2021 GMC SIERRA 2500 Recalls, Complaints & Safety

The contact owns a 2021 GMC Sierra 2500. The contact stated that while driving at 55 MPH, the vehicle stalled unexpectedly. There were no warning lights illuminated. The vehicle was taken to the local dealer, where it was diagnosed, and determined that the engine needed to be replaced. The engine was replaced; however, the failure recurred. While at a stop and attempting to drive around a curve, the vehicle stalled. No warning lights were illuminated. The vehicle was taken to the local dealer, where it was diagnosed with engine failure. The vehicle was not repaired. The failure mileage was approximately 77,000. The VIN was not available.

While driving on the highway at normal speed, my vehicle was operating completely normally with no warning lights, messages, or prior issues. Without any warning, the vehicle suddenly lost the ability to accelerate and felt as if it had been shifted into neutral. I immediately had to pull over to the side of the highway, as this created a dangerous situation with surrounding traffic. The vehicle had to be towed to a mechanic. Upon inspection, I was informed that a coolant line connected to the transmission had completely blew off, causing a rapid loss of transmission fluid and resulting in total transmission failure. I was told this was not due to a rusted or deteriorated clamp, but rather a sudden component failure. This vehicle has been meticulously maintained and I have owned it for less than one year. There were no prior symptoms, leaks, or warning signs leading up to this incident. This appears to be a sudden and unexpected mechanical failure, not caused by neglect or misuse. The loss of power while driving at highway speed posed a serious safety risk to myself and others on the road.

80,000 Miles, complete engine break down. 12,000 to repair

My right headlamp/ turn signal assembly began flashing at random intervals. The high beam would come on and off randomly. The entire assembly would randomly flash along with the turn signal. The headlamp would go on and off randomly. This included switching between setting. High beam, low beam, daytime running light, and completely off with no warning. This causes blinding conditions for oncoming drivers, loss of visibility for driver, and loss of visibility during inclement weather due to high beam coming on and off, then entire unit turning off. As of right now, the vehicle is undrivable due to incorrect lighting, and flashing lights.

Pulling into a driveway and the truck made a loud clunk and the check engine light, traction control light, and a reduced engine power light came on and the truck came to an abrupt stop. When the gear shift was put into reverse or any forward gear the truck would rev up without touching the gas pedal. The left rear wheel locked up. After paying over $700 in tow bills to get the truck towed to our house and then to the dealer we were told that the transmission had a catastrophic internal failure. This truck only has 82,000 miles on it and is a 2021!

The contact owns a 2021 GMC Sierra 2500. The contact stated that while driving at 50 MPH, the contact was pulling a trailer that he had loaded, and he drove around a curve, the gear shifted down independently, and the trailer pushed the vehicle off the right side, causing him to crash into a post and embankment. The contact mentioned he was able to shift the gear into Four Wheel Drive to get back on the road. The contact mentioned he pulled over to the right side of the road, exited the vehicle to inspect, and noticed damage to the vehicle and the trailer. The contact stated no air bag deployed. The contact stated that he sustained injuries left arm and neck, causing his muscles to tighten. No medical attention was required. The contact stated no police report was filed. The contact mentioned that the vehicle was previously repaired for a manufacturer's recall with the transmission, but failed to prevent the failure. The contact was relating the failure to NHTSA Campaign Number: 24V797000 (POWER TRAIN). The vehicle was serviced by the dealer, but the remedy failed to repair the vehicle. The contact stated that the failure was not diagnosed by a dealer or independent mechanic. The manufacturer was not notified of the failure. The approximate failure mileage was 78,000.

Crash 1 injured

2021 GMC Sierra 2500HD 6.6L gas 6 speed automatic transmission W/4wd After a brake service job the vehicle will randomly kick on the traction control/ABS and the right front brake will lock up. The steering wheel jerk is violent enough to remove the wheel from the drivers hands. No Traction control or ABS lights flash on the dash when this occurs and it has caused the vehicle to veer into oncoming traffic and also off the road. The dealer was unable to recreate the issue nor are there any stored codes/issues found when having the truck diagnosed. ABS and speed sensor wires have been reviewed and none were damaged during the brake job. All wheel speed sensors are functional and reading when the issue happens. This issue happens during dry or wet conditions and is random without warning.

When I’m in reverse the up the cameras turn off. On one incident I was backing up and the camera turned off causing me to back up into the wall of my house

Crash

The contact owns a 2021 GMC Sierra 2500. The contact received Manufacturer's Recall Number: N232426400, for water intrusion into the electronic gate-release switch. The vehicle was repaired. The contact stated that six months after the vehicle was repaired, the tailgate failed to operate as intended. While at the residence, the taillights and headlights were flashing. The contact also became aware that the tailgate had unlatched independently while the vehicle was parked. The message "Integrated Tailgate Open or Integrated Tailgate not Latched" was displayed. The contact stated that there was an abnormal clicking sound coming from the actuator when the tailgate opened independently. The vehicle was taken to the dealer, where it was diagnosed that there was water in the switch. The dealer informed the contact that the repairs were already made and, due to the water intrusion into the switch, the dealer refused to redo the repair under the previous recall. The vehicle was repaired. The manufacturer was notified of the failure, and denied assistance since the recall repair was already performed. The failure mileage was approximately 53,000.

