DTC P0447: EVAP Vent Valve Control Circuit Open: Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2001 Saturn SW2, 2001 Saturn SL2, 2001 Saturn SL1, 2001 Saturn SL, and 2001 Saturn SC2. However, it is still accessible from the selected car via links, so may be relevant.
The Evaporative Emission (EVAP) system is used to store fuel vapors to reduce amount of unburned fuel from escaping into atmosphere. The function of the EVAP vent solenoid is solely for EVAP leak diagnostics. Outside airflows around the normally open valve (except during portions of EVAP diagnostics) through the EVAP canister to the fuel tank, allowing fuel tank to be at atmospheric pressure (about 101 kPa). PCM controls EVAP vent solenoid by controlling an internal driver that pulls the solenoid circuit to ground. The EVAP vent solenoid circuit is monitored for low and high voltage faults. DTC will set when EVAP vent solenoid is commanded off and feedback voltage at PCM is low.