Unless physically broken, In order to diagnose this component, you must use the Saab Tech-2 or GM MDI with security access.  Often times these units if defective can cause false alarms.  You can see with the proper diagnostic tools what sensor input device set the alarm off last.  If yours is defective, good used is your only option, as these have recently gone NLA from Saab!

Saab part number 12802486  - These are located in your upper console, where the map lights are.