Parking brake locking up. There is recall on the brake module for my year make and model but my vehicle isn't on the list and I feel it should be. I'm having the same issues as they are. I can't drive it until it is fixed. Very dangerous.

The contact owns a 2021 GMC Sierra 2500. The contact stated that the VIN was included in NHTSA Campaign Number: 24V060000 (Latches/Locks/Linkages) and the main exterior touchpad switch assembly was replaced. The contact stated that after the recall repair the second exterior touchpad switch assembly suddenly short circuited and caused the trunk to open unintendedly. The vehicle was returned to the dealer who stated that that only one exterior touchpad switch assembly was replaced, despite the remedy stating that the exterior touchpad switch assemblies would be replaced. The vehicle was not repaired. The manufacturer was informed of the failure and opened a case. The manufacturer referred the contact to the NHTSA Hotline to report the failure. The failure mileage was 55,700.

Radiator hose connection broke and loose fluid and transmission got broken

While driving down the highway pulling a trailer the truck started to slow down rapidly. We were able to pull to the side of the road before the truck came to a complete stop on its own. From that point forward, we could not get the truck to move forward even in 4WD. Ended up towing the truck back and a repair shop determined the transmission needed replaced. About 4 months later, we received notice of a recall describing a similar scenario. I submitted the invoice and documentation to GM, but my claim was denied because the codes and symptoms did not match the criteria for the recall.

Hard shifting. Back wheels locking up

Known issue and has been attributed to a manufacturing defct, but no recall- Leaking headlight caused damage to headlight- now turn signal and headlight do not work. Entire assembly needs to be replaced, GM / Extended Warranty Company will not cover, this safety part. Head light and turn signal were working on the way to the dealer, 1 month later when we picked it up - Right turn signal malfuction reading appeared on dash, headlight blinking and will not work. Picked up on Friday 1/30/25, and made an appointment for the following Wednesday to take it back in. Was told by dealer today that the replacement will not be covered and will cost $2100.00 to replace. This is a safety part and the truck can not be driven legally or safely without both headlights working.

Headlight vent failed. Hid control board filled up with moisture. Headlight is flashing like emergency vehicle if it turns on at all.

The front left headlamp assembly low beam light unexpectedly began to flicker repetitively until the vehicle was turned off. In addition, the left front turn signal was failed, but an indication of the failed turn signal was not always present. The headlamp assembly was taken in for replacement at a local GMC dealership promptly due to safety concerns of operating the vehicle on public roadways with this condition. The safety of others was at risk due to the strobing effect of the flickering lights and not being able to drive the vehicle during conditions where headlights are necessary. The flickering/strobing condition of the headlamp was highly distractive and puts other drivers are risk. In addition, due to the natural height of the vehicle the cast of the beam is closer to the rear view mirror height of the majority of vehicles. The problem was confirmed by a local GMC dealership and was identified as a faulty headlamp assembly. The vehicle was not inspected by any other party besides the dealer who performed the diagnosis and repair. There were no symptoms of warning messages prior to the failure.

Headlights and turn signals failed. Flickering of various lights (Daytime running lamp, low beam, high beam, turn signals) followed by total failure. 3700 dollar repair at dealer to replace both headlamp assemblies. Barely over miles of warranty, but still in the 3 year warranty time period. Not having forward lighting is of course a major safety issue. Vehicle should be recalled. Many others are having the issue.

The contact owns a 2021 GMC Sierra 2500. The contact stated while driving 40-55 MPH, the vehicle started losing motive power. The contact stated while pulling into a nearby independent mechanic shop, the vehicle started jerking significantly and stalled midway. The check engine warning light was illuminated. The mechanic diagnosed the vehicle with transmission failure. The vehicle was towed to the residence. The local dealer and several unknown dealers were notified of the failure and informed the contact that the transmission assembly was not available and could not be ordered. The vehicle was towed to CJ's Transmission, where the transmission was taken apart. The mechanic determined that the transmission needed to be replaced. The vehicle was being repaired with a rebuilt transmission. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the failure and offered a modest monetary compensation for the repair. The failure mileage was approximately 134,000. Parts distribution disconnect.

Seems to be a known problem according to a google search but brake fluid leaking from brake pedal onto drivers floor mat. Seems to be a bad brake booster according to google and happening for some at a few weeks to a couple months old in the newer ones. I noticed first on my truck around 58,000 miles.

