Truck is a 1997 dodge 1500 4x4 with 360.Can the speed sensor cause this or is it something else.The brake pedal feels fine with good braking.I checked the codes by grounding pin 13.It showed code 6 which was erratic speed sensor reading while rolling.I replaced the sensor.Didnt work so I took it back out and cleaned the mounting area really well (rust buildup)and replaced it.I have driven it about 50 miles with no lights coming on so maybe its fixed.Thanks to all who helped.