OBD-II code · Powertrain (generic, extended)
P23BB NOx Sensor Heater Resistance Bank 1 Sensor 3
The resistance of the NOx sensor heater on bank 1 sensor 3 is outside the calibrated band - aged element or contact resistance increased.
Is it safe to drive with P23BB?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyHeater element aged
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)
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–2 h
- Emissions test
- Likely to fail
- Parts involved
- Nox Sensor B1s3 Heater
Related codes
- P23B8NOx Sensor Heater Sense Circuit Low Bank 1 Sensor 3
- P23B9NOx Sensor Heater Sense Circuit High Bank 1 Sensor 3
- P23BANOx Sensor Heater Sense Circuit Intermittent Bank 1 Sensor 3
- P23BCNOx Sensor Calibration Memory Bank 1 Sensor 3
- P23BDNOx Sensor Performance Signal Biased or Stuck High Bank 1 Sensor 3
- P23BENOx Sensor Performance Signal Biased or Stuck Low Bank 1 Sensor 3
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.