P235ACylinder 10 Pressure Variation High
- 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
- P235A is the counterpart to P2359: the cylinder 10 pressure signal swings more than the combustion can explain, with spikes or steps from one cycle to the next. A public manufacturer description of this tenth-cylinder code does not exist. In the Saab 9-5 diesel the cylinder-1 version P039D belongs to the signal performance group; it is Type B and responds within 0.2 s of leaving its window. Electrical noise is the usual reason: a signal wire with damaged shielding or chafed insulation, a poor engine ground, or unstable sensor electronics. Genuinely irregular combustion is rarer, for instance when an injector dribbles after closing. VW's TDI bulletin recommends watching the maximum pressure reading while flexing the harness – jumps then betray the wiring. The warning lamp is mostly the only sign.
- What you may notice
- Check engine light on
- Usually no noticeable symptoms
- Likely causes
- PossibleInterference on a damaged or poorly shielded signal wire
- PossiblePoor engine ground or corroded ground point
- PossibleSensor electronics delivering an unstable signal
- RareInjector dribbling after closing, combustion varies
- 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 – €550
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.