Valve actuation system comprising in-series lost motion components for use in cylinder deactivation and auxiliary valve actuations

A method of operating an internal combustion engine comprising a cylinder and at least one engine valve associated with the cylinder and further comprising a single cam configured to provide a main single cam motion and an auxiliary single cam motion so as to actuate the at least one engine valve via a valve actuation load path, the method comprising:

• providing a lost motion subtracting mechanism arranged in the single cam load path and configured, in a first default operating state, to convey at least the main single cam motion and configured, in a first activated state, to lose the main single cam motion and the auxiliary single cam motion;
• providing a lost motion adding mechanism configured, in a second default operating state, to lose the auxiliary single cam motion and configured, in a second activated state, to convey the auxiliary single cam motion, wherein the lost motion adding mechanism is arranged in series with the lost motion subtracting mechanism in the single cam load path at least during the second activated state;
• and
• operating the internal combustion engine in:
• a positive power mode in which the lost motion subtracting mechanism is in the first default operating state and the lost motion adding mechanism is in the second default operating state, or
• a deactivated mode in which the lost motion subtracting mechanism is in the first activated operating state and the lost motion adding mechanism is in the second default operating state, or
• an auxiliary mode in which the lost motion subtracting mechanism is in the first default operating state and the lost motion adding mechanism is in the second activated operating state.