Got home tonight after work, came in the house and a few minutes later I heard my factory installed alarm system is going off. I disarmed the system and unlocked all the doors and came back inside. My key is lying on the end table here next to me and the alarm just started going off again for no reason (it wasn't armed or locked). Anyone have any ideas about what's going on? I didn't even have it locked or armed... this is weird. One other symptom I am noticing now, if I lock it with the remote it doesn't beep the horn like it normally does.

 

it automatically locks again if you dont open a door within a certain time period. are any of your windows down at all or sunroof? could be the interior sensors if wind is coming in. also its easier to diagnose when you include what car you have.

 

^ yup, after 30 seconds, the car locks again if the doors were never opened after they were unlocked. and my horn won't honk if all the doors aren't properly shut. had this happen to me the other day, turns out my passanger didn't close his door correctly.. strange thing is, i didn't remember it showing up on the lcd.