I too have been fighting this issue for several months. I've replaced all of the brake calipers, disks, checked the steering wheel angle position, bled brakes, bled brakes, and bled brakes and it seems to be son almost all of the time. Twice in the past week or two, the light would be off when I was starting my trip going to or coming home from work, but inevitably it would illuminate a few minutes into the trip. What sucks is that everything works great, except I can't use the cruise control with that light on. I changed the rear calipers a week ago when the sudden, but very momentary improvement started occurring. Four or five months ago, I replaced the speed sensors even though they worked. Iv'e use alfaobd several times to clear the fault, then to graph what I can and see if some signal falls off or spikes when the light comes back on, but nothing seems to change, all of the speed sensors work, everything looks normal as far as I can tell.