P218F
- Powertrain
- Manufacturer-specific
- Emissions
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Driving may cause further damage or leave you stranded. Arrange service promptly rather than waiting.
Reductant No Flow Detected
This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.
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.
A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.
- Safe to drive
- Driving may cause further damage or leave you stranded. Arrange service promptly rather than waiting.
- Urgency
- Get it looked at now
- Will it pass emissions
- No
- Check engine light
- Solid
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
Many vehicles show no symptom at all beyond the warning light. The absence of a symptom does not mean the fault is not real.
| # | Cause | How often | Component |
|---|---|---|---|
| 1 | Dosing line or nozzle fully blocked | Very common | — |
| 2 | Pump dead | Common | — |
| 3 | Line frozen at very low ambient temperature | Occasional | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- Reductant Metering Unit
- Reductant Pump
- Reductant Injection Valve
- Definition
- Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
- Diagnostic guidance
- Written and reviewed in-house. See our editorial policy.
- Review status
- Awaiting review
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