Evaporative Emissions System: Description and Operation

Description
The fuel evaporative system temporarily stores in the canister the evaporative fumes generated in the fuel tank. The stored gas is then passed into the air intake system for combustion when the engine is running. This operation prevents evaporative fumes from flowing out to the atmosphere.
Sending a large volume of evaporative fumes at one time into the air intake system deteriorates the air fuel ratio; thus, the powertrain control module engine (PCME) uses the solenoid valve (purge control) to regulate this volume.

Operation
With Engine Stopped And No Load Applied
The evaporative fumes from the fuel tank are absorbed by the charcoal canister.
With Engine Running And Load Applied
The evaporative fumes absorbed by the charcoal canister are drawn into the engine via the solenoid valve (purge control). The volume of fumes drawn depends on engine conditions.