Code result
P20AA
Reductant Injection Air Pressure Control Valve Stuck Open
Moderate severity
What it means
Reductant air-pressure control valve mechanically stuck open — air pressure cannot be reduced, dosing atomisation off-spec.
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 stuck open
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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