Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2021 GMC Sierra 1500 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2021 GMC Sierra 1500. The contact stated that the grandson was driving in stop-and-go traffic, the braking system suddenly malfunctioned causing the vehicle to crash into the rear of a second vehicle. The grandson was driving approximately 10 MPH when suddenly while pressing the brake pedal to stop the message "brake failure" displayed before the vehicle crashed into the rear of the second vehicle. During the crash, no injuries were reported and a police report was taken at the scene. The vehicle was taken to the local dealer who replaced the master cylinder and brake booster and the failure was remedied. The failure mileage was 21,539
My truck had smoke rolling out at work when I noticed it. Tried to put it out it Burnt my hands ! destroyed the inside I had it towed and insurance investigator said it was do to a brake controller for the trailer. And I took it to get estimate and the service dept said it was do To brake controller my truck was totaled my wallet toast my coat was toast my I phone my deposit my truck i drove daily to work out of and personal. General Motors would not help I called the. First. Then I was frustrated called my insurance they started a claim and low balled me now I lost 2 months of work bills stacked and low ball price on what the offer was) and haven't gotten one yet. Called gm back they said I had an active claim they woundenr help it's there defect I lost my job my mind etc on this. Two investigators state the same thing even there service dept. A gm service dept said the same thing. …
The contact owns a 2021 GMC Sierra 1500. The contact stated that while her son was driving 55 MPH and depressing the brake pedal, the vehicle failed to slow down as intended. The driver attempted to use the parking brake to slow the vehicle, but the vehicle failed to slow down. The message "Braking System Failure" was displayed. The driver pulled over to the side of the road, and the passenger's side front wheel detached and started leaning to the right before the vehicle came to a stop. The driver exited to inspect the vehicle and became aware that the front passenger's side wheel was lying on the ground. The vehicle was towed to an independent mechanic, but was not diagnosed. …
The contact owns a 2021 GMC Sierra 1500. The contact stated that when pulling a trailer with electric brakes with their vehicle, a warning light stating to check the trailer would illuminate on their instrument panel. The warning light would also state that the electric brakes had disconnected and then reconnected shortly after. The failure would occur on a consistent basis. The main control computer system in the center where the radio is located would flash the message that the trailer brake gain not been recalled. The contact contacted the dealer who confirmed that the computer system was known to have an issue due to the interference between the electric brakes and the LAD lights on the vehicle, however, there was no recall. The vehicle had not been repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 21,000.
The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the brakes seized, and the service brakes warning light illuminated. Additionally, the contact stated that the vehicle jerked forward. The vehicle was driven to the residence and parked. The contact stated that the vehicle was turned off; however, the service brakes warning light remained illuminated. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 34,500.
While traveling on the interstate the vehicle lost all propulsion and started to rapidly decelerate. Shortly after propulsion was lost the engine turned off completely affecting the steering and braking of the vehicle. The vehicle was towed to the GMC dealership that we purchased it from. repairs have not begun so I assume it would be available for inspection. We were traveling on a three lane interstate up a grade at 80 MPH. Had I not been able to safely get the vehicle stopped and out of traffic or had we lost control going down a grade we would not have been able to stop the vehicle and there would've potentially been a catastrophic accident most likely resulting in injury or death. No the dealership has not diagnosed the failure physically. The service writer did suggest that it sounds like the failure reported from the recall not being addressed. …
The 2021 GMC Sierra 1500 has an Electronic Parking Brake (EPB) that bolts on to the rear calipers. The EPB does not release, in order for service, you have to long press the parking brake, then the truck goes into service mode & will release the brakes for service, some newer models may not have this feature. The vehicle has 36,000 miles on it & the inside rear brake rotors are worn down from the EPB dragging & not releasing as supposed to, causing excessive premature wear & that could cause a safety hazard fleet wide. The EPB should not be in use while the vehicle is moving, but it is coded to not release, meaning whenever you press the brake it never moves back out away from the rotor, causing drag & or even can cause warping of the rotor. …
[redacted] 2021 GMC Seria 108,339 miles driving home from [redacted] in town and out of nowhere the lights on the dash light up I saw it say adaptive steering and something breaking. There was a lot going on as the steering was rapidly shaking limited breaking while trying to avoid a collision. The engine started a loud knocking sound and sudden smoking out tail pipes. I was able to get the truck stopped turned it off and sat there for a while trying to collect myself. Restarted the truck and slowly drove it to my home 2 miles away. It was flatbed to local GM dealer that quickly diagnosed it saying heavy smoke knocking needs New Engine! They won't confirm exactly what the internal engine failure is. Other than its Failed. …
I received a notice of a recall for a known problem with GMC transmissions. it is very well known that these transmissions lock up and cause problems with braking and can cause the vehicle to slide off the road when the tires lock up. it also causes hard shifting, which I have experienced. GMC said they will not fix the transmission, they instead will add a device to monitor the transmission, so when the transmission locks up and causes an accident, it will let me know that it was the transmissions fault!!! How is this legal? they will let me know that their transmission caused the accident after the fact? why not fix it? typical of government to do nothing about safety... and instead make laws that allow big corporations and government to make money off of peoples deaths!
Left rear parking brake actuator malfunction. The truck would brake unexpectedly. The brake would not completely release at times. Took it to the dealer on June 6, 2024 and they replaced the rear rotors and pads. I asked them if the parking brake actuator was faulty and may have caused the premature wear. They laughed and said no, it wasn't possible. On Aug 7, 2024 I returned the truck to the dealer with the fault codes C1114 & C060B caused by a failure of the parking brake actuator. It was impossible to use the emergency brakes when the codes were present. For several months after the repair, brake faults would appear and disappear randomly. Took it to the dealer, and they found nothing wrong. Electric-actuated emergency brakes should be illegal.
Brake complaints in other Sierra 1500 years
Frequently asked questions
How common are brake problems on the 2021 GMC Sierra 1500?
NHTSA has 25 complaints about the brakes of the 2021 GMC Sierra 1500, 4% of the model year's 594 complaints.
Is there a recall for 2021 GMC Sierra 1500 brake problems?
No. NHTSA lists no brakes recall for the 2021 GMC Sierra 1500, though it has 7 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2021 GMC Sierra 1500 brake problems start?
Half of the complaints with a recorded mileage happened before about 22,000 miles, and 60% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 1 fire and 0 injuries to brakes problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.