MeMySelf&I

Recently bought a 2000 Totoya Camry with an Autopage RF-225a already installed but without the remotes. So I went on Ebay and found the same alarm controller with fobs for $30 so I simply swapped the old controller with the new one and programmed the settings I wanted and whaalaa! Recently, the alarm has been going off while im driving at random. I have to pull over, turn the car off then ignition on and hit the valet switch and it turns off. Like I mentioned before, I bought this car used so I have no idea what the wiring is about, it has no hood pin nor trunk pin either, manual trunk release. Any ideas as to why this is happening?