Patent ID: 7836693

Claim:
An exhaust recirculation apparatus for an internal combustion engine, the exhaust recirculation apparatus comprising: a high-pressure EGR passage branching from an exhaust system of the internal combustion engine for recirculating exhaust gas to an intake system of the internal combustion engine; a high-pressure EGR regulating unit for controlling a flow amount of exhaust gas recirculated through the high-pressure EGR passage; a low-pressure EGR passage branching from downstream of the high-pressure EGR passage in the exhaust system for recirculating exhaust gas to the intake system; a low-pressure EGR regulating unit for controlling a flow amount of exhaust gas recirculated through the low-pressure EGR passage; and a control unit for controlling the high-pressure EGR regulating unit and the low-pressure EGR regulating unit, wherein the control unit feedback-controls one of the high-pressure EGR regulating unit and the low-pressure EGR regulating unit, and open-controls an other of the high-pressure EGR regulating unit and the low-pressure EGR regulating unit, in a combination EGR range, in which exhaust gas is recirculated through the high-pressure EGR passage and the low-pressure EGR passage, wherein the control unit determines the high-pressure EGR regulating unit to be abnormal when the amount of exhaust gas recirculation through the high-pressure EGR passage is out of a normal flow range, and the control unit determines the low-pressure EGR regulating unit to be abnormal when the amount of exhaust gas recirculation through the low-pressure EGR passage is out of a normal flow range.