Description and Operation

Description

The evaporative emission control system prevents fuel vapors stored in the fuel tank from escaping into the atmosphere. When fuel evaporates in the fuel tank, the vapor passes through vent hoses or tubes to the charcoal canister. The canister temporarily holds the fuel vapors in charcoal. The ECM controls the system to draw the stored vapor into the combustion chambers under certain operating conditions. Intake manifold vacuum is used to draw the vapor into the intake manifold.

Operation

Evaporative System Monitoring

The evaporative system and ORVR (Onboard Refueling Vapor Recovery) emission control system consist of a fill valve, fuel cut-off valve, roll-over valve, two-way valve (pressure/vacuum relief), fuel liquid/vapor separator installed near the filler neck, charcoal canister installed under the rear floor on the left side member and protector, hoses, and various connections. During refueling, ambient air is drawn into the filler neck, so fuel vapor is not released into the air. Fuel vapor in the tank is then forced into the canister through the vent valve. The fuel liquid/vapor separator isolates liquid fuel and passes clean vapor to the charcoal canister. While the engine is running, vapor stored in the canister is drawn into the intake manifold and then into the combustion chamber. Through this purge process, the charcoal canister is cleaned and restores its absorption capacity.

1. Fuel Tank Cap 2. Filler Neck 3. Fuel Cut-Off Valve 4. Fuel Tank 5. ORVR Valve 6. 2-Way and Roll-Over Valve 7. Evaporative Hose

8. Evaporative Hose 9. Charcoal Canister 10. Canister Close Valve (CCV) 11. Fuel Feed Line 12. Fuel Tank Pressure Sensor (FTPS) 13. Purge Control Solenoid Valve (PCSV)