2020 GMC Sierra 1500: brake failure

Filed Apr 29, 2026 · Acceleration, Brakes · 80,000 miles · MI

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle decelerated to 30 MPH. The check engine warning light was illuminated. The vehicle was taken to a local dealer, where it was diagnosed, and determined that the timing belt needed to be replaced. The part was on back order. The vehicle was not repaired. The contact stated the vehicle previously experienced brake failure, sensor failure, and glow plug failure. The manufacturer was contacted, but no assistance was provided. The BBB referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was approximately 80,000.

Filed Feb 20, 2026 · Brakes, Driver assistance · NV

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.

Filed Aug 20, 2025 · Brakes · FL

My vehicle displayed numerous brake failure codes and limited my speed to 43mph. When taken into my local GMC dealer the diagnostics I was given were a bad/leaking master cylinder. This vehicle has 16,200 miles on it and was never used for towing or hauling. The brakes are hard and brake assist has clearly failed. I’ve found numerous recalls and issues with other year vehicles from GMC, yet they are denying any liability on my vehicle. They want over $3000 to replace the master cylinder even though there’s no physical leak observed via fluid loss. This is a major safety concern when a major brake component fails on such a low mileage vehicle. This truck also has a well known seal leak on the rear window that causes mold to grow inside of the vehicle cabin. Apparently no one has died yet so they have not been forced to put out a recall. Consumers should not be forced to spend thousands of dollars on major components on such low mileage vehicles. Especially when it comes to safety items like braking. I’ve researched this for hours and have found this has been a known issue on these 2020 models many people. Some even brand new after driving them off the dealership lot. Clearly there is an issue and the manufacturer refuses to address it.

Filed Jun 11, 2025 · Brakes · NY

I was driving my 2020 GMC Sierra 1500 on a local street when the dashboard suddenly displayed a “Brake Failure” warning. I immediately realized I had no braking power and had to safely roll into an uphill parking space to stop the vehicle. While waiting for the tow truck, I researched the issue and discovered there is a known recall related to the brake calipers on some 2020 Sierra 1500 models. However, when I entered my VIN, it showed no open recalls. I also contacted GMC directly, and they confirmed that there are no active recalls associated with my vehicle. Additionally, the vehicle's onboard information system indicated that the front brakes were at 65% and the rear brakes at 80%, suggesting that brake wear was not a contributing factor.

Filed May 15, 2025 · Brakes, Electrical · OK

I was driving about 45 mph when the vehicle started to brake on its own. Message center said "Brake Failure max speed 62 mph". I had to move the vehicle, so I continued forward. It was still trying to self-brake, i decided to stop and turn ignition off so computers could re-set but I had no brakes. I had to stand on brake pedal to get it stopped. Turned ignition off and restarted. The problem was gone, but it happened again 2 weeks later. Took to dealership where purchased and they said it needed a computed recalibration. Something I didn't know about. They charged me $200 to recalibrate the computer. My issue is the danger of not having brakes, not the $200. How many similar vehicles could this happen to?

Filed Apr 23, 2025 · Driver assistance, Electrical · 125,000 miles · NJ

The contact owns a 2020 GMC Sierra 1500. The contact stated while driving 40 MPH, the vehicle failed to properly respond. There were no warning lights illuminated; however, the message ESC was displayed. The contact stated that the brakes, steering, and a message to check the trailer brakes was also displayed. The contact pulled over to the side of the road and the brake pedal was depressed several times however, the brakes failed to respond, and the vehicle was difficult to control. The vehicle was towed by AAA and then towed to a dealer however, the vehicle was not yet diagnosed. The contact stated that the brakes were inoperable, and the control center was destabilized. The vehicle was not yet repaired. The manufacturer was made aware of the failure and referred the contact to the federal safety agency Hotline. The failure mileage was approximately 125,000.

