Q: Car not moving in gear

If your Buick does not move in either drive or reverse, I suspect an internal mechanical problem. The reason for this is that a vehicle will generally be able to move forward and backward if the main mechanical components are intact. So, the transmission’s electronic and hydraulic controls can most likely be ruled out. However, I would suggest having a professional inspect your vehicle’s first hand before condemning the transmission. They will be able to diagnose your gear issue and determine what repairs are needed.