Pcm questions need help please

[Jackofalltrades]

Ok I have a 2003 jeep grand cherokee limited and it died on me. So I put a crank sensor in it thinkin maybe it would do the trick like on older models. But no change sentry light is on not flashing so I narrowed it down to the pcm but I have no tools to program new so to the dealer we go they diagnose pcm bad didn't even ask for quote. So I went to a you pull place got one from a 99 limited looked identical besides color. Put it in same thing as expected but now my overhead display says perform service. Did not have this before. So I am wanting to figure out if a 99 pcm will work? And if I'm on the right track