my paycheck depends on me continuing to work, not answering questions that Mercedes employees really ought to know the answers to already. So, this is my attempt at limiting the number of people who will inevitably come to take money from my paycheck before it’s even written, as well as educate and entertain anyone else who doesn’t work for a crazy German car company.

Feel free to ask any questions you have and I will do my best to answer them.

Here are some of the most commonly asked questions and their answers:

Q: How is it doing that!?

A: It’s the ABC, or Active Body Control, hydraulic suspension. This is a cyclical activation of all four hydraulic struts, or rodeo test as it’s commonly referred to. The system uses a pump, hydraulic lines, and hydraulic struts, etc. in place of “normal” coil and shock suspension systems. The pump sends pressurized hydraulic fluid to the struts via an electronically controlled valve block to control both ride height as well as damping force. The fluid typically operates somewhere in the range of 150-200 bar. If you don’t know what that is, the Google will be happy to assist you, and no it does not mean that you have to remain within the vicinity of a drinking establishment at all times.


Q: Does it just do that on its own?

A: Honestly I’m not entirely sure what you mean by that. Can You be more specific?


Q: Umm, I mean, can the driver make it do that?

A: No, it’s a special actuation that can only be initiated with a compatible scan tool or computer. But they can change the ride stiffness and overall height by pushing some buttons on the dash.


Q: That’s pretty cool. Is it complicated?

A: That’s subjective. To me? Not so much. To you and your mouth-breathing friends? I’ll put it this way, ABC suspension alone is more complicated than your riced-out civic and your buddy’s fart-canned STI combined.


Q: Sounds expensive.

A: That’s not a question. But yes, very. And also subjective, again. Most components require many hours of labor on top of their high parts prices. Repairs on average begin at around $1000 minimum and may require $400-500 just to diagnose. ABC repairs can easily reach an excess of $3000 for a single repair.


Q: Does it break a lot?

A: Apparently you have a difficult time figuring this whole subjective thing out. Be that as it may, yes, in my highly tempered opinion. Especially as the components age they develop leaks, fluid gets old and dirty which can gum up sensors, pumps can fail, and pulsation dampers/accumulators can rupture internally and thus stop damping pulsations. Many components in the system are quite reliable, however there are a few components that like to ruin the fun for everyone (as well as ruin your bank account).


Q: Why haven’t I ever heard of this system before?

A: No idea. Especially considering it’s been used in S and SL class Mercedes cars since the introduction of the W/V220 S and R230 SL chassis in the early 2000’s.


Q: Can anything be done to make the system more reliable?

A: Of course! Buy a car that doesn’t have it! Barring that, I personally recommend flushing the fluid and changing the filter periodically, which isn’t a standard maintenance item by the way. But that is also expensive and won’t necessarily always prevent failures. But there are some ABC problems that are resolved by simply flushing the system and that is often a first step in diagnosis. Plus, all fluids break down over time, ABC fluid is no different and it certainly can’t hurt to have new fluid in there.


Q: ABC is super cool and now I want a car that has it. Do you have any recommendations?

A: See a therapist and a financial adviser.

Q: No, I’m being serious.

A: So am I. But fine. Get the newest and nicest one you can afford. Get a warranty. Always have at least $3000 set aside to put into this car when it breaks down. If possible, find one that’s already had some ABC components replaced.


Q: I found this dope S55 AMG for $9900. It’s so cheap but I can’t afford all that extra stuff you were talking about. I think I’m going to get it, it can’t be that bad.

A: You’re dumb. Pick your knuckles up off the ground and think for a second. You can’t afford this car and it will bankrupt you. We haven’t even begun talking about brakes, tires, and other normal maintenance items, which each cost the equivalent of multiple months worth of payments on a brand new civic. If you can afford a brand new STI and have excellent money management skills and high limit credit cards then you can think about affording this car.


Q: Oh, fine. You sound like you really hate these cars.

A: To the contrary! They’re friggin’ awesome! But most people can’t even afford to own used ones, and I hate to see people ruin themselves financially over a car. I am just being pragmatic and I am only capable of having empathy towards automotive things. I would also hate to waste what little empathy I do have on someone’s stupidity.


In summary, stop pestering me when I work.