abs and brake light on?

i have a 2000 5.3, and as i am driving i will have both the abs light and the brake light come on. when i restart the truck they are both off again, but after i drive a few miles they come on again. they are not triggered by anything, meaning i dont hit the brakes or anything they just come on while driving. im hoping i dont have to replace the ehcu but i would appreciate any feedback. thanks in advance.

Welcome to the forum. Lots of good info here. Do a search and you should come up with a number of possiblities and solutions. The same thing happened to my '01. Get underneath and inspect the ECBM located under the drivers seat and bolted to the frame. Check the wiring. The ground wire on mine was completely corroded. Instead of having to replace the ECBM, I was able to cut out the corroded section and solder a new ground wire splice in. Lights went out on their own and ABS function was restored. Problem solved.

thanks for the tip, ill give it a try as soon as the weather lets up