2021 GMC YUKON XL Complaints

My 2021 GMC Yukon XL recently suffered a failure of its fuel pump control module. This occurred at just 44,000 miles, mere weeks after my manufacturer warranty expired in June of 2026. This issue goes far beyond a financial inconvenience or a matter of consumer reimbursement; it is a severe, life-threatening safety hazard that GM has failed to permanently resolve. My Experience: Sudden Power Loss While Towing The gravity of this part failure became clear during a recent drive. I configuration-matched this vehicle—a heavy-duty Yukon XL with a 6.2L engine and a 4x4 towing package—specifically for its capacity to safely haul heavy loads. While traveling with a trailer attached, the vehicle experienced a sudden, catastrophic loss of engine power. Without warning, the engine sputtered and died. Had this occurred on a steep incline, a blind curve, or in heavy highway traffic, a catastrophic multi-vehicle collision would have been entirely unavoidable. Critical Safety Hazards and Concerns •Inability to Maintain Speed, Loss of Vital Assist Systems, & Compounded Towing Risks Systemic Failure and Inadequate Remediation What makes this situation entirely unacceptable is that this specific vehicle was already subject to previous GM safety campaigns regarding this exact component (including Safety Recall #N212332040 and subsequent Emission Recall #N252516900). GM is fully aware that their supplier produced defective modules that are prone to premature internal short-circuits. Yet, their remediation strategy has been entirely inadequate. By managing this through piecemeal, phased rollouts and limited VIN inclusion lists, they are leaving dangerous vehicles on the road until the point of failure. Drivers are effectively acting as crash test dummies, waiting for their engines to die in dangerous environments before GM acknowledges that their specific VIN was fitted with the defective supplier part.

Issue Description: The vehicle experienced a failure of the Dynamic Fuel Management (DFM) system, resulting in a collapsed lifter. This caused a cylinder misfire and a sudden loss of engine power while driving at highway speeds. Safety Concern: While traveling at highway speeds, the sudden misfire and loss of power created a dangerous condition. The vehicle could not maintain speed or accelerate properly with surrounding traffic, significantly increasing the risk of a collision. Failure Details: The issue was diagnosed as a collapsed lifter related to the DFM system. This caused persistent misfiring, rough engine operation, and severe drivability issues. Repair Outcome: Due to the extent of internal engine damage caused by the lifter failure, the vehicle required complete engine replacement.

The contact owns a 2021 GMC Yukon XL. The contact stated that while starting the vehicle, the engine stalled and the vehicle failed to start. The check engine warning light was illuminated. The vehicle was towed to an independent mechanic, who determined that the fuel pump power control module needed to be replaced. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 21V739000 (Fuel System, Gasoline); however, the VIN was not included in the recall. The manufacturer was made aware of the failure and advised the contact to file a complaint with the NHTSA Hotline. The failure mileage was approximately 59,000.

Check engine light comes on and an alert says "acceleration reduced" dealer says the coolant control valve is bad but the engine never overheats but the fans are running max speed 100% of the time.

While I was driving home from the grocery store with my 4 kids our 2021 GMC Yukon XL (5.3L V8 engine), the vehicle suffered a sudden, catastrophic mechanical engine failure without warning. The engine began violently shaking, lost major propulsion, and dropped into a severe misfire state when we were coming down the highway. This created an immediate safety hazard on the road, as I suddenly lost the ability to safely accelerate or maintain highway speeds while hauling my children.A certified technician diagnosed the issue as a complete failure of the active fuel management hydraulic valve lifters and bent pushrods, a known manufacturing defect explicitly documented in GM Technical Service Bulletin PIP5776F. The internal failure required a total engine teardown and valvetrain replacement, costing over $10,000 out of pocket.General Motors has failed to issue a safety recall for this specific 5.3L valvetrain defect, despite it causing unexpected engine stalls, severe power loss, and immediate traffic hazards for drivers. This defective component poses an ongoing safety risk to families and should be upgraded to a mandatory safety recall. I am afraid to drive it every time I get on the highway in fear it could shut down again.

