not necassarily, the ABC light indicates there is a problem in the system anything from accumulators not working, to valve body plugged up, or a blown cylinder/strut or even a leaky line.
while the most common problem is the pump not working properly (making correct pressure)
it is a situation that needs to be diagnosed with a Mercedes specific computer (Star Diagnostic System)
that will let you know what the issue is. Alot of this system depends on clean fluid, (specific CHF 11s)
DO NOT USE ANY OTHER FLUID. Change out the filter in the "oel" reservoir at the front of the drivers side fender. (LHD Cars) then perform a flush, then change out the filter one more time, and youre good to go.
this skims over the basic stuff. there is alot of pretty technical stuff connected to the Automatic Body Control system. when it works its amazing, when its malfunctioning its terrible!!!
good luck with repair!