The P0302 diagnostic code on your 2023 GMC Yukon indicates that the engine control module has detected misfires in cylinder 2 exceeding acceptable parameters. This full-size SUV requires proper diagnosis to maintain its powerful V8 performance.
2023 Yukon Powertrain Options
The 2023 GMC Yukon offers either the 5.3L V8 or the more powerful 6.2L V8 engine. Both engines feature Dynamic Fuel Management (DFM), GM's sophisticated cylinder deactivation technology that can shut down any cylinder, including cylinder 2, under light-load conditions.
Dynamic Fuel Management System
DFM allows the V8 to operate on as few as 2 cylinders to maximize fuel economy. The system uses specialized hydraulic lifters that can collapse to deactivate individual cylinders. Problems with these lifters or their solenoids commonly cause cylinder-specific misfires.
DFM Lifter Analysis
GM has documented lifter issues with the DFM system on some vehicles. A failing lifter may cause intermittent misfires, valve train noise, or complete cylinder deactivation failure. Lifter-related misfires often occur specifically during cylinder deactivation transitions.
Standard Ignition Diagnosis
Not every cylinder 2 misfire relates to DFM. Traditional causes include worn spark plugs, failed ignition coils, or fuel injector problems. The coil-on-plug ignition design allows easy testing and replacement of individual cylinder components.
Diagnostic Strategy
Begin by monitoring DFM operation using a scan tool. If the misfire correlates with cylinder deactivation events, focus on DFM components. If misfires occur regardless of DFM status, prioritize ignition and fuel system inspection.