2003 Toyota Sienna Owners Manual - Page 252
2003 Toyota Sienna Manual
Page 252 highlights
03 SIENNA_U (L/O 0207) CAUTION Never turn off the engine to coast down hills. Your power steering and brake booster will not function without the engine running. Also, the emission control system operates properly only when the engine is running. 252 2003 MY SIENNA (OM45410U)