P235FCylinder 11 Pressure Sensor Circuit 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
- P235F is logged when the cylinder 11 pressure sensor signal remains above its plausible maximum. Only twelve-cylinder engines have this cylinder, and no maker documents the code; the Saab 9-5 diesel serves as the model with P0398 for cylinder 1, a Type B code that needs more than 2 s over the threshold. In that wiring layout three faults produce a high reading: an open low reference, an open signal wire and a reference or signal shorted to battery voltage. Saab's test plan therefore measures less than 5 Ohm between the low reference and ground, and it requires infinite resistance between every sensor terminal and the plug body – broken insulation inside the glow plug would also distort the signal. The cylinder runs on without pressure feedback; P235E is the opposite case.
- What you may notice
- Check engine light after two trips
- Implausibly high fixed pressure value for cylinder 11
- Likely causes
- LikelyLow reference (ground) wire of the sensor open
- PossibleSignal wire interrupted or connector off
- RareReference or signal shorted to battery voltage
- RareInsulation failure between sensor terminals and plug body
- 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: €50 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.