Reductant Metering Unit 2 Performance
The reductant metering unit 2 does not deliver the expected DEF/AdBlue dosing within the calibrated profile. Pump aging or pressure regulator drift.
Affected components
- Reductant metering unit 2
Common causes
- High likelihood: Pump output degraded
- Medium likelihood: Pressure regulator drifted
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
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.