I've looked at the schematics on my alldatadiy subscription, and it shows identical schematics for keyless entry and perimeter alarm. So the GEM is already aware of the status of all doors, and is the receiver for the keyless entry (for arm/disarm OR lock/unlock). It controls the door locks, horn, and lights. Therefore, it already has all the necessary stuff to act as a perimeter alarm...
That's why I have come to believe that maybe it is just a software thing. Any thoughts?
Does anyone know how (with what) can the GEM settings be changed? Or better yet, does someone have the list of options it has?
Here is an example from GM (Dodge)
To switch operating modes or to configure a new module, a DRB III scan tool must be used.
(1) Hook up the DRB III scan tool to the Data Link Connector (DLC).
(2) With the key in the ignition, turn the key to the RUN position.
(3) After the DRB III scan tool initialization, perform the following:
(a) Select "Theft Alarm."
(b) Select "VTSS."
(c) Select "Miscellaneous."
(4) Once in the "Miscellaneous" screen:
(a) If you wish to configure a new module, select "Configure Module."
(b) If you wish to put the module into customer usage mode,
select "Enable VTSS."
(c) If you wish to put the module into dealer lot mode, select "Dealer Lot."