Powertrain
generic / SAE
P2000
NOx Adsorber Efficiency Below Threshold (Bank 1)
The lean NOx trap (LNT) on bank 1 is no longer storing or releasing NOx within the required efficiency window. Detected by the downstream NOx sensor or model-based monitor — typically caused by sulphur poisoning, thermal aging, or a failed regeneration strategy.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / 00
Possible causes
- Sulphur poisoning from high-sulphur fuel — desulphation regeneration not running high
- Thermal aging of washcoat after high-temperature exposure medium
- Downstream NOx sensor reading drifts medium
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: hard
- DIY: shop recommended
- Estimated cost: 400–3500 €
- Estimated time: 2–6 h
- Component: nox adsorber catalyst
- Component: nox sensor downstream
- Component: exhaust temperature sensor
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012