You have a broken "hard part" in the transmission lingo.  For an example of
what
might have broken, take a look at this:

http://www.freebsd-corp-net-guide.com/94tcpics/project.html

specifically pictures fig52.jpg and fig53.jpg  In fact that gear is likely
what
is broken because it is used in all shift positions except 1st gear, and
it's
a known weak point.

The transmission often won't throw a code when something inside of it snaps.
In any case I didn't think the tans codes are available on a pure OBD-II
scanner
I thought you needed a scanner that was more sophisticated than the $100
ones from the auto parts store.

The loss of reverse gear is the giveaway here.  If the trans gearing was
intact
you would have reverse.

By the way, if you do decide to get it rebuilt, there's some good info worth
reading on http://www.allpar.com/fix/trans.html  And most importantly, when
calling around to the transmission shops, ask what fluid they use for this
transmission (make sure to get a tech, not the dumb broad at the front
counter)
and if they don't say ATF+4 then don't use them, and tell them why.

Ted