GMC Yukon 2019

The engine continues to slip and slows down when driving. The following codes are returned back from the onstar diagnostics, Transmission Control Module Requested Malfunction Indicator Lamp Illumination. The DTC is an informational DTC. The DTC indicates an emission related DTC set in the Transmission Control Module. The vehicle has only 132,000 miles, and I have maitain the vehicle in excellent shape. With maitainance, the transmission should last at least 300,000 miles. The Engine and Transmission System is not performing as expected. An issue has been detected in the Transmission System that transfers power from the engine to the drive wheels.

The car was clicking when it was first started up, a short time later it started to shake terribly which forced my [XXX] son who was driving the vehicle at the time to pull over, on a major toll-way in heavy traffic. Engine light started to blink and traction control light came on. I immediately took the car into the dealer and was told I need new lifters ($3800 + Tax) and most likely a new engine (they quoted me $15,865). From what I am reading this issue is common place with the 6.2L engine...frightening and very lucky my son was not injured. I have filed a case with GMC - Case #[XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The vehicle experienced a sudden and rapid mechanical failure of the 6-speed automatic transmission (6L80 model) within a span of less than two weeks. The light did not come on until the transmission was past salvage. The failure escalated rapidly from initial minor slipping to a severe loss of vehicle propulsion. A loss of acceleration while driving poses an immediate crash hazard, as the vehicle cannot safely maintain speed with surrounding traffic or accelerate out of dangerous situations. The failure required towing and a complete out-of-pocket replacement of the transmission unit at 116,374 miles to restore safe operation. The manufacturer has failed to issue a safety recall despite widespread failures of this component causing unexpected power loss on public roadways.

The contact owns a 2019 GMC Yukon. The contact stated that after starting and exiting the vehicle to allow it to warm up, the contact later noticed that the vehicle had turned off. The vehicle was towed to a first mechanic, who was unable to restart the vehicle or determine the cause of the failure. The vehicle was towed to a second mechanic, where it was diagnosed and determined that the engine had failed and needed to be replaced. The vehicle was not repaired due to the cost. The dealer was contacted and provided an estimate for the repair, but the vehicle was not diagnosed or repaired. The contact stated that the dealer's estimate was higher than the mechanic's estimate. The manufacturer was notified of the failure and suggested purchasing a new vehicle. The failure mileage was approximately 170,000.

My wife drives this vehicle to work, it has started to experience reduced engine power driving on the highway causing her to pull to the side of the road due to no throttle to maneuver the vehicle in and out of traffic, leaving her on the side of the busy highway, we have now parked the vehicle after investigating problem there is a knocking noise coming from the lower part of the engine, after research of this 6.2l engine there are reports of the crankshaft and connecting rods seizing up and coming through the side of the engine block, knowing this we are hesitant to continue driving the vehicle. We continue to make payments on a vehicle that we can't use and can't afford to make a engine replacement at the moment. Very frustrating to say the least, as expensive as these vehicles are we have lost faith in the gm name.

Loss of power steering, loss of electronic stability control, loss of all transmission gears forward and reverse, loss of automatic headlight control, loss of instrument cluster gauges including tachometer, engine oil pressure, and engine coolant temperature, loss of heated seat functionality, loss of heating, ventilation, air conditioning, and loss of infotainment/stereo system. This problem has occurred on two occasions now, the first on 01/13/2020 and then again on 02/20/2020. The vehicle was towed in to the dealer on 01/13/2020 and was also transported to the same dealership again on 02/20/2020. A TSB was performed by the dealership when it was towed in the first time that obviously did not fix the root cause of this problem. Normally the problem will go away after a period of time and then the dealership claims that they were not able to reproduce the customer's complaint. I do have video footage of the issues I experienced on two occasion as proof.

The contact owns a 2019 GMC Yukon. The contact stated that while driving at slow speeds in a parking lot, the transmission unexpectedly downshifted and the vehicle jerked abnormally. The contact stated that when the gear shift lever was shifted to drive(D), the vehicle failed to function as designed. The contact was unable to drive the vehicle, and the vehicle was towed to the residence. No warning light was illuminated. The vehicle was towed to the dealer, where it was diagnosed that metal shavings were found in the oil and the transmission needed to be replaced. The warranty had expired, and the vehicle was not repaired. The contact stated that the failure persisted. The vehicle was then taken to a transmission specialty shop, where it was confirmed that metal shavings were found in the oil and that the transmission was defective and needed to be replaced. The contact took the vehicle back to the private dealer where the vehicle was purchased. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was 125,870.

Driving out a town 400 miles away, with a young passenger in my car on [XXX] in rush hour traffic, i started hearing a slight ticking sound then moved into a full blown knock on my drivers side ( I recorded it). within minutes, my oil light came on and my dash notification reading "engine overheating idle" with the knocking really load. I had to cross 3 lanes to traffic quickly to get to the shoulder of the road, which was NOT a safe place. I smelled smoke and cut the the engine off. I popped the hood to see that there was now no coolant (that is all I knew to look for). I immediately called OnStar Roadside assistance. 2 hours later, I was towed to a local hotel room. Car completely dead. not lights, couldn't lock it, nothing. I had to pay a large fee (almost $2k) to have my car towed back to NC from AL not to mention having rent a rental car to get us home. the car is now at a GMC dealership in Monroe NC. of course the Powertrain extended warranty doesn't cover the Battery replacement, belt replacement and water pump replacement so now I'm out of pocket $1300 just to get those install to be able to try and start the engine to further diagnose if my I have complete engine failure AND without transportation. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

