My vehicle was stationary. I stopped the vehicle and placed the shift lever into the park position. When I pressed the start/stop button, the button's amber warning light came on, an audible warning began sounding and all instrument lights stayed on. When I looked at the driver's display, it stated, "shift to park". (the shift lever was already in the park position. I could not shut the vehicle down and could not leave the vehicle in that condition. I continued to move the shift lever from drive to park and after 8-10 shifts, the vehicle finally recognized that it was in park. Then, the start/stop button functioned correctly. Upon investigation, I found that this is a very common problem with 2017-2018 GMC Acadias (there is even a class action law suit pending). Some owners even report their vehicles rolling when in this condition. As of this date (5/19/2020) GM has not recognized this as a design problem and has not issued a recall. This is obviously a design issue since it happens within and out of the 3yr/36,000 mile warranty. If it happens at 36,500 miles the vehicle owner is out of luck! this is also, obviously, a safety issue. Thanks for your time and help.

- Corinth, MS, USA

The contact owns a 2018 GMC Acadia. The contact stated that after stopping the vehicle and placing the gear shifter in park, a message displayed to shift the vehicle into park. The contact shifted through the gears and the vehicle operated as intended. The vehicle was not taken to be diagnosed nor repaired. Neither the manufacturer nor the dealer were notified of the failure. The failure mileage was 41,000. The VIN was invalid.

- Oroville, CA, USA

When gear lever is shifted into park and you try to turn of the engine a notice comes on telling you to put your car into park. I can not turn off the car until this message disappears. Sometimes it takes 7 or more tries to finally be able to shut off the car. If I leave it with the message then all electrical seems to stay on.

- Crete, IL, USA

When attempting to turn the vehicle off after shifting to park and then pressing the start/stop button, the vehicle gives an error message that says "shift to park" even though the shift lever is in the park position. The error message prevents the vehicle from shutting down. This occurs when the vehicle is stopped, put into park, and then when attempting to shut down the vehicle.

- Phoenix, AZ, USA

Shifter assembly went out, known issue and GM won't cover part

- Unionville, TN, USA

The contact owns a 2018 GMC Acadia. The contact stated that when the gear was shifted into park, a warning beep sounded, informed the driver that the vehicle was not in park. The contact was unable to turn the vehicle off. After several attempts, the contact was able to shift the vehicle into park and turn the vehicle off. The manufacturer was contacted. The vehicle was not taken to the dealer to be diagnosed. The vehicle was not repaired. The failure mileage was 37,000. The VIN was invalid.

- Lyford, TX, USA

When I put my vehicle in park, it will not shut off and dashboard it says 'action required. Shift to park.' Vehicle won't turn off and it keeps beeping. It is when I'm parked

- Albrightsville, PA, USA

Went car is park the dash still shows 'put car in park' car will continue to pee, will not lock. From what I read GMC knew of this problem but continue to sell GMC arcadia from 2017 to 2018. Even though this is a known problem they still charge the consumers for the repairs. This only happened went trying to put vehicle I park.

- Pensacola, FL, USA

Vehicle will not acknowledge that it is in park. Forces electrical to stay on, and sometimes will not engage park so vehicle can move as if I'm neutral. Has thus far happened with vehicle stopped, but you can sometimes shut off engine and exit vehicle when it is not in park and can roll against you, or on kids exiting etc. Vehicle rolled in garage and struck, and could have crushed child against door.

- Darien, CT, USA

After putting the vehicle in park, "shift to park" is displayed on the dash. I have to shift the car in and out of park several times to get the vehicle to recognize being in park.

- Coats, NC, USA

When the vehicle is warm, the transmission appears to slip when shifting from 2nd to 3rd gear. The engine will rev between 500 to 1000 RPM while shifting. During this time (half to full second) the vehicle is not accelerating and does not respond to throttle inputs. The vehicle has been taken into dealerships 4 times for this complaint. At 35000 miles (3rd dealer visit), GM replaced the valve assembly. The problem reoccurred and GM is only offering to replace the same part, or extend the warranty on the transmission, but not both. No one at the dealership or GM technical assistance center has any idea what is actually wrong and is not taking any steps to find the cause of the issue. The service manager has admitted that there is a problem, but GM denied him any help in resolving the issue.they have said that this is not a safety issue, but I do not feel comfortable driving a car that may become unresponsive to accelerator pedal input for a full second. Note that this issue is still covered by the powertrain warranty at this time.

- Oakland, MI, USA

Park the car shut off engine and a message comes up please shift to park. The car is in park but it's not being recognized by the computer or drivetrain? have to play with the shifter to be able to shut off car. Only happens when parked and shutting off car.

- Sterling, CT, USA

Put car in park went to kill it and it wont turn off says shift to park it is in park had to do this like 10 times..twice today..my car wont turn off finally got it off. I have only had this 2018 Acadia lead than 1 mth.. I have read where this is a big major issue.. what do I

- Powderly, TX, USA

When the vehicle is shifted into park and the ignition is turned off, an error message is shown saying "shift vehicle into park". usually pushing the shift knob forward and releasing it will make the error message disappear but there have been times that the vehicle had to be turned on and off multiple times as well as shifting from drive to park multiple times to make it go away and turn the vehicle off.

- Oxnard, CA, USA

The vehicle sometimes fails to recognize that it has been put into park, flashing a message on the dash instructing me to 'shift to park' even when the gear lever have already been moved to the 'P' position.

- Fairfield Glade, TN, USA

I shifted the gear into park, and a message appeared saying to "shift to park" and wouldn't allow the car to be turned off or its doors locked. This is a safety issue because the car is unable to shift into park and could roll back.

- Webster, NY, USA

2018 GMC Acadia. The crossover (automatic gear shifter) is failing to recognize that it has been put into park, flashing a message on the dash instructing the driver to 'shift to park' even when the gear lever have already been moved to the 'P' position.

- Ventura, CA, USA

Recevied "action required - shift to park" message on instrument panel screen. Motor turns off but vehicle stays in accessory mode and chimes continuously. Dealer replaced wiring harness that promised to fix the problem, went away for 1 month and came back. Jiggling the shifter or flicking the shifter button is the only way it will go away.

- York, ME, USA

Experienced the "vehicle not in park " when shifter was in park. Engine would not turn off because electrical switch did not recognize the vehicle was in park. After many tries I was able to turn vehicle off. Had vehicle serviced and shifter was replaced (3 weeks ago ). today shifter froze in park yet console indicated vehicle was in drive. Did not remove foot off of brake because vehicle would move forward because it was in gear. Could not shut off vehicle because it is a push button start/stop and foot must be off brake to stop engine. Called dealer for help. Finally we put emergency brake on and pushed stop button. The engine turned off but electrical system was still on. Had vehicle towed to dealer. They will advise in a week or so they are short handed.

- Calabash, NC, USA

Vehicle states "action required - shift to park" even though vehicle is in park. Accessories stay on and vehicle continuously sounds warning chime. This problem occurs every time the vehicle is shifted to park and engine is shut down.

- Weirton, WV, USA