Toyota 2012 Prius Owner's Manual page 330

2-3. Operating the lights and windshield wipers
■
The windshield wipers and washer can be operated when
The "POWER" switch is in ON mode.
■
If no windshield washer fluid sprays
Check that the washer nozzles are not blocked if there is washer fluid in the
washer fluid tank.
302
PRIUS PHV_OM_OM47818U_(U)
Increases the intermittent
windshield wiper frequency
Decreases the intermittent
windshield wiper frequency
Washer/wiper dual opera-
tion
The wipers will automatically
operate a couple of times after
the washer squirts.
If the headlights are on, the
headlight cleaner will operate
once.