P235E code meaning
Cylinder 11 Pressure Sensor Circuit Low
Powertrain system Generic code P23xx codes Check engine light
What P235E means
With P235E the signal of the cylinder 11 combustion pressure sensor is too low, typically close to zero. No manufacturer documents this code, as twelve-cylinder engines with pressure sensors are not described publicly; the analogue is P0397 for cylinder 1 in Saab's 9-5 diesel, where a low signal must persist beyond 2 s with the engine running before the Type B code is logged. The first check there concerns the supply: 4.8 to 5.2 V on the reference terminal with ignition on; less voltage means the reference is interrupted or shorted to ground. Across reference and low reference of the plug itself, 3 to 12 Ohm are expected. A signal wire chafed through to the cylinder head also drags the input down. With bank-wise numbering the plug sits between cylinders 10 and 12, so their harness branches deserve a look too.
P235E at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P235E
- Warning lamp after the second faulty trip
- Peak pressure of cylinder 11 shown as zero
Common causes of P235E
- Most likely5 V reference interrupted or shorted to ground
- PossibleSignal wire chafed through to ground
- PossibleSensor glow plug outside its 3–12 Ohm specification
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 P235E 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. |
| 5E | The exact fault in that area. |
What to do next
- Note P235E 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 P235E
What does P235E mean?
P235E means "Cylinder 11 Pressure Sensor Circuit Low". With P235E the signal of the cylinder 11 combustion pressure sensor is too low, typically close to zero. It is a generic code, so it means the same on every make.
Is it safe to drive with P235E?
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 P235E fail an emissions test?
Yes, it can. P235E 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 P235E to fix?
Difficulty: medium. A typical repair takes 0.5 to 3.5 hours of work. This is a job for a workshop.
Will P235E 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.