Active Body Control System Can Leak Hydraulic Fluid on Mercedes-Benz SL550

Problem Description and Possible Solution

The active body control system can leak fluid from numerous areas, including the tandem pump, hydraulic lines, struts, and/or seals. If it is not repaired, the vehicle ride height could drop too low and cause damage to the undercarriage.

Problem Data
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Average mileage: 48,305 (23,000–85,000)
4 model years affected: 2007, 2008, 2009, 2011
39 people reported this problem
Viewing 1 - 20 of 20 comments
ABC malfunction showed on dash and car went into limp mode. Dealer diagnosed as pump failure $4,700 to replace. No observable leaks and fluid level was correct. Car did not squat. Problem occurred at end of winter could be temperature related. All this was after front strut and hydraulic hose replacement 5mo earlier.
Instramentation went all red. Displayed "stop car now". I pulled over, the car proceded to drop to the ground and hydrolic fluid poured out from under the front of motor area. I believe a pump and a hose were replaced.
Received warning "ABC Malfunction Stop Car" Had car towed to dealership. Hydraulic line had come apart and hydraulic fluid sprayed over engine. Estimated $1200. They called later that day to say that system is still not operating correctly. Initially had told me that the pump was okay, but I suspect after reading the other posts that the pump may be bad as well. Seems by the number of posts that perhaps this system was not engineered very well. Damn Germans...
I was leaking fluid on left side & replaced Left front strut (1400) but next day noticed one loud bump noise in mid-undercarriage when engine was cold & I went in reverse (out my garage). No other bumps but I had a whirring/grinding noise once when driving. A few days later, ABC light came on, car riding very low, looks like front Right strut.....this is disappointing but I know it's going to be $5000 before this nightmare is over...have heard it's the entire system that goes bad (not just strut).
vibration and noise at idle and when accelerating. Dealer found noise coming from ABC/Power steering pump and PS hose leaking. Estimated repair cost $4470.
ABC Alarm came on and when I stopped, the body dropped onto the wheels had to have it towed and the dealer replaced a hydraulic hose.
The outside temperature is below ten degrees, my tire pressure sensor alarmed and I checked the tire pressure and it was in spec (I'm told the sensors freeze up) it has always gone away once the temp reached 30) now to complicate matters the ABC alarm went off and when i stopped the suspension was high enough to steer so i drove it home, but when i turned it off the body dropped onto the front wheels, so now I have to have it towed again.
Ruptured ABC line. Mercedes dealer did the repair. No charge with MBZ Extended Warranty. Cost would have been $2052.
My car started bouncing as I was driving down the road and the ABC red warning light came on. I looked it up in manual and it
said to pull over and not drive. Had to have car towed into dealership and lucky for me, it was covered under warranty. The ABC system had failed!

A year later, there was a leak in the hydraulic system and it was also covered under warranty.

I now have 64,000 miles and took in for scheduled service and the ABC pulsation damper needs replacing ($1143).
The car makes a whirling sound and it also makes a knocking noise when slowing down?

Very disappointed.
I have a 2009 SL550 and have just taken it in for this same problem. Glad to have read this report. The Service Dept is keeping my car another day to make sure it has no other leaks.