2009 Toyota Avalon Owners Manual - Page 178
2009 Toyota Avalon Manual
Page 178 highlights
2 -3 . Ope ra t ing t he light s a nd w indshie ld w ipe rs Fog light sw it ch (if e quippe d) The fog lights improve visibility in difficult driving conditions, such as in rain or fog. They can be turned on only when the headlights are on low beam. OFF ON 152