abc suspension on 2003 Mercedes-Benz S600

left rear of vehicle lays down over night,comes up when i start the car and push suspension button,and works fine all day,no visible leaks,no trouble lights on in car,is it the pump,shock,control module,a leaking valve,ect?????

2 answers
I agree with the above. Identical symptoms as my car. This started yesterday and today a pressurized hose for the power steering pump busted. Have this serviced immediately and do not put it off or it will seriously cost you.
ABC and air-mattic suspension problems, like the one you are experiencing, are common. There are many different causes for these problems. The problem could be caused by anything from a bad shock, leaking line, valve distribution block malfunction, ect.. I recommend having a professional diagnose and repair your issue. In addition, if the suspension does not come up, with the vehicle running, you should have it towed to prevent any further damage.