In this study, the dynamic behaviour of a non-linear full vehicle model having active suspensions and a controlled passenger seat is examined. The non-linearity comes from the dry friction on dampers. The suspensions considered are Me Pherson strut type of independent suspensions. Three cases of control strategies are taken into account. First, only the passenger seat is controlled. Second, only the vehicle body is controlled. Then, both the vehicle body and the passenger seat are controlled at the same time. The method is chattering free sliding mode control, which is robust and successfully applicable to non-linear systems with superior performance. The time responses of the non-linear vehicle model due to road disturbance and frequency responses of the linear vehicle model are obtained for each control strategy. At the end, performances of these strategies have been compared and discussed.