The P0304 code in your 2024 Mercedes-Benz GLC indicates the engine control module has detected persistent misfires in cylinder 4. The second-generation X254 GLC features Mercedes' advanced turbocharged engines requiring proper diagnostic approach for this popular luxury compact SUV.
Understanding P0304 in the 2024 GLC (X254)
The 2024 GLC X254 offers the M254 2.0L turbo four-cylinder (GLC 300) and M256 3.0L turbo inline-six (GLC 43/63) with mild hybrid technology. Cylinder 4 location varies—rear on the four-cylinder, fourth position on the six-cylinder. Both use sophisticated direct injection and turbocharging.
Luxury SUV Considerations
The GLC combines SUV practicality with Mercedes driving refinement. Turbocharged engines demand robust ignition systems. Direct injection allows carbon accumulation over time. Misfires significantly affect the driving experience expected from this premium vehicle.
Diagnostic Methodology
Identify your engine—M254 I4 or M256 I6. Use Mercedes-compatible diagnostics supporting X254. Locate cylinder 4 based on your configuration. Test ignition coil output and spark plug condition. Verify fuel injector operation.
Repair Solutions
Install Mercedes-specified spark plugs appropriate for your engine. Replace degraded ignition coils with genuine parts. Address fuel system concerns. New vehicle warranty should cover manufacturing defects.