I have a 2001 celica vvtli, my alarm keeps bleeping, it does my box in, on my old 1 i had same problem, last time i tried lots of things and what ended up working was simply changing the battery on the key,, unfortunatly i dont have a battery at hand and my alarm is going off constantly, but i cane up with a solution, that you guys will love, if its a bleep alarm like mine and its located in the rear of the car behind plastic cover in boot, there a sleeve connecting the two wires, its should be covered in foamy stuff, like a protection cloth, once you remove that you cant take them apart, the lights still flash but the noise finally is quiet, hope this helps until you find main reason