Patent ID: 8746215
Filing Date: 2014-06-10
Classification: B60K,F02M

Abstract:
1. A method of determining a leak in a vapor management system of a vehicle, the system including a fuel tank having liquid fuel therein and a vapor cavity above the liquid fuel; a vapor collection canister; a tank pressure control valve between the tank and canister and defining a high pressure side, including the fuel tank, and a low pressure side, including the canister; a vacuum source; a purge valve between the canister and vacuum source; a leak detection valve connected with the canister; and a processor, the method comprising the steps of: providing a sense tube in the tank, the sense tube having an open end disposed near a bottom of the tank such that fuel in the tank may enter the open end, providing a differential pressure sensor with one side thereof being connected to the sense tube and another side thereof being connected to the vapor cavity so that the pressure sensor can measure a differential pressure (DP) between a volume of the vapor cavity and a volume of the sense tube containing the liquid fuel, providing a temperature sensor in the vapor cavity, with signals from the pressure sensor and temperature sensor being received by the processor, measuring the differential pressure (DP) and the temperature (T) at certain time intervals to determine the temperature at time zero (T determining if (T