I'm pretty sure that your" winter mode " is just putting the car in 3rd gear yourself. Even though you have the symbol on the gauge cluster for winter. And I don't recall if the 3.6l cars actually have a sport button?? I just remember that no winter mode turns on, with the 3.6l car. Pretty sure

 

My sport mode nor winter mode is working. I checked to see if maybe it wasn't plugged in and that's not it. Cleaned it the gunk out and still nothing. Pressed it to see if maybe a difference in shifting but there's no help there.