Evaporative Emissions: Notes
The Evaporative Emission (EVAP) system consists of the:
- EVAP canister.
- EVAP canister purge valve.
- fuel tank.
- fuel vapor tubes
- natural vacuum leak detection module.
The EVAP system:
- prevents hydrocarbon emissions from reaching the atmosphere.
- stores fuel vapors in the EVAP canister that are generated during vehicle operation hot soak or vehicle refueling, until they can be consumed by the engine during normal engine operation.
- routes the stored fuel vapors to the engine during engine operation.
The fuel vapors are routed:
- to the EVAP canister through a vapor tube.
- to the engine when the EVAP canister purge valve is opened.
The EVAP canister:
- is located under the rear of the vehicle.
- contains activated carbon.
- stores fuel vapors.
The EVAP canister purge valve:
- is normally closed.
- regulates the purging of the EVAP canister.
The natural vacuum leak detection module:
- completes a series of checks to confirm the integrity of the enhanced EVAP system components in the engine running state and the ignition OFF state.
Refer to the INTRODUCTION - GASOLINE MODELS for additional information on the EVAP system.