After refueling, turn the fuel tank cap until you hear a click. Once the cap is released, it will turn slightly in the opposite direction.

Caution
When replacing the fuel tank cap
Do not use anything but a genuine toyota fuel tank cap designed for your vehicle. Doing so may cause a fire or other incident which may result in death or serious injury.
Opening the fuel tank capDiagnosis system
Description
Air conditioning system data and the diagnostic
trouble codes (dtcs) can be read through the
data link connector 3 (dlc3) of the vehicle. When
the system seems to be malfunctioning, use the
intelligent tester to check for malfunctions and
perform troubleshooting.
...
Vacuum switching valve
Components
Removal
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove purge vsv
Disconnect the purge vsv ...
Combination meter ecu communication stop mode
Description
Wiring diagram
Inspection procedure
Notice:
Turn the ignition switch off before measuring the resistances of the
main wire and the branch
wire.
After the ignition switch is turned off, check that the key reminder
warning system and light
reminder warning system ...