Purpose, Function
Releases evaporative gas from the fuel tank if there is a malfunction in the evaporative gas passage between the fuel tank and the intake manifold. As a result, deformation of the fuel tank caused by evaporative gas pressure is prevented.
Construction
The fuel-filler cap is installed to the fuel filler opening.

The fuel-filler cap consists of a valves, retainer, and springs.

Operation
When there is positive pressure in the fuel tank due to evaporative gas, evaporative gas is released into the atmosphere. When there is negative pressure, air is introduced to the fuel tank.

Fuel Filler Cap Inspection
Fuel Filler Lid AdjustmentPositive Crankcase Ventilation (PCV) Valve
Purpose, Function
Prevents release of blow-by gas (unburnt gas) into the atmosphere.
The PCV valve is open/closed by the intake manifold vacuum.
Construction
The PCV valve is installed to the oil separator.
The PCV valve consists of a spring and valve.
...
Before Service Precaution
WARNING:
Fuel vapor is hazardous. It can very easily ignite, causing serious injury
and damage. Always keep sparks and flames away from fuel.
Fuel line spills and leakage from the pressurized fuel system are dangerous.
Fuel can ignite and cause serious injury or death and damag ...
Seat Warmer Control Unit Removal/Installation
WARNING:
Handling a side air bag improperly can accidentally operate (deploy) the
air bag, which may seriously injure you. Read the service warnings/cautions
in the Workshop Manual before handling the front seat (side air bag integrated)..
1. Switch the ignition off (LOCK).
2. ...