On 3/14/26, on I-75 in Troy, Michigan at 70mph the vehicle, with 4000k miles on the odometer completely shut off. I pushed to restart the engine and it would not restart. My whole family was in the car and we were on a curve. I was able to coast to a flat shoulder. The vehicle would not restart or shift out of park. OnStar took seven hours to tow the vehicle. The dealer is installing a new L87 6.2L engine. I do not have the vehicle back yet. I received an economy car as a loaner. The dealer says GM will not extend the factory warranty despite the engine replacement. My family could have been easily killed.

I am submitting supplemental information regarding Complaint #11716907 involving a 2026 GMC Yukon XL AT4 equipped with the Brembo brake package. Following my original submission, GM's Executive Resolution Office provided written clarification of its disclosure position. GM states that the spare tire compatibility limitation associated with the Performance Brake Upgrade is disclosed through a hang tag affixed to the spare tire/wheel assembly mounted beneath the vehicle; and the owner’s manual. GM has not indicated that this limitation appears on the Monroney label, buyer’s order, or delivery documentation. The hang tag provided to me as an example states that the original spare tire/wheel does not fit the front axle when the performance brakes are installed. It instructs that, in the event of a front-axle flat, the consumer must install the spare on a rear wheel position & move a rear wheel to the front axle; and stow the flat tire. The spare tire is mounted underneath the vehicle. The tag is attached to the spare assembly and exposed to road conditions. In my case, when the spare was accessed following a roadside flat tire event, only a small piece of yellow plastic remained. Additionally, no printed owner’s manual is provided at delivery. During my roadside event, the dispatched service provider was unaware of any two-wheel rotation procedure and attempted to install the spare directly on the affected axle. The incompatibility rendered the spare unusable at that time. My concern is that current owners of vehicles equipped with the Performance Brake Upgrade may reasonably assume that a “full-size spare” is compatible with all wheel positions. Unless the undercarriage hang tag remains intact and is specifically read at the time of a flat tire, the incompatibility and required rotation procedure is not apparent. GM has not indicated it intends to notify new or existing owners regarding the spare tire limitation and required rotation procedure.

On [XXX], I was driving on the highway with my family in the vehicle and the check engine light came on, then it started running roughly. I headed off the highway on an exit ramp and the engine died about halfway down the ramp. It wouldn't restart after that. This happened about an hour away from my house in Painesville, OH. I live in Erie, PA. I had to tow it to the nearest GMC dealer. They've since concluded that the engine failed and have ordered a replacement engine from GMC. The yukon only had about 4,900 miles on it. GMC has claimed that their engine problems were fixed for the 2025 and 2026 model years, or else I would not have purchased this vehicle. Obviously there are still major issues and the 2026 6.2L engines need to be recalled. I understand that there is an ongoing investigation into these issues: RQ26001. Please see that the investigators are made aware of this incident. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

This issue affects all vehicles in the GMC lineup. The forward collision alert system is so sensitive that it gives false positives constantly which causes 2 major safety issues with the vehicle. First is that it brakes without warning and when completely unnecessary. The 2nd is that vehicles like mine with a heads up display, have the entire display flash a very bright yellow blocking the field of vision to the front of the vehicle. The system is not able to be disengaged permanently and can cause rear end collisions by braking when no obstacle exists and blocks the ability to see in front of you via the heads up display warning.