Code result
P20F7
Reductant Injection Valve Stuck Open
Moderate severity
What it means
The DEF injection valve at bank 2 unit 1 does not close when commanded — DEF flows continuously into the SCR. Risk of crystallisation in the catalyst and over-dosing.
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
Valve seat eroded or contaminated
highOne of the most commonly reported causes for this code — check this first.
Carbon or debris buildup preventing free movement
lowLess common, but worth ruling out after the more likely causes.
Component wear with age - mechanical play
lowLess common, but worth ruling out after the more likely causes.
Related help
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