| 摘要 |
PURPOSE:To enable abnormality of a sensor to be surely detected in the ignition timing control device of an internal-combustion engine provided with a knocking feed-back control device, by carrying out fail-safe operation when the intensity of a knocking sensor output signal becomes out of a predetermined range. CONSTITUTION:At the step 103 a judgement is made for determining whether a knocking sensor signal VSP is within a range between -alpha and +beta which is a possible automatic gain control range with respect to a sensor signal VAS on the sensor sensing, that is, VAS-alpha>VA>VAS+beta, or not. If it is ''No'', at the step 104 the previous spark retardation compensating amount thetaKN is selected. If it is ''Yes'', at the step 105 a spark retardation compensating amount is computed. Thereby, abnormality of the knocking sensor may be surely detected. |
