The current state of automation and vehicle autonomy demands components capable of transmitting control signals with minimal delay. In mechanical systems, this is challenging due to inherent signal transmission inertia. To address this, complex mechatronic units are integrated to shorten decision-making time in automatic or autonomous systems. In such systems, a “reaction” is a condition where a change in one parameter triggers a corresponding change in another. This study examines the reaction of the input stage of a centrifugal adaptive variator to the influence of its output stage and external factors acting on the vehicle. A dedicated test bench was developed at Cherkasy State Technological University, based on parametric and structural synthesis of mechanisms and the authors’ prior research in automatic control theory. The bench determined stability conditions, steady-state modes, and equilibrium of the self-regulating centrifugal variator. Modeling of experimental results confirmed its role in an adaptive autonomous control system for a continuously variable mechanical transmission (CVTs). The system’s response depends on stability and equilibrium criteria for control signal transmission. Stability was evaluated under varying input-output shaft speeds, idle/load conditions, and simulated dynamic loads using the Lyapunov function and its derivative. No conditions were found where the system failed to react.