My C5's a stick but I checked in the '02 owners manual.  Cause isn't
mentioned but, reading between the lines in the 'getting it out of Park'
section, the manual seems to imply either a mechanical problem (release
pin, blocker plate or whatever they use in the shifter).  Or, a logic
problem.

I think the '02 computer logic is different than the '97.  Check your
manual.  If there's nothing in that book, give a shout and I'll post the
whole bit from the '02 manual.

--
PJ
'89 Hookercar,  '02 e-blu 6-spd coupe