NOx Adsorber Over Temperature (Bank 1)
A temperature sensor at the NOx adsorber on bank 1 reports a value above the safe limit. Sustained over-temperature destroys the storage washcoat.
Affected components
- Nox adsorber catalyst
- Exhaust temperature sensor
Common causes
- High likelihood: Runaway desulphation regeneration
Possible 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)
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- Reduced-power or limp mode may occur
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.