storage canister stored fuel amount is greater than the threshold amount the answer is yes and method 400 proceeds to 422 otherwise the answer is no and method 400 proceeds to 428 at 422 method 400 opens the fuel vapor storage canister purge valve closes the fuel vapor storage canister vent valve and maintains electrical current flow to the fuel vapor storage canister vent valve by opening the fuel vapor storage canister purge valve fuel vapors may be drawn from the fuel tank and through the fuel vapor storage canister purge valve to evacuate fuel vapors from the fuel tank further opening the fuel vapor storage canister vent valve allows air to be drawn from atmosphere through the fuel vapor storage canister where fuel vapors are liberated and into the engine intake manifold via the fuel vapor storage canister purge valve a constant voltage may be supplied to the fuel vapor storage canister vent valve to heat the fuel vapor storage canister via the fuel vapor storage canister vent valve alternatively a time varying current with a higher frequency than the natural frequency of the canister vent valve may be supplied to the fuel vapor storage canister vent valve to heat the fuel vapor storage canister by supplying current at a higher frequency than the natural frequency of.