EMISSION CONTROL SYSTEM


  1. FUNCTION OF MAIN COMPONENTS

    Component Function
    Charcoal Canister Assembly Contains activated charcoal to absorb the fuel vapor that is created in the fuel tank assembly.
    Duty Vacuum Switching Valve Opens in accordance with the signals from the ECM when the system is purging in order to send the fuel vapor that was absorbed by the canister into the intake manifold.
    Charcoal Canister Filter Prevents dust and debris in fresh air from entering the system.
    ECM Controls the duty vacuum switching valve in accordance with the signals from various sensors in order to achieve a purge volume that suits the driving conditions.

  2. SYSTEM CONTROL


    1. Purge Flow Control


      1. When the engine has reached a predetermined state [closed loop, engine coolant temperature above 80°C (176°F), etc.], stored fuel vapor is purged from the canister whenever the duty vacuum switching valve is opened by the ECM.

      2. The ECM will change the duty ratio cycle of the duty vacuum switching valve, thus controlling purge flow volume. Purge flow volume is determined by intake manifold pressure and the duty ratio cycle of the duty vacuum switching valve. Atmospheric pressure is allowed into the canister to ensure that purge flow is constantly maintained whenever purge vacuum is applied to the canister.

        A001LMNC01
        *1 Throttle Valve *2 Intake Manifold
        *3 Purge Port *4 Duty Vacuum Switching Valve
        *5 ECM *6 Canister
        *7 Fuel Tank Assembly - -
        *a Intake Air *b Duty Signal
        *c Atmosphere Release/Intake - -