Method of managing an engine brake procedure in a diesel cycle engine (E), comprising a first process (CTRL1) arranged to control the variable geometry of the turbocharger to achieve a predetermined value of back pressure at the exhaust manifold and a second process (CTRL2) to control the throttling valve according to a function inversely proportional to an error given by the difference between the current speed value and the limit speed value of the turbocharger, according to a closed loop control.