There is no ONE module that works the alarm system. Use the search for "panic alarm". I gave a pretty accurate explanation of ALL the modules involved. It really is a difficult system to deal with. Do you have access to a repair manual?

Be prepared the siren will go off when you disconnect it. That is the reason for the secondary battery. I'd say do it outside the garage or wear ear protection. That noise is worse then the seat belt when it comes to annoying. It is really loud in the garage.