I had the same problem. A friend of mine works for gtspec.com and he spoke with a bunch of people from Subaru to the makers of the product. With the factory alarm, you can not arm the security system but you can lock the doors. I've installed the Blitz turbo timer on both a factory and a dealer installed turbo timer. The dealer security system is the only one which worked. What i do is i set the turbo timer to 10-30 seconds and by the time the car turns off i can arm it while still by the car. Hope this helps.