Bi-xenon headlight self leveling

[Green is good]

Anyone know the answer to this? Headlight self levelling doesn't seem to work now. Tonight on the way home I noticed that the lights on dip are pointing at the ground in front and have no range. They used to light up in front of the car so well. Before, turn on lights and you would see the lights lift up, now nothing. Have I managed to switch this function off somehow or is it a malfunction with the self level system? Anyone had this experience? Car is a 2005 3,200 C class estate, don't know what W type this car is!