Volvo All Engines (2013 Emissions) Fault Code: P20AA00 PID: ACM Reductant Injection Air Pressure Control Valve Stuck Open

Circuit description
This function is used to calculate the EGR Mass Flow. The Engine Control Module (ECM) monitors the EGR differential pressure sensor and the EGR temperature sensor after cooler and uses these signals to calculate the EGR Mass Flow data.

Conditions for diagnostic trouble code (DTC)
The air valve is controlled to closed position
The DEF and the air pressure sensors measure pressure

Observable symptoms
Constant air purge of Aftertreatment DEF Line(s)

Probable cause
1) Reductant Injection Air Pressure Control Valve Control
2) Nozzle

Detailed information
To fully verify the repair it may be necessary to activate vehicle functions or perform a test drive