The evaporative emission control system prevents fuel (hydrocarbon: HC) from being discharged from the fuel tank into the atmosphere.
How the system works:
- The charcoal canister temporarily absorbs the HC evaporated from the fuel tank.
- When the engine operates and the purge control valve opens, the absorbed fuel is purged from the charcoal canister and returned to the intake pipe by the negative pressure in the intake pipe.
- The returned fuel is sucked into the engine cylinder together with the fuel injected from the injector and air.
The engine ECU calculates the amount of HC returned through the purge line and controls the amount of fuel injected from the injector to keep the stoichiometric air fuel ratio at any driving conditions.
DENSO develops and supplies both the evaporative emission control system and the engine ECU, providing excellent absorbing and purging properties of the evaporative fuel as well as the excellent control property of the air fuel ratio. |