P2339Cylinder 4 Above Knock/Combustion Vibration Sensor Threshold
- 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
- P2339 covers cylinder 4. On a four-cylinder engine this is the last cylinder of the series, which is why Stellantis bulletin 09-009-26 lists exactly P2336 to P2339 for the 2.0L turbo PHEV (sales code ECX, Jeep Wrangler 4xe 2024–2025, Grand Cherokee 2023–2025): any of the four codes with the MIL on, often together with a knocking noise, qualifies for an engine replacement under an extended warranty because of machining debris and casting sand. In general the code means the knock control has seen vibration above the limit in the combustion window of cylinder 4 and retards that cylinder's spark. On six- and eight-cylinder engines the series continues with P2340; GM reports such cases as P0324, and Saab uses the sensor codes P0326/P0331 once more than one cylinder knocks.
- What you may notice
- MIL on
- Knocking noise from the engine compartment
- Reduced power
- Likely causes
- PossibleMachining debris or casting sand damaging the engine (Stellantis bulletin 09-009-26)
- PossibleLow-octane fuel or high intake temperature
- PossibleDeposits raising compression in cylinder 4
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €0 – €8,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.