GMC Yukon 2021

I am filing a complaint regarding my 2021 GMC Yukon due to a serious engine failure involving the camshaft, lifters, and crankshaft. The vehicle began exhibiting engine ticking and knocking noises, rough idle, loss of power, and reduced performance. These symptoms progressively worsened and ultimately resulted in major engine damage. The vehicle was diagnosed with failed lifters and camshaft damage, which required extensive repairs. In addition, the crankshaft failed, resulting in catastrophic engine damage and making the vehicle unsafe to operate. These are critical engine components that should not fail prematurely under normal driving and maintenance conditions. The most serious concern is safety. The engine's loss of power and deteriorating performance created the risk of sudden failure while driving. A vehicle that loses power in traffic, while merging, crossing intersections, or traveling at highway speeds can create a dangerous situation and increase the risk of a crash. Occupants and other motorists could be placed at risk if the engine fails without warning. My vehicle has been properly maintained and serviced. Despite regular maintenance, these major engine components failed unexpectedly. I am aware that other owners of GMC and Chevrolet vehicles equipped with similar engines have reported comparable camshaft and lifter failures, suggesting a potential defect rather than an isolated incident. The failure resulted in significant repair costs, loss of vehicle use, and concerns about the long-term reliability and safety of the vehicle. I believe these engine failures may indicate a manufacturing or design defect affecting 2021 GMC Yukon vehicles. I respectfully request that NHTSA investigate camshaft, lifter, and crankshaft failures in the 2021 GMC Yukon and determine whether a safety-related defect exists that warrants corrective action or a recall.

On July 28, 2026, while traveling on vacation with my family, our vehicle experienced a catastrophic engine failure. There were warning lights displayed for 30 seconds prior to the engine failure. On July 23, 2026, one day before taking the vehicle to the dealership, the following warning indicators appeared on the dashboard and then disappeared: “Service ESC,” “Service Traction Control,” and a flashing engine light. We took the vehicle to the dealership on July 24, 2026, because we wanted to be proactive and ensure that the vehicle was safe to operate. The dealership inspected the vehicle but reported that no diagnostic trouble codes were identified and no issue was found. We picked the vehicle up from the dealership on the evening of July 27, 2026. On July 28, 2026, while traveling on the highway approximately 2.5 hours from home, the same warning messages appeared on the dashboard again. Because we were traveling at highway speeds and vehicle speed management was becoming an issue, I immediately exited the highway and stopped in a parking area. I placed the vehicle in park, at which point the engine began idling extremely rough. I could feel the vehicle shaking while sitting in the driver's seat. I exited the vehicle to open the hood, but before I was able to do so, I noticed gray smoke coming from the exhaust. We located a GMC dealership approximately two miles away. Because of the vehicle's condition, we drove there slowly on the frontage road at approximately 15 mph and dropped the vehicle off for diagnostic inspection. The GMC dealership subsequently diagnosed the vehicle with catastrophic engine failure and recommended that the engine be replaced. The vehicle remains at the dealership and is available for inspection.We made a reasonable effort to have the vehicle inspected before our trip because we were concerned about the warning indicators and wanted to ensure that the vehicle was safe to travel.

While driving my 2021 GMC Yukon Denali with the 6.2L L87 V8 on a high-speed highway near Somers Point, New Jersey, the vehicle suddenly began bucking and the accelerator stopped responding normally. The vehicle rapidly lost propulsion while I was surrounded by highway traffic and approaching a bridge. I was fortunate to get the vehicle onto the shoulder before reaching the bridge. I was then stranded on the shoulder of a high-speed highway, where the disabled vehicle created a serious safety risk to me and other motorists. The engine shut down and would not restart. It initially cranked as though it was attempting to start, but it did not start. I received a diagnostic alert stating, “Service the engine and transmission system immediately.” The vehicle required a tow. The tow operator later reported that it appeared locked up and could not be shifted into neutral. The vehicle has approximately 77,000 miles and has been serviced regularly. Its most recent oil-change sticker indicated the next oil service was due at approximately 81,000 miles. While safely pulled over, I checked the engine-oil dipstick and confirmed that the engine had oil, with oil visible across the dipstick’s normal measuring area. Despite this vehicle having the 6.2L L87 engine and experiencing a sudden loss of propulsion and no-start condition, its VIN does not currently appear in GM’s public recall lookup for the existing L87 recall. The vehicle is being transported to an authorized GMC dealer, and the precise failed component has not yet been confirmed. This sudden loss of propulsion created an immediate risk of a serious highway collision, particularly because it occurred immediately before a bridge. I understand NHTSA is investigating continuing L87 engine failures, including failures involving vehicles outside the original recall population. I am submitting this complaint so this incident is formally documented and considered as part of that investigation.

