| 摘要 |
PURPOSE:To self-diagnose positively and precisely acting condition of a crank- angle sensor, by calculating a ratio of change of frequency of a detecting signal from the crank-angle sensor and judging an abnormality by its magnitude. CONSTITUTION:A crank-angle sensor A generates a detecting signal P by a pulse every time when an engine crankshaft passes the reference rotational position. A detecting signal frequency counting means C counts period T1 of the signal P per every signal P. Next, a ratio of change calculating means c divides the currently counted period T1 by the previously detected period T0. By this arrangement, the ratio of change of period of the signal P is calculated per each signal P. Later a judging means self-diagnoses acting condition of the sensor A basing on the calculated ratio of change.
|
