P2349: Cylinder 9 Pressure Sensor Circuit Range/Performance
What to do
Usually symptomless — the module quietly stops trusting one cylinder's trace. The overrun comparison makes this a clean diagnosis for a workshop with the right scan tool; wiring first regardless.
What this code means
Cylinder 9's pressure reading is electrically alive but implausible — and this family has an elegant built-in cross-check: during cranking and overrun, with no fuel injected, every cylinder's pressure trace should be nearly identical, pure compression with nothing burning. One sensor reading adrift of its eleven siblings under those conditions has convicted itself. Drift is the sensor's ageing mode, as with most in this corpus; the family's context is at P2348.
Likely causes
Start here
- Sensor drifted out of calibration · moderate
- Faulty cylinder pressure sensor · moderate
Less common
- Corroded or loose connector · easy
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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