I just read my build/option sheet and I noticed it has Sentry Key option and by this explanation explains maybe is the reason I have no alarm in my 2013 Ram Big horn. Looks like someone had a brain fart and thought of this. Why not leave the audible sound alarm and screw the Sentry Key deal.
As you read it mentions it will stop someone from stealing/starting the vehicle and have no Sounding Alarm to scare a person away.
By reading this I feel that MY 2013 Big horn alarm will not show in using the AlfaOBD program and see my alarm disabled. I could be wrong.
Again why keep screwing with options that have worked and most people have gotten use to it.
I know I would have liked a audible sound as I park truck out front on street and would be nice to hear the alarm if some one is screwing with your ride.
What is the Sentry Key(R) Theft Deterrent system?
The Sentry key system (SKIM for short) is an immobilizer type of theft deterrent, the engine won't run, so it's assumed the vehicle will be too much trouble to steal. It doesn't produce any warning to bystanders that the vehicle is being tampered with, like a traditional horn and light type alarm, so there may be no sense of urgency to the perpetrator to get in and get out. They may have plenty of time to rifle and strip the vehicle even if it isn't stolen outright.
You might consider a traditional alarm system if you have concerns with the safety of items inside the vehicle or if it's parked in an area that would afford a certain degree of "privacy" to anyone looking to tamper with it. I have little to no experience with aftermarket alarm systems, so (unfortunately) I won't be a good resource for picking the right system. Check with a good repair shop or audio store that does installations for more information on the subject, they'll have information on the latest systems.