Filed Jan 18, 2025 · Electrical, Engine · AK

On [XXX], I was driving my truck on [XXX] through Phoenix, AZ. It was 5 days after I had purchased the vehicle and only had 250 miles on the odometer. I was in the left lane was traveling at approximately 75mph. Within the span of about 20 seconds, several lights on the dash annunciated and several messages including a message about a brake failure and steering assist failure and then the engine suddenly turned off. The steering seemed heavy and the brakes seemed less responsive. I was able to coast to a stop on the side of the road thanks to the help of a couple truckers who blocked traffic across multiple lanes. The truck was towed to the dealer and they told me the entire engine needed to be replaced. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 22, 2024 · Brakes, Electrical · TX

My truck 2020 gmc sierra 1500 AT4 denali is not working properly since July 2024. I took it to 2 different dealership to get a diagnostic and i finally ended doing the repairs for brake issues. I have been towed 6 or more times and almost experienced 2 car accidents since I drive the truck after the supposedly repairs where done but i ended stranded again with no brakes. The dealership has repair the truck 3 times but im still getting sevaral codes the fact that i had to pay out of pocket and have to deal with this and expose myself to danger and my family in driving a vehicle that is no safety condition its absurd. I call several times the recall GM hotline and i was told GMC 1500 are included in the recalls just not the AT4 and i have a family member with the same truck and same issues she ended up trading in the truck recently since she kept experiencing the same issues over and over again just like me.

Filed Aug 28, 2024 · Acceleration, Brakes · GA

My brakes failed 2 times. One time I almost got into a horrible wreck with my daughter in the truck. "Brake system failure" " max speed 43mph" I have not had any brake work or anything done. The dealer is trying to charge me to replace the whole brake system when [XXX] this says to reprogram. Still waiting on gmc to tell me if it's covered under warranty. From my own research this has been a major problem for hundreds of people if not more. I could have died because of a faulty brake system or a bad software update. I need help with this and so do the countless other 2020 gm owners. There is a recall on the 2019 for the exact problem but not the 2020s. GM safety recall N192268090 please advise INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 4, 2020 · Brakes, Driver assistance · 11,000 miles · TX · crash

My 2020 gmc sierras brakes failed on may 22nd and ECM and now the engine and transmission are experiencing issues based on the onstar report.

Filed Aug 28, 2020 · Brakes, Electrical · 73 miles · NJ

Electronic ABS brake failure with 73 miles on odometer while stopped at red light alarm chimes sounded and power brakes were lost. Warning lights on dash ABS brake failure multiple engine warning lights came on. Dealer service was puzzled needed to contact gm technical support. Final outcome they are replacing the electronic brake module.

Filed Jun 17, 2020 · Brakes, Steering · NM · 1 injury

Tl* the contact owns a 2020 gmc sierra. The contact stated that while driving at 25 MPH, the system brake failure warning message illuminated on the instrument panel. Once the warning light illuminated, the contact experienced complete brake and steering failure. The contact was able to steer the vehicle into a curb to slow down the vehicle and avoid a possible collision with another vehicle. The contact stated that he had suffered pain to his left shoulder blade and left knee; however, he did not seek medical attention due to covid-19. After experiencing the failure, the contact had the vehicle towed to desert sun motors, inc. (2600 n white sands blvd, alamogordo, nm 88310) where they cleared the system's computer and informed the contact that they found no defects with the vehicle. Upon return of the vehicle, he experienced another brake failure as the check engine light illuminated while driving at 55 MPH. Due to the failure, the contact was forced to run a red light and drive up an incline in order to bring the vehicle to a complete stop. The vehicle was then towed shamaley buick gmc (955 crockett st, el paso, tx 79922) where it remained in their possession. The manufacturer was notified of the failure and a field inspector was sent to inspect the vehicle. The contact stated that know brake failure codes were detected. The contact stated after the third failure the vehicle was towed to shamaley gmc where it was awaiting diagnosis. The vehicle had yet to be repaired. The failure mileage was unknown.