A system and method for controlling a free-wheeling motor vehicle including at least one internal combustion engine connected to drive wheels by a transmission. The method includes: determining engine torque at wheels; determining longitudinal acceleration of the vehicle when a free-wheeling driving mode is activated, on the basis of resisting torques on the wheels; determining longitudinal acceleration of the vehicle when the free-wheeling driving mode is deactivated on the basis of the engine torque and the resisting torques on the wheels; determining the difference in longitudinal acceleration between when the free-wheeling driving mode is activated and the free-wheeling driving mode is deactivated; and opening the transmission chain when the longitudinal acceleration difference leans substantially toward a value of zero.