Vehicle intermittently shifts to a high gear when starting to accelerate or starting from a stop without pressing the gas. As a result, the vehicle starts to shake and sputter, much like what would happen if trying to start from a stop in 4th gear with a manual transmission. Check engine light comes on, traction control and stabilitrak error appears on the display. Pressing the gas simply makes the vehicle jerk. After a few seconds, the error corrects itself and everything clears. Unable to duplicate at will. Took to the dealership today after this has happened around 5 times in the last month; however, no error codes we logged in the computer. Service department unable to do anything. Updated 1/15/2016

- Prattville, AL, USA

Vehicle drove backwards out of the garage while the transmission indicated that the vehicle was still in park. The vehicle accelerated and backed out if the garage on its on, no driver was in the car. The only thing that stopped the car was anther vehicle that was parked in front of our mailbox in which both were struck. I am not sure what went wrong, leaning into the car putting the key in the ignition. Turned around to talk to my son and when I turned back around I was caught by the door. The car dragged me down the driveway and also my son was struck by the car. I suffered a contusions to my right wrist, knee and leg, back pain on the right side, and contusion to the right ankle. My son suffers from bruises to the chest area and contusion as well in the chest area. His leg was also hurt. My daughter who was in the car complained of pain in her jar after the vehicle struck the other vehicle. At this time we have returned the vehicle to hendricks GMC of cary, nc were we originally purchased the vehicle awaiting diagnostics from the service department and collision center.

- Raleigh, NC, USA

I parked the vehicle and left it running with my mother in the car with her seat belt on. As she was sitting there the vehicle rolled forward on its own and hit a Ford F150 parked across from my vehicle causing damage to my vehicle as well as the truck. I filed a claim with GMC and they had someone come to my home and run test on my vehicle and was told they could find nothing. After they finished the test NY locking mechanism is not working properly.

- Norco, LA, USA

When accelerating between 10 and 20 miles per hour, something underneath the body of the car, moves in a circular motion and clunks underneath the gas pedal. This movement can be felt under the gas pedal and floor as well as heard. This occurs 80-90 percent of the time after starting the vehicle. The vehicle also shifts hard into gear at about this mph. The dealership has tested several Acadias and found a GM bulletin on this event. The GM bulletin indicates this is a "normal" cycling of the ABS brake system that occurs on the Acadia and Chevy traverse models. So far GM has been unwilling to resolve this issue, yet because it is a brake issue and is felt under the gas pedal, the safety of this vehicle is highly concerning to me. I drive a variety of vehicles for work and do not experience this rotation and clunk with any other vehicle. I am concerned about my safety.

- Austin, TX, USA

Was going to back out of my garage when I put the shifter into reverse. When the shifter was in reverse, it shifted out of gear on its own into drive and it went forward slamming front end of the vehicle into a refrigerator. Causing the refrigerator to be completely destroyed and the front end of the hood to become crooked. This is very dangerous and concerning as had their been someone in front of the vehicle it would have more than likely seriously hurt them or killed them. I have also had other incidents when driving the vehicle that it will shift from drive to low on its own and this happens frequently at least 3 times per week.

- Sunnyside, WA, USA

I was driving on a highway with the speed limit increasing from 35 mph to 55 mph. I was going about 35 mph. The car in front of me signaled to turn. I applied the brake and slowed down until the car in front of me completed their turn. When I moved my foot from the brake to the gas pedal and attempted to accelerate, the engine roared loudly, but the car would neither shift nor accelerate. I had traffic behind me, but I was not able to go faster than about 20 mph in the 45 mph zone. I took my foot completely off the gas pedal and allowed the car to coast for a few seconds. I was finally able to get the car to shift gears and eventually accelerate to keep up with traffic. I was worried that the car behind me would hit me, but they did not. I was grateful that I was not driving on a busy freeway or attempting to merge into heavy traffic as it could have caused an accident.

- Clear Lake, IA, USA

Vehicle jerks and lurches when slowing to turn a corner, then accelerating, especially when turning left. The transmission seems to downshift, but pauses, then jerks into gear when upshifting when the gas pedal is pressed. This only occurs when I slow down to turn a corner (approx. 10-15 mph), then press on the gas pedal. The lurch usually happens between 15-20 mph. I've taken it to the GMC dealership where it was purchased several times, but they don't know what to do with it. They mentioned that it could just be the vehicle "learning, " but it now has over 4000 miles on it. Their latest thinking was that it was a programming problem, but they said that GMC has not created a software fix for the program, and therefore there is nothing that can be done. They told me that it is safe to drive, so I should just keep driving it. I've contacted GMC, but they just refer me back to the dealership, and they don't know what to do. There are similar complaints from others who are experiencing the same problem on www.acadiaforum.net.

- Clear Lake, IA, USA