Reductant Pump Control Circuit Open
The control circuit to the reductant (DEF) dosing pump is open — no current flow detected. Without pump pressure no AdBlue reaches the SCR catalyst and NOx reduction stops.
Affected components
- Reductant pump
- Reductant pump wiring
Common causes
- High likelihood: Pump motor open
- Medium likelihood: Connector unplugged or corroded
- Low likelihood: Pin pushed back out of connector body
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
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.