Hi! I'm sorry about my english, I'm from Catalunya in Europe, and I don't speak it very well. We have a Tahoe 2003 and it shows the message "4WD Service" sometimes, also the light "neutral" on the traction buttons apears ON, and all-traction doesn't run. now it has 60k miles, what can it be? In my region/province there are only Opel/GM Services, and don't know so much american cars, only european, maybe I can help them with your info. Thanks a lot.