Evaporative Emission Control Canister: Description and Operation

The charcoal "carbon" canister array (4 carbon canisters with one liter volume of carbon each) is located under the spare tire carrier on the outside of the vehicle, and each canister is filled with activated charcoal granules. Activated charcoal is used as a vapor trap because of its great surface area, holding up to one-third its own weight in fuel vapors. Each gram of activated charcoal has a surface area of 1,100 square meters, or more than a quarter acre.

The fuel vapors are vented from the fuel tank through the vapor valve (located in the top of the fuel tank) through a single line to the refueling control valve. The fuel vapors are then routed through the refueling control valve to the carbon canister array. The carbon canisters within the array store the fuel vapors until they can be delivered to the engine for consumption.