Inter-turn fault (ITF) is considered an early stage in the spectrum of motor stator faults. If not promptly detected and mitigated, ITF can cause extensive damage to the entire winding. In this article, the MPC principle is fully exploited, and a novel method of ITF detection and location under MPC is proposed. The proposed method incorporates the effect of various fault locations into the faulty machine model and constructs fault indicators using the difference and ratio of the current residuals. Additionally, the method enables efficient online ITF fault detection and location through simple operations and offers superior real-time performance. Requiring no additional observers, hardware, or changes to the control structure, the method presents an advantageously lean implementation. The proposed scheme can be easily embedded into the existing control system, which is suitable for industrial applications. Experimental results verify the method's accuracy and robustness.