P2349Cylinder 9 Pressure Sensor Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2349 is the plausibility code for the combustion pressure sensor of cylinder 9: the signal is electrically valid but does not match what the ECM expects for the operating point. CARB requires input sensors to be checked for rationality where feasible, in both directions. A natural test point is overrun, when no fuel burns and the peak pressure should match the pure compression pressure; GM's European diesel in the Saab 9-5 already uses that peak to locate top dead centre. No manufacturer publishes this cylinder-9 code; its counterpart for cylinder 1 is P0396. Likely causes are carbon on the sensing element, a leaking glow plug seat or a plug fitted with the wrong torque, which detunes the sensor. The ECM ignores the signal, and the driver hardly notices anything.
- What you may notice
- Check engine light on
- Usually no noticeable driveability change
- Likely causes
- LikelySensor drift from combustion deposits
- PossibleGlow plug seat leaking or plug tightened to wrong torque
- RareGenuinely low compression in cylinder 9 distorting the comparison
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.