NHTSA Complaint #11502077 — 2015 GMC SIERRA 1500

I was driving my GMC Sierra upon entering the highway, I was at a stop sign waited for clear traffic when it became safe to do so, I entered the highway and upon excelling up a small incline the vehicle transmission just completely stopped working so as I depressed the accelerator the engine would would wind the RPMs up but the vehicle wasn't going anywhere. I pulled the car over to the side of the road and placed the car in park. Put my emergency lights on and couldn't get the truck to the to go to the area to be free and clear of traffic to transmission engage. I put the car into reverse this is the second time this has happened and this is what my husband recommend I do. When I called him is to place the vehicle in reverse reverse a little bit and then place the car into park and then turn it off. Start the car up again and see if it would engage the gear, it took placing the vehicle in park. After adjusting the steering column and trying it again, the transmission engaged but would not reach the full acceleration. I was on a hill so I put the brakes on and the car brakes would not stop the vehicle. It would bounce and skid a bit as I was on an incline. The transmission was not engaging in reverse either. After resting then it didn't get any speed. There are RPMs just kept whining out. I wasn't able to at first get the car to go into gear after wiggling or adjusting the steering column then it seemed to go in gear but it would only go a few feet and then it the process would start over. this was dangerous as I was on a highway with an incline which means I had no break ability so I was rolling without control. I was able to get the car home and parked in my driveway but as this is the second event that has happened since we purchased the truck I'm making this report. Feel free to contact me if needed