Reductant System Flow – Blocked
The SCR module detects fully blocked flow in the reductant system. No reductant reaches the injector despite commanded dosing.
Affected components
- Reductant lines
- Reductant injector
- Reductant pump
- Scr module
Common causes
- High likelihood: Reductant injector clogged
- Medium likelihood: Frozen reductant in cold weather
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.