Method and apparatus for controlling an EGR system dependent on the state of an SCR system

System for exhaust gas recirculation in a supercharged engine equipped with an ATS device, the engine (E) comprising an intake manifold (4), exhaust manifolds (5, 5'); wherein at least one of the exhaust manifolds is connected to the intake manifold (4) to recirculate an exhaust gas flow rate (EGR), according to predetermined operating conditions (rpm, T) of the engine (E), means for monitoring the efficiency of the ATS, processing means configured to control an exhaust gas recirculation as a function of the ATS efficiency.