look under the back of your car on the passenger side, just in front of the canister will be the vent control soleniod, first make sure the connector is connected and not corroded, also make sure the wires didnt get ripped out of the connector.
I'm assuming you're talking about the black box right in front of the rear bumper. I checked it and the only connection I see is with two wires, both of which seemed connected and fine. Was that the right area? Any other ideas?