2012 Toyota Sienna Owners Manual - Page 307
2012 Toyota Sienna Manual
Page 307 highlights
2 -3 . Ope ra t ing t he light s a nd w ipe rs Aut om at ic H igh Be a m ∗ The Automatic High Beam uses an in-vehicle camera sensor to assess the brightness of streetlights, the lights of oncoming and preceding vehicles, etc., and automatically turns high beam on or off as necessary.