Which parts fail
Components named in complaints (battery, alternator, wiring, ignition, instrument cluster, infotainment).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2021 GMC Yukon owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2021 GMC Yukon. The contact stated that upon the start of the vehicle, the vehicle independently reversed without warning upon touching the gear shifter. The vehicle first reversed into a cement barrier and then lunged forward into an intersection while she repeatedly depressed her brake pedal to no avail. The contact managed to call 911 and while speaking with an operator, she was able to regain control of the vehicle. The contact crashed into a parked vehicle as well as a barrier during the failure. Once the contact regained control of the vehicle, she pulled into a gas station where she was met by police. A police report was filed. The contact suffered mental anguish as a result of the failure. Due to the failure, the vehicle was towed to a dealer where they were unable to duplicate or diagnose the failure. …
Vehicle: 2021 GMC Denali Mileage: ~48,000 miles Purchase Price: $62,000 Issue: Airbags & crash sensors failed to deploy Complaint Text: I am filing a safety complaint regarding my 2021 GMC Denali. I was involved in a rear-end collision at approximately 45 mph, where I struck another vehicle straight on from behind. The impact was severe enough to total my vehicle, yet no airbags deployed, and no forward collision warning or crash sensor systems activated. This is especially concerning because this vehicle was previously involved in a front-end collision (not my fault) and underwent extensive repairs. I was assured all systems were repaired and functioning properly. Additionally, my vehicle had completed recall work related to safety systems prior to this crash. This is the second front-end crash involving this vehicle where airbags failed to deploy. …
The contact owns a 2021 GMC Yukon. The contact stated while driving at an undisclosed speed, the engine seized. The brake pad sensor warning light illuminated. In addition, the contact stated that the vehicle continued to roll forward. The contact was able to drive the vehicle to the shoulder of the road. The contact stated while attempting to restart the vehicle, the vehicle failed to start. The contact stated that a nearby driver assisted by providing a jumpstart. The vehicle was driven to the residence. The vehicle was then taken to an independent mechanic where it was diagnosed with alternator failure. The contact stated that the vehicle was previously taken to two independent mechanics, and the vehicle was diagnosed with alternator failure. The dealer was made aware of the failure. The contact was informed that the failure was a known failure with similar vehicles. …
The contact owns a 2021 GMC Yukon. The contact stated that while driving at an undisclosed speed, the odometer was inoperable. There was an abnormal odor of fuel while starting the vehicle. The parking brake and TPMS warning lights were illuminated and flashing. The parking brake was inoperable. Additionally, the seat belts were inoperable. The contact stated that there was a cut in brake line. The vehicle was taken to the local dealer where it was diagnosed and determined that the brake master cylinder needed to be replaced. The vehicle was repaired but the failure persisted. The manufacturer was contacted but provided no additional assistance. The failure mileage was approximately 60,000.
The contact owns a 2021 GMC Yukon. The contact stated that while driving approximately driving 45 MPH and turning onto an exit the vehicle suddenly reduce speed and lost power and the message "Press Start" had displayed. The contact stopped the vehicle and eventually restarted the engine and the vehicle operated as normal. The next day the vehicle was driven to the local dealer who was unable to duplicate the problem and determine the cause of the failure. The manufacturer was not yet contact regarding the failure. The failure mileage was 42,000.
The contact owns a 2021 GMC Yukon. The contact stated while driving at various speeds, the message "Safety Restraint Unavailable" was displayed. The vehicle was taken to a dealer where it was diagnosed that the battery voltage was low. The battery was replaced; however, the failure reoccurred. The vehicle was taken to the dealer on two other occasions, where the system was reset, but the failure reoccurred approximately two months later. The manufacturer was notified of the failure. The failure mileage was approximately 16,000.
Vehicle: 2021 GMC Yukon Denali Component: Fuel System, Gasoline - Fuel Pump Control Module Incident Date: 7-10-2025 Mileage 61,263 Location: SR 2006 Coats, NC Summary of Complaint: While my wife was pulling out of our neighborhood in our 2021 Yukon Denali, the vehicle suddenly shut off while navigating a slight curve. It came to a complete stop in the roadway and could not be restarted. The engine would not crank, and the vehicle could not be shifted into neutral, making it impossible to move out of traffic. The Yukon remained disabled in the roadway for over an hour and ultimately had to be towed. Upon inspection, the dealership mechanic immediately identified the issue without even running diagnostics. He confirmed it was a failed fuel pump control module, which he stated is a common issue with this model. …
I purchased the vehicle in July 2024. I drove the car for 10 days, and when I was driving 65 mph, the check engine light blinked three times and then went off. After that, the engine made a sound that was not there before. I took the vehicle to the dealership and they had the car for many weeks, concluding that the lifters broke and the engine needed to be replaced. The dealership said they replaced the engine and the car was returned to me towards the end of August. Since then, the AC has been worked on three different times in the past year and on the third attempt, there is finally cool air coming out of the driver's air vents. The driver's seat AC blowers malfunctioned and were repaired. The dealership put the original engine's belt back on and then broke. The electric system inside glitches from time to time when you first start the car. …
I'm not happy with just a change in oil viscosity because the car has already been on the road for 70000 miles before we were aware of the recall on the engine. Changing the oil viscosity doesn't help when there is a underlying engine problem it should be replaced not just change your oil and send you on your way because now I'm always wondering and worried if the engine will still fail when my kids and wife are in the car. Furthermore I just had it inspected and the oil changed to new viscosity a week ago and the oil level is already half way on the dipstick so I'm taking back to the dealership to express my concern. If I would have known this was going to be an issue with this suv I would have purchased something else. I'd just like the engine replaced so that I don't have to worry every time I pull out of the driveway with my family. …
Water is entering the passenger cabin through failed front sunroof drain tubes on both the left and right sides. The drains discharge inside the A pillars rather than to the exterior, pooling in the driver's side floorboard. An authorized GMC dealer diagnosed the cause in writing on August 12, 2026 as rubber grommet shrinkage and hardened internal buildup preventing water from flowing through, on both the left and right sides simultaneously. The identical bilateral failure mode indicates a component or assembly defect rather than debris blockage. Water is accumulating in the driver's footwell in proximity to cabin electrical components and the fuse block area, creating a risk of electrical shorting, connector corrosion, and circuit failure. Mold has developed in the front carpet and padding on the driver's side, and water intrusion staining is present on the passenger side. …
Electrical complaints in other Yukon years
Frequently asked questions
How common are electrical problems on the 2021 GMC Yukon?
NHTSA has 30 complaints about the electrical system of the 2021 GMC Yukon, 9% of the model year's 341 complaints. The component named most often is instrument cluster/panel (1 mentions).
Is there a recall for 2021 GMC Yukon electrical problems?
No. NHTSA lists no electrical system recall for the 2021 GMC Yukon, though it has 13 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 Yukon electrical problems start?
Half of the complaints with a recorded mileage happened before about 20,000 miles, and 63% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 2 injuries to electrical system 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.