A powertrain includes an engine, a transmission having a first input connected to an engine output shaft, and a variator. The variator includes a pump connected to the engine output shaft and a motor connected to a second input of the transmission. The pump has a variable setting that is determinable by a position of a pump actuator in response to a command signal. A controller associated is disposed to control operation of the variator, at least in part, by providing the command signal to the pump actuator. The command signal is determined based on an operator command and on a compensation term, which depends on a correlation function of a parameter related to the speed ratio between a pump speed and a motor speed and a flow characteristic of the pump actuator.