Volvo All Engines (2013 Emissions) Fault Code: P20A400 PID: ACM Reductant Purge Control Valve Stuck Open

Volvo All Engines (2013 Emissions) Fault Code: P20A400 PID: ACM Reductant Purge 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 must provide approximately 150?kPa (21.8?psi) air pressure
The overflow valve must be closed below 300?kPa (43.5?psi)
The DEF pressure sensor measures air pressure when the overflow valve should be closed

Probable cause
1) Aftertreatment DEF dosing valve
2) Air line
3) Aftertreatment diesel exhaust fluid (DEF) line

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