alarm issue hopefully someone has experienced this

[hirsch328]

hey all. so i am working on a 2000 4 runner and I'm having a really weird alarm issue. vehicle has the factory alarm not the add on vip alarm. anyways the alarm will activate fine when locked with the switch on the door, the key, and the key fob. when i go to disarm the alarm with the fob as soon as i hit the unlock button the alarm will go off. if i keep pressing the unlock button it will eventually turn off. sometimes this takes one or two more press and sometimes up to 8 or 10. the alarm will disarm fine when using the key in the door and will also turn off if i put the key in the ignition and switch it on. I've tried replacing the fob battery with no luck. i work at a toyota dealership with roughly 35 techs and none have them have seen anything even remotely similar. I'm hoping that someone out there somewhere has had this same issue corrected who can give me some feedback. looking at diagrams it seems as though all of the alarm components are contained inside the body control module with the exception of the door switches. i appreciate any feedback you can give me