초록 ▼

A fuel system includes a pair of electronically controllable high pressure fuel pumps operable to supply high pressure fuel from a lower pressure fuel source to a high pressure fuel accumulator having a pressure sensor associated therewith. The fuel collection chamber feeds an electronically control

A fuel system includes a pair of electronically controllable high pressure fuel pumps operable to supply high pressure fuel from a lower pressure fuel source to a high pressure fuel accumulator having a pressure sensor associated therewith. The fuel collection chamber feeds an electronically controllable valve operable to dispense the high pressure fuel to a fuel distribution unit supplying fuel to a number of fuel injectors. A control computer is provided for controlling the high pressure fuel pump and valve in response to requested fueling, engine speed and fuel pressure provided by the pressure sensor. The accumulator pressure signal is processed in accordance with the present invention for diagnosing erratic pressure sensor failures. The control computer is operable to compute error pressure values based on differences between peak accumulator pressure values and a target pressure value, and compute pressure error variance values based on subsets of the pressure error values. A fault code is logged and a limp home fueling algorithm is executed if a predefined number of variance values exceed a variance threshold.

대표청구항 ▼

[ What is claimed is:] [1.] Apparatus for diagnosing a fuel system of an internal combustion engine, comprising:an accumulator receiving pressurized fuel from a source of pressurized fuel;means for sensing fuel pressure within said accumulator and producing a pressure signal corresponding thereto, s

[ What is claimed is:] [1.] Apparatus for diagnosing a fuel system of an internal combustion engine, comprising:an accumulator receiving pressurized fuel from a source of pressurized fuel;means for sensing fuel pressure within said accumulator and producing a pressure signal corresponding thereto, said pressure signal having peak values corresponding to peak pressures of fuel supplied thereto by said source of pressurized fuel; anda control computer sampling a number of first pressure values each near a separate one of said peak values and determining a number of pressure error values each between a separate one of said number of first pressure values and a corresponding reference pressure, said control computer determining a variance of at least some of said number of pressure error values and incrementing an error counter if said variance exceeds a variance threshold.