To confuse things further, section 413-01 on the Instrument Panel Cluster contains the following entry:
Low Washer Fluid Level Sensor
"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. "
It just doesn't say where it is or what the BCM does with the information. It doesn't appear to have an indicator on the panel, but I guess it could keep the washer motor from running with the tank empty and possibly burning up.