Not sure of it matters, but on a 2011...
Anytime, single press engages/disengages traction control.
Applying brakes anytime (moving or stopped) puts into "sport mode" on premium models.
While in park (for us autos), press and hold (5 or 10 seconds... Can't remember) completely disables advanced trac (traction and stability control).
2011 Black Mustang GT Premium
Corsa XO & Sport AB/Airaid/Bama 93R
Best 1/4 mile to date 60' 2.009
12.538 ET @112.33
100+ Deg 85 Hum RPR 3PM 1/2 tank street tires