After finishing a long drive south, I shut the engine off and a yellow engine code popped on. I connected my computer to it and revealed a P129F code (fuel pump control module). I have noticed that other GMC models have been included in a recall concerning this problem. The 2021 GMC 2500 Denali should be also since it is the same problem. This needs to be covered by the manufacturer since it is a constant problem.

Source: NHTSA complaint ODI #11753689 · view all complaints for this vehicle at nhtsa.gov

XXX Power Assist Step Reversing I have a 2021 GMC Sierra 2500HD that the local dealership (Ozark MO 65714) is stating has expired and not covered by the warranty. I researched online and as I understand this recall falls under SAFTEY recalls and is to be fixed and doesn't expire? It requires no parts but the reprogramming of the K4 Assist Step Control Module. What is my next step or recourse?

Source: NHTSA complaint ODI #11733017 · view all complaints for this vehicle at nhtsa.gov

The left rear internal "top-hat" parking brake shoes suffered a total manufacturing bonding failure, causing the friction lining to completely delaminate and detach from the metal backing plates inside the rotor hub. This triggered Diagnostic Trouble Code (DTC) C060B (Left Park Brake Actuator Circuit). The failed components were replaced by the servicing facility and are unavailable, but the official dealer diagnostic scan sheet and itemized repair invoice are preserved and available for inspection upon request. Safety was compromised in two ways. First, the mechanical failure completely disabled the electronic parking brake system, forcing a heavy-duty truck to rely exclusively on the transmission's parking pawl to remain stationary. This creates a severe rolling vehicle hazard, especially on inclines or when hauling/towing heavy loads. Second, when these shoes disintegrate, the loose friction debris trapped inside the enclosed drum can shift, wedge, and cause a sudden mechanical wheel lockup or severe brake dragging at highway speeds, threatening vehicle control. The problem was officially confirmed and diagnosed by an authorized General Motors dealership service center. The technician scanned the vehicle, retrieved DTC code C060B, and confirmed upon inspection that the internal parking brake shoes had completely disintegrated. There were absolutely no physical symptoms, abnormal noises, dragging sensations, or brake pedal changes prior to the failure, as the parking brake shoes sit isolated inside the rotor hub. The issue appeared suddenly on May 23, 2026, when the vehicle immediately displayed a parking brake malfunction warning lamp on the instrument cluster dashboard and completely refused to engage the electronic parking brake.

Source: NHTSA complaint ODI #11755097 · view all complaints for this vehicle at nhtsa.gov

The “Service Safety Restraint” alarm goes off continually on my 2021 GMC Sierra 2500HD AT4. The warranty is no longer valid as at the time of occurrence I was at 34,500 miles and when I took it in the warranty had expired due to exceeding 36,000 miles. Extended warranties were not purchased and this began approximately 8-9 months after purchase. The code given is “b0014 Driver Seat Side Air Bag Deployment Loop” with a description of high resistance in wiring or wiring harness. After much research I have found that many GMC 2021 vehicles and previous models have had this exact same issue. No dealership as of yet has offered to help or understand that this defect was of their own flawed design. The issue that I am having is exactly the same as other models such as the 2021 Yukon, Sierra 1500, Suburban and others. This is a safety issue and only want GMC to account for their flaw. I do not believe I should have to pay for a design flaw or equipment malfunction that is well known amongst GMC vehicles. I am asking the NHTSA to help me in this matter and the many others who are having the same issue and for the manufacturer to be accountable for their own flaw.

Source: NHTSA complaint ODI #11478489 · view all complaints for this vehicle at nhtsa.gov

The contact owns a 2021 GMC Sierra 2500. The contact stated that no visible tailgate was attached, and the contact was unaware if the vehicle had been repaired under NHTSA Campaign Number: 24V060000 (Latches/Locks/Linkages); however, the recall had been marked as completed under the VIN. The vehicle was taken to a local dealer where they advised the contact that the recall repair was completed. The vehicle was taken to another local dealer, Littleton Chevy (851 Meadow St Littleton, NH 03561); for a second opinion and was informed that the recall repairs had not been performed. In addition, the contact stated that the tailgate was replaced with an after-market part due to backorder issues. The contact stated that there was no failure experienced with the original part. The manufacturer was made aware of the issue. The contact had not experienced a failure. The failure mileage was 125,000.

Source: NHTSA complaint ODI #11624010 · view all complaints for this vehicle at nhtsa.gov

The contact owns a 2021 GMC Sierra 2500. The contact stated that on several occasions, the automatic power side-out step failed to extend as designed. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was 93,726.

Source: NHTSA complaint ODI #11733416 · view all complaints for this vehicle at nhtsa.gov