What it means
A general electrical fault on the cylinder 11 combustion pressure sensor — used on engines with closed-loop combustion control (e.g. some Volvo and BMW direct-injection diesels) to measure cylinder pressure directly via a sensor at the glow plug or injector position.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Cylinder 11's combustion-pressure sensor measures pressure inside that cylinder, commonly through a sensor integrated at the glow plug or injector position on equipped engines. The control module monitors the sensor circuit, and this code sets when it detects an electrical fault in the cylinder 11 sensor circuit.
Common causes
Most likely first.
- Faulty cylinder 11 pressure sensor
- Open or damaged sensor wiring
- Loose or corroded connector
Symptoms
- Check-engine light
- Rough running or misfire
- Reduced engine power
- Poor acceleration
How to diagnose it
- Record freeze-frame data and check for related cylinder 11 or sensor-circuit codes before clearing anything.
- Locate the cylinder 11 pressure sensor and inspect its connector and harness for looseness, corrosion, abrasion, or a break.
- Check that the connector pins are seated and that the sensor wiring has continuity, following the manufacturer's circuit information.
- Compare cylinder 11 pressure-sensor data with other cylinders while the engine runs, if the scan tool provides those values.
- Test the sensor and its power, ground, and signal circuits against the manufacturer's specification to distinguish a sensor fault from a wiring fault.
Common fixes
- Reconnect and secure the cylinder 11 sensor connector.
- Repair damaged or open wiring in the cylinder 11 sensor circuit.
- Clean or repair corroded connector terminals.
- Replace the cylinder 11 pressure sensor if circuit tests confirm it has failed.
Can I keep driving?
A short, cautious drive may be possible if the engine runs smoothly, but avoid hard acceleration. Stop if rough running or power loss worsens, as poor combustion can increase emissions and engine stress.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.