NOx Sensor Heater Control Circuit Open Bank 1 Sensor 3
The heater control circuit for the NOx sensor on bank 1 sensor 3 is open. Without the heater the sensor cannot reach operating temperature; readings stay invalid.
Affected components
- Nox sensor b1s3 heater
Common causes
- High likelihood: Open in heater control wiring
- Low likelihood: Pin pushed back out of connector body
- Low likelihood: Cracked solder joint inside the module or sensor
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
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.