NOx Sensor Heater Sense Circuit Intermittent (Bank 1 Sensor 2)
The feedback line that monitors the NOx sensor heater current draw on bank 1 sensor 2 jumps or drops out intermittently — connector loose or chafed wire near the exhaust heat zone.
Affected components
- Nox sensor
Common causes
- High likelihood: Intermittent connector
- Low likelihood: Connector with intermittent contact under vibration
- Low likelihood: Harness routed against vibrating component
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.