ABC active body control light came out and the car rear level is not the same... on 2001 Mercedes-Benz CL600

since the ABC light came out the rear leveling system is not the same, can some one help me if you know the answer.. thanks my car is 2001 600cl and it is V12

Asked by for the 2001 Mercedes-Benz CL600
It can be several things. One or both of the rear struts require replacement($2,000 each), hydraulic leak or level low, hydraulic pump malfunctioning. I have the same car and have spent $7,000 so far this year on the suspension.