Trac off light

I've had my car for about a year and a half now and
I have had nothing but problems. Now somthing
new has came up. Everytime i turn my wheel all the
way over ether way the Trac off light comes on. If
Im going down a steep hill and applying the brakes
it does the same thing. I've had a abs problem
before and i believe I got ether one or both of the
front "tie ends" replaced. Not sure what's going on
not really good with cars. I do plan on selling it
soon so I'm not sure if i need to have it taken care
of.