2010 Toyota 4Runner Owners Manual - Page 334
2010 Toyota 4Runner Manual
Page 334 highlights
3-1. Using the air conditioning system and defogger Windshield wiper de-icer∗ This feature is used to prevent ice from building up on the windshield and wiper blades. Turns the windshield wiper deicer on/off The windshield wiper de-icer will automatically turn off after approximately 15 minutes. CTH31AS020