DTC Description: Notes
WARNING: This page is about a different car, the 2018 Nissan Titan XD. However, it is still accessible from the selected car via links, so may be relevant.
The heater relay supplies power to the DEF supply pump assembly. The DEF Line heater power supply and ground circuits are controlled by the DEF Control module. After treatment DEF Line heating is based on the input of the ambient temperature sensor. Heating of the line is initiated when the ambient temperature is below 0 degrees Celsius. The DEF supply pump assembly reports status back to the Engine Control Module (ECM) via CAN communication.