Volvo All Engines (2013 Emissions) Fault Code: P20FE9A PID: EMS Reductant Metering Unit Performance

Circuit description
The DEF quality, level, and temperature sensor detects the concentration of fluid in the DEF tank. The sensor is connected to the DL7 data link which sends a signal to the Aftertreatment Control Module (ACM) and Engine Control Module (ECM). The relevant control module interprets the information and activates a lamp in the instrument cluster, inducement mode or both if necessary

Conditions for diagnostic trouble code (DTC)
Buffer control saturated high

Probable cause
1) DEF concentration, Aftertreatment Diesel Exhaust Fluid (DEF) quality
2) DEF quality, level and temperature sensor
3) Exhaust leakage
4) Defective SCR catalyst
5) B96B, NOx sensor
6) B96, NOx sensor

Detailed information
Max DEF dosing capability reached