Exhaust vane braking strategy for gasoline engine with variable geometry turbine

A method of controlling vane braking on a gasoline engine having a turbocharger including a compressor and a turbine, the engine further having:

• a throttle that moves between open and closed positions to permit air into an intake manifold of the engine;
• vanes provided on the turbine that move between open and closed positions by a vane actuator to control an amount of exhaust air that flows through the turbine;
• at least one cam that rotates causing a valve to open and allow an amount of air to flow through the engine, the at least one cam having a cam actuator that impacts the rotation of the at least one cam;
• and a controller that controls a transition into vane braking, the method comprising:
• determining, at the controller, whether fuel is shut off;
• determining, at the controller, whether the vehicle is accelerating faster than a limit for a given amount of engine braking based on a wheel speed sensor input;
• determining, at the controller, whether a brake pedal input exceeds a threshold;
• determining, at the controller, whether a speed of the gasoline engine satisfies a threshold;
• and
• commanding, at the controller, the transition into vane braking based on a determination that the fuel is shut off, the vehicle is accelerating faster than the limit for the given amount of engine braking, a brake pedal input exceeds a threshold, and a speed of the gasoline engine satisfies a threshold.