Mine is a 2013 GT.
Click TC button once and TC is off
Click TC button twice fast and Sport mode is engaged.
Hold TC button for 5 seconds and Advance TC is off
On the street with bald tires I would spin with TC on and definitely with Advance TC off. With sport mode it would just launch with little wheel spin.
I have also got my best time at the track with Sport mode on.
There is also a sport mode for the steering feel on the screen menu but that's completely different.