Automatic Emergency Braking problems of the 2020 GMC Sierra 1500

The brakes suddenly activate and cause the vehicle to rapidly stop with no warning of any kind and without any braking action being taken by the driver. Then, the brakes do not release and the vehicle cannot be moved as the brakes remain on. Turning the engine off and then restarting it or shifting to other gears does not release the brakes. The vehicle remains immobile and cannot be driven. After a few hours have passed, like overnight, the brakes release and the vehicle can started and driven just as if nothing had happened. A message briefly appears on the vehicle information screen each time this inadvertent braking occurs. It reads, “brake failure system”. These brake lockdowns occurred when driving on streets and in the driveway. No accident resulted but could have easily occurred. This is dangerous for a driver and occupants of a vehicle with this safety flaw as well as for other people and vehicles in the vicinity. This has happened five times. The last two instances resulted in the vehicle being loaded onto a tow truck and taken to a dealer of the vehicle’s manufacture. Thus far the dealership has not found what may be causing this intermittent braking problem.

Recently when starting truck brake message alert comes across on dash reading brake error, and not to drive above 45 miles per hour and brakes are not totally operational, meaning brake pedal has alot of play in it to bring truck to a stop. Have to turn off vehicle , sometimes repeatedly before it apparently resets computer system. This has now occurred four times in last five months. Events and dash warning message very similar to recall issued 3/3/20, but listed as "complete" on recall data base. Need to seriously and immediately looked into and corrected!.

I have had no issues with my vehicle since I purchased it in July 2022 and keep up with the routine maintenance on it. About 2. 5 weeks ago I was driving to work like I normally do and the truck started making a knocking noise and all these sensors lights came on the dash. The alerts were saying to service the parking brake, service esc, and that steering assist is reduced and to drive with care. The vehicle also started shaking and would not accelerate properly or shift gears. We ended up taking it to the closest GMC dealership and they were in able to diagnose it just by simply hooking it up, they had to fully dismantle the engine in order to diagnose it. They came back and said cylinder number 4 is damaged as well as the lifters and cam shaft. I am no car expert but it is weird that a car that is relatively new and has the maintenance kept up on it should not experience a serious malfunction like this. What is even weirder is my sister in law has a 2020 chevy silverado where the almost identical thing just happened to theirs and it too is now in the show as well needing its engine and stuff repaired.

At 103,000 my 2020 at4 5. 3l v8 had a p0307 code thrown. Cylinder 7 misfire. Driving highway speeds, sudden loud pop and then the service engine light came on and automatic braking engaged, and the idle got extremely rough. Ended up being a bad lifter, bent rod, tore lobe off of the camshaft. Roughly 8,000 for the repair, new cam, new lifters, spark plugs and coil packs. Now only about 3,000 miles later, driving, sped up to pass on the interstate and another misfire, p0306 this time cylinder 6. Same symptoms check engine light, automatic braking, rough idle. Seems to be another failed lifter and bent rod. Currently awaiting diagnostic for this second misfire issue. When speaking with the tow truck driver and the mechanic both mentioned a significant rise in cases like this. There is definitely something wrong with the design that the manufacturer needs to be help responsible for. I have less than a month ago replaced all the lifters only to have another one fail again.

Lifters failed in November 2023 and had repaired major engine damage including 4 cylinders, cam shaft, lifters, gaskets etc. After major repair work done. Truck is now doing same exact thing in January 2024. The dealership is stating they will not look at the vehicle unless I buy a new battery. I asked them to try a used battery to see if that makes a difference. And then if it is the battery I will replace. I was hung up on after the technician doug pedersen stated ill have a supervisor call you back.

Abs light limited to 43 mph esc system steering assist reduced service trailer brake system engine light on.

Own a 2020 GMC sierra at4 with 13k miles and I owned the truck for 1 year. All of a sudden my vehicle started receiving multiple warning messages. Electronic stability control, antilock braking system, ecm, reduced engine power, etc. I see there was a recall for 2019 GMC sierra's for the same issues. Why isn't 2020 GMC sierra's not also part of that recall ? it is ridiculous that a brand new truck has these types of serious issues affecting so many vehicles. Why is GMC allowed to continue to sell later model trucks after the 2019 recall with the exact same esc and anti-lock braking system problems ?.

2020 GMC sierra slt VIN:1gtu9ded5lz310106 15,700 miles. Braking system failure at about 45mph on highway 78 in loganville, GA aproching an intersection with red light, vehicle seemed to loose all power braking. I stood with all I could on the pedal, and turned to avoid rear ending stopped vehicles, running into middle of the intersection before it stopped; no accident ! dealer is replacing master cylinder and booster braking system, along with computer system ugrade. My concern is the dealership and NHTSA is aware of this issue, yet no cease and desist driving directive has been issued !.