Powertrain
generic / SAE
P23B1
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.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number3 / B1
Possible causes
- Open in heater control wiring high
- Pin pushed back out of connector body low
- Cracked solder joint inside the module or sensor low
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)
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
- Estimated cost: 400–850 €
- Estimated time: 1–2 h
- Component: nox sensor b1s3 heater
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012