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 water in fuel sensor is in the fuel filter. The Engine Control Module (ECM) provides a 5V reference signal to the water in fuel sensor. When the water collected in the fuel filter covers the sensor probes, the water-in-fuel sensor pulls the 5V reference voltage down, indicating high water accumulation in the fuel filter.