The 2023 GMC Yukon continues with the 5.3-liter and 6.2-liter V8 engines featuring Dynamic Fuel Management (DFM). Additionally, the Yukon Denali Ultimate offers a 3.0-liter Duramax diesel inline-6 where cylinder 5 is also legitimate. A P0305 diagnostic trouble code indicates misfire detection at cylinder 5.
P0305 Code Analysis
P0305 translates to "Cylinder 5 Misfire Detected" in OBD-II terminology. All 2023 Yukon engine options—5.3L V8, 6.2L V8, and 3.0L Duramax I-6—include cylinder 5 as a legitimate position requiring proper diagnosis when this code appears.
V8 Engine with DFM
The V8 engines use Dynamic Fuel Management that can deactivate individual cylinders including cylinder 5. DFM lifter issues remain a diagnostic consideration. Misfires correlating with DFM cycling suggest lifter problems; steady misfires suggest ignition or fuel causes.
Duramax Diesel Consideration
If your Yukon is equipped with the 3.0L Duramax inline-6, diesel misfire diagnosis differs significantly. Without spark plugs, focus shifts to fuel injector function, compression, glow plug operation, and fuel quality.
Warranty Coverage
As a 2023 model, your Yukon likely remains under warranty. Document symptoms and have the dealer evaluate the misfire. DFM lifter failures on covered vehicles should be addressed under powertrain warranty.