99 ranger anti-theft

[BackwoodsSaint]

ok so the battery in my dad's '99 Ranger 4wd died yesterday, no biggie, just hooked up some jumper cables and she started right up, but then today (after starting flawlessly several times) it all of a sudden decided it would just not start- it cranks over really well, but the anti-theft light is flickering like mad and it just plain won't start
I thought it was just the key, but after trying a different key with no luck i've started thinking it might be the anti-theft module; i've disconnected the battery for 5 minutes and re-connecting it, locking the doors and unlocking them with the key but nothing's working, all the fuses are good, anybody got some suggestions?
Also, it has the chipped key, that's why i tried both keys we have

 

[adsm08]

Could be a bad antenna, could be a bad module, hard to say without codes and diagnostic tools.

 

[BackwoodsSaint]

unfortunately i don't have a scan tool with me- will it show up if i run codes?

 

[adsm08]

A generic scanner might not show them because most PATS codes set in the Instrument Cluster, not the PCM.

 

[rtg143]

Try unhooking the battery for a few seconds. Sometimes that resets things.