On 11/21/24 noticed passenger headlight day light running light flickering. On 11/22/24 right turn indicator intermittent fast blink, dash message stated turn indicator failure. Once home, inspected passenger headlight assembly. Found DRL, turn signal, and low and high beam head lights were inoperative. On 11/25/24 went to GMC dealer/service. Staff seemed aware of issues and stated they are common, that they carry the $1,400 sealed assebly in stock. Vehicle is 4 months over warranty, but only has 29,000 miles. There is no visible damage to the assembly, but there is visible condensation inside the lens. GM has a published service bulletin, 01-08-42-001P, that specifically addresses this issue for my vehicle. The earliest date the issue could be diagnosed/service date is 12/10/24. A complete failure of this non-servicable headlight assembly is an absolute safety issue. Decreased daytime visability with the loss of one of two Daytime Running Lights, the lose of the front turn indicator to alert other drivers of my intentions, the lose of a set of low and high beam headlights. As mentioned, there assembies are a sealed LED light assembly. If any one of these lights fail, the only remedy is the replacement of the entire unit with a $1,400 part. GM has had multiple recalls of this same issue among their vehicle, but continues to produce the same failing pieces.

The contact owns a 2021 GMC Sierra 2500. The contact stated that no visible tailgate was attached, and the contact was unaware if the vehicle had been repaired under NHTSA Campaign Number: 24V060000 (Latches/Locks/Linkages); however, the recall had been marked as completed under the VIN. The vehicle was taken to a local dealer where they advised the contact that the recall repair was completed. The vehicle was taken to another local dealer, Littleton Chevy (851 Meadow St Littleton, NH 03561); for a second opinion and was informed that the recall repairs had not been performed. In addition, the contact stated that the tailgate was replaced with an after-market part due to backorder issues. The contact stated that there was no failure experienced with the original part. The manufacturer was made aware of the issue. The contact had not experienced a failure. The failure mileage was 125,000.

I purchased a 2021 GMC Denali 2500 in December 2023. A couple days after purchasing the vehicle I received a message on the dash saying the front camera was not working. I took the vehicle into the dealership where they said they reset the computer and nothing was wrong with the vehicle. One month later I was involved in a collision where a vehicle turned in front of my vehicle and the Automatic Emergency Braking failed to activate. I applied the brakes but due to my delayed reaction time 1.5 seconds, I broadsided the small vehicle with my large truck. Luckily the speed was only 20 mph and no one was hurt or killed. At this time I did not know my vehicle was equipped with AEB. In October I discovered through GM and a different dealership that my vehicle was equipped with Automatic Emergency Braking. I have had several occasions when the AEB including the crash where the AEB should have activated but never did. In 11 months I have never had the AEB activate. I took the vehicle into the dealership where I bought the vehicle and they said their computer said everything was operating correctly. The tech never drove the vehicle where the AEB should have activated. I have driven many cars and even the same model vehicle as mine, so I know what the AEB feels like and my vehicle the AEB is not working. The dealership told me to take the vehicle they checked everything GM told them to check. When I talked to GM they told me to immediately take the truck to the dealership and the dealership did nothing.

Crash

The contact owns a 2021 GMC Sierra 2500. The contact stated while driving approximately 70 MPH, the vehicle lost motive power. The contact stated that the message “Vehicle will not Exceed 50 MPH" was displayed. The vehicle was taken to a dealer and remained for over four months after being diagnosed that the solenoid valve and transmission needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 50,000.

The transmission started lurching and surging power while driving

Smog system check and Engan warning light keeps come on.

The contact owns a 2021 GMC Sierra 2500. The contact stated while driving approximately 25–35 MPH, the tailgate unlatched and opened unexpectedly. The contact stated that while the vehicle was parked, the tailgate opened independently. The contact stated that the tailgate down message was displayed after the failure. The vehicle was taken to an independent mechanic at a body shop, who determined that the failure was due to the touchpad. The vehicle was repaired. The vehicle was taken to a body shop, where it was replaced. The contact received notification of NHTSA Campaign Number: 24V060000 (Latches/Locks/Linkages); however, the part to do the recall repair was not yet available. The local dealer was not contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The failure mileage was approximately 49,000. Parts distribution disconnect.

3 year old truck. The left headlight enclosure gained water and caused the whole headlight system to have issues. Water caused the Headlights to Flash high beams (both), turn off and blinkers not to work. This defect the whole side that is effective. This can cause other drivers or the owner to have an accident. 6 months later, Now the right side headlight is doing the same. I’m out of warranty with only 40k miles. The seal is not strong enough to keep water out the enclosure. This can also cause the whole light system to shut down while driving. Very dangerous especially at night.

