Shift to Park Warning Message When Shifter is Already in PARK

Leaking coolant from a cracked intake manifold gasket is an extremely common problem on most GM vehicles made from the late 90s to the mid-2000s. Most experts agree that the problem stems from GM's 'DexCool' coolant which erodes away at the intake manifold gasket

GMC Acadia “Shift to Park” issues have caused a lawsuit that alleges the SUVs fail to detect when the gear shift lever is moved to PARK, something that prevents drivers from shutting off and locking the Acadias.

The proposed class-action lawsuit includes all persons or entities in the U.S. that bought or leased 2017-2018 GMC Acadia SUVs.

According to court documents, the Acadia SUVs show a message on the instrument clusters that says shift to PARK even though the gear shift levers are already in PARK.

In addition to losing the ability to shut off and lock the SUVs, owners claim they must resort to all kinds of theatrics to get the SUVs to recognize they are in PARK. Drivers also say the batteries drain and GM has no clue how to fix the issues.

Plaintiff Marlaina A. Napoli-Bosse says she leased a new 2017 GMC Acadia, but in July 2018 the SUV showed a shift to PARK message as she attempted to shut off the vehicle. The plaintiff says the message shouldn’t have been there because the SUV’s shift lever was in PARK, yet she couldn’t shut off the vehicle.

Considering she was on her way to daycare with her child, the plaintiff says she left the Acadia running and unlocked and later took it to the dealer. GMC technicians allegedly confirmed the problem but told the plaintiff there was no fix available.

According to the lawsuit, GM said it was working on a solution but didn’t know when it would be ready, something that caused the plaintiff to park the Acadia.

Napoli-Bosse says she finally resumed driving the Acadia in August but continues to suffer from the shift to PARK problems, leaving her stranded multiple times inside the vehicle and unable to shut it down.

The plaintiff says she must continuously wiggle the shifter and repeatedly shift to other gear positions and back to PARK just to get the vehicle to recognize it is in PARK.

GM knows about the issues because the automaker sent a technical service bulletin (TSB PIT5616A) to GMC dealers in June 2018. The TSB talks about a shift to PARK message when the Acadia is already in PARK. The TSB further says the vehicle may not shut off when in PARK and may not start due to an “unknown” cause.

The Acadia TSB gives technicians directions in an effort to fix the issues, but in the end the bulletin says:

“Engineering is still investigating the root cause. DO NOT CALL GM Technical Assistant Center for an update on the PI. The PI will be updated to a bulletin once the final root is understood.”

Model year 2017 GMC Acadia owners complain about the same symptoms as the plaintiff suffered.

“Placed the vehicle in park, it was stationary and it rolled forward. Message in the info center said “shift to park”. I was parking in a mall parking lot.this has occurred 5 times. I can push the gearshift back and forth and then it can be turned off and the message will disappear. I took it to the dealership and was told they are waiting on GM to see what can be done.”

The lawsuit alleges GM continues to benefit from selling and leasing defective SUVs as consumers are left questioning if they should have purchased the Acadia SUVs.

The GMC Acadia shift to PARK lawsuit was filed in the U.S. District Court for the District of Connecticut - Marlaina A. Napoli-Bosse and Brandy Smith, et al., v. General Motors LLC.

Vehicles That Might Have This Problem

Model Generation Years PainRank
Acadia 2nd Gen 2017–2018 9.58

Story Timeline

Get FREE email alerts from with new information about this problem.

Learn about the news before others. Impress your friends. Be a hero.

Free Vehicle Alerts

OK, Now What?

Maybe you've experienced this problem. Maybe you're concerned you will soon. Whatever the reason, you can help make sure it gets the attention it deserves.

  1. File Your Complaint is a free site dedicated to uncovering problem trends and informing owners about potential issues with their cars. Major class action law firms use this data when researching cases.

    Add a Complaint

  2. Notify CAS

    The Center for Auto Safety (CAS) is a pro-consumer organization that researches auto safety issues & often compels the US government to do the right thing through lobbying & lawsuits.

    Notify the CAS

  3. Report a Safety Concern

    The National Highway Traffic Safety Administration (NHTSA) is the US agency with the authority to conduct vehicle defect investigations & force recalls. Their focus is on safety-related issues.

    Report to NHTSA

  4. Contact GMC

    GMC Support

    P.O. Box 33172 Detroit MI 48232-5172 USA

    This site is not affiliated with GMC.