Toyota 2012 Yaris Hatchback Owner's Manual page 18

1-2. Opening, closing and locking the doors
Rear door child-protector lock (5-door models only)
■
Customization that can be configured at Toyota dealer
Settings (e.g. unlocking function using a key) can be changed.
(Customizable features →P. 368)
36
The door cannot be opened from
inside the vehicle when the lock
is set.
Unlock
Lock
These locks can be set to prevent
children from opening the rear
doors. Push down on each rear
door switch to lock both rear
doors.