2021 GMC Yukon: sudden loss of power

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 Oct 20, 2026 · Engine, Transmission · PA

VEHICLE: 2021 GMC Yukon, 5.3L V8 (L84). VIN: [XXX]. Mileage at failure: approximately 88,000. Component: Engine. INCIDENT DATE: XXX While I was driving on a highway, the engine began to misfire and I heard a ticking noise. The check engine light then began flashing, indicating a severe misfire. I pulled off the highway immediately to a rest area. The vehicle was towed to a GMC dealer. The dealer's diagnosis suspected failed valve lifters, and the repair orders call for a misfire diagnosis with the Bank 1 cylinder head removed, and replacement of the camshaft, lifters, and related parts. This failure caused sudden loss of engine performance at highway speed. The engine began smoking. My family and I were in the vehicle, and we were fortunate there was a safe place to stop. I believe this is a known defect. GM Service Bulletin PIP5776, "Misfire Due to Collapsed Lifter," covers 2021 GMC Yukons with the 5.3L L84 engine. It describes a misfire with a bent pushrod leading to a collapsed lifter or a lifter that comes apart, and it attributes the cause to an internal lifter concern. Many other owners of GM V8 trucks and SUVs have reported the same failure, and a class action over the AFM/DFM lifters has been pending against GM in federal court in [XXX] since 2021. I bought this vehicle new and have maintained it. This is the second time this vehicle has left my family stranded on a highway. In 2024, a separate known issue left us, including three children under [XXX], on the side of a major highway about 7 hours from home. GM repaired that issue. For the current failure, GM has not agreed to cover the repair. It has offered $5,951.39 toward an engine replacement, which would leave me responsible for $13,886.59 plus teardown labor. I am filing this complaint so the federal safety agency is aware of this failure, which can cause sudden loss of power on the highway. GM case number: XXX. Dealer: Fred Beans Buick GMC, [XXX]. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 6, 2026 · Engine · TX

While driving on the highway with my child in the car, the car suddenly began shaking and warning lights to check the power train came on the dash. There was also a loss of power in acceleration. Other error codes (303) also appeared with the check engine light also coming in. Upon checking the code later once home, it indicated there was an issue with the lifters. The car was then towed to the dealership where it was confirmed there are issues with both the lifters and the cam shaft and both need to be replaced.

Filed Sep 21, 2026 · Fuel system · PA

My 2021 GMC Yukon has approximately 36,900 miles. On September 12, 2026, the vehicle was at an authorized GMC dealership and passed a state safety inspection. On September 19, 2026, the check-engine warning light illuminated and I returned to the dealership. The dealer performed diagnostic testing and told me the fuel pump pressure was approximately 400 PSI when it should be approximately 700 PSI. I was told the fuel pump needs to be replaced. The vehicle is currently at the dealership awaiting the replacement part: Fuel pump I was not aware of a fuel-pump failure before the warning light appeared. I am particularly concerned because this failure occurred at only approximately 36,900 miles. GM previously recalled 3,386 2021 GMC Yukons under the federal safety agency Campaign 21V‑739/GM Recall N212332040 for a fuel-pump power-control-module defect that can cause the fuel pump to fail or operate intermittently, interrupt fuel flow and potentially cause the engine to stall. My 2021 Yukon is not included in that recall and currently shows no unrepaired recalls associated with my VIN. I believe this represents a potential safety concern because inadequate fuel delivery or a fuel-system failure while driving could cause reduced engine power or an unexpected stall, increasing the risk of a crash. Given the low mileage, the dealer-confirmed fuel-pressure problem, and the existing fuel-pump-related safety recall affecting other 2021 Yukons, I am concerned that my vehicle may have the same or a related defect despite not being included in the recalled population. I believe the federal safety agency should evaluate whether additional 2021 Yukons should be included in a safety investigation or recall. I am paying out of pocket to have the fuel pump replaced and am filing this complaint to document the failure.A fuel-pump failure at only 36,900 miles is extremely concerning. I ask the federal safety agency to determine whether my vehicle has the same or a related defect and whether the existing recall population should be expanded.

Filed Sep 3, 2026 · Engine · MS

My 2021 GMC Yukon began experiencing severe engine problems, including shaking/rough running, a noticeable ticking/knocking noise from the engine, and a flashing check-engine light. The vehicle also displayed Service ESC and traction control warnings and exhibited symptoms of an engine misfire. I took the vehicle to a dealership for evaluation. I was advised that the problem may involve failed lifters and that the vehicle could be out of service for several weeks for repairs. I was also advised that the repair could be very costly. At this time, I have not been given a final diagnosis, so the exact internal engine component responsible for the failure is UNKNOWN. I am concerned that the condition presents a safety risk because the engine is running extremely rough and the check-engine light is flashing. I am afraid the engine could lose power or fail while the vehicle is being driven, potentially putting me, my passengers, and other motorists at risk. I have also become aware of the federal safety agency's investigation involving failures of the 6.2-liter L87 V8 engine in GM vehicles, including the GMC Yukon, as well as reports of engine failures occurring after certain repairs or recall remedies. This has increased my concern about whether repairing or replacing individual engine components will permanently resolve the problem. I am submitting this complaint so that my vehicle's symptoms, dealer evaluation, and potential engine failure are documented. The vehicle and affected components are available for inspection upon request. The dealership has evaluated the vehicle, but a final determination of the exact cause has not yet been provided.

