there was once my friend accidentally leaned on the PIW bell
button on 8109U, and the beeping sound wouldn't go off
the BC thought it was the air pressure that was low, so he
revved the engine.
then when it still wouldn't go off, he smacked the
dashboard.
and it still wouldn't go off 
Hopefully the BC doesn't cause any damage to the new bus 
Anyway today I was onboard SMB32T, one standing passenger
pressed the PIW bell button as if it is just a normal bell
button. The beeping sound came on, the BC didn't say anything and
let the passenger alight
.