P0312
Cylinder 12 Misfire Detected
What it means
P0312 means Cylinder 12 Misfire Detected.
Check these first
- A fouled spark plug on cylinder 12
- A failing coil or boot on cylinder 12
- A clogged fuel injector on cylinder 12
- A vacuum leak at the cylinder 12 intake port
- Low compression on cylinder 12
What to do next
- Check misfire data to confirm cylinder 12
- Inspect the cylinder 12 spark plug for fouling
- Swap the cylinder 12 coil with another and recheck
- Test the cylinder 12 injector circuit and flow
- Check compression on cylinder 12
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.