Patent ID: 8707932

Claim:
A method for controlling a fuel transfer pump delivering fuel to a high pressure fuel injection pump; said method comprising: providing a fuel transfer pump having an inlet port which is connectable in fluid communication with a fuel source and an outlet port which is connectable in fluid communication with a high pressure fuel injection pump; providing a motor for driving the fuel transfer pump for drawing fuel through the inlet port from the fuel source and pumping pressurized fuel out the outlet port; measuring a fuel pressure at a location which is in fluid communication with the outlet port; controlling an operating speed of the motor driving the fuel transfer pump as a function of the measured fuel pressure for defining a closed loop pressure control mode for controlling the measured fuel pressure to a target fuel pressure; measuring a current utilized in operating the motor; comparing the measured current to a predefined threshold current value; correlating the measured current to at least one anomalous condition when indicated by the comparison step; and switching from the closed loop pressure control mode for controlling the operating speed of the motor as a function of the measured fuel pressure to a current control mode for controlling the operating speed of the motor as a function of the measured current when the measured current is correlated by the correlation step to at least the one anomalous condition.