| 摘要 |
PURPOSE: An on-board diagnosis method is provided to obtain more reliable result in a fuzzy area, and to reduce fuel system diagnosis calibration time, thereby reducing EMS development time and cost. CONSTITUTION: In a method to diagnose FSD(Fuel System Diagnosis), whether it is an FSD condition is decided in an ECU of an automobile. If the FSD condition is satisfied, the FSD is started. Whether the value of (Short term fuel trim + Long term fuel trim) is larger than the FSD error determining threshold(%) is determined. If the value of (Short term fuel trim + Long term fuel trim) is larger than the FSD error determining threshold(%), it is decided whether the total time to pass the FSD threshold is larger than the FSD error determining time. If the value of (Short term fuel trim + Long term fuel trim) is smaller or equal to the FSD error determining threshold(%), previous steps are repeated.
|
