Hi, Im considering buying a Mercedes SL 55 AMG, 2002 model and 81.000km/50331miles.
The car itself is in very good shape, but there is no warranty that comes with the purchase. Im scared that there will be a lot of faults and problems with the ABC system after reading many bad reviews online. So my question is if the ABC system is really as bad as it sounds? Are there any methods that can be used to test the ABC system to see if it has faults? Is it possible to use OEM parts for the ABC system?

Basically, this ABC system is the only reason I havent bought the car yet.

It's worse. It's not a question "if" but "when" it will fail. The struts break. The pump breaks. The hoses deteriorate (and then break). The hydraulic valve blocks break. However, when it's working it works great. There's a reason why these cars plummet in value: "it's the maintenance stupid"

ABC is like quantum mechanics on a particle level: when you test the system to see if it will break down, it will break down. The "rodeo test" to stress the system puts so much stress on ABC it will likely break while testing or shortly after.

This all applies up to the ABC 2 upgrade on the 2006 facelift.

It all depends on the previous owner. Has he had all the trouble and fixed everything properly, then you might be lucky. But you could also end up with a true lemon.