Clean your sesnor.

Re: ABS issues.....so my ABS light came on today....
 

For me, it was a cracked ABS Sensor ring on my left rear outer CV Joint. It looks like a stamped piece of metal that is pressed on. Apparently mine was under too much stress, and literally cracked. A friend of mine helped me pull the axle shaft and replace the CV. The sensor ring is not sold separately... You have to buy the entire CV joint.