As I was driving the automatic emergency brakes went off and stopped me so hard and fast that I feel like I got whiplash. The seatbelt yanked me backwards, smacking my head against the headrest, I have an instant headache from it and my neck and shoulder still hurt 20 minutes later. It scared me and my child half to death, my heart was pounding and I could have been rear ended. I was driving about 40mph and was in no way in any harm/needing to break (specially this hard) for anything when this happened. This is not the first time my car has unnecessarily automatically slowed down quickly but this is the first time it’s ever been this abrupt and severe. I will be taking my car to be inspected for this issue and if my neck and shoulder still hurt in the next day or two, I will also be going to the doctor about the incident.

I am reporting a serious safety defect and unreasonable delay in addressing it under safety recall N252494000 (L87 Engine – Loss of Propulsion). My GMC Yukon has an illuminated check engine light and is now also overheating. According to GM’s own customer service r, this can lead to knocking, unusual engine noises, hesitation, high RPMs, abnormal shifting, reduced propulsion, and sudden loss of propulsion while driving, increasing the risk of a crash. I have contacted multiple dealerships for urgent repair: Cappllino GMC Keller Chevrolet Joe Basil All three have advised me that they do not have enough technicians to get my vehicle in for repair. Each has urged me to continue driving the vehicle despite the active check engine light and recall, and all have refused to provide a loaner vehicle. I have also contacted GMC Corporate directly for intervention. Instead of providing a loaner or expediting repairs, they have only offered post-repair rental reimbursement (up to $44/day after a repair order is opened). This leaves me with no safe transportation option. I have been told I can “drop off” the vehicle, but I have no alternative way to get home or to work. GMC and its dealerships are putting my safety (and the safety of other road users) at serious risk by directing me to continue operating a recalled, overheating vehicle with an active check engine light while refusing to provide any loaner or timely repair. My vehicle has 34,700 miles and is nearing the end of its warranty coverage, which raises additional concerns about potential delay tactics. Please review: The L87 engine defect and related check engine/overheating issues in GMC Yukons. GMC’s handling of this recall, including widespread failure to provide loaners and instructions to customers to keep driving defective vehicles. I authorize the release of my contact information to GMC to assist with the investigation. Attachments I can provide: Screenshots of communications with GMC

For the third time, my vehicle died on me while I was driving; 2 of those times were on the highway going highway speeds. The last (3rd) time, I was towing my travel trailer/RV on the highway. In all incidents, the engine stopped propelling the vehicle. I could see and hear the engine revving but I failed to accelerate. After various warnings on the dash, I was able to pull safely off the road and then the engine just stopped, and nothing else worked. It failed to restart. This could have been a potentially dangerous situation because had I not been able to safely pull over, I would have been rear-ended. My vehicle was not part of the L87 recall for the 6.2L GM engines but the symptoms sound the same as those that were. The recall probably should have been expanded beyond the dates that GM originally included.

Engine suffered catastrophic failure without warning while traveling highway speeds after being cleared during recall check and suggested oil viscosity change. Most recent dealer performed service on 4/3/26 showed no mechanical issues and engine failed 2 weeks later on 4/17/26.

The contact owns a 2024 GMC Yukon. The contact stated that while the vehicle was stopped at a red traffic light, the accelerator pedal was depressed and the vehicle stalled. The message "Conditions not Available to Change Gear" was displayed. The vehicle was restarted and driven to the residence. The contact stated that several days later, while pulling into a parking lot, the vehicle unexpectedly stalled. The vehicle was restarted and was then towed to the dealer; however, the failure could not be duplicated. The manufacturer was notified of the failure. The failure mileage was approximately 24,000.