Electric power steering (EPS) systems are rapidly replacing existing traditional hydraulic power steering systems due to their important advantages such as fuel and cost savings, environmental compatibility and flexibility. Many articles are available in this field in which EPS is viewed only from one specific aspect. Other aspects have been introduced only by brief equations neglecting some main details regarding the important effects of ignored parts. Therefore, it is quite necessary to make a complete analysis of every part of this system with a right combination between them. It makes a comprehensive simulation system for EPS. This matter needs sufficient knowledge in mechanical, electrical and control sciences and how to assemble them with each other properly. Therefore, Mechatronic is the most appropriate branch of science to achieve this goal. In this paper, a complete model of EPS is presented which includes a 7-D.O.F mechanical model of steering system. A Permanent Magnet Synchronous Machine (PMSM) is used to supply the assist torque to steering column. Vector Control Method is utilized for controlling the motor. A PID controller determines the reference assist torque value. The results are presented to estimate the model precision and evaluation of model.