2021 GMC Yukon: won't start

Filed Oct 28, 2026 · Fuel system · NC

While stopped in a parking lot. I returned my vehicle to drive home, and the car would not start. I had it towed to the dealer. They did a diagnostic inspection for "crank-no-start ". Two trouble codes: P0340 intake single camshaft ignition sensor circuit and P00C6- fuel rail pressure load during engine cranking. Performed diagnostic checks and suspect a broken timing chain and timing tensioner that causes the bottom of the engine to free spin while the top 0.5 does not. These engines are known as interference engines, and anytime there is a mismatch between the top 0.5 and the bottom 0.5, there is the potential for catastrophic failure due to the design of the valve train and bottom 0.5 of the engine. The technician suggested a full engine replacement. I went to the dealer and spoke with the Service Manager, Greg, and he stated that he would reach out to GMC because the VIN number was not part of the recall, although the YEAR/MAKE/MODEL is. I also reached out to GMC to open a claim. To date, I have not heard back, and they have not yet accepted responsibility for replacing the engine.

Filed Oct 26, 2026 · Engine · AR

As I was driving down the road at 60mph, no dash lights or warnings were present. All of a sudden, my 2021 yukon lost all power and I nearly crashed as I was in heavy, fast paced traffic. I got to the side of the road, and it was at this time the engine light came on. Car died and wouldnt start back up.

Filed Sep 2, 2026 · Engine · PA

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 the federal safety agency 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.

Filed May 20, 2026 · Engine, Fuel system · OH

I was driving in the left lane on [XXX] , a 4 lane interstate just outside of Cleveland when i lost engine propulsion. Engine RPMs dropped to under 1000rpm, and quit responding to throttle. I had to change lanes and coast until there was a shoulder available to stall out at while i awaited a tow. No warning lamps until i tried to restart vehicle. Engine cranked but wouldnt start. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 2, 2025 · Fuel system · NJ

Vehicle would not start. Vehicle was towed to GMC dealership for inspection. Vehicle diagnosed with "Fuel Pump Driver Control Module" issue and needed to be replaced. This was a known issue for the 2021 GMC Yukon: GMC Service Bulletin: #24-NA-139 (Release Date August 2024) Emission Recall: N212332040 (Release Date September 2021) Emission Recall: N252516900 (Release Date September 2025) However, this VIN was not covered under the recalls and payment was required out of pocket. Recall(s) need to be expanded to include additional 2021 GMC Yukon VINs - including this one.

Filed Jul 16, 2025 · Electrical, Fuel system · NC

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. This failure represents a serious safety risk, particularly had it occurred on a high-speed interstate or in dense traffic. A sudden loss of power and inability to move the vehicle can result in dangerous roadside situations or collisions. GMC needs to address this recurring defect before it leads to more severe incidents or injuries. No warning lights or indicators appeared prior to the failure.

Filed Jul 15, 2025 · Engine · WA

Vehicle engine seized. Approx 80,000 miles. After discussion with mechanic and dealership, this problem is common with GM L87 6.2L gas engines. Engine seize likely caused from defective crank bearings. No warning light, oil was in engine, vehicle recently serviced. No oil warning light on dash or temperature sensor on dash, or check engine light. Drove car on road trip - when arrived at destination parked car - few hours later went to start vehicle and wouldn't start. My VIN is not subject to recall - currently; however, many 2021 GM engines are recalled. Why wouldn't my 2021 engine be included in this recall? Or all customers notified of potential dangers? I frequently drive carpools with many children in the car - and an engine seizure at any point while driving puts me as driver and any passengers at risk. Vehicle currently being towed to dealer for 2nd diagnosis. First autobody shop diagnosed with engine seizure.

Filed Apr 7, 2025 · Engine · NM

I was driving my vehicle at a speed of around 50 MPH when the vehicle had an sudden loss of power. The vehicle displayed press the start button while the vehicle was still moving with the motor off. I pressed the start button and the vehicle shifted to park and went to complete loss of power functions. The hazard lights would not work, the vehicle would not start or move out of park. The vehicle was stuck in the fast lane in park with no way of moving it or warning others with hazard lights. My daughter and I almost got hit by a semi due to the vehicle issues. I had to call 911 to get police there for safety concerns and a tow truck to take the vehicle back to the dealership. The tow truck couldn't get the vehicle out of park as well, so he had to drag my vehicle onto the tow truck. I have a 2021 Yukon Denali with the 6.2 engine. The dealership told me I need a new engine because of a known failure with the engine. They can't promise me replacing the engine will fix the issue. The vehicle has less then 60,000 miles on it. This engine issue put my life and my daughters life in danger. I had to carry my daughter across the highway because it was unsafe to stay in the vehicle. I can only imagine what could of happened if we were traveling at higher speeds with no way to exit the vehicle. The dealership told me it is going to be 3 to 4 months before I get my vehicle back and they can't promise the new engine won't do the same thing. This is a huge safety concern that GMC needs to address. I am stuck paying for a vehicle that puts my family in danger. Something needs to be done immediately. The dealership told me they have several Yukons in the shop with the same issue waiting for an engine replacement.