My tailgate unexpectedly open as I was driving down the road. (2021 GMC 2500 Denali Sierra) This was the second time this has happened and lost things driving down the road. (3 propane tanks and a small grill the first and then an air compressor the second time) Both times it happened I opened and closed the tailgate with the vehicle running. Both times I was unaware of tailgate opening and did not notice until I got home. The first time it happened I thought it was operator error but after this weekend, I looked into this and see there was a recall on it this month. I still felt it was necessary to report incidents.

The harness that hooks to bumper plug for trailer lighting is not completely water tight. Allows water in and creates buildup that weakens the connection as well as allows the plug wire connection to snap out and push out from the pin. Further inspection it was causing a short in the system. I attempted to clean and put some-electric grease on the plug to help clean it but then relaized 3 pins were broken and pushed back.

The contact owns a 2021 GMC Sierra 2500. The contact stated that the vehicle was equipped with an engine block heater that he plugged into the vehicle when the weather was below 32 degrees to start the vehicle. The contact stated that he noticed that the engine block heater was causing the GFCI outlet in his residence, to experience an electrical short circuit. The dealer was notified of the failure and informed the contact that it was a known failure. An appointment was scheduled for diagnostic testing. The vehicle was not diagnosed or repaired. The contact related the failure to NHTSA Campaign Number: 19V328000 (Engine) however, the VIN was not included. The manufacturer was notified of the failure and a case was opened. The failure mileage was approximately 55,000.

While driving the entire dash cluster (speed,rpm etc) turns off entirely, reloads as if truck is just starting with all lights coming off and on, needles cycling max/min. Unable to recreate on command, multiple others reported same issue with no cause/cure listed.

The tailgate latch is not waterproof, and opens on its own sometimes. this can allow things to fall out of your truck.

The driver side headlamp stopped working, Condensate buildup may be a contributing factor. No accident and vehicle is meticulously maintained. No reason for lamp seals to be damaged or wear. Barely three years old and requires a replacement at $1400 for the part and another $1000 in labor. Outside of 36000 mile warranty.

The contact owns a 2021 GMC Sierra 2500. The contact stated that on several occasions while in park(P) with the parking brake engaged, the parking brake warning light was illuminated. The contact also stated that the parking brake would not disengage until the vehicle was shifted into reverse(R). The contact stated that he observed a loud banging sound coming from the rear of the vehicle when the parking brake was finally disengaged. The vehicle was taken to a dealer where it was diagnosed that the driver’s side rear actuator needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 51,248.

Passenger headlight light fills up with moisture resulting in the HID module filling up with water and shorting out. The high beam starts flashing when you try to use your turn signal and eventually the headlights completely stop working. Is a known problem, but GM won’t do anything to help if you’re outside of the 3year/36,000 mile warranty. Currently unable to get a new headlight because of the on going strike.

The owns a 2021 GMC Sierra 2500. The contact stated while driving 70 MPH, the RPM revved up to 6,000 RPM. Additionally, the vehicle lost motive power. The vehicle was taken to the dealer, who informed the contact that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was 47,000. The VIN was not available.

The contact owns a 2021 GMC Sierra 2500. The contact stated while approaching a stop sign and depressing the brake pedal, the brakes were squeaking. The vehicle was taken to the dealer and the contact was informed that the brake pads needed to be replaced. The brakes on the vehicle were replaced but the failure reoccurred. The vehicle was taken to another dealer and the caliper on the front driver’s side was replaced and the failure reoccurred. The vehicle was taken to another dealer who was aware of the issue however, there was no recall for the failure. The manufacturer was not contacted. The failure mileage was 800.

The “Service Safety Restraint” alarm goes off continually on my 2021 GMC Sierra 2500HD AT4. The warranty is no longer valid as at the time of occurrence I was at 34,500 miles and when I took it in the warranty had expired due to exceeding 36,000 miles. Extended warranties were not purchased and this began approximately 8-9 months after purchase. The code given is “b0014 Driver Seat Side Air Bag Deployment Loop” with a description of high resistance in wiring or wiring harness. After much research I have found that many GMC 2021 vehicles and previous models have had this exact same issue. No dealership as of yet has offered to help or understand that this defect was of their own flawed design. The issue that I am having is exactly the same as other models such as the 2021 Yukon, Sierra 1500, Suburban and others. This is a safety issue and only want GMC to account for their flaw. I do not believe I should have to pay for a design flaw or equipment malfunction that is well known amongst GMC vehicles. I am asking the NHTSA to help me in this matter and the many others who are having the same issue and for the manufacturer to be accountable for their own flaw.

Hit in the driver side tire, air bags didn’t release. Truck then went up in flames.

Crash Fire

Hit in the driver side tire, air bags didn’t release. Truck then went up in flames.

Crash Fire

Hit in the driver side tire, air bags didn’t release. Truck then went up in flames.

Crash Fire