Table 1 shows one common suspension related problems of the 2021 GMC Yukon.
| Problem Category | Number of Problems |
|---|---|
| Suspension problems |
The vehicle has experienced recurring suspension, drivability, and pulling issues associated with the 4-corner air ride leveling suspension system since early ownership. The first major incident occurred at approximately 4,600 miles when the vehicle displayed suspension warnings and would not accelerate properly past highway speeds. Since that time, the vehicle has repeatedly experienced pulling during acceleration, unstable ride behavior, suspension/leveling concerns, alignment-related issues, and drivability instability. The problem has been reproduced multiple times and documented through approximately 16 repair visits and roughly 74 cumulative days out of service. Dealership service records include repeated suspension inspections, drivability evaluations, wheel alignments, and related repair attempts. The issue remains unresolved and the vehicle is currently back in service again for the same concern. The recurring pulling and instability create safety concerns because the vehicle does not consistently track properly during acceleration and normal driving conditions. Suspension warning messages and drivability symptoms first appeared early in ownership while the vehicle was still under factory warranty. I have also found many similar owner complaints online involving the same suspension system in comparable gm full-size SUV models.
Air bag suspension does not work in sub freezing temperatures. Vehicle bounces up and down excessively and is extremely unstable and unsafe to drive at any speed. Vehicle speed was limited to 56 mph. Dealer stated that this is a known flaw but not recall has been issued. This is a design flaw that GMC should be responsible to correct.
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!.
When driving at slow speed and wheels turning right or left you can hear a humming coming from the suspension. Unable to identify the issue. When wheels get straight the humming goes away.
12/16/25 (evening): warnings began cycling across the screen: 1) service esc, 2) vehicle leveling for stability, 3) rear axel system off, 4) engine symbol began flashing, and 5) service traction control. I felt vibration/bouncing while driving as well. 12/17/25 9 took 2021 GMC Yukon denali to GMC dealership. They ran a computer scan and reported a misfire, but nothing else appeared to be wrong. They told me that sometimes a low battery can cause the warning lights and messages to cycle. They recommended that I keep driving it and return if the warnings appeared again. 12/17/25 9:18 I left the dealership. I drove 4. 5 miles, and all the same warning lights came back on. When I pulled into a parking lot, it smelled like my engine was on fire, and dark smoke was coming from my rear exhaust pipe. I called a flatbed tow truck and had the car returned to the dealership. Mileage: 52,285 GMC 2021yukon denali xl 6. 2l v8 engine well-maintained with regular oil changes. The dealership told me there was a lifter failure and that the engine could be damaged and would need to be replaced if the cam, pushrods, etc. , were damaged. They also told me I was out of warranty by less than 60 days. The dealership said my warranty expired in October 2025, even though my vehicle is a 2021 with only 52,285 miles. They just informed me that the left lifter was replaced at 6,000 miles and that they will replace the right lifter. I am concerned about further damage down the road, given the recalls on the GMC 6. 2l engines.
The contact owns a 2021 GMC Yukon. The contact stated that the service suspension and low oil warning lights were illuminated. The contact stated that the engine oil had leaked out of the vehicle. The contact received notification of NHTSA campaign number: 25v274000 (engine and engine cooling); however, the part to do the recall repair was not yet available. The local dealer was contacted. The vehicle was not diagnosed or repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The failure mileage was approximately 83,000. VIN tool confirms parts not available.
Subject: formal complaint – engine failure in 2021 GMC Yukon denali xl VIN: 1gksjkl2mr242441 defect number (gm): 11662402 gm case numbers: 9-12578008672 / 53598259 / 54106961 dear NHTSA office of defects investigation, I am writing to formally report a critical mechanical failure in my 2021 GMC Yukon denali xl, which resulted in a complete engine failure, rendering the vehicle inoperable and exposing my family to significant safety and financial risks. Despite following the recommended maintenance schedule and driving under normal conditions, the engine failed prematurely. The vehicle has been out of service for over four months, and I have yet to receive a definitive resolution or timeline from general motors. I have incurred over $13,000 in out-of-pocket costs, including towing, repair estimates, rental vehicles, and continued loan payments on a non-functional vehicle. Key details: vehicle: 2021 GMC Yukon denali xl VIN: 1gksjkl2mr242441 failure type: total engine failure requiring full rebuild or replacement time out of service: 4+ months and ongoing financial impact: $13,335. 58 in documented costs gm defect number: 11662402 (noted internally by gm) dealer(s) involved: midas auto service, beaman GMC (nashville, TN) I have made repeated efforts to escalate this through gm’s case advisors and executive team, but have received no meaningful resolution or written acknowledgment of my request for either reimbursement or a good faith vehicle buyback. Given the safety implications of such a catastrophic failure in a relatively new vehicle, I believe this may represent a broader manufacturing defect or quality control issue and warrants NHTSA investigation. I respectfully request that NHTSA: log this complaint into your safety database investigate whether similar failures have occurred in other 2021 Yukon denali xl vehicles contact gm for further information regarding this defect and associated safety risk thank you for your attention to this matter.
GMC currently has bulletin out on the issue and how to fix it. Unfortunately this doesn't not fix it and I am going to have to replace my whole rear differential at only 60,500 miles. GMC is well aware of the situation and has not done a recall. The fix the bulletin proposes would not work and there was over and inch of metal shaving found. This is a huge issue in the specific vehicle and the part to replace the rear differential isn't even available (national backorder with no eta) leaving customers without a vehicle or solution for their faulty issues. GMC should be liable for their negligence and putting customers in potential harm if the vehicle is continued to be driven with a failing rear differential. The vehicle did not prompt any warning messages but the grinding sound was very loud. Bulletin no. : 21-na-028 date: January, 2023.
Out of no where the right side makes a clicking noise when I turn.
My blind spot warning light and signal doesnt work all the time. For example, if a pass a car, or a car passes me at a speed of more than 5 miles per hour, there is no notification from the blind spot warning light in the mirror, or an audalble signale either. I have taken the car to the GMC dealership 3 times and I was told that is normal, and nothing is wrong. I own other GMC models and I have never experianced this intermitant issue.
Vehicle has been at the dealer with gm involvement starting January 6th and it has been out of the repair facility for less than 2 weeks up to today, 4/1/2021. The vehicle has an adaptive suspension system that has not only failed, but has continued to fail after multiple repair attempts. There seems to be an issue with this new adaptive suspension, specifically when the �vehicle access� option is toggled in the settings. This has caused multiple safety warnings; �vehicle too high, drive slowly vehicle unsafe� and �vehicle too low, drive slowly, vehicle unsafe�. Dealer and gm have replaces millie parts, software and sensors, to no avail. The major concern is that most owners don't realize the risk and this is a flaw in the design which could lead to accidents. My vehicle had to be towed in at the last resurgence because it was not in as state to be driven. The suspension collapsed after having 35 days in the shop. It seems that the software and the system aren't properly functioning/designed. This could be endemic in every denali, or other gm vehicle with this system, that enables the automotive access (vehicle lowers when in park). This issue occurred while parked and while driving, both locally and highway. The scariest was when I was driving to the dealer and the suspension started bouncing causing me to go no more than 40mph on the interstate to the dealer.
We were coming back from a trip with my children and this vehicle was barely 2 weeks old with 0 miles and we were on a highway when all the emergency lights on the dash went off. It was flagging the electrical system, the engine, the brakes. Honestly all the lights possible went off. The vehicle was lagging and it felt force when we pushed on the gas. Our hands were gripping the steering wheel to keep it in lane till we could get off.