The driver's seat inboard airbag assembly and internal structural wiring harness failed due to a direct short circuit, completely deactivating the vehicle's supplemental restraint system. General Motors has a known engineering bulletin for this issue (#23-NA-085), noting that sharp internal seat frame components slice the airbag wiring harness. Rather than permanently fixing this structural design flaw while under warranty, dealership technicians repeatedly executed temporary, non-compliant field patches, including plastic zip-ties and Velcro tape inside the cushion. These temporary patches continuously failed, leaving the airbags disabled. Furthermore, the vehicle was sold under "Certified Pre-Owned" designation with an active, uncompleted 2020 manufacturer Customer Satisfaction Program Campaign (#N202310850-02) for this exact airbag circuit defect. Component failed & available for inspection: The driver's seat inboard airbag assembly and internal structural wiring harness failed due to a direct short circuit. The components are available for inspection inside the vehicle at the servicing dealership. Safety risk: Safety was put at extreme risk because active Diagnostic Trouble Code B14DC completely deactivates the airbags. This means the airbags may fail to deploy in a collision, leaving the driver completely unprotected in an accident. Confirmed by dealer: The problem has been explicitly reproduced and confirmed by an authorized franchise dealership across seven separate service visits spanning from August 2025 to June 2026. Inspected by manufacturer/others: The components have been physically inspected multiple times by authorized franchise dealership technicians acting on behalf of the manufacturer. Warning lamps & symptoms: The vehicle displays "Service Safety Restraint System" warning message on the dashboard. The warning lamp first appeared on August 26, 2025, at 78,472 miles while the vehicle was strictly within its CPO warranty

1. What component or system failed or malfunctioned. The Fuel Pump Module failed unexpectedly while the vehicle was being driven. Failure caused the engine to stall, resulting in a complete loss of power and mobility. Unsure if part is available for inspection. 2021 GMC Yukon have a recall N252516900, but our VIN is not included in this. Can our VIN be added to this recall please? 2. How was your safety or the safety of others put at risk? The vehicle abruptly stalled while being driven through a parking lot, causing a complete loss of power and leaving the vehicle disabled in an active traffic area. Because the vehicle could not be shifted out of PARK, it became an obstruction, creating a hazard for other drivers navigating the parking lot and increasing the risk of a collision. 3. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. After the vehicle was towed to a local mechanic on a flatbed truck, the dealer diagnosed and confirmed that the Fuel Pump Module had failed, which caused the vehicle to stall and lose power. 4. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives, or others? The vehicle was inspected by a local repair shot, which diagnosed the failed Fuel Pump Module. The vehicle was also evaluated during the towing process. To my knowledge, the manufacturer, police, or insurance representatives have not separately inspected the vehicle or component. 5. Were there any warning lamps, messages, or other symptoms of the problem prior to the failure, and when did they first appear? Prior to the failure, there were no significant symptoms indicating an imminent fuel system failure. When the incident occurred, the vehicle abruptly stalled, lost all power, and displayed a message indicating that the vehicle was "not in a condition to shift," preventing it from being shifted out of PARK. This message first appeared immediately following event.

This new 2021 GMC Yukon Denali we purchased on June 2, 2021 has a very sophisticated controls system that includes a feature, entitled "Brake Assist," that is designed to detect "rapid brake pedal applications due to emergency braking situations and provides additional braking to activate the Antilock Brake System (ABS) if the brake pedal is not pushed hard enough to activate ABS normally." "Brake Assist disengages when the brake pedal is released." After I left the dealership (June 2nd), I noticed that the "Service Brake Assist" light had illuminated on the Driver Information Center (DIC). I pulled off the road to check the Owner's Manual, and then continued home trusting that no immediate hazard existed. I subsequently set up an appointment with the dealership for a checkup. A week later, the dealership downloaded a new software package from GMC. The Brake Assist light did not appear when the engine started, so I left for home (50-minute drive at moderate speeds). Enroute to my home, I stopped at a store and turned the engine off. Started home a few minutes later. While accelerating past 45 mph, the brake system independently engaged, which threw me against the steering wheel and into the windshield. As the SUV decelerated through 20 mph, the brakes automatically released. I was not hurt, nor did I lose angular control of the vehicle. I completed my drive home and parked the Yukon normally. Did not drive it again until returning to the dealership a few days later. This second visit did not bear fruit. After significant explorative work, the lead mechanic drove the vehicle several miles under a multitude of conditions, but could not duplicate the problem or get the light on the DIC to extinguish. At my request, the dealership returned possession to me with the light still illuminated. I have driven the vehicle several miles since then with the "Service Brake Assist" light still illuminated. I suspect this is a GMC software problem.

