P20A9

Reductant Injection Air Pressure Control Valve Circuit High

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine Light Is On
Reduced engine power
Increased urea consumption (AdBlue)
Increased NOx emissions
SCR system error message on dashboard

Causes

Short circuit in valve circuit
Air pressure control valve malfunction
Broken or damaged wiring
Problems with the SCR control unit
Corrosion of contacts or connectors

How to Fix

Check the integrity of wiring and connectors
Measure valve resistance
Check control circuit voltage
Replace faulty valve if necessary
Reset the error and check the system operation

Related codes

P20A8 P20EA P20EE