Circuit Description

To reduce HC emissions, evaporated fuel from fuel tank is routed through charcoal canister to the intake chamber for combustion in cylinders. ECM changes the EVAP system Vacuum Switching Valve (VSV) duty signal so the intake quantity of HC emissions is appropriate for the driving condition (engine load, engine speed, etc.) after engine is warmed up.

DTC is set if the proper response to the ECM command does not occur. Possible causes are:

• VSV for EVAP system.
• Open or short circuit in VSV circuit for EVAP system.
• Disconnected or blocked vacuum hose.
• Charcoal canister.