2024 GMC P0306: What It Means & Is It Safe to Drive?
P0306 on the 2024 GMC: Cylinder 6 Misfire Detected. Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
What this code means
Misfire on cylinder 6, found on V6 and V8 engines. On transversely-mounted V6 engines the rear bank cylinders (including cylinder 6) often have higher labor costs due to access difficulty.
Common causes on the 2024 GMC
- Worn spark plug on cylinder 6
- Failed coil-on-plug
- Fuel injector fault
- Low compression
Symptoms
- Check Engine Light, may flash under load
- Rough idle or vibration
- Hesitation and power loss
Typical fixes
- Replace spark plug and COP coil on cylinder 6
- Replace or clean injector on cylinder 6
- Compression and leak-down test if no improvement
Repair cost range
For a 2024 GMC, repairs for P0306 typically fall between $150 and $1200, depending on the root cause and labor rates in your area.
Known issues on GMC
GMC 5.3L P0306 is a non-AFM cylinder. Standard coil and plug diagnosis applies on Sierra and Yukon. On the 3.6L DI V6 Acadia, P0306 rear-bank cylinder may indicate carbon buildup. The 3.6L intake valves benefit from periodic walnut blasting past 80k miles.
Most commonly affected models