Evaporative Emissions System: Description and Operation

The fuel evaporative system consists of the fuel vapor valve, the two-way check valve, the charcoal canister, the purge solenoid valve, the engine control module, and the input devices. The amount of evaporative fumes introduced into the engine and burned is controlled by the solenoid valve in relation to the engine's operating conditions. To maintain the best engine performance, the solenoid valve is controlled by the engine control module.

Operation
The purge solenoid valve is controlled by duty signals from the engine control module to perform purging of the charcoal canister. Purging is done when these conditions are met:
- After warm-up
- Driving in gear
- Accelerator pedal depressed (closed throttle position switch OFF)
- Heated oxygen sensor functioning normally