NOx Sensor Heater Sense Circuit Range or Performance Bank 1 Sensor 3
Same as P23B4 with the sense voltage in plausible range yet not matching the heater model.
Affected components
- Nox sensor b1s3 heater
Common causes
- High likelihood: Heater current drifted
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.