T - Traction control
Traction control - An electronic system which limits the amount of slip through the driven wheels of a car during acceleration. This should stop the wheels from spinning in low-grip situations, such as on wet or muddy roads.
In some cases, the traction control system can be turned off by the driver via a switch on the dashboard.
Traction control is not to be confused with stability control, which keeps a car under control during emergency manoeuvres.