Leak detection system for use in motor vehicle fuel tank ventilation system has improved accuracy and reliability as a temperature compensation factor is applied to compensate for fuel vaporization being temperature dependent

摘要

Method in which a vacuum pressure is created inside the tank ventilation system, valves to the system are closed and pressure variations within the tank are monitored. A correction value is applied to compensate vaporizing of fuel which causes an increase in pressure. An additional temperature dependent correction value is determined that compensates for the fact that fuel vaporization is temperature dependent. An Independent claim is made for leak detection system for use in motor vehicle fuel tank ventilation systems. The inventive system includes a temperature sensor in addition to a pressure sensor so that temperature compensation can be applied. As a further development a pressure sensor is provided to monitor ambient pressure so that its effect can be compensated.