Volvo All Engines (2017 Emissions) Fault Code: P20B172 PID: ACM Reductant Heater Coolant Control Valve Control

Volvo All Engines (2017 Emissions) Fault Code: P20B172 PID: ACM Reductant Heater Coolant Control Valve Control

Circuit description
This diagnostic trouble code (DTC) indicates malfunction in the aftertreatment diesel exhaust fluid (DEF) tank heater valve or related wiring. The function of the aftertreatment DEF tank heater valve is to allow engine coolant flow to the aftertreatment DEF tank heater element which keeps the DEF from freezing. Frozen DEF may result in no DEF dosing which causes limited vehicle operation.

Conditions for diagnostic trouble code (DTC)
DEF in tank temperature too high

Probable cause
1) Aftertreatment Diesel Exhaust Fluid (DEF) Tank Heater Valve