EVAP canister purge valve (321)
WARNING: This page is about a different car, the 2001 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
The EVAP canister purge valve comprises a solenoid valve located in the line between the EVAP canister and the intake manifold. It is used to regulate the amount of air/hydrocarbons that is passed from the EVAP canister to the engine for combustion. The EVAP canister purge valve is also used during the tank integrity diagnosis.
When the ignition is off, the valve is closed.