abs brakes/traction control light

[kelvin 1995 hawk#29]

Every so often while car is not warmed up the lo-traction light will come on and there will be no braking for about 5 ft then front brakes will lock up. This happens below 5 mph. Car has done this for last two years on and off (possibly 10 times). Car has been two the dealership twice but no ABS codes or any thing ends up showing. They currently cannot trace it to any thing. I haven't noticed any rust build up on rotors prior to this happening. The biggest problem with tracing problem is that it is intermittent and recently has occurred more often 2-3 times in the last month. My GMPP will expire soon and hope to resolve this soon. Any one with any suggestions?