Automatic Emergency Braking problems of the 2021 GMC Yukon

Phantom braking when moving forward after a stop. Dealer can’t replicate or diagnose it, therefore won’t repair it under warranty. It’s happened 6 times now and almost caused 3 accidents.

Vehicle: 2021 GMC denali mileage: ~48,000 miles purchase price: $62,000 issue: airbags & crash sensors failed to deploy complaint text: I am filing a safety complaint regarding my 2021 GMC denali. I was involved in a rear-end collision at approximately 45 mph, where I struck another vehicle straight on from behind. The impact was severe enough to total my vehicle, yet no airbags deployed, and no forward collision warning or crash sensor systems activated. This is especially concerning because this vehicle was previously involved in a front-end collision (not my fault) and underwent extensive repairs. I was assured all systems were repaired and functioning properly. Additionally, my vehicle had completed recall work related to safety systems prior to this crash. This is the second front-end crash involving this vehicle where airbags failed to deploy. Given the speed and severity of the impact, airbags should have deployed. The failure of these systems placed my life at serious risk. The vehicle has since been totaled and taken by insurance, but I am requesting that this failure be formally investigated as a potential safety defect in the airbag and sensor systems. I am extremely concerned that the vehicle’s safety systems were either defective or not properly restored following repairs and recalls.

Font camera failure. Front camera controls many "safety features" which fail without the camera. Vehicle under mileage warranty amount but not under time warranty ( 3 years ). Camera only covered under bumper to bumper.

On 4-5 occasions since purchasing a new 2021 GMC Yukon denali the automatic breaking function has engaged for no reason, with no obstruction in the roadway. It has occurred at low speed (after disengaging break and starting to drive). Obviously, this is a major safety issue.

Driving down the interstate at 70mph and it randomly slams on the brakes. At about 45mph it let's loose and speeds back up. There's never anything in front of the car and it does it a few times a week. Usually throws everything on the floor that was on the seats and scares the hell out of anyone inside the vehicle. Waiting for it to do it with a semi behind us that can't stop as fast!.

2 different times I have been driving once at a high speed of 70 on the highway and then driving 15-20 miles an hour today my automatic braking engaged and threw me forward which is a very scary feeling. I have not taken it in for service for that as it had only happened once a few months ago and there have been no warning lamps indicating an issue.

I was driving on the interstate on a low speed and my SUV came to a complete stop with no notice. Nothing was in the road or close in front of me. Jerked me to the front and seat belt left a red spot on my neck from the seat belt, scared the crap out of me. I thought I was hit from behind. The is a hug safety concern that needs to be recalled and fixed immediately before it causes an accident.

The contact owns a 2021 GMC Yukon denali. The contact stated that on numerous occasions while accelerated at approximately 70 mph, the brake pedal engaged without warning then proceeded to acceleration. As a result, the vehicle inadvertently stopped and jerked forward. No warning lights were illuminated. The vehicle was taken to the dealer where the failure could not be duplicated. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 20,504.

I had just left the house driving through my neighborhood at about 35 mph when for no reason the emergency braking engaged. The road was deserted, no other vehicles, pedestrians, dogs or objects in roadway. There was a momentary red dash alert, but I didn't have time to read it.

On Wednesday, January 12, 2022, while driving from columbia, SC to cincinnati, we were heading northwest through the mountains of north carolina, on I-40, just east of the TN border. Traffic was fairly steady and heavy, so we were traveling at approximately 45 mph, in the right lane, winding through the mountains. Our friend, ** ***** was driving, my wife, ********* *****, was sitting in the right front passenger seat, working on her laptop, and I was sitting immediately behind her, also working on my laptop. With a semi-trailer truck slowing ahead of us, *** signaled to make a lane change into the left lane (this is only a two lane highway). As we were transitioning to the left lane, the vehicle suddenly – without any warning or driver inputs – slammed on its brakes, bringing the truck to a sudden and violent stop. Given the violent halting of the truck, we all assumed we had been rear-ended by a truck. The braking was so serious, luggage from the rear of the vehicle shot forward like a missile, striking my wife in the back of the head. She suffered what we believe to be a concussion, and she did seek medical attention in the days following the incident. Sitting behind her, the sudden stopping action caused me to twist my left knee, resulting in what might be a cartilage tear. I also saw my physician in the days following, and he acknowledged the swelling of the left knee. He advised me to monitor the knee carefully, and if the pain persists, to get an mri. The pain has not gone away, and I plan to get an mri in the next week or so. Our friend suffered a severely strained back in the incident, and has been treating his back with both ice and heat therapy. This was the third time this happened, each nearly resulting in a tragic accident. The dealer said "it's just a software glitch. " the "brake assist" program is clearly defective and unsafe.

This new 2021 GMC Yukon denali we purchased on June 2, 2021 has a very sophisticated controls system that includes a feature, entitled "brake assist," that is designed to detect "rapid brake pedal applications due to emergency braking situations and provides additional braking to activate the antilock brake system (abs) if the brake pedal is not pushed hard enough to activate abs normally. " "brake assist disengages when the brake pedal is released. " after I left the dealership (June 2nd), I noticed that the "service brake assist" light had illuminated on the driver information center (dic). I pulled off the road to check the owner's manual, and then continued home trusting that no immediate hazard existed. I subsequently set up an appointment with the dealership for a checkup. A week later, the dealership downloaded a new software package from GMC. The brake assist light did not appear when the engine started, so I left for home (50-minute drive at moderate speeds). Enroute to my home, I stopped at a store and turned the engine off. Started home a few minutes later. While accelerating past 45 mph, the brake system independently engaged, which threw me against the steering wheel and into the windshield. As the SUV decelerated through 20 mph, the brakes automatically released. I was not hurt, nor did I lose angular control of the vehicle. I completed my drive home and parked the Yukon normally. Did not drive it again until returning to the dealership a few days later. This second visit did not bear fruit. After significant explorative work, the lead mechanic drove the vehicle several miles under a multitude of conditions, but could not duplicate the problem or get the light on the dic to extinguish. At my request, the dealership returned possession to me with the light still illuminated. I have driven the vehicle several miles since then with the "service brake assist" light still illuminated. I suspect this is a GMC software problem.

Driving approx. 62 mph on a highway, went to slow down and unable to brake, upon pushing down on the break there was resistance, after pumping the breaks multiple times I was eventually able to slow down with a lot of force. Messages on dashboard read "brake system failure" "62 max speed esc, service esc, service trailer break system, and forward collision system unavailable. " abs, esc and check engine light all illuminated on dash screen.