Code status
Needs verification
Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.
- System
- Ignition / Misfire
- Scope
- iso-sae-controlled-p0
- Standard
- SAE J2012 / ISO 15031-6
- Source
- legacy-import
Diagnostic boundary
A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.
Do not assume the coil is bad just because cylinder 1 is named; prove whether the fault follows spark, fuel, compression, or wiring.
Useful checks before replacing parts
- Compare cylinder 1 misfire counts with neighboring cylinders under idle, cruise, and load.
- Swap-test ignition parts only when safe and appropriate, then confirm whether the misfire follows the part.
- Check injector operation, compression, leakdown, vacuum leaks near that runner, and connector condition.
Related OBD-II codes
These nearby ignition / misfire entries can help compare wording and fault area. They may share the same verification status as the source database.