2024 GMC Yukon

Issues with the google voice, transmission issues, engine failure to start or restart. Reported same year vehicle was bought. Repeatedly. Dealership even with video evidence stated could not repeat issue and nothing wrong. My car then starts rattling in the engine and they do a full replacement had it for over three months. Now it’s leaking fluid and smoking. They try to send the consumer away and delay delay until the warranty is over. Unethical practices. They knew there was an issue with my engine as it was on the recall list but kept denying any issues until complete failure. Now less than 20 days after that repair the car is leaking and smoking.

This is a supplemental report to my original complaint (NHTSA ID XXX) regarding my 2024 GMC Yukon (VIN [XXX]). I am providing additional detail: prior to GM's recall being issued, I contacted Hatchett Buick GMC by phone and visited in person on multiple occasions reporting engine sputtering, stalling, hesitation, and total loss of power and electrical shutdown while driving. I was repeatedly told these were minor issues not affecting anyone and not to worry about them. As a result, the vehicle was not formally serviced for these issues until September 2025 — roughly three months after the recall was finally announced, more than a year after I purchased the vehicle. Since that recall repair and a subsequent "best guess" repair performed by GM technicians (their own description, not mine), the vehicle continues to sputter, hesitate, stall, and intermittently lose power. I have ongoing safety concerns driving this vehicle INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

On August 6, 2026, I was driving my family up to Whitefish Mountain Resort (a steep mountain road to a ski resort) for dinner when the ESC warning and "Brake System Failure" warning appeared. I immediately attempted to pull safely to the side of the road. When I pressed the brake pedal, the vehicle did not respond normally. I pushed the brake pedal as far down as I could and had essentially no braking ability. Because we were traveling uphill, the vehicle eventually rolled to a stop. When my brother came with his car he had a vehicle scanning tool. He hooked my vehicle up to it and the tool displayed diagnostic codes P25A2 and P3499. This was an extremely serious safety event. Had we been traveling downhill, approaching an intersection, or driving in heavier traffic, the outcome could have been catastrophic.

The contact owns a 2024 GMC Yukon. The contact stated that there was a strong mildew odor coming from the vehicle while entering the vehicle, and there was moisture around the trunk near the wiring harness. The vehicle was taken to Modern Auto Company (6224 MO-100, Washington, MO 63090), but the cause of the failure was not found. O'Fallon Buick GMC (2150 Technology Dr, O'Fallon, MO 63368) diagnosed the vehicle with a failure of the wiring harness and stated that there was moisture entering the vehicle through the wiring harness. However, after the contact inquired about the odor inside the vehicle, the dealer refused to continue working with the contact. The manufacturer was notified of the failure, and a claim was filed, and an appointment was scheduled for service at Dave Sinclair Buick GMC (5655 S Lindbergh Blvd, St. Louis, MO 63123). The dealer informed the contact that the wiring harness appeared to have already been replaced. The dealer found no leaks inside the vehicle and informed the contact that the vehicle would be returned. The contact hired a mold expert to inspect the vehicle while the vehicle was at the dealer. The mold expert discovered several cases of toxic mold inside the vehicle and deemed the vehicle unsafe to drive. The contact stated that her daughter had severe respiratory issues and was transported in the vehicle. The daughter had several doctor’s visits, was put on several medications, and missed 40 days from school due to her illness. The contact associated the failure with her daughter's illness and stated that her daughter’s health improved once she was no longer transported in the vehicle. Since the failure, the contact had to pay out-of-pocket for a rental vehicle. A field investigator had been hired by the manufacturer to inspect the vehicle, and the contact was awaiting the results. The vehicle remained with the dealer unrepaired. The failure mileage was approximately 27,000.

From the time i got my 2024 yukon denali i have had problems with the electrical systems not working, it was in the shop for 2 months upon delivery to me when it was brand new, and since then i have had issues with the engine racing, the start button not working, or cutting off and on , on its own, recently the motor cuts on but never turns over. It has been in the shop again for over a week now and they replaced the engine control module and it is still doing the same thing. The dealership is now telling me its a wiring issue causing it. It has been something the entire time I have owned it. I paid 90k for a vehicle that has major issues. I am looking into the Lemon law in my state of NC, and filing a complaint with GMC to see if I can get a replacement vehicle or traded.

