OBD-II code · Powertrain (generic, extended)
P23BC NOx Sensor Calibration Memory Bank 1 Sensor 3
The NOx sensor on bank 1 sensor 3 reports a calibration memory check-sum failure - factory calibration data corrupted or unreadable.
Is it safe to drive with P23BC?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyCalibration memory corrupted
- Less likelyModule software outdated, reflash may resolve
- Less likelySupply voltage outside specification
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
Related codes
- P23B9NOx Sensor Heater Sense Circuit High Bank 1 Sensor 3
- P23BANOx Sensor Heater Sense Circuit Intermittent Bank 1 Sensor 3
- P23BBNOx Sensor Heater Resistance 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
- P23BFNOx Sensor Performance Slow Response Low to High Bank 1 Sensor 3
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.