| 摘要 |
A control system for an internal combustion engine (3), which reduces the frequency of operation of an EGR bypass valve (17), thereby making it possible to prolong a service life of the EGR bypass valve (17) and reduce the power consumption of a negative pressure-switching valve (19) that actuates the EGR bypass valve (17). The control system includes an EGR bypass valve (17) that switches an EGR passage (14) between a cooler passage (14a) and a bypass passage (14b), a negative pressure-supplying passage (40) connected to a negative pressure source (43), a negative pressure-switching valve (19) that drives the EGR bypass valve (17) toward the cooler passage (14a) or the bypass passage (14b) according to energization and deenergization thereof. When the engine (3) is stopped, a negative pressure discharge operation is executed, and when it is determined that the discharge of the negative pressure by the operation is completed, the energization of the negative pressure-switching valve (19) is stopped. |
