This keeps happening usually from a stop (stop light etc) when I've had the brakes pressed. I hear them grind a little bit and the the ABS light comes on, and the problem seems to go away. A mechanic told me that it has to do with how the brake pads are made. They contain a substance that acts like a magnet, or rocks getting into my brakes. This is a frequent issue, is there anything I can do to fix this problem? Do I just need different pads?