Abstract: With the government's strong support and policy drive for the new energy vehicle industry, the popularity rate of new energy vehicles has increased significantly, and the corresponding rise in the failure rate of new energy vehicles has been accompanied. In this paper, the abnormal faults in the startup and acceleration process of 2018 Geely Emgrand EV450 vehicle are analyzed and successfully eliminated. The fault performance is that the vehicle is powered on normally, but it cannot run normally when accelerating, and then the system fault indicator is lit and powered off. By reading and analyzing the fault codes of the vehicle controller and the drive motor controller, and combining the structure and working principle of the drive motor position sensor, it is determined that the fault originates from the cosine signal circuit. The maintenance team follows the principle of simple to complex, and gradually checks the rotating transformer, sine/cosine signal circuit and excitation signal circuit, and finally locates and replaces the damaged drive motor position sensor. After the fault is solved, the vehicle returns to normal operation, which verifies the validity of diagnosis and elimination steps. The research not only solves the specific faults, but also provides valuable experience in fault diagnosis and elimination of electric vehicles, which has important reference value in the field of electric vehicle maintenance.

Key words: vehicle fault; drive motor; sensor; troubleshooting

摘要： 随着我国政府对新能源汽车产业的大力扶持与政策驱动，新能源汽车的普及率显著增 长，伴随而来的是新能源汽车故障率的相应上升。文章针对 2018 款吉利帝豪 EV450 轿车在 启动及加速过程中出现的异常故障进行了深入分析和成功排除。故障表现为车辆上电正常， 但加速时无法正常运行，随后系统故障指示灯点亮并下电。通过读取并分析整车控制器和驱 动电机控制器的故障码，结合驱动电机位置传感器的结构与工作原理，确定了故障源于余弦 信号电路搭铁异常。维修团队遵循由简至繁的原则，逐步排查了旋转变压器、正弦/余弦信号 电路及励磁信号电路，最终定位并更换了损坏的驱动电机位置传感器。故障解决后，车辆恢 复正常运行，验证了诊断思路与排除步骤的有效性。研究不仅解决了具体故障，还提供了电 动汽车故障诊断与排除的宝贵经验，对电动汽车维修领域具有重要参考价值。

关键词: 车辆故障；驱动电机；传感器；故障排除