A powertrain in a vehicle includes an electro-mechanical transmission having a selectable one-way clutch mechanically-operatively coupled to an internal combustion engine and configured to selectively transmit mechanical power to an output member. A control method includes monitoring a vehicle speed, monitoring a transmission gear state, comparing the vehicle speed to a threshold low speed range, transitioning a selectable one-way clutch into an engaged mode when said vehicle speed is not in a forward direction in excess of the threshold low speed range, and maintaining the selectable one-way clutch in the engaged mode based upon the transmission gear state remaining in a first gear state and the vehicle speed remaining within said threshold low speed range, a neutral state, or a reverse state.