| 摘要 |
PURPOSE:To properly and rapidly judge abnormality by enabling a knocking detector or a detecting circuit including said detector to be judged to be abnormal by detecting the presence of an electric output signal from said knocking detector caused by mechanical vibration produced at starting of an engine. CONSTITUTION:When an internal combustion engine is started by a starter and enters its operation state, very large mechanical vibration is produced in an engine body. A large electric output signal generated from a knocking detector 2 in responce to said mechanical vibration is inputted to a microcomputer 4-2 via a BPF 4-1 provided in an ignition timing control device 4. When an interruption signal caused by starter-on stays at an H level, a peak value of the aforesaid output signal is investigated, and when a peak value exceeding a prescribed fault deciding level appears, the knocking detector 2 is judged to be normal. Then, in responce to this decision result, ignition timing is controlled or corrected, allowing an igniter 5 to be controlled. |
