Reductant Control Module Requested MIL Illumination
The dedicated reductant/SCR control module has requested that the master PCM illuminate the malfunction indicator lamp — a generic forward of an internal SCR fault. Read the SCR module subcodes for the actual cause.
Affected components
- Scr control module
Common causes
- High likelihood: Internal SCR module fault — read subcodes
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
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.