Powertrain
generic / SAE
P2BAA
NOx Sensor Range/Performance (Bank 1, Sensor 1)
The upstream NOx sensor on bank 1 returns values that are not plausible for the current operating point. NOx sensors are slow to warm up, sensitive to soot and water, and are a frequent failure on diesel SCR systems.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberB / AA
Possible causes
- NOx sensor element failed high
- Sensor contaminated with soot or condensate medium
- Sensor element aged beyond calibration window 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: possible
- Estimated cost: 200–800 €
- Estimated time: 0.5–2 h
- Component: nox sensor upstream
- Component: nox sensor wiring
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012