Vehicle shut-off while driving on the expressway, around 70-75mph. Upon vehicle turning off, I had no option but to "coast" off to the left side, which thankfully, freed me from traffic for the most part. If anyone who have been a foot over, they would've hit me. I have had numerous electrical issues with this vehicle and have taken it to the dealership but they have been "unable" to duplicate the issue. Vehicle was immediately taken to the dealership (and they still have as of this incident report submission). They told me last night that they will keep it again today and test drive it again to see if they can get it to do anything but if it doesn't show anything new, they have nothing to diagnose and will give me my car back. After requesting a copy of repair orders and a list of the history codes in my car, I am beside myself that anyone thinks giving me this vehicle back to drive is ok. See the history code report in documents uploaded. These are MAJOR safety failures in a large vehicle.

The SUV has 46,000 miles on it. Recently, the check engine light illuminated, prompting me to take it to the dealership for servicing. The diagnostic codes retrieved were U0285 and U1345. I was informed that the aero shutter required replacement. There was no physical damage; it merely ceased functioning. The dealership confirmed the active check engine light and conducted a diagnosis. While my safety was not immediately compromised, I felt extremely frustrated upon learning that GM would not cover the repair under warranty, despite this being a recognized issue that GM has yet to address. This situation is simply unacceptable and warrants further investigation and resolution.

This report documents two separate safety incidents involving the same vehicle that occurred on different dates. Approximately one month prior to the most recent incident, while driving my young children to school, the vehicle experienced a sudden and severe loss of braking effectiveness while in motion. I was unable to stop normally at stop signs and had to roll through and roll to a stop. I was required to press the brake pedal fully to the floor to slow the vehicle, and even then braking response was significantly reduced and not functioning as designed. The engine remained running and the vehicle could still accelerate. After stopping and restarting the vehicle, braking function temporarily returned. On a later date, while again transporting my children, the vehicle experienced a complete loss of power while driving. The vehicle abruptly shut down while in motion. I was unable to accelerate and experienced loss of power assisted braking. The vehicle only came to a stop after coasting. Following this shutdown, a burning or melted plastic odor was present. The vehicle was later towed and inspected by a dealership. The battery was replaced; however, this did not resolve the issue. After the battery replacement, the vehicle later hesitated to start again. The exact cause of these failures remains unknown. These incidents occurred without warning and represent serious safety critical failures involving braking and propulsion systems. Both incidents placed my children, myself, and other motorists at risk. Had either event occurred on a highway or heavily trafficked roadway, there would have been little to no ability to safely slow or stop the vehicle, creating a significant risk of collision or serious injury. Due to these events, I no longer feel safe operating this vehicle and have stopped driving it. The vehicle remains available for inspection.

Start transmission was replaced by dealer at 75 miles. 2nd transmission was replaced at 175 miles transmission was humming and slipped at around 30 to35 mph this was around April of 2024 August 1 2025 while driving at 45 dash board lit up went flashing and suv slowed dramatically down to 30 mph Got to dealership and they kept the vehicle for about a week and returned it with it being supposedly fixed. About mid October while driving at 60 mph it shut down again almost causing a wreck went to 30 miles per hour again. Hurt my wife’s neck when it reduced speed so quickly. Took back to dealership and I told them this car is dangerous this was with about 20 k miles Been in shop was told it is scanning with 22 repair codes we have not had the car for 5 weeks and are trying to work with gm and dealer to get us out of it. But as of this report no progress. On interstate in city traffic this car will hurt or kill many people. I’m refusing to let my family or myself drive it. There is no warning when it will flash lights in dash and reduce speed. Also the front crash sensors went out and are currently not working we have all service records and paperwork that has been done including maintenance records We were given vehicle back with no warnings. I went to Nita’s and ran vin and it still shows issues. We are still making payments but driving a loaner car. The car is dangerous. I advised the dealer the first time it happened. I didn’t want it back. My wife went and got it and it sis it the second time and now she agrees it is dangerous contacted GM and they want to fix it but dealer implies they can’t ?..

I am the owner of a 2024 GMC Yukon (VIN: [XXX] ), purchased from Hatchett Buick GMC on [XXX]. This vehicle was purchased at a high price with the expectation that it would provide reliability and keep my family safe. Unfortunately, that is clearly not happening. The Yukon continues to suffer from severe power loss that neither the dealership nor GM technicians have been able to diagnose or repair. In addition, this vehicle is subject to an unresolved engine recall, further undermining safety and confidence in the vehicle. Multiple times while driving I have had total power loss with no warning or indicators of this happening through lights or warnings on the vehicle. This is separate from the engine recall issues I am currently experiencing as well. While driving the Yukon will lose all electrical power. The vehicle is still currently at the dealership trying to be diagnosed. It has been 2 weeks. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)