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 capOccupant classification sensor power supply circuit malfunction
Description
The occupant classification sensor power supply circuit consists of the
occupant classification ecu and
the occupant classification sensors.
Dtc b1793 is recorded when a malfunction is detected in the occupant
classification sensor power
supply circuit.
Wiring diagram
...
Rear seat outer belt assembly
Components
...
Disassembly
Caution:
Wear protective gloves. Sharp areas on the seatback
frame, seat cushion frame and reclining adjuster may
injure your hands.
Remove rear seat headrest assembly
Remove rear seat center headrest
assembly
Remove center armrest hinge cover rh
Return the seatback to the upr ...