Fuel Filler Cap: Description and Operation

The fuel tank filler cap is a threaded screw-on design and is secured to the vehicle by means of a tether. It is a sealed cap with a built-in pressure-vacuum relief valve. Fuel system vacuum relief is provided after negative 1.7 kPa (0.25 psi) and pressure relief above 14 kPa (2 psi). Under normal operating conditions, the fuel tank filler cap operates as a check valve, allowing air to enter the fuel tank as gasoline is used, while preventing vapors from escaping the fuel tank through the fuel tank filler cap.

CAUTION: When replacing the fuel tank filler cap, use only the proper pressure/vacuum relief cap to prevent possible system malfunction.