Car Alarms: Alarm siren, toyota corolla, siren

Question
The alarm siren on my Toyota Corolla 1.6. has started sounding off when the vehicle is garaged, unlocked and the alarm not armed. Is there a way to disconnect the siren?

Answer
Sure, you can simply clip the black wire
going to it. This disables the siren but...
My trouble is that the siren is driven
by an output from the alarm. The alarm is
my focus here.

You may have a sensor set too high, and needs
to be turned down, but the trouble is
that you don't know when the alarm is armed
or not.

Have you used or tried to reset the alarm using
the valet/overide switch?

ALARMTEK