Method for recovering vapor during an onboard refueling operation

A method for recovering vapor during an onboard refueling operation, comprising the steps of:

• providing a flow path between a fuel tank and a purge canister;
• providing a fuel level sensor that indicates a level of fuel in the fuel tank, a vapor pressure sensor that indicates a pressure of fuel vapor in the fuel tank, and a refueling event indicator;
• providing an electronic valve in said flow path, which is actuated in response to signals received from the fuel level sensor, the vapor pressure sensor, and the refueling event indicator;
• actuating the electronic valve to open the flow path when a start of a refueling event is detected;
• monitoring a level value received from the fuel level sensor when the flow path is open;
• actuating the electronic valve to close the flow path when the level value reaches a predetermined fuel level;
• monitoring a pressure value received from the vapor pressure sensor when the flow path is closed;
• and
• actuating the electronic valve to cyclically open and close the flow path depending on the pressure value until a determination is made that the refueling event is finished on the basis of the monitored pressure value,
• wherein said actuating of the electronic valve to open and close the flow path depending on the pressure value comprises the steps of:
• measuring and storing a pressure value received from the vapor pressure sensor;
• determining a peak pressure value by comparing the measured pressure value to a previously stored pressure value;
• storing the peak pressure value;
• monitoring the pressure value received from the vapor pressure sensor until the pressure value decays to a predetermined percentage of the peak pressure value;
• and
• actuating the electronic valve to open the flow path for a predetermined length of time if and when the pressure value decays to a predetermined percentage of the peak pressure value, then actuating the electronic valve to close the flow path.