Filed Apr 3, 2025 · Engine · WA

I started the 2021 Yukon Denali this morning and there was a slight squeaking noise coming from the front of the car. I began driving and the noise went away. I parked the car and completed an errand. I then started the car to return home and on the way it started making the noise but much louder. I pulled over and the car died and refused to start. GMC Roadside Assistance sent two different tow truck that were not able to tow the car. Tow Truck #1 - Flatbed truck. Car did not go in to neutral because it couldn't start so the driver said that he was unable to pull it up onto the flatbed. Tow Truck #2 - Tow truck w/ Dolly wheels. Driver said it was too heavy for his Dolly to tow the Denali. GMC Roadside Assistance then said that they're two trucks were unable to pickup the Denali and that I was on my own to call and get a tow truck and they would reimburse me. I am on the side of the road all morning not knowing what tow truck company nor what type of tow truck to ask for...... Denali still does not start and am now awaiting a local tow company to make the pickup. GMC Roadside Assistance was a total failure.

Filed Jan 19, 2025 · Engine, Fuel system · NC

My 2021 Yukon Denali has roughly 70k miles and this is now the SECOND time that my engine shut off while driving >55mph on the interstate in the past 3 months. The first time, I had the sensation that the car was running out of gas when I went to accelerate. After about 5-10 seconds, the engine turned off, but the electronics stayed on. I coasted to the side of the road and tried multiple times to start it without success. The engine sounded fine while turning over and over, but it would never start. That episode turned out to be a bad fuel pump control module, and after roughly $400 at the local Firestone auto repair shop, I was on my way (FYI, they didn't diagnose it; I learned that was the likely problem by reading online forums and basically demanded they replace the FPCM). Now, here I am about 3 months later, and it happened again, just two days after I had the vehicle serviced at the GMC dealership for a check engine light that was intermittently coming on. The technicians said I needed an update to the Engine Control Module which was completed. The main difference was that this time, I had zero warning. There was no sensation of running out of fuel or funny noises from the engine. I just went to give it gas and noticed it wasn't working. There was a warning on the dash saying push button to start the vehicle (once again, the electronics stayed on when the engine shut off). After coasting to the side of the road, the battery seemed to be good, but the engine wouldn't turn over. I had it towed to the shop and am being told I will likely need a new engine!

Filed Jan 18, 2025 · Engine · IN

In July of 2024 while coming back from vacation pulling our boat our 2021 Yukon Denali with 6.2L motor started making noise while traveling on the interstate. I started to get over to the shoulder as the car lost power. I finally got it over to the shoulder as traffic was heavy and it was pouring down rain. As soon as I got it to the side of the road the check engine light came on and the engine died. It would not turn over or restart. After about 3 hours along side the very busy highway in bad weather GM finally sent a tow truck to take it to the dealer. After a week in a half it was finally diagnosed with spun rod bearings and main crankshaft bearings. The car had just over 21,000 miles and had been serviced per the manufactures recommendations. It took over 7 weeks for the car to be repaired where they replaced the engine with a remanufactured engine. We did not get a loaner car since it happened in KY and we live in IN. Our family had to find our own way home and a way to get our boat home also. We then had to find our own way back to get the vehicle once it was repaired. GM did reimburse us for a rental car at $44 a day only and they did not pay any taxes or fees only the rental rate. You cannot rent a similar sized vehicle for $44 dollars a day. We spent approx. $2K out of our own pocket for expenses related to this breakdown. The vehicle now has approx. 29,000 miles on it and we have not had any problems since we got it back

Filed Jan 5, 2025 · Engine · WI

I was driving on the highway at about 70 miles an hour and my vehicle started to decelerate without warning, dash lights came on. I was able to safely get off to the side of the road. The vehicle would not start, so I had to call a tow truck. Once towed to the GMC dealership and looked at by mechanics, I was told the engine failed and I would need to replace it. I was also told there were metal shavings in the oil. My vehicle did this without any warnings. I never had the check engine light come on before this incident, nor were there any noises that would make me think something was wrong with my vehicle.