Hello, I have a 2017 Chevy Silverado 1500 4X4, 110,000 miles, was driving down the road and suddenly stopped moving, truck still on but won't move. Goes into drive and reverse but wont move. No check engine light, transmission fluid full, and clean, no crazy noises. Any clue what it could be? I have been told the linkage, or the transmission pump... Any advice is appreciated.