Body Control Module (BCM)
WARNING: This page is about a different car, the 2003 Buick Park Avenue. However, it is still accessible from the selected car via links, so may be relevant.
Washer Fluid Level: The scan tool displays Ok/Low. The BCM supplies a signal to the Washer Fluid Level Switch. When the washer fluid level is full, the washer fluid level switch will open. The signal supplied by the BCM is near system voltage, which the scan tool displays as Ok. When the washer fluid level is low, the washer fluid level switch will closed.
The signal supplied by the BCM is pulled low, which the scan tool displays as Low.