P28B5 — Cylinder 10 Ion Current Sense Circuit Range/Performance
The ion current signal from cylinder 10 is outside the expected range for combustion conditions. Combustion quality cannot be assessed reliably.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Spark plug cyl 10
- Ignition coil cyl 10
- Ion sense module
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Spark plug aged - electrode shape changed
- Ion sense circuit gain drift
- Sensor element aged beyond calibration window
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.