This paper is aimed at robust control of a Permanent magnet DC motor based actuator used in the control of the inlet swirl valve of a diesel engine. The actuator has uncertainty issues related to parameter identification and variation, and load disturbance. These issues lead to faults in controllers, resulting in poor performance and failure. The actuator has been modeled taking parameter uncertainties and friction nonlinearities into account. To cope with these uncertainties, an output feedback control system has been developed by means of output 2nd order sliding-mode control. The controller is expected to compensate for nonlinearities, thereby avoiding operational faults related to them. Practical implementation of the controller on an experimental setup shows the effectiveness of this controller.