Apparatus for diagnosing exhaust gas recirculation and method thereof

摘要

An exhaust gas recirculation diagnosis device may include an EGR module that supplies an intake manifold with exhaust gas from an exhaust manifold, a MAP (manifold absolute pressure) sensor that measures pressure of the intake manifold, and a control portion that controls the EGR module such that the flow rate of the exhaust gas that is supplied from the exhaust manifold to the intake manifold is controlled by stages and monitors the value of the MAP sensor in a fuel cut off condition to diagnose whether the EGR module is faulty. The exhaust gas recirculation diagnosis device uses MAP sensor to perform exhaust gas recirculation and to diagnose the fault of the exhaust gas recirculation device.

主权项

1. An exhaust as recirculation diagnosis device, comprising:
an EGR module that supplies an intake manifold with exhaust gas from an exhaust manifold; a manifold absolute pressure (MAP) sensor that measures pressure of the intake manifold; and a control portion that controls the EGR module such that the flow rate of the exhaust gas that is supplied from the exhaust manifold to the intake manifold is controlled by stages and monitors the value of the MAP sensor in a fuel cut off condition to diagnose whether the EGR module is faulty; wherein the EGR module includes:
an EGR pipe that connects the exhaust manifold with the intake manifold;an EGR valve that is disposed on the EGR pipe to control the flow rate of the exhaust gas that is supplied to the intake manifold from the exhaust manifold; andan operating portion that is controlled by the control portion to operate the EGR valve; and wherein the control portion obtains a first MAP sensor value in a first section where the EGR valve is closed, obtains a second MAP sensor value in a second section where the EGR valve is opened until a first point, obtains a third MAP sensor value in a third section where the EGR valve is opened until a second point, and obtains a fourth MAP sensor value in a fourth section where the EGR valve is closed.