2019 GMC Acadia

My Acadia keeps an error message of "Shift to Park" this has been happening on and off for about 8 months. Now it goes on every time I try to shut my car off. I have to stop and start it up to 20 times before it shuts off. I am concerned that I may be somewhere and won't be able to turn it off. I know there have been recalls for this and I need this repaired. It's obviously a flaw on GMC and honestly, I should not have to pay for it. At this point, the car is only used close by my home. I don't feel safe using it. Please help. Not only me but all drivers affected. Thank you

Owner of a 2019 GMC Acadia Denali (VIN: [XXX] , current odometer ~87,164 miles), purchased new. In early February 2026, the check engine light came on. Independent diagnostic scan confirmed persistent P0420 code (“Catalyst System Efficiency Below Threshold Bank 1”) as current, history, pending, and permanent. Inspection showed the front exhaust pipe bracket had snapped, damaging the flex pipe and causing an exhaust leak. This failure mode directly triggers the P0420 code and requires replacement of the bracket and affected flex pipe section. This is a known recurring issue on GM’s Lambda-platform vehicles (shared platform, 3.6L V6 engine, and exhaust system design). GM Special Coverage Adjustment N212356540 covers 2019 Chevrolet Traverse and Buick Enclave models for front exhaust pipe bracket separation (resulting in pipe damage, holes, leaks, rattling, or efficiency codes), providing free repair for 15 years or 150,000 miles from in-service date, regardless of ownership. The failure on this Acadia is mechanically identical, yet the model is excluded from coverage despite matching part design and numerous similar owner complaints documented on NHTSA and BBB reports. Multiple attempts were made to resolve through the selling dealership (no response to service inquiries). Matter was escalated to GM Executive Resolution. GM required a redundant diagnostic scan at an authorized dealer (additional cost incurred), despite independent confirmation of the issue. GM ultimately denied any coverage, TSB applicability, goodwill assistance, or further support. The snapped bracket and resulting exhaust leak can produce noise, fumes in cabin, potential component damage, and emissions noncompliance via false/legitimate catalyst efficiency codes. Inconsistent application of coverage for the identical defect across equivalent Lambda-platform models raises concerns about a widespread safety/emissions issue affecting 2019 GMC Acadia. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

My 2019 Acadia often will not turn off because it has a Shift to Park issue. Apparently it is caused by a faulty microswitch in the shifter assembly that fails to signal the Body Control Module when in park, leading to a persistent warning message, inability to turn off the vehicle and battery drain. It has been going on for at least 4 years. It appears there is a recall for this problem but when I search my VIN number a recall does not come up. There are many posts that say "certain" models in years 2017-2019 but why not mine? It is definitely a safety issue because it does not turn off.

Vehicle experiences multiple simultaneous failures including “Steering Assist Reduced / Drive With Care” warning, extremely loud cooling fan operation, temperature gauge not functioning, tire pressure monitoring system failure, and widespread electrical issues (windows, mirrors, infotainment delay). Issues occurred together and are consistent with numerous owner reports for 2019 GMC Acadia models. Condition affects steering assist and engine temperature monitoring, creating a potential safety risk.

Check Engine Light came on with message of "Steering Assist is Reduced Drive with Care". This same thing happened to my sister-in-laws 2019 Acadia 2 months earlier. Took it in right away to the dealership to find out it's the thermostat, it's a common/known issue and it isn't covered under my extended warranty and will cost ~$1300. I'm seeing this is a common issue for Acadia's and has not had a recall, don't understand why. It's one thing if this is a easy part to replace, but GM has made it so that most people now need a dealership or auto repair shop to fix it.