Check Brake Lining Warning? 2002 3.0i

Does anyone know what this means? The light came on last week and I'm not sure if I need to pay to have someone look at it. The brake pads seem to be brand new...PLEASE HELP!!! APPRECIATED!!!!

same problem found on my 02 3.0 x5...i had just recently replaced pads and sensors when the check lining warning came on...took it in to my mechanic and he fixed the prob with a new caliper...the caliper was evidently putting pressure constantly using one of the rear brakes...couple of weeks later and same problem shows up...he doesnt kno wat it is so i guess imma have to bring it to bmw...if u fixed this prob please let me kno...the light can be temporarily turned off by putting key into position 2 and leaving there until light goes out on dash