2021 GMC Yukon Driver assistance Problems

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.

NHTSA ID

11756194

Incident

Jul 28, 2026

I bought the vehicle used with 40,000 miles it’s has 100,856 now the engine shot off while I was driving and brought it to the GMC dealer that GM instructed me to the dealer had me pay 284.95 for inspection and then try to charge me 1284.95 for a complete tar down of the engine because of misfiring and ESC error codes.

NHTSA ID

11747447

Incident

Jun 19, 2026

2021 Yukon Denali. Inspected by dealer under recall. Passed dealership test and new oil viscosity adjustment completed by dealer at 39k miles. Told no issues with vehicle continue to drive it. Today 4-14-26 on the interstate traveling 75mph the engine seized and lost all power. Instrument panel showed 0rpm as I coasted to a stop and the engine lost all power. I placed the vehicle in park on the shoulder and attempted to restart. Nothing! Engine would crank. Towed to Olathe gmc dealer and they took one looke at it , diagnosed it said it had all symptoms of total engine failure. Ordered me an engine and told 6 weeks out. Sent me home in a loaner. Service department told me They get one everyday sometime more than 1. They have hertz rental on standby for warranty loaner vehicle. I find it spilling that these vehicles come time to be sold. They’re all bad according to the service department. I also find it very frustrating that they park the broken defective vehicles at the very back of the dealer lot to hide the graveyard of 6.2’s from the public. My vehicle is under 5 year 60k warranty and engine is being replaced, but the tech could not share the extent of what would be replaced. All he mentioned was the block. Zero warning engine just went up like a grenade at 75mpg on the highway. Wife’s vehicle and left me stranded 2 hours from home on a work trip.

NHTSA ID

11731242

Incident

Apr 14, 2026

The contact owns a 2021 GMC Yukon. The contact stated that while driving at various speeds, the vehicle shuddered abnormally with blue smoke coming from the exhaust, with the message "Lane Departure Assist" displayed. The check engine and stabili-trak warning lights were illuminated. The vehicle was taken to a local service center, where it was diagnosed with cylinder #1 misfire. The local dealer was contacted. The vehicle was not diagnosed or repaired. Upon further investigation, the contact related the failure to the GMC Service Bulletin:15-06-01-002L. The manufacturer was made aware of the failure. The failure mileage was approximately 110,000.

NHTSA ID

11725844

Incident

Mar 14, 2026

Mileage

110,000 mi

I had just pulled off from street light, hit button to turn auto engine shutoff off, all of sudden I lose power as if I'm in neutral, engines reving up but won't go. Then kicks in but with less power like gears will not shift. I get to my destination but car will not go in reverse.

NHTSA ID

11722391

Incident

Feb 27, 2026

I was driving and a message popped up "Service Traction Control", then another message popped up "Forward Collision System Unavailable". Then the car started making this knocking sound and every time I would try and accelerate there would be a loud sound and almost a pulling stopping it from picking up much speed. I took the car into the dealer/repair shop and they said it was an issue with the lifters that had to be replaced and potentially an issue with the cam. They said this repair would cost upwards of $6,000 and I have never had this issue with the car before. This came out of nowhere and the car had not been showing any signs of this occurring before. This is a 2021 GMC Yukon and I drive my Wife and three sons in that car daily.

NHTSA ID

11709048

Incident

Jan 2, 2026

traction control system ESC system Suddenly and without warning, multiple warning lights started flashing including check engine. The vehicle lost power and traction. There was a loud knocking and metallic whining sound. The vehicle began to vibrate and struggled to move forward and felt like the wheels were slipping. The loss of these functions was alarming because it was dark, we were in a construction zone, and my 15-year old daughter was driving having recently earned her driver's permit. The car following us almost rear ended us. It was such an abrupt engine failure it scared me and my daughter.

NHTSA ID

11707007

Incident

Dec 22, 2025

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. Given the speed and severity of the impact, airbags should have deployed. The failure of these systems placed my life at serious risk. The vehicle has since been totaled and taken by insurance, but I am requesting that this failure be formally investigated as a potential safety defect in the airbag and sensor systems. I am extremely concerned that the vehicle’s safety systems were either defective or not properly restored following repairs and recalls.

NHTSA ID

11706440

Incident

Dec 1, 2025

While driving vehicle on 11/08/2025, vehicle made a popping noise and loss power. We were out of town and had to pay out of pocket to have vehicle towed to a dealership and hour away from our home. Dealership diagnosed issue with engine failure due to lifter fell and caused damage to cam shaft and bore. I will be without a vehicle for an additional 2 to 4 weeks waiting on a back ordered engine from GM, and continue making payments on vehicle as well. This issue seems to be an ongoing problem that GM is ignoring…….GM should compensate towing, car rental, and repair/ replacement charges due to failure.

