P236FCylinder 12 Combustion 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
- P236F is the ECM's verdict that combustion in cylinder 12 falls short, judged from the evaluated pressure curve rather than from a single limit. No manufacturer documents it, as no twelve-cylinder engine with cylinder pressure sensing is public. BorgWarner states that its pressure glow plug lets the controller correct, cylinder by cylinder, how much fuel is injected and when, with the measured pressure as feedback. A performance code of this type follows when that trimming has used up its range for one cylinder and the result is still off target. For diesels, CARB links combustion sensors to more demanding misfire monitoring. Worn or coked injectors, poor compression, a restricted intake or contaminated fuel are typical findings. Rough running, extra smoke and P0312 may appear alongside.
- What you may notice
- Check engine light on
- Rough running
- More visible exhaust smoke
- Likely causes
- LikelyInjector of cylinder 12 coked or worn
- PossibleWeak compression in cylinder 12
- RareContaminated or poor-quality fuel
- RareRestricted intake path
- 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: €150 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.