Reductant Metering Unit Temperature Sensor Circuit
A general electrical fault is reported on the temperature sensor inside the DEF metering unit — used to protect the unit from over-temperature and to compensate for fluid viscosity.
Affected components
- Reductant metering unit
- Reductant metering temp sensor
Common causes
- High likelihood: Sensor element failed
- Medium likelihood: Harness fault
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.