NOx Exceedence - Interruption of Reagent Dosing Activity
NOx emissions are above the legal threshold and the ECU isolates the cause to interruption of reductant dosing. The injection valve, pump, or supply line is impaired.
Affected components
- Reductant injection valve
- Reductant pump
- Scr module
Common causes
- High likelihood: Reductant injection valve clogged
- Medium likelihood: Reductant pump output insufficient
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
- A drive cycle may be required after repair
- Reduced-power or limp mode may occur
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.