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.Google+
Car Problem Reports
Mercedes-Benz CL600 Active Body Control System Can Leak Hydraulic Fluid
Mercedes-Benz CL600 Problem
Average Mileage: 65,833 mi (25,000 mi - 140,000 mi)
Visitor, 2004 Mercedes-Benz CL600, 81,000 mi
Found hydraulic fluid all over the garage floor. Vehicle being towed to the shop. ABC warning popped up
Visitor, 2001 Mercedes-Benz CL600, 140,000 mi
my front struts will not raise when i press the leveling buttons...
Visitor, 2001 Mercedes-Benz CL600, 36,000 mi
The dual power steering/active suspension pump is leaking. To avoid the system going out I am replacing the pump, flushing the system etc. cost $3000+. It's a pain way to expensive etc but the car is a dream in performance,m comfort, looks etc. It is after all a very expensive car so repairs will be expensive. To bad a car this expensive and good can't also be reliable.
Visitor, 2002 Mercedes-Benz CL600, 58,000 mi
For some reason the car decided to lose pressure and the ABC system is going out. The dealership says that it is the purge valve and is going to cost $600 to fix. This is an extreme set back in the overall quality of this car.
Visitor, 2004 Mercedes-Benz CL600, 65,000 mi
After stored for the winter the suspension has dropped on all 4 wheels to the point they are higher than the fenders.
Visitor, 2003 Mercedes-Benz CL600, 36,500 mi
ABC light is on. Suspension sags after 2 days sitting in the front of the car.
Visitor, 2005 Mercedes-Benz CL600, 77,000 mi
7 failures in the first 77,000 miles. 2 pumps, 4 struts, 2 accumulators,3 lines
My ABC lights are on and it says that the car is too low to drive. Had it repaired and two weeks later the same thing happen to my 2000 S 430.
Visitor, 2004 Mercedes-Benz CL600, 68,000 mi
I had a similar issue on my 2004 CL 600- V12. Both the Red and white ABC light dispalyed in the instrument cluster. I had to replace the dual stage hydrauic pump. Found an OEM on ebay for $800. Mercedes dealer quorted me $2000. I had the dealer repalce and install. Total cost to repair was $2000.
Visitor, 2003 Mercedes-Benz CL600, 46,000 mi
Leaking hydraulic fluid from the suspension reservoir. May install solid metal struts instead.
Also warn suspension bushings. Have to purchase the whole part, not just the bushings,
(crappy German engineering) Most unreliable car I have ever owned!