A scan tool can do this.  The chrysler scan tools can do it of course.
So can others.

Reduced engine and transmission wear, better fuel economy.

Would it pay for itself over the life of the vehicle?  I
don't know, how long do you intend on owing it?

$160 isn't bad IMHO.  But you might negotiate a bit.  Ask them if you
would be willing to buy a transmission fluid change (make sure it's a
regular change not a flush with one of those pressure flushing systems)
would they do the firmware update for less money, since they would
already be spending time on it.

Yes and no.  Yes, the Chrysler dealers are the only ones with the
firmware (that an ordinary person can get to)  But, there are companies
that rebuild the things, and they firmware update them.  You can buy
a reman unit from the aftermarket that will come with current firmware.
But, it will be more expensive.

Another way you can do it at least with the transmission computer is you
can find them in wrecking yards.  Chrysler tags the case of the trans
computer
with the firmware version, if a dealer flashes it, they are supposed to
write the
fact on a tag on the computer.  All you have to do is go to a wrecker and
find
another 2002 Caravan the same model as yours and same tire size, and check
the computer in it, if it's a newer firmware version, just swap the
computers.

Ted

no check engine lite? and it runs good then they are  just  trying to
relieve you of your money and some aftermarket shops can do the
reprogramming