Abs and traction lights come on randomly...

Hey. I've had my '12 kk for 2 weeks now and it's happened about three or four times but randomly while braking my ABS and traction lights both come on. When I shut the jeep off they aren't there when I start it back up. My dealer checked for error codes but found nothing (while lights out) but I haven't had a chance to go there with lights on...
has this happened to anyone else? Or any ideas?

Is it only the Trac/ABS lights, or is it all the lights in this picture? If its the ESP/BAS and Serv 4WD as well, its probably a wheel speed sensor or associated wiring. Is the dealer reading the codes via the WiTech or just a standard OBDII reader? ABS codes are stored for about 50 key cycles, so they should have shown up when they checked the ABS module for codes.

My 06 started doing that and it was the speed senser. Not sure about newer models, but they had to replace my wheel bearings because the speed sensor is built into them. I thought it would be expensive, but it didn't turn out too bad, less the $300 if I remember correctly.