P2349 code meaning
Cylinder 9 Pressure Sensor Circuit Range/Performance
Powertrain system Generic code P23xx codes Check engine light
What P2349 means
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.
P2349 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P2349
- Check engine light on
- Usually no noticeable driveability change
Common causes of P2349
- Most likelySensor drift from combustion deposits
- PossibleGlow plug seat leaking or plug tightened to wrong torque
- Less likelyGenuinely low compression in cylinder 9 distorting the comparison
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cylinder pressure sensor glow plugSensor wiringEngine control module
What each part of P2349 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 3 | Area: ignition system or misfire. |
| 49 | The exact fault in that area. |
What to do next
- Note P2349 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2349
What does P2349 mean?
P2349 means "Cylinder 9 Pressure Sensor Circuit Range/Performance". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2349?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2349 fail an emissions test?
Yes, it can. P2349 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2349 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2349 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.