Reductant Injection Valve Stuck Closed Bank 1 Unit 2
The reductant injection valve on bank 1 unit 2 is stuck closed. No DEF/AdBlue can be dosed on this unit.
Affected components
- Reductant injection valve b1 u2
Common causes
- High likelihood: Valve mechanically seized closed
- Medium likelihood: DEF crystallization blocks valve
- Low likelihood: Carbon or debris buildup preventing free movement
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.