摘要 |
An object of this invention is to easily establish a learning condition for learning an output characteristic of a differential pressure sensor in an internal combustion engine including a high-pressure EGR mechanism and a low-pressure EGR mechanism, by merely performing control utilizing the pre-existing configuration. When fuel cut-off control is being executed, an ECU 60 closes intake throttle valves 18 and 20 and opens EGR valves 40 and 46. Therefore, since a pressure difference between an upstream section 44a and a downstream section 44b of a low-pressure EGR passage 44 becomes zero, the output characteristic of a differential pressure sensor 54 is learned utilizing this state. Thus, in the internal combustion engine equipped with two EGR mechanisms, when learning the output characteristic of the differential pressure sensor 54, a learning condition can be easily established by simple valve control utilizing the pre-existing system configuration and fuel cut-off control. |