Entry Interior Alarm does not Sound: Description
WARNING: This page is about a different car, the 2011 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
The smart key system uses the combination meter buzzer to perform various vehicle interior warnings. When each warning's conditions are met, the certification ECU (smart key ECU assembly) sends a buzzer signal to the meter ECU, and the combination meter buzzer sounds.