OBD-II DTC · SAE J2012

P0309

Cylinder 9 Misfire Detected

Misfire → Do NOT suppress

What P0309 means

P0309 is a standard SAE J2012 powertrain diagnostic trouble code with the defined meaning: Cylinder 9 Misfire Detected. This is the OEM-agnostic definition; specific manufacturer interpretation may add detail (subsystem, bank, sensor location) but the core meaning is consistent across all OBD-II compliant vehicles since 1996.

Can this code be suppressed via ECU tuning?

Should NEVER be suppressed. Misfires indicate genuine combustion issues (ignition, injector, mechanical). Suppressing them risks engine damage.

Related codes in the P03xx family

P0300P0301P0302P0303P0304P0305P0306P0307P0308P0310P0311P0312

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