2012 Toyota Sienna Owners Manual - Page 630
2012 Toyota Sienna Manual
Page 630 highlights
3 -8 . Ot he r int e rior fe a t ure s Se at he at e rs ∗ For driver's seat For front passenger's seat On The indicator light comes on. Adjusts the seat temperature The further you move the dial upward, the warmer the seat becomes.