I had my Acadia serviced yesterday - oil change, tire rotation, etc. Today I was going home for lunch and tried the "L" manual gears. Transmission kicked into 4th, but no press on the +/- button would move gears up or down. I stopped completely and went into park and then back into L and then it would not leave 1st. I called the dealership - they will be getting it back tomorrow to look at, but figured I would ask here - any ideas on what issue is?