Volvo All Engines (2013 Emissions) Fault Code: P20B111 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)
The voltage at pin A137.A:4 is below normal value

Observable symptoms
Aftertreatment diesel exhaust fluid (DEF) temperature too low
Possible engine de-rate

Probable cause
1) Short circuit to ground, Control wire (-)
2) Short circuit to ground, Common voltage supply
3) Wiring harness
4) Aftertreatment diesel exhaust fluid (DEF) tank heater valve
5) Aftertreatment Control Module (ACM)