Code result
P20F4
Reductant Consumption Too Low
Moderate severity
What it means
The DEF consumption observed over the dosing window is below the model expectation — typically a clogged dosing nozzle, weak pump, or leak between pump and injector that recirculates DEF back to the tank.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Dosing nozzle clogged with crystallised DEF
highOne of the most commonly reported causes for this code — check this first.
Pump weak — flow under target
mediumA plausible cause — test and verify before replacing parts.
Related help
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