P0449, P0498, P0499
WARNING: This page is about a different car, the 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
With the ignition ON and the engine OFF, command the EVAP canister vent solenoid valve ON and OFF with a scan tool. Listen for a click when the valve operates. Verify that both the ON and the OFF states are commanded. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.