2019 GMC Youkon with 94,659 miles. I am the second owner of this vehicle. I purchased it used in February 2025. Check engine light came on in route to work on March 5, 2026. Immediately took vehicle to Auto Zone to scan for codes. Multiple codes were returned. I drove it directly to a repair shop for further diagnostics. Return Results were massive lifter failure and cam shaft damage. Why would the check engine light not come on sooner to prevent TOTAL FAILURE. Vehicle was towed to a GMC certified mechanic where it was confirmed that all Lifters and cam shaft were damaged beyond repair and must all be replaced. Estimated Cost of repairs so far: $8,596.80 Labor: Remove & Replace Left And Right Valve Lifter (Both Sides) Coolant Service Oil Change Labor Parts: Engine Camshaft 1 , Genuine GM Engine Valve Lifter Oil Manifold Gasket 1 , Genuine GM Fuel Pump Gasket 1 Engine Timing Cover Gasket Set 1 Engine Valve Lifter Guide 1 Engine Valve Lifter Guide 1 Coolant/Antifreeze Orange Dex-Cool 1 Gal 3 Engine Push Rod 8 Engine Oil Filter 1 0W-20 Full Syn 8 Engine Cylinder Head Bolt Set 1 Engine Valve Lifter Guide 1 Engine Valve Lifter Guide 1 Stock Engine Valve Lifter 4 Stock Engine Valve Lifter 4 Engine Cylinder Head Gasket Kit 1 Engine Cylinder Head Bolt 10 APPROVED Subtotal $8,422.71 + est. Tax $174.09 $8,596.80 Estimated time for repair: going on three weeks

The contact owns a 2019 GMC Yukon. The contact stated while driving at various speeds and depressing the accelerator pedal, the vehicle hesitated to respond and jolted while responding. There was no warning light illuminated. The vehicle was taken to the dealer and an independent mechanic; however, the failure could not be duplicated. The contact stated while driving 65 MPH, the vehicle decelerated to 25 MPH independently while the RPMS were significantly high. The contact depressed the accelerator pedal, and the engine revved. The vehicle jolted and accelerated to 65 MPH; however, the failure recurred. The contact depressed the accelerator pedal and the vehicle resumed speed, then the vehicle jerked and lost motive power. The contact was able to pull to the side of the road. The contact restarted the vehicle and continued driving; however, the vehicle stalled. The contact pulled over to the emergency lane. The contact parked and restarted the vehicle. The contact was able to drive into a parking lot, where the failure recurred. The vehicle failed to restart with the check engine warning light illuminated. The messages "Transmission Hot - Idle Engine" and "Action Required" were displayed. The vehicle was towed to the residence. The dealer was notified of the failure. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 82,000.

I was driving home on the interstate from vacation and I was set on cruise control it was 1 am so not a lot of traffic was on the road thank god. It could have been really terrible if lots of traffic was present as the engine just died without notice! The vehicle was decelerating nothing was working I could not speed up. I was able to get over to the side of the road. I got a notification on my phone that said battery critically low start vehicle to charge battery. Well nothing would start at this point. I lot all power seconds later. I thought that the cruise control was locked up and restarting it would reset it. I called roadside assistance to get a jump and that did not work. I got towed into an auto repair shop. They called me and told me that the engine is locked up that they drained the oil and found metal in it and metal pieces in the oil filter as well. They checked for leaks and said there was none that they could find. They said there was a recall but it was for the exact same symptoms that was diagnosed here but only starting with year 2021. Mine is a 2019 Yukon Denali with low mileage so not sure if all the other Yukons were aged out or already past engine death and that’s why they were not part of this but this should be included in with the open recall considering how everything is the same that is effecting this year that I have and they should pay for a new engine! Clearly the v8 6.2 gmc engines are having major issues I’m just glad I wasn’t going that fast and traffic was slow so I was able to get over safely before catastrophic things happened since there was no warning when this all happened!

MEMORANDUM To: National Highway Traffic Safety Administration (NHTSA) Subject: Safety Defect Report – 2019 GMC Yukon Denali 6.2L V8 (L87) with AFM/DFM I am reporting a serious and recurring safety defect involving my 2019 GMC Yukon Denali equipped with the 6.2L V8 L87 engine and GM’s AFM/DFM system. In the past twelve months, I have experienced two separate engine failures, both occurring at highway speeds and both involving valve-train/VLOM failures on the same side of the engine. In each incident, the vehicle suddenly lost power, misfired violently, and became unable to maintain speed. This created an extremely dangerous situation for my family. One failure occurred while my wife was driving; the other occurred while my [XXX] son was driving. Both were forced to maneuver across high-speed traffic with a failing engine to reach the shoulder. These events posed a clear risk of a high-speed crash, injury or even a fatality. There are hundreds—possibly thousands—of documented complaints from owners of GM vehicles with AFM/DFM-equipped engines reporting the same issues: collapsed lifters, valve failures, VLOM malfunctions, and sudden loss of propulsion. These failures often occur without warning and show a consistent pattern across multiple model years and engine variants, including the L87. The sudden loss of power at highway speeds represents a significant safety hazard. The frequency of similar reports suggests a systemic mechanical defect rather than isolated incidents. I respectfully request that NHTSA open a formal investigation into AFM/DFM-related failures in GM’s L87 and related V8 engines, with a focus on lifter, valve, and VLOM failures that lead to abrupt engine shutdown. Appropriate safety action, including a mandatory recall, should be done immediately to prevent potential injuries or fatalities. I will provide repair documentation, service reports, and other additional information. [XXX] , Esq. [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF