Entry Interior Alarm does not Sound: Procedure

WARNING: This page is about a different car, the 2012 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

CHECK COMBINATION METER ASSEMBLY (OPERATION)
1. Turn the engine switch on (IG). Place luggage on the front passenger seat to cause the front passenger seat belt warning light to blink.
2. When driving the vehicle at 15 km/h (9 mph) or higher, check that the seat belt warning buzzer sounds to inform that the passenger seat belt is not fastened.
  HINT:
  
  The smart key system sounds the buzzer built into the combination meter for indoor warnings. This buzzer is also used for the seat belt warning system. Therefore, check the operation of the combination meter buzzer by checking if the buzzer sounds to inform that the seat belt is not fastened.
  
  OK
  
  Combination meter buzzer sounds.
NG → See step 2

OK → See step 3
GO TO METER / GAUGE SYSTEM. Refer to HOW TO PROCEED WITH TROUBLESHOOTING
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to REMOVAL