LEAKING DIAGNISING METHOD FOR GAS LINE IN BI-FUEL VEHICLE

摘要

The present invention relates to a leaking diagnosis method for a gas line in a bi-fuel vehicle, including the steps: verifying whether the bi-fuel vehicle runs using a gas fuel; checking the preheated state of the engine of the vehicle; storing the pressure value of the gas line supplying a gas fuel; determining whether the pressure value of the gas line is higher than a preset maximum value; determining that abnormality occurred in a control device controlling the gas line, when the pressure value of the gas line is higher than the preset maximum value; and determining that a gas leaks from the gas line, when the pressure value of the gas line is equal to or lower than the preset maximum value. Therefore, by measuring the pressure value of the gas line, it is possible to distinguish the abnormality of the gas line control device from a gas fuel leak from the gas line. When the gas fuel leaks from the gas line, a slope variation of the pressure value of the gas line is measured, and a first slope value and a second slope value are respectively set in advance according to the size of the slope value. By determining that the measured slope belongs to any range, it is possible to determine whether it corresponds to a first leaking range in which much gas fuel leaks, or whether it corresponds to a second leaking range in which little gas fuel leaks.