NOx Sensor Circuit Range/Performance (Bank 2)
The bank 2 NOx sensor returns values outside the expected range for the operating point — for example a non-zero reading at engine off or unchanged values during load changes.
Affected components
- Nox sensor b2
Common causes
- High likelihood: Sensor drift due to ageing
- Medium likelihood: Sensor contaminated with soot or condensate
- Low likelihood: Sensor element aged beyond calibration window
Possible symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Related codes
Sources
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.