2006 Chevy Cobalt traction control light stays on

Every time I pulled out of the McDonalds close to home, I would make a left at the light, over a low point on the road, like a ditch, or a continuation of the water drain I guess.
Every time my front wheels crossed this dip, while accelerating, the front wheels lost a bit of traction, causing the TC light to come on. After that, gear shifting would get VERY ROUGH and sudden (Automatic trans.). I took it to the dealer because I got the extended warranty. They found the problem and fixed it but were never specific about what exactly it was they fixed. I think they called it a recall and was free of charge. The light has never come back on, but the Traction Control definitely works. They blamed something in the front end. Maybe something having to do with the Electric Steering.
Chevy needs to start building quality vehicles for a change.