| 摘要 |
PURPOSE:To ensure high safety travelling without abnormally lean air fuel ratio by replacing the output signal of atmospheric pressure sensor with a predetermined output signal when the atmospheric pressure sensor is failured. CONSTITUTION:An electronic control fuel supply unit controls air flow to control air fuel ratio on the basis of various information of an engine including an atmospheric pressure sensor. When any failure of the atmospheric pressure sensor is detected, a signal So corresponding to the output signal of the atmospheric pressure sensor in a certain atmospheric pressure Po is set and employed in place of the output signal S of the failured atmospheric pressure sensor to control air fuel ratio on the basis of this signal So. Thus, since supercharging condition is not obtained when the atmospheric pressure sensor is failured, high safety travelling is ensured without any abnormally lean air fuel ratio. |