In 2024, while the vehicle was still under warranty, we brought it to our GM dealer due to an air suspension fault. The problem typically occurs in extreme cold weather, and following that visit, we did not experience further issues during the remainder of that winter as it was never that cold again. However, the following winter the same issue returned and was diagnosed yet again, and this year we are again experiencing the identical problem with the same diagnostic code which has been diagnosed by 2 dealers and a private mechanic in the last week. It has since become clear that the underlying issue was never properly repaired during the 2024 warranty visit. We recently learned that approximately 3.5 weeks after our 2024 service appointment, GM released a service bulletin outlining the correct repair procedure for this exact issue. We were not notified of this bulletin by the original servicing dealer. This information only came to our attention when we brought the vehicle to a GM dealer last week, where the issue was properly diagnosed and now they are refusing to fix it without us paying $4300 even though it was brought to their attention in 2024 while under warranty. A failed air suspension presents a safety concern, not merely a ride-comfort issue. When the system fails, the vehicle may sit unevenly or at an incorrect ride height, which can affect vehicle stability, steering response, braking geometry, and traction—particularly in cold weather and at highway speeds. Because the failure is intermittent and temperature-related, it is unpredictable and increases the risk of loss of control. The vehicle is not operating as designed when the air suspension is compromised. GM knows about this issue as they did indeed issue a bulletin that covers our vehicle and this was done when my car was still under warranty, but it was not brought to our attention that it existed until this year after the car's warranty was up. 2 seal kits, air springs and the struts!

On Sept 17, 20123 my SUV stalled while driving in heavy traffic causing a sudden and unexpected loss of power and putting me in jeopardy of a crash My vehicle was towed to the dealer as it would not start. The dealership replaced the Fuel Pump Power Control Module. There is a recall for this part on 2021 Yukon. My vehicle was not included in the recall. Further, this make /year SUV has 11 safety recalls . I contacted GMC and opened a case. No one has contacted me to discuss the issue. I called several times and have been provided little information other than “the Regional Service Rep” will contact me and that GMC sent an email to the dealership. I have been repeatedly told my vehicle is not part of the recall. Logic dictates otherwise. I do not believe the part failure was a coincidence. Rather, the recall should have included my SUV. Further, GMC should contact me to discuss this issue as a consumer with a safety concern. I cannot operate this vehicle with confidence knowing that some of the other recall items could cause a sudden loss of power. I do not have trust in GMC to accurately identify vehicles with issues. I want GMC to explain how any driver should feel safe to operate a vehicle on the roads under these facts- knowing a vehicle was not included in one of the recalls and could be left out of others. I also question why GMC makes a vehicle that cannot be put in neutral without the vehicle running. This creates a whole other safety issue if the vehicle stalls on a highway and needs to be pushed off the road. I had an issue with the tow because of this fact. In summary for required information: 1)Unknown if the part is available as the dealer removed it 2) I was in traffic and my vehicle stalled 3) The dealer confirmed the part needed to be replaced as the SUV would not start 4) See number 1 5) There were no warning lights or other. The SUV stalled. I know GMC wants to make a profit. It should not be at consumer’s safety and peace of mind..

I am filing this complaint regarding repeated catastrophic engine failures in my 2021 GMC Yukon Denali equipped with the 6.2L L87 V8. I purchased this vehicle as a GM Certified Pre-Owned vehicle. At approximately 7,000 miles, the engine developed a knocking noise and was determined to require complete replacement. I brought the vehicle to the dealership on May 19, 2025, and it remained there until September 17, 2025—nearly four months—while the replacement engine was obtained and installed. Since receiving the replacement engine, I have driven approximately 6,000 miles. On August 4, 2026, I was informed by the dealership that the replacement engine has also failed and requires another complete engine replacement. This means my vehicle has now experienced two major engine failures at extremely low mileage, including failure of the replacement engine. I understand that the 6.2L L87 engine has been subject to a GM recall involving potential engine failure and loss of propulsion. I have now learned that NHTSA has escalated its investigation into continued failures involving these engines, including failures occurring after the recall remedy. My experience appears directly relevant to that investigation. I regularly transport my children in this vehicle and am extremely concerned about the possibility of an engine failure occurring while traveling at highway speeds or with my family in the vehicle. I feel fortunate that the previous failures did not occur under those circumstances. I have contacted GM and requested that they repurchase or replace my vehicle. GM denied my request and has refused to provide me with a reason for the denial. I am asking NHTSA to document my complaint and investigate whether the existing recall remedy is adequately addressing the underlying safety defect, particularly given that my replacement engine failed after only approximately 6,000 miles.I can provide repair orders, recall documentation, mileage records, and correspondence with GMC

