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(11) | EP 0 342 376 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Electronic position sensor assembly and control system |
| (57) An electronic position sensor assembly and engine control system (10) in which two
sensing elements (13, 14) in a dual sensor (12) provide separate, independent position
signals (A, B) related to multi-cylinder engine cycle position by sensing the angular
position of a engine-rotated slotted wheel (11). The sensing elements provide identical
sensing signals shifted from each other by a predetermined angular amount (d). In
response to the simultaneous providing of a pulse by both sensing elements, a first
reference signal (at 22) identifying a reference cylinder is provided for controlling
electronic distribution of spark timing and/or fuel injection signals to engine cylinders
(17-20). In response to a selected one of the sensing elements producing a pulse which
has a predetermined longer duration than a preceding produced pulse, a second reference
signal (after 50) is produced indicative of top-dead center engine cylinder cycle
position for one of the cylinders. In response to detecting a fault in the position
signal produced by the one selected sensing element, a switch (27) selects the other
of the sensing elements for utilization in producing the second reference signal,
and a substitute reference signal circuit (40) provides a substitute first reference
signal. A less expensive and more reliable engine position sensor assembly and engine
control system is provided since proper system operation is maintained despite a fault
in one of the position signals. |