P218F Reductant (AdBlue) no flow detected
What P218F means
The AdBlue (reductant) system pumps fluid from its tank to an injector in the exhaust. P218F means the system commanded dosing but detected no flow. Without AdBlue the SCR system cannot reduce NOx, and many cars start a countdown that eventually prevents restarting.
P218F is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.
At a glance
- Severity
- Medium
- Typical repair cost
- 200–2000 €
- Workshop time
- 1–5 h
- Repair difficulty
- Hard
- DIY possible
- No
- Check engine light
- Yes
- Affects emissions test
- Yes
- Limp mode possible
- Yes
Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.
Symptoms
- AdBlue or check engine warning light
- Start-restriction countdown message
- Possible reduced power
- White crystal deposits around the AdBlue injector
Common causes
- Crystallised AdBlue blocking the dosing injector or lines
- Frozen AdBlue or failed line heater in cold weather
- Faulty AdBlue pump or pump module
- Clogged filter in the AdBlue pump
- Empty tank or a very low level
Can I keep driving with P218F?
You can drive for now, but have it repaired within one or two weeks. Keep an eye on any countdown; once it reaches zero, the engine may not restart.
What to check first
- Check the AdBlue level and quality
- Inspect the dosing injector and lines for crystal deposits
- Run a pump and dosing test with a scan tool
- Clean or replace the injector, lines or pump module depending on test results
Related codes
- P2101 Throttle actuator control motor circuit range/performance
- P20EE SCR NOx catalyst efficiency below threshold (bank 1)
- P2099 Post-catalyst fuel trim system too rich (bank 2)
- P2098 Post-catalyst fuel trim system too lean (bank 2)
- P2097 Post-catalyst fuel trim system too rich (bank 1)
- P2096 Post-catalyst fuel trim system too lean (bank 1)
- P2291 Injector control pressure too low during cranking
- P2293 Fuel pressure regulator 2 (B) performance
Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
Updated: