Toyota FJ Cruiser Instructions For Adjusting And Operating page 282

4−3. Do−it−yourself maintenance
Washer fluid
If any washer does not work, the washer tank may be empty.
NOTICE
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Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid.
Doing so may cause streaking on the vehicle's painted surfaces.
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Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures listed on the washer fluid tank.
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Open the lid.
Add washer fluid.