Reductant Pressure Too High
The reductant line pressure exceeds the upper limit. A blocked return path, a stuck pump or a faulty pressure sensor are common causes; over-pressure can damage the dosing valve and the pump head.
Affected components
- Reductant pump
- Reductant pressure sensor
- Reductant lines
Common causes
- High likelihood: Return line blocked or frozen
- Medium likelihood: Pressure sensor reads high
- Medium likelihood: Dosing valve stuck closed
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
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.