This just started recently. When I put my truck in gear, especially after backing out, the Tow/Haul is engaged. I have to drive a short way, then stop, put it in Reverse, and then back in gear to get the light on the dash to go out. It then drives and shifts normallly. The truck doesn't respond to the button on the end of the gearshift. The gearshift is on the column. Any ideas on what is going on?