Low Washer Fluid Level Sensor
WARNING: This page is about a different car, the 2018 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.
The low washer fluid level sensor is hardwired to the BCM through a single signal circuit and hardwired to ground through a separate ground circuit. The BCM provides a reference voltage to the low washer fluid level sensor. When the washer fluid level is low, the low washer fluid level sensor closes to ground, pulling the reference voltage low. When the washer fluid level is high, the low washer fluid level sensor opens to ground, sending the reference voltage high.