My 2021 GMC Yukon has approximately 36,900 miles. On September 12, 2026, the vehicle was at an authorized GMC dealership and passed a state safety inspection. On September 19, 2026, the check-engine warning light illuminated and I returned to the dealership. The dealer performed diagnostic testing and told me the fuel pump pressure was approximately 400 PSI when it should be approximately 700 PSI. I was told the fuel pump needs to be replaced. The vehicle is currently at the dealership awaiting the replacement part: Fuel pump I was not aware of a fuel-pump failure before the warning light appeared. I am particularly concerned because this failure occurred at only approximately 36,900 miles. GM previously recalled 3,386 2021 GMC Yukons under NHTSA Campaign 21V-739/GM Recall N212332040 for a fuel-pump power-control-module defect that can cause the fuel pump to fail or operate intermittently, interrupt fuel flow and potentially cause the engine to stall. My 2021 Yukon is not included in that recall and currently shows no unrepaired recalls associated with my VIN. I believe this represents a potential safety concern because inadequate fuel delivery or a fuel-system failure while driving could cause reduced engine power or an unexpected stall, increasing the risk of a crash. Given the low mileage, the dealer-confirmed fuel-pressure problem, and the existing fuel-pump-related safety recall affecting other 2021 Yukons, I am concerned that my vehicle may have the same or a related defect despite not being included in the recalled population. I believe NHTSA should evaluate whether additional 2021 Yukons should be included in a safety investigation or recall. I am paying out of pocket to have the fuel pump replaced and am filing this complaint to document the failure.A fuel-pump failure at only 36,900 miles is extremely concerning. I ask NHTSA to determine whether my vehicle has the same or a related defect and whether the existing recall population should be expanded.

I have had major transmission failure in my 2021 GMC Yukon Denali (6.2L V8, 10-speed automatic). The vehicle has approximately 72,000 miles. Recently, a critical internal clip/retainer in the transmission broke loose, sending metal debris throughout the transmission. This catastrophic failure has rendered the vehicle undrivable and requires a complete transmission replacement. Unfortunately, the vehicle is just outside the powertrain warranty, yet I firmly believe this failure is due to a manufacturing/design defect – not normal wear and tear. I purchased this Yukon Denali as a premium, flagship SUV and have maintained it carefully. I expected the transmission to last well beyond 72k miles under normal use. It is disappointing and that a core component failed so early. Not only has this imposed a significant financial burden, but it also undermines my confidence in the vehicle’s safety and reliability for my family. A modern transmission should not self-destruct at this mileage, especially given GM’s reputation and the Denali’s top-of-the-line status. Importantly, I have discovered multiple known issues and GM bulletins related to the 10-speed automatic transmission used in my Yukon. For example, GM issued a major recall in late 2024 (NHTSA Campaign 24V797000, GM recall #N242454440) affecting 2021 Yukon models (among others) due to a defective transmission control valve that could fail and cause the rear wheels to lock up, this demonstrates that GM has acknowledged serious problems in the 10L80/MQC 10-speed transmission design. Additionally, a recent GM service bulletin (PIP6008C, Jan 24 2025) indicates that internal transmission retaining rings can dislodge, causing the internal gears to separate – which leads to loss of reverse and internal damage. This scenario is similar to what happened in my transmission. My family was left stranded away from home with no warning. The vehicle just stopped working. The warning lamp did not come on until diagnostics was run.

[XXX] on [XXX] Yukon stalled mid-drive as we exited [XXX] toward [XXX] . This is the SECOND stall on this Yukon. I had reported the first stall on June 04-2024 [11594097]. This time it would not start at all, and locked into P. There was a strange noise coming from the engine when we were on [XXX].We were going 65mph. My husband told me to start recording a video so that we can capture the noise, within 1-min as we started to exit on [XXX] towards Wake Forest, the sound was getting louder, the car started shaking as we started to slow down towards the entrance to [XXX], the engine cut-off. It smelled like burning, there was no smoke but the smell was strong. It would not start after multiple attempts, it would not shift it locked on P. At this point, the ENGINE LIGHT went on! Electric was still on, air conditioning turned off, no messages on the dashboard. The only warning was a metal like rubbing coming from the engine. I will upload this 16-min video to TikTok as a multipart series, since my multiple complaints have been falling on deaf ears! We called Gm Roadside for a tow, they said to call 911. We called 911 about 4 times and they did not have anyone to come. Gm roadside assistance could not get AAA to come until 9:45pm. AAA called us around 9:40 informing us that the available tow cannot move this Yukon because it would not shift gear to N and it will require a specific tow truck. We called back GM roadside about 5 times, just run around with no solution and a lot of attitude and lack of concern! Finally the Raleigh police Supervisor arrived, minutes later a State trooper offered assistance. They wanted the car off the road, GM was still on the phone and put them on speaker with the officer. Finally the office requested their tow as GM FAILED to get a compatible tow truck, we paid out of pocket, CASH! The Police drove us home around 11:30pm! GM DID not have contracted equipment for their OWN Trucks! New lows for GM! Incredible! POST COVID INFORMATION REDACTED