NHTSA ID

11699201

Incident

Nov 8, 2025

The contact owns a 2021 GMC Yukon. The contact stated that while driving at various speeds, the Forward Collision Avoidance system erroneously activated, causing the vehicle to suddenly slow down. The vehicle was taken to the local dealer who serviced the Forward Collision Avoidance system camera and sensors. No further information was available. Additionally, while driving at highway speeds, there was a knocking sound coming from the engine compartment, and the seat restraint failure message was displayed. The cause of the failure was not yet determined. The manufacturer was notified of the failure. The failure mileage was 20,000.

NHTSA ID

11659001

Incident

May 5, 2025

Mileage

20,000 mi

The contact owns a 2021 GMC Yukon. The contact stated that while his wife was driving at an undisclosed speed, the vehicle lost automotive power. The Electronic Stability Control warning light was intermittently illuminated. The vehicle was towed to a local independent mechanic where it was diagnosed with a spun rod bearing failure; however, further investigation was needed. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 102,000.

NHTSA ID

11647571

Incident

Feb 13, 2025

Mileage

102,000 mi

The component that failed was the Camshaft and Lifters in the Engine - My safety and others was put at risk because while going 45mph, I suddenly lost forward moving power and couldn't go faster than 35 - braking power was sketchy and only responsive when pumped. - I received the following errors on my dash "Service ESC" "Service Traction Control", Reduced Acceleration Drive with Care", "Forward Collision System Unavailable", "Service Emission System" the vehicle would shudder violently- this problem has been confirmed and corrected at a huge expense (see bill) -

NHTSA ID

11647336

Incident

Dec 18, 2024

Font Camera failure. Front camera controls many "safety features" which fail without the camera. Vehicle under mileage warranty amount but not under time warranty ( 3 years ). Camera only covered under bumper to bumper.

NHTSA ID

11641343

Incident

Sep 18, 2024

My vehicle has software that controls the rear gate, cameras, and my safety features for blind spots—seat buzzer to warn of collisions and voice activated phone system. I recently had a safety recall involving my back wheels locking up during driving. I had the recall done by Power Chevrolet and it affected my cameras, which I noticed were longer accurate immediately after leaving the dealership. My seat buzzer kept buzzing warning me of a collision due to the cameras inaccuracy. I am unsure if it affected my blind spot warning but my car was unsafe to drive as the safety features fill in many blind spots in this big vehicle. Additionally I had been having issues with my back gate opening when it should not resulting in two stops to close it— one in Costco and one on [XXX] outside of Philomath, Oregon. These are safety issues. To get the software issues resolved, it cost an additional $210 for the updates and my back gate is still not fixed and no solution is offered. My fear is that people will be unaware their cameras or safety features are no longer properly calibrated and hit something or even worse, be unable to pay for software updates to make these features functional resulting in more crashes. I was unaware of the software updates ( I did all updates GMC pushed) needed to be done and this just continues on with more software updates to be released requiring future payments. I bought this car new and this was not disclosed or even discussed. GMC can push down updates that make other updates necessary and be an unending source of revenue for them. Oregon just passed a right to repair law but cars are exempt. This will result in unsafe vehicles on the road. My oil change cost me $350 with $210 the software updates. What were these safety related updates not done as recalls? INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11637648

Incident

Jan 22, 2025

Upon cold start vehicle rattles when idling down and growling noise when accelerating upon left or right turns. Also, has constant vibrations with sound of metal rattling at speeds above 30 mph. Forward collision light on without a significant amount of mileage on vehicle. I have taken my vehicle to dealership at least 5 times referencing the vibrations. Growling noise was heard by service advisor last visit October 2024, and he stated it probably were the tires. I advised him that brand new tires were put on vehicle, April 18th 2024, rear vibration has never stopped from time of purchase. I have asked dealership to check drivetrain as it is a know issue for 21 Yukon Denali. Vehicle has not received recall but was manufactured at Arlington plant where the parts of the drive shaft was not properly heated and differential is known for issue upon cold start. Vehicle powertrain warranty is due to expire August 2025 or 60,045 mileage. Therefore with that, the vehicle was placed in service August 2020 months before unproperly heated driveshaft recall was determined. My vehicle should be on the list for this recall as GMC noted this to have occurred on vehicle prior to 07/2021. In addition, a chirping noise comes from front of vehicle while idling and when automatic stop starts back up.There are already known recalls for two of issues noted above.

NHTSA ID

11637446

Incident

Apr 1, 2024

The contact owns a 2021 GMC Yukon. The contact stated while driving approximately 60 MPH and depressing the accelerator pedal, the vehicle started shaking and shuddering. There was an ESC service warning light illuminated. The vehicle was taken to a local dealer where it was diagnosed that the right lifter and the camshaft were damaged and needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 72,000.

NHTSA ID

11600265

Incident

Jul 1, 2024

Mileage

72,000 mi

On 4-5 occasions since purchasing a new 2021 GMC Yukon Denali the automatic breaking function has engaged for no reason, with no obstruction in the roadway. It has occurred at low speed (after disengaging break and starting to drive). Obviously, this is a major safety issue.

