My ABS/TCS lights came on again recently. My wife said she heard a noise under the car recently, but I don't know what that was. I decided to rotate the wheels and try to see what the sensors looked like. I didn't see anything fishy, but I tried to wipe what seemed to be the sensors. Nothing seemed amiss, so I decided I'd live with it and tape over the lights someday.
As far as I could tell, I had TCS codes 49, 31, and 20.
Later yesterday we were riding to Frys Electronics and I noticed the lights had gone out. I haven't driven through any puddles or mud so I wonder if they just got dirty? It kinda reminds me of the electric eye on garage door openers. When they get dirty the door won't close.