I did some searching to why this happened, and read about dirty connectors. here's the scenario, I was rounding an on-ramp (taking it about as fast as my tires would hold) in 2nd gear, when I hammered down coming out of the turn, the traction light flashed (normal), a few seconds later the ABS, brake, and traction light all came on and stayed on until I found an empty lane and turned the car off and back on. The lights didn't return, but just curious as to what would make all three lights come on. car is a '05 MT touring with 39k miles. I will see later if they stay off all the way home.

 

do you have aftermarket wheels on? do you have different tires in the front/back?
if so that could be the cause.

otherwise it could be either dirty connector or bad speed sensor.