While I can't offer any official diagnosis, the manual for your vehicle states that the Traction Control light may come on "if there is an engine-related and brake system problem that is specifically related to traction control, the traction control system will turn off and the warning light will come on." There are other reasons the light may illuminate, and they can be found on p. 3-28.
Are you planning on getting this looked into? If you decide to do so with a GM dealership, please let me know as I would like to be available to you in any way I can be of assistance.
Sarah
GM Customer Service