NHTSA Complaint #11706741 — 2019 GMC SIERRA 1500

While traveling in high-speed traffic, the vehicle experienced a sudden and catastrophic mechanical engine failure without any prior warning lamps, messages, or symptoms. The failure manifest as a loud, rhythmic ticking and knocking noise immediately followed by a sudden loss of propulsion and severe engine shuddering. Safety Risk: The loss of power occurred in active traffic, creating an immediate crash hazard. Because the engine could no longer maintain speed, I experienced multiple near-miss collisions while attempting to navigate the vehicle to safety. This "limp mode" state placed myself and other motorists at extreme risk of a rear-end or side-impact collision. Component & Inspection: The failed component is the engine (6.2L L87 V8), specifically believed to be a failed lifter or bearing within the Dynamic Fuel Management system. The vehicle and its engine are currently available for inspection. Confirmation: The problem has been confirmed by a certified dealership service center. Diagnostic codes include P0300 (Random Misfire) and P0016. The dealership identified the symptoms as consistent with internal mechanical failure.