Evaporative Emissions System: Description and Operation

PURPOSE
The Evaporative Emissions (EVAP) system limits the amount of fuel vapor a vehicle may release to the atmosphere, enabling the vehicle to meet current federal and state requirements for fuel evaporation.

OPERATION
- Fuel vapors trapped in the sealed fuel tank are vented through the orificed evaporative emission valve. The vapors exit the valve assembly through a single vapor line and continue to the charcoal carbon canister for storage.

- When the engine has reached operating temperature and the throttle plate is past idle position, the powertrain control module opens the control valve, allowing vacuum to be applied to the canister, purging it of stored fuel vapors into the induction system.