Powertrain and method of determining residual gas volume

A method of determining a total residual gas volume when a piston of an internal combustion engine is at a bottom dead center (BDC) position, the internal combustion engine being in fluid communication with an intake manifold and an exhaust manifold, the internal combustion engine including an engine block, the engine block defining at least one cylinder, the piston being movable within the at least one cylinder, at least one intake port being in fluid communication with the at least one cylinder and the intake manifold, and at least one exhaust port being in fluid communication with the at least one cylinder and the exhaust manifold;

• the method comprising:
• measuring an intake manifold pressure and an exhaust manifold pressure;
• determining, via a control module, a residual gas volume in the at least one cylinder originating from a current engine cycle based, at least in part, on the intake manifold pressure and the exhaust manifold pressure;
• determining, via the control module, a residual gas volume in the at least one intake port originating from at least one previous engine cycle based, at least in part, on the intake manifold pressure and the exhaust manifold pressure;
• and
• determining, via the control module, a total residual gas volume when the piston is at the BDC position based, at least in part, on the residual gas volume in the at least one cylinder originating from the current engine cycle and the residual gas volume in the at least one cylinder originating from at least one previous engine cycle.