2023 GMC Yukon Speed Control & Cruise Problems

While driving in approximately 10°F weather after the vehicle had been parked outside overnight during snowfall in Chicago, the vehicle displayed a warning that said “Do Not Drive — Maximum Speed 43 MPH.” At the same time, the brake pedal became extremely hard and the vehicle had significantly reduced braking ability, requiring much longer stopping distance. This occurred without any brake warning lights beforehand. After the vehicle warmed up and was restarted, the message eventually cleared but then there was a new transmission warning and the check engine light went on. After driving for a long commute, eventually all warnings disappeared. I personally know another 2023 Yukon owner who experienced the exact same message and braking loss under similarly cold conditions, which suggests this may be a broader safety issue affecting this model year. Because this involved a sudden safety-system activation combined with temporary brake loss, there was a real risk of being unable to stop the vehicle safely or avoid a collision. My vehicle is within the year range of GM’s brake-system software recall N242447990 (eBCM brake fluid loss detection issue), and it is unclear whether my case is related, but the symptoms point to a potential systemic braking or electronic brake control problem in the 2023 Yukon. This issue warrants investigation due to the combination of: • Hard brake pedal • Reduced braking performance • Speed-limiting safety warning • No prior diagnostic warning • Occurrence in very cold temperatures A sudden loss of braking ability is a serious safety defect.

I bought my 2023 Yukon Denali Ultimate on or around August 9 2023, and I bought it brand new. On May 28 2024, around 30k miles, I was on the highway and could no longer accelerate. I luckily got myself into the breakdown lane before my car shut down & lost power, ended up being towed to the closest dealership. After 18 days at the dealership, I finally had my car back with a "new engine". Fast forward to November 25, 2025, I was on the highway again, my dash lit up telling me to "press start". As i figured that was not a good idea while driving in the fast lane on the highway, I did not. in a panic I got myself over to the breakdown lane where my car turned off. This time (November 2025), I still had power, but no car turnover. After 6 days of my car sitting at the dealership, they finally had the time to look at the issue. The Dealership did the recall and got the car started, but the car still had a funny sound that the mechanics didn’t like , so they were waiting to hear back from higher up people as to what to do. Today I got the call that they will be replacing the engine for a second time and I will not have my car back until the first week of January. There were zero warning lamps, Zero Symptoms, nothing. I am Lucky that the Highway wasn’t too busy in that moment, because there were many 18 wheelers on the road that day, and one almost swerved into my car missing it by about two feet while my dead car sat in the breakdown lane. Yes I called the state police, Yes one trooper kindly pulled behind me to ask if I was safe and had a tow on the way. But that truck that nearly plowed into my dead car could have prevented me from picking my [XXX] [XXX] [XXX] daughters up from school, forever . To say that I am disgusted with GM, is an understatement. They’re risking lives. I should not fear for my life, my kids lives in a new, "safe" vehicle. No pun intended, but this is highway robbery. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The vehicle was crawling to a stop in preparation to park in front of my garage door. When I move my hand across the steering wheel, my hand must have come in contact with the toggle/scroll for the “resume speed” function of the cruise control. The vehicle abruptly began accelerating towards my house. I was able to press the brake pedal to deactivate and stop the vehicle safely. I note that in the past week, perhaps even two, the cruise control has not been used. The vehicle is driven 2-4 trips a day.