| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a diagnostic tool which can identify an individual short-circuited fuel injector and a method of operating the diagnostic tool. Ž<P>SOLUTION: The method identifies individual short-circuited fuel injectors (12a, 12b) in an injector bank of an engine comprising: piezoelectric actuators (16a, 16b) constituting part of a fuel injector drive circuit (30); and a plurality of fuel injectors (12a, 12b) having respective related fuel injector selection switches (SQ1, SQ2). The method includes: (i) charging all of the piezoelectric actuators of the fuel injectors in the injector bank during a charge phase (tC); (ii) waiting for delay periods (t<SB>D</SB>, t<SB>DL</SB>) from an end point of the charging phase; (iii) closing an injector select switch (SQ1) of one of the fuel injectors to select the fuel injector; (iv) determining stack voltage (V<SB>S1</SB>, V<SB>S2</SB>) at both ends of the piezoelectric actuator of the selected fuel injector and storing the stack voltage indicating a charge amount of the selected fuel injector at an end point of the delay period, in a data storage; (v) repeating steps (i) to (iv) for each fuel injector in the injector bank in turn; and (vi) identifying an injector which has discharged beyond a predetermined voltage drop limit within the delay period as the individual short-circuited fuel injector and generating a short circuit fault signal. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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