2019 GMC Acadia problems

“While attempting to turn vehicle off, the message shift to park was given. Could not shut vehicle off! Has happened multiple times in the past, then disappears for awhile. Comes back again at will. Have seen multiple complaints on this issue falling back to a defective micro-switch within the shifter assym. Former GM tech here---”

“When putting the vehicle in park to turn it off, the dash indicates that I need to put the vehicle in park. But it is in park and it will not let me shut off the vehicle.”

“I own a 2019 GMC Acadia equipped with the 3.6L V6 engine. VIN. See form above In 2025, the engine coolant thermostat failed on my vehicle and required replacement at my expense. I am submitting this complaint because I believe this may represent a recurring component problem affecting 2019 GMC Acadia vehicles and I would like NHTSA to determine whether the condition presents an unreasonable risk to motor vehicle safety. General Motors has published service information addressing thermostat-related conditions on GMC Acadia vehicles equipped with the 3.6L engine. GM has also issued special coverage for an engine coolant thermostat condition on certain GM vehicles. GM’s special coverage describes a thermostat that can open at a lower temperature than intended, resulting in a malfunction indicator/check-engine light and diagnostic trouble code, and in some cases causing the engine cooling fans to continue running after the vehicle is shut off. My 2019 Acadia uses the 3.6L engine and the thermostat assembly addressed in GM’s service information. Despite this, my 2019 model year is not included in the current extended thermostat coverage. There is also a second,…”

“I am submitting this complaint to request that NHTSA investigate a potential safety defect involving the engine coolant temperature monitoring system, thermostat/engine coolant temperature sensor system, and its relationship to reduced steering assist in 2019 GMC Acadia vehicles. My 2019 GMC Acadia, currently at approximately 91,500 miles, has experienced the following symptoms: • The engine temperature gauge remains flat or reads abnormally low/cold. • The cooling fans run continuously at extremely high speed, creating a loud "screaming" fan noise. • The vehicle displays the warning message "Steering Assist is Reduced — Drive with Care." • The vehicle has a history of diagnostic trouble code P0128, "Engine Coolant Temperature Below Thermostat Regulating Temperature." I am concerned that these symptoms are related and represent a potential safety defect rather than an isolated thermostat or cooling-system repair. GM has issued bulletin PIT5967, "Service Steering Message With P0128," which applies to GMC Acadia vehicles from model years 2017 through 2023. The bulletin states that when P0128 is present, the ECM may be reading coolant temperature incorrectly and…”

“• Gearshift- It is, available for inspection upon request. • You are unable to turn off Vehicle, your trapped in vehicle. Until parking gear shifts into park and you’re able to shut off the vehicle. • Independent service center. • No • No”

“Headlights are so dim that we will not drive the car at night. Dealer's service manager says that he knows about the problem but "there's nothing I can do to fix it". I see a few similar complaints on this site, but nothing as to who to contact to get the problem solved NOR any action on this on the part of the NHSTA. Where do we go from here?”