Powertrain
generic / SAE
P218F
Reductant No Flow Detected
The DEF dosing system commands flow but the pressure or flow sensor reports no actual delivery — typically a fully blocked dosing nozzle, a frozen line, or a dead pump.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number1 / 8F
Possible causes
- Dosing line or nozzle fully blocked high
- Pump dead medium
- Line frozen at very low ambient temperature 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: 200–2000 €
- Estimated time: 1–5 h
- Component: reductant metering unit
- Component: reductant pump
- Component: reductant injection valve
- MIL / check engine light
- emissions-relevant
- limp mode possible
Sources
References
sae:J2012