Automatic Emergency Braking problems of the 2021 GMC Acadia

On March 27, 2026, I experienced a complete brake failure while driving a 2021 GMC Acadia in a school zone at approximately 3:00 pm. When I pressed the brake pedal, the vehicle did not respond. I attempted multiple times, including using the emergency brake, which did not activate immediately. The vehicle remained in motion for several minutes in an area with children and parents present. The emergency brake only engaged after approximately 30–45 seconds of repeated attempts. I was forced to steer off the road to avoid a collision. The vehicle had been inspected at a gm dealership on March 16, 2026, just eleven days prior, where the brake system was evaluated and no issues were identified. After the incident, the dealership diagnosed a leaking vacuum pump, which is a component that supports the brake booster system. This failure occurred without warning and created a dangerous situation. I am concerned this may indicate a broader safety defect.

My vehicle stops working while in traffic when the auto stop is engaged. The abs, parking brake, and dash flashes prior to the engine stopping. I have been to the dealership multiple times and they are never able to recreate the issue. The check engine light codes produced are p0014 and c0800-03.

While driving down a busy road automatic braking engaged for no reason causing the Acadia to abruptly come to a dead stop in the middle of the road with nothing in front of me. Red collision lights came on at the same time as braking with no prior warnings. Could not get the car to move for a few minutes (when giving gas there were grinding sounds) then the braking system let up. Drove for another few minutes and it did it again. Called gm and we had to figure out how to get the car to the dealership with a major safety issue. Took the car in and it was throwing b390f, u0184, b395a codes. When we received the vehicle back one of the codes was for a bad back up camera so the new rear back up camera view is so stretched you can’t use it to back up nor does it have the lines anymore. The rear view camera now has a view that is sideways. So I took the car back to the dealership and they had no clue how either could be happening and would look into it again. Did my own research and figured out there are two cameras on the tailgate so the rear view camera was reinstalled wrong. Sent proof of how I came to the conclusion and that I wanted the backup camera replaced/fixed also. Its been over a month and I cannot get my car fixed because I refuse to pay for a rental on something they messed up because they have no loaners. Well on 11/14/2022 my cars automatic braking system activated again only this time it stopped in the middle of the road and was not as dramatic as last time. The warning lights came on as the car was coming to a stop. This time I was able to move shortly after it came to a complete stop. Gm dealership wants me to bring the car in somehow and I will be carless for who knows how long. There is also a safety recall for a cable for the backup camera with no parts available. I have an ro number and a complaint number.

While driving through intersection auto braking system activated for no apparent reason . Could have caused a crash due to sudden unexpected braking. No warning lights or alarm noted during or after event. Dealership was unable to find any problems with the automatic braking system.

Was on the interstate driving when the emergency brake engaged causing the car skid the tires and almost completely coming to a stop in heavy traffic. Shortly after this the transmission had issues which caused the car to be undrivable and had to be towed. The dealership had the car for over a month and replaced the tcm. There were no other warnings prior to this.