Toyota 2015 Prius Owner's Manual page 458

4-3. Do-it-yourself maintenance
Washer fluid
STEP 1
STEP 2
STEP 3
438
PRIUS_OM_OM47A17U_DVD_(U)
Open the lid.
Check the washer fluid level on
the level gauge.
"NORMAL"
"LOW"
If the washer fluid level is at
"LOW", add washer fluid.