Powertrain
generic / SAE
P206B
Reductant Quality Sensor Circuit Range/Performance
DEF quality sensor reads in range but reports an off-spec urea concentration — typically diluted DEF or non-DEF fluid in the tank.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / 6B
Possible causes
- DEF diluted with water high
- Wrong fluid in DEF tank medium
- Sensor element aged beyond calibration window low
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: 80–1500 €
- Estimated time: 0.5–4 h
- Component: reductant quality sensor
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012