Abstract:
A method of testing the operational functionality of a component (15), said component being supplied by a supply voltage V via switching means (16), comprising connecting the output of the switching means to further circuitry comprising a first resistor (R1) connected to a first reference voltage (Vcc), and a second resistor (R2) connected to a second reference voltage, and determining the voltage at a point (A) between said resistors when the switching means is in either a nominally "on" and/or an "off" state.
Abstract:
The invention relates to a drive circuit (20a) for an injector arrangement comprising a fuel injector (12a,12b), and a method of detecting faults in the drive circuit (20a). The drive circuit (20a) comprises diagnostic means (R F ). The diagnostic means (R F ) is operable to sense a detected current (I dect ) and to provide a fault signal on detection of a fault, when the detected current (I dect ) is at variance from a threshold current (I trip ).