Volvo All Engines (2010 Emissions) Fault Code: SPN 3031 FMI 2 PID: PPID 274 Aftertreatment Diesel Exhaust Fluid (DEF) Tank temperature

Aftertreatment Control Module (ACM) monitors DEF tank temperature and uses it to control the Aftertreatment DEF Tank Heater valve to keep the DEF from freezing.
This temperature monitoring is also used to avoid stopped DEF dosing due to high DEF tank temperatures. If the DEF temperature is too high, reverse flow will be activated, if the temperature stays high for a short duration, a DTC is set.

Conditions for diagnostic trouble code (DTC):
1) The temperature in the tank is below normal

Probable cause
1) Aftertreatment diesel exhaust fluid (DEF) tank, Temperature Sensor
2) Wiring harness
3) Aftertreatment diesel exhaust fluid (DEF) tank heater valve
4) DEF Tank Heating Valve installed backwards