Cylinder 9 Misfire Detected
P0309 — Cylinder 9 Misfire Detected
System: Powertrain | Type: Generic (OBD-II Standard) | Make: Generic
P0309 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.
Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.
Because P0309 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.
The P0309 fault code is set when the powertrain control module (PCM) detects a misfire in cylinder 9. A misfire occurs when the air-fuel mixture in the cylinder fails to ignite correctly, leading to symptoms such as rough running, loss of power, or increased emissions.
Detailed possible causes for P0309 are available to TaT members.
Unlock with Free TrialStep-by-step diagnostic guidance for P0309 is available to TaT members. Our Diagnostic Assistant provides professional-level troubleshooting procedures written by experienced technicians.
Unlock with Free Trial| Code | P0309 |
| System | Powertrain |
| Type | Generic (OBD-II Standard) |
| Make | Generic |
| Causes | Available |
| Diag. Assistant | Available |
| Video | — |
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