The 2024 GMC Sierra continues to deliver premium full-size truck capability with advanced V8 engines featuring Dynamic Fuel Management. When your Sierra displays a P0304 code indicating a cylinder 4 misfire, understanding the DFM system helps target diagnosis effectively.
Understanding P0304 in the Sierra
The Sierra's V8 engines (5.3L and 6.2L) feature Dynamic Fuel Management, which can deactivate any combination of cylinders for fuel efficiency. Cylinder 4 is located on the right (passenger) bank of the V8. The powertrain control module monitors combustion events with precision to detect misfires across all operating modes.
DFM System Considerations
Dynamic Fuel Management is more sophisticated than previous cylinder deactivation systems, controlling individual cylinders rather than fixed patterns. The DFM lifters require proper oil flow to function correctly. Issues with lifter operation can cause misfires, particularly during transitions between active cylinder counts. Monitor when misfires occur for diagnostic clues.
Diagnostic Approach
Access the cylinder 4 ignition coil on the right bank. Inspect spark plug condition and ignition coil output. Check DFM lifter operation if misfires correlate with cylinder deactivation events. Verify oil level and condition, as proper lubrication is critical for DFM operation. Check for technical service bulletins.
Resolution Strategy
On 2024 models, warranty coverage applies to component failures. Replace spark plugs with AC Delco specifications if needed. Test ignition coil output. If DFM-related, lifter inspection may be necessary. Ensure software is current.