NOx Sensor Heater Circuit (Bank 2)
A general electrical fault on the heater of the bank 2 NOx sensor. NOx sensors must reach roughly 800 C to measure correctly; without heater current the sensor never enters its operating range.
Affected components
- Nox sensor b2
- Nox sensor heater
Common causes
- High likelihood: Heater element failed
- Medium likelihood: Heater wiring open or connector loose
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.