2012 Toyota Prius Owners Manual - Page 392

1-3. Opening, closing and locking the doors Locking the front doors from the outside without a key STEP 1 STEP 2 Move the inside lock button to the lock position. Close the door. The door cannot be locked if the "POWER" switch is in ACCESSORY or ON mode, or the electronic key is left inside the vehicle. The key may not be detected correctly and the door may be locked. Rear door child-protector lock 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. 88