Filed Aug 26, 2026 · Electrical, Fuel system · MN

1. What component or system failed or malfunctioned. The Fuel Pump Module failed unexpectedly while the vehicle was being driven. Failure caused the engine to stall, resulting in a complete loss of power and mobility. Unsure if part is available for inspection. 2021 GMC Yukon have a recall N252516900, but our VIN is not included in this. Can our VIN be added to this recall please? 2. How was your safety or the safety of others put at risk? The vehicle abruptly stalled while being driven through a parking lot, causing a complete loss of power and leaving the vehicle disabled in an active traffic area. Because the vehicle could not be shifted out of PARK, it became an obstruction, creating a hazard for other drivers navigating the parking lot and increasing the risk of a collision. 3. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. After the vehicle was towed to a local mechanic on a flatbed truck, the dealer diagnosed and confirmed that the Fuel Pump Module had failed, which caused the vehicle to stall and lose power. 4. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives, or others? The vehicle was inspected by a local repair shot, which diagnosed the failed Fuel Pump Module. The vehicle was also evaluated during the towing process. To my knowledge, the manufacturer, police, or insurance representatives have not separately inspected the vehicle or component. 5. Were there any warning lamps, messages, or other symptoms of the problem prior to the failure, and when did they first appear? Prior to the failure, there were no significant symptoms indicating an imminent fuel system failure. When the incident occurred, the vehicle abruptly stalled, lost all power, and displayed a message indicating that the vehicle was "not in a condition to shift," preventing it from being shifted out of PARK. This message first appeared immediately following event.

Filed Aug 18, 2026 · Brakes, Electrical · TX

As I was driving, the vehicle's air conditioning suddenly began blowing warm/hot air. Moments later, the check engine light and all electronic service stability lights illuminated on the dashboard. Simultaneously, the vehicle suffered a complete loss of electronic brake assist, resulting in an extremely hard brake pedal and a severe reduction in braking power. The vehicle also displayed a "No Drive Mode Available" message. Third-party diagnostic scanning revealed network power codes U3018, U3505, P00FF, and P0700, indicating a total loss of power to the Body Control Module (BCM). This is the second life-threatening incident with this vehicle I have experienced following a previous highway engine stall due to engine recall. The vehicle was towed to a GM dealership for diagnostic and emergency electrical repairs.

Filed Jun 5, 2026 · Engine · OK

I am filing a complaint regarding my 2021 GMC Yukon due to a serious engine failure involving the camshaft, lifters, and crankshaft. The vehicle began exhibiting engine ticking and knocking noises, rough idle, loss of power, and reduced performance. These symptoms progressively worsened and ultimately resulted in major engine damage. The vehicle was diagnosed with failed lifters and camshaft damage, which required extensive repairs. In addition, the crankshaft failed, resulting in catastrophic engine damage and making the vehicle unsafe to operate. These are critical engine components that should not fail prematurely under normal driving and maintenance conditions. The most serious concern is safety. The engine's loss of power and deteriorating performance created the risk of sudden failure while driving. A vehicle that loses power in traffic, while merging, crossing intersections, or traveling at highway speeds can create a dangerous situation and increase the risk of a crash. Occupants and other motorists could be placed at risk if the engine fails without warning. My vehicle has been properly maintained and serviced. Despite regular maintenance, these major engine components failed unexpectedly. I am aware that other owners of GMC and Chevrolet vehicles equipped with similar engines have reported comparable camshaft and lifter failures, suggesting a potential defect rather than an isolated incident. The failure resulted in significant repair costs, loss of vehicle use, and concerns about the long-term reliability and safety of the vehicle. I believe these engine failures may indicate a manufacturing or design defect affecting 2021 GMC Yukon vehicles. I respectfully request that the federal safety agency investigate camshaft, lifter, and crankshaft failures in the 2021 GMC Yukon and determine whether a safety-related defect exists that warrants corrective action or a recall.

Filed Jun 3, 2026 · Electrical, Engine · 42,000 miles · NY

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.

Filed Apr 28, 2026 · Engine · CT

Hello, I was driving on the highway with my family and my engine had a sudden loss of power. I only have 52,000 miles on the engine and it has been serviced the entire time. We almost got in a major accident as we had cars and trucks moving around us at a very high speed as we tried to pull over in the breakdown lane. I brought the car to Daddario GMC in Shelton, CT. They did a diagnostic test and said that cylinder 2 was misfiring. Upon closer inspection they saw that there was oil sitting on top of the piston head which indicates engine failure. I have since contacted GM warranty services given my car was just past the warranty date of November 2025, but still under the 60,000 miles of coverage. I did some research and have seen this is a very common with these engines as GM did a recall on 600,000 already. For some reason my VIN # is not listed on the current recall even though my engine is in the same year as the others that were. I would like GM to cover my engine 100% but was told they may only pay a % to fix it. Can you do anything to help me get them to cover the engine at 100%? I also wanted to let you know about this issue as my VIN was not under recall and this may happen to other people/families who have the same engine as mine that isn't recalled. Thank you, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 27, 2026 · Engine · AR

While operating my 2021 GMC Yukon AT4, my vehicle suddenly developed a popping noise, the check engine light began flashing, and the traction control warning illuminated. The vehicle lost power and had reduced acceleration, forcing me to pull off the road because it was unsafe to continue driving. This created a serious safety risk and appears consistent with reported GM lifter or engine defects.

Filed Apr 14, 2026 · Acceleration, Engine · KS

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.