Powertrain
generic / SAE
P20AC
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.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / AC
Possible causes
- Sensor element failed high
- Harness fault medium
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)
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 200–1500 €
- Estimated time: 1–4 h
- Component: reductant metering unit
- Component: reductant metering temp sensor
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012