The contact owns a 2021 GMC Yukon. The vehicle was taken to the local dealer for a routine oil change. While driving, the oil low light illuminated. The vehicle was burning an excessive amount of oil. The local dealer was contacted again, but the vehicle was not diagnosed or repaired. The manufacturer was contacted, who referred to the local dealer. The failure mileage was approximately 149,000.

The vehicle suddenly began vibrating noticeably when idling and at low speeds. About 30 minutes after this started happening a warning lamp lit up. We drove the vehicle about 2 miles to a local auto parts store to get an initial computer diagnosis of the issue. The test resulted in a code of "P0304" which detected a cylinder #4 misfire and recommended a fuel injector replacement. We brought the vehicle to a local mechanic to get the issue further evaluated. After this evaluation, it was determined that the cylinder #4 misfire was related to a lifter failure. The mechanic explained that this situation could possibly have caused more damage, specifically to the camshaft, but that job was bigger than he was willing to take on. He recommended we get the vehicle towed to the dealership for further evaluation. He also informed us that this situation was common with the engine in this vehicle and GMC is aware of it. He directed us to some articles online that elaborated on the potential known issues related to the automatic fuel management (AFM) system and the related engine damage. The vehicle was towed to a local GMC dealership for evaluation. They found the failed cylinder #4 with associated lifter failure and damaged camshaft. We went forward with the repair at the dealership. We asked the dealership about the known engine issues with this vehicle. They acknowledged the widespread issues but informed us that our particular VIN has not been included in any recalls or safety notifications, so we were responsible for the repairs. The vehicle spent nearly 3 weeks at the dealership. One of the parts was on backorder due to a national shortage, which delayed the repair by about one week. That seems to imply that the parts involved in this repair are in high demand, which raises the question of this being a manufacturing/parts issue that may need to be investigated further.

I took my GMC Yukon in for a recall. They changed the oil, programmed my module, changed the cap, and tested the engine, saying it was good. I took it on a trip, 7000 miles later engine locked up.

The vehicle drove normally earlier in the day with no major drivability concerns. Later, reverse gear suddenly stopped functioning and the engine would rev abnormally without the vehicle moving properly while in reverse. Shortly afterward, while driving, the vehicle displayed the warning message “Reduce Acceleration – Drive with Care” and began losing acceleration and propulsion. The vehicle would not accelerate normally and later could not exceed approximately 20-35 MPH. The condition created a significant safety concern due to sudden loss of acceleration and propulsion while operating in traffic. The engine RPM would increase abnormally while the vehicle failed to respond properly in drive and reverse. An independent mechanic inspected the transmission and found diagnostic trouble codes P0747, P0776, and P0700 related to transmission pressure control and valve body operation. Inspection also revealed significant metal contamination, sludge, and clutch material inside the transmission pan and filter. Reverse and 2nd gear were determined to be failed/burnt internally. The vehicle was later transported to an authorized GMC dealer for inspection. Dealer confirmed reverse gear would not engage even after adding transmission fluid. Vehicle is currently available for inspection.

The vehicle has experienced recurring suspension, drivability, and pulling issues associated with the 4-corner air ride leveling suspension system since early ownership. The first major incident occurred at approximately 4,600 miles when the vehicle displayed suspension warnings and would not accelerate properly past highway speeds. Since that time, the vehicle has repeatedly experienced pulling during acceleration, unstable ride behavior, suspension/leveling concerns, alignment-related issues, and drivability instability. The problem has been reproduced multiple times and documented through approximately 16 repair visits and roughly 74 cumulative days out of service. Dealership service records include repeated suspension inspections, drivability evaluations, wheel alignments, and related repair attempts. The issue remains unresolved and the vehicle is currently back in service again for the same concern. The recurring pulling and instability create safety concerns because the vehicle does not consistently track properly during acceleration and normal driving conditions. Suspension warning messages and drivability symptoms first appeared early in ownership while the vehicle was still under factory warranty. I have also found many similar owner complaints online involving the same suspension system in comparable GM full-size SUV models.