NHTSA ID

11599180

Incident

Jul 5, 2024

20221 GMC Yukon Denali Suddenly comes to a stop ,” it brakes hard “ It acts like when you are almost gonna hit someone and brakes engage so hard. Jerks everyone to the front !no other lights coming on or anything else! For now it’s been doing it at slow speed , really don’t wanna experience it at a high speed , pls help these vehicles are so expensive to be dealing with this . This is my wife and kids vehicle

NHTSA ID

11567953

Incident

Jan 26, 2024

2 different times I have been driving once at a high speed of 70 on the highway and then driving 15-20 miles an hour today my automatic braking engaged and threw me forward which is a very scary feeling. I have not taken it in for service for that as it had only happened once a few months ago and there have been no warning lamps indicating an issue.

NHTSA ID

11553511

Incident

Nov 3, 2023

I was driving on the interstate on a low speed and my SUV came to a complete stop with no notice. Nothing was in the road or close in front of me. Jerked me to the front and seat belt left a red spot on my neck from the seat belt, scared the crap out of me. I thought I was hit from behind. The is a hug safety concern that needs to be recalled and fixed immediately before it causes an accident.

NHTSA ID

11538531

Incident

Aug 14, 2023

The contact owns a 2021 GMC Yukon. The contact stated while stopped at a traffic signal, the engine started revving without the accelerator pedal being depressed. The contact stated that the vehicle occasionally independently accelerated. The contact state that the failure also occurred while the vehicle was in park(P). The contact stated no warning light was illuminated. The contact had not taken the vehicle to a local dealer or independent mechanic. The vehicle had not been diagnosed or repaired. The manufacturer had not been informed of the failure. The failure mileage was approximately 17,000.

NHTSA ID

11512883

Incident

Mar 20, 2023

Mileage

17,000 mi

I was involved in a vehicle accident on 10/6/2021 where my vehicle was stuck by an uninsured motorist driving recklessly on the interstate causing a total of 4 car collision. My vehicle was a a 2021 GMC YUKON SLT SUV, in which I was struck on rear drivers side quarter panel and again by another vehicle in the front bumper by another vehicle that struck in the rear bumper by the reckless driver. With my vehicle being struck by two vehicles I was shocked to learn the Onstar safety security features did not detect or contact me regarding the accident. It wasn’t until the wrecker driver arrived to pull my vehicle onto the tow truck that I received a diagnosis notification email from o star about my antilock braking system. Although I was wearing my seat belt, the impact of the collision was very shocking, my chest and neck struck the steering wheel, my glasses were knocked completely off my face on to the passenger side floor board, my personal belongings in the passenger seat, were thrown and scattered over the passenger floor area. Once the emergency authorities were on the scene everything was about over I contacted Onstar via phone, and asked why wasn’t I contacted or my accident detected, and the call taker/on star representative advised me because my airbags wasn’t deployed, they did not receive a notification or alert regarding my emergency. I have attempted to make contact with Onstar several times since the accident and as of today I have yet to get an answer of why my air bags did deploy and why the emergency sensors did detect the impact notify emergency services as this is a feature that i was charged for monthly and added protection that I counted on to assist me but very much failed me at my time of need.

NHTSA ID

11485786

Incident

Oct 6, 2021

I had just left the house driving through my neighborhood at about 35 MPH when for no reason the emergency braking engaged. The road was deserted, no other vehicles, pedestrians, dogs or objects in roadway. There was a momentary red dash alert, but I didn't have time to read it.

NHTSA ID

11484954

Incident

Sep 17, 2022

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.

NHTSA ID

11457792

Incident

Mar 10, 2022

The contact rented a 2021 GMC Yukon. The contact was driving at 75mph, the contact stated they felt the steering wheel was moving independently causing the vehicle to veer in the opposite direction. Both hands were required in order to control the steering wheel. The contact attempted to avoid a large puddle, the vehicle independently veered to the right causing a crash with a curb and crossed an exit ramp which caused the vehicle to crash then into an embankment and into a ditch. This caused damage to the front passenger side tire of the vehicle. The side air bags did deploy but not the front driver or passenger side airbag did not deploy. No warning lights illuminated from the vehicle. The medical treatment was at the scene in which they checked the contact father in- law and their baby and took them to the hospital by ambulance with the contact's wife who was also in the vehicle. The contact also sustained a cut from the airbag being deployed, the contact wife also had bruises to their upper chest and leg, The contact father-in-law was also injured with his upper body and also a small rash on their face when the side airbag was deployed, as well the contact mother-in-law has complained of a headache. A police report was filed. The vehicle was towed from the scene to an impound lot. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximate 16,000.

NHTSA ID

11430208

Incident

Aug 18, 2021

Mileage

16,000 mi