Code result
P218F
Reductant No Flow Detected
High severity
What it means
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.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
Dosing line or nozzle fully blocked
highOne of the most commonly reported causes for this code — check this first.
Pump dead
mediumA plausible cause — test and verify before replacing parts.
Line frozen at very low ambient temperature
lowLess common, but worth ruling out after the more likely causes.
Related help
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