Powertrain
generic / SAE
P203B
Reductant Level Sensor A Circuit Range/Performance
DEF level sensor A reading is in electrical range but plausibility check fails — value sticks, jumps, or does not match consumption.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / 3B
Possible causes
- Float arm sticks high
- Sensor element aged beyond calibration window low
- Sensor mounting loose - signal damping 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: 120–800 €
- Estimated time: 1–4 h
- Component: reductant level sensor
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012