Volvo All Engines (2013 Emissions) Fault Code: P20B173 PID: ACM Reductant Heater Coolant Control Valve Control

Volvo All Engines (2013 Emissions) Fault Code: P20B173 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)
Aftertreatment diesel exhaust fluid (DEF) temperature too low

Observable symptoms
Possible engine de-rate

Probable cause
1) Mechanical fault
2) Damaged or restricted actuator coolant lines
3) Aftertreatment diesel exhaust fluid (DEF) tank heater valve