Circuit Description
WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
The DTC P0441 Evaporative Emission (EVAP) System No Flow During Purge diagnostic monitors changes in vacuum pressure in the fuel tank. Powertrain Control Module (PCM) will command EVAP vent valve ON (closed), and vacuum pressure switching valve ON (open), with engine running. This allows engine vacuum into entire EVAP system. PCM continues to operate purge valve until vacuum has reached a specified limit, at which time the PCM commands purge valve OFF (closed). If PCM detects vacuum level was not achieved, or vacuum level increased beyond the specified limit, a DTC P0441 will set.