No. But;
The van may seem to act a little different until it re-learns what it forgot.
There could be several reasons why a Toyota Sienna will not start. the most common problem would be a dead battery.
It's a group 34 battery.
From $65 to $265 depending on the quality battery you buy.
530 cca and 575 cca
If they sell batteries, then yes.
The tank that is located under the battery on a 2004 Toyota Sienna is a windshield washer fluid tank. Toyota put this tank in this position on the 2004 to 2010 models of the Sienna.
My Toyota Sienna 2000 axle nut measures 30 mm Sprayed the threads as I will be replacing an axle shortly. Probably the same size.
Toyota recommends replacing the belt every 100,000 miles.
A failing alternator.
Just happened to me too, 3 year battery was 3 years and 3 m. old, tightened the alt. belt that helped but still idles at about 600 rpm. Ran well before the battery went,
only the bottom pan
What do you mean he recommends replacing it? It is either defective and needs replacing or it isn't. Take it to another Toyota dealer or trusted independent and get a second opinion. A salvage computer would be another choice if it does indeed need replacing, which I would bet to be highly unlikely. Spend the money for a professional diagnostics by someone who knows what they are doing, and you will be money ahead.