Code result
P207F
Reductant Quality Performance
High severity
What it means
The ECU has concluded that the AdBlue/DEF in the tank does not meet specification. Diagnosed by comparing expected NOx reduction against the dosed reductant volume — too much dosing for too little NOx drop indicates diluted or wrong fluid.
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
AdBlue diluted with water or wrong fluid filled
highOne of the most commonly reported causes for this code — check this first.
NOx sensor drift gives false reductant-quality verdict
lowLess common, but worth ruling out after the more likely causes.
Related help
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