Ambulatory infusion device, including: a pump drive unit , the pump drive unit including a pump actuator and a pump driver coupled to the pump actuator , the pump driver being designed for coupling to a piston of a metering pump unit for transmitting a pump driving force and/or pump driving torque from the pump actuator to the piston ; a valve drive unit , the valve drive unit including a valve actuator and a valve driver coupled to the valve actuator , the valve driver being designed for coupling to a valve unit for transmitting a valve switching force and/or valve switching torque from the valve actuator to the valve unit , a control unit , the control unit being configured to control a repeated execution of a sequence of: a) operating the valve actuator to switch the valve unit into a filling state, thereby fluidic coupling a dosing cylinder of the metering pump unit with a reservoir ; b) operating the pump actuator to displace the piston in a retraction direction; c) operating the pump actuator to displace the piston into an advancing direction, the advancing direction being opposite to the retraction direction, by a backlash compensation distance; d) operating the valve actuator to switch the valve unit from the filling state into a draining state, thereby fluidic coupling the dosing cylinder with an infusion site interface ; e) operating the pump actuator to further displace the piston in the advancing direction in a number of incremental steps over an extended time period. a pump drive unit , the pump drive unit including a pump actuator and a pump driver coupled to the pump actuator , the pump driver being designed for coupling to a piston of a metering pump unit for transmitting a pump driving force and/or pump driving torque from the pump actuator to the piston ; a valve drive unit , the valve drive unit including a valve actuator and a valve driver coupled to the valve actuator , the valve driver being designed for coupling to a valve unit for transmitting a valve switching force and/or valve switching torque from the valve actuator to the valve unit , a control unit , the control unit being configured to control a repeated execution of a sequence of: a) operating the valve actuator to switch the valve unit into a filling state, thereby fluidic coupling a dosing cylinder of the metering pump unit with a reservoir ; b) operating the pump actuator to displace the piston in a retraction direction; c) operating the pump actuator to displace the piston into an advancing direction, the advancing direction being opposite to the retraction direction, by a backlash compensation distance; d) operating the valve actuator to switch the valve unit from the filling state into a draining state, thereby fluidic coupling the dosing cylinder with an infusion site interface ; e) operating the pump actuator to further displace the piston in the advancing direction in a number of incremental steps over an extended time period. a) operating the valve actuator to switch the valve unit into a filling state, thereby fluidic coupling a dosing cylinder of the metering pump unit with a reservoir ; b) operating the pump actuator to displace the piston in a retraction direction; c) operating the pump actuator to displace the piston into an advancing direction, the advancing direction being opposite to the retraction direction, by a backlash compensation distance; d) operating the valve actuator to switch the valve unit from the filling state into a draining state, thereby fluidic coupling the dosing cylinder with an infusion site interface ; e) operating the pump actuator to further displace the piston in the advancing direction in a number of incremental steps over an extended time period. <EOS>