Beginning with the 2002 model year, the Electronic Throttle Control was redesigned ,due to issues with the previous model years design. The design of the ETC you have on your vehicle originally came out in 1999 and was last used on the 2001 model year (issues just like yours).

So, you'd think that any 2002 or newer Volvo with ETC would be be of a more robust design, but alas, MY 2002 V70 had it's ETC replaced under warranty at 15,000 miles. (shorted out)

I now have 27,000 miles on it and so far so good, but I have to tell you that in the back of my mind I'll always have a lack of confidence in my ETC. I don't wish to spend $1100.00 on a new one if this one gives up the ghost.
so, I will trade her in before the warranty runs out.

p.s. most all of todays automobiles are going the way of "drive by wire"
and I sure hope they get it perfected soon or there will be many more pissed off consumers such as yourself and Frankly, you have every right to be angry.
--
You will never leave where you are until you decide where you would rather be.