The Sienna hit the market in 1998, offering a powerful V6 engine with 194 hp, five-star safety specs, standard antilock brakes, tire pressure warning system and top-rated crash test scores. A right-side powered-sliding door was added in 1999, along with daytime running lights, remote entry, an antitheft system and a full-size spare tire.
A standard AM/FM/cassette audio system complemented all trim levels for 2000. An optional entertainment system was offered for 2001, with updates being made to all upper trim levels. Model years 2002-2003 yielded no major changes. The Sienna was redesigned for 2004, offering more room and a new fold-flat third-row seat. Following the redesign, 2005 would see no major changes.
For 2006, front side-impact airbags and three-row head-protecting side curtain airbags were added as standard features, alongside a new grille, updated gauges, new head lights, tail lights and fog lights and new gauge clusters. A new 3.5-liter V6 engine was introduced for 2007, boasting 266 hp. Meanwhile, the tire-pressure monitoring system was made a standard feature. Model years 2008-2010 would see no substantial updates. An all-new Sienna was introduced for 2011, offering a new four-cylinder and sport-tuned version. 2012 yielded no changes with the four-cylinder model being discontinued in 2013. The Sienna was status quo for 2014.