Dodge: brakes, 2002 dodge 1500, abs brake

Question
hello i have a 2002 dodge 1500 ,v-8 ,4 doors truck one day i had to apply brakes really hard an noticed my abs/brake light came on . i checked the pads and found them low so i changed all pads thinking this would cause the light to go off but it didn't.now i'll drive about 4 miles and the light pops back on and it apply light pressure to the brakes not where it smokes but i can tell the speedometer jumps.thank you for any help

Answer
Byron,
There is a sensor located on the top of the differential on the rear end.Change this part and see what happens.It costs about 12$.This can cause the light to stay on.Did you bleed the brakes after installing new ones?The only thing is,the sensor will not cause the brakes to smoke.Could be a bad caliper.