NOx Sensor Heater Control Circuit High (Bank 2)
NOx Sensor Heater Control Circuit High (Bank 2): the control-circuit voltage is above the expected range. The NOx sensor heater brings the sensor to operating temperature; a fault delays accurate NOx readings used for SCR control.
Affected components
- Nox sensor
Common causes
- High likelihood: Short to B+
- Low likelihood: Connector pins corroded - high contact resistance
- Low likelihood: Supply wire pinched against B+ source
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
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.