Drive circuit for an injector arrangement and a diagnostic method

摘要

The invention relates to a drive circuit for an injector arrangement comprising a first fuel injector in parallel with a capacitive component. The drive circuit comprises: a selector means (SQ1, SQ2) and diagnostic means. The selector means (SQ1, SQ2) is operable to select the first fuel injector and/or the capacitive component into the drive circuit and to deselect the first fuel injector and/or the capacitive component from the drive circuit. When the capacitive component is selected and the first fuel injector is deselected, the diagnostic means is operable to sense a current (Isense) through the first fuel injector. When the sensed current (Isense) is at variance from a first threshold current (Ilimit) the diagnostic means is operable to provide a first signal on detection of a stack terminal short circuit fault associated with the first fuel injector. The capacitive component may be a second fuel injector.