| 摘要 |
PURPOSE:To maintain a function of fuel injection when a crank angle sensor is in failure, by performing the fuel injection with a prescribed frequency pulse signal in no relation to a crank angle at abnormality of the crank angle sensor. CONSTITUTION:If a crank angle sensor 6 causes a trouble, a reference signal S1 or a unit angle pulse S'1 is not output. This phenomenon is decided by a cpu2, and a selective signal S7 becoming a high level at fault time is output from an I/O interface 3. A back up signal generator circuit 9 outputs a pulse signal S8 of prescribed frequency. When the crank angle sensor is in failure, if the signal S7 becomes a high level, the signal S8 is output as an injection pulse S9. In this way, self running can be performed even when the crank angle sensor is in failure. |
