Abstract: For common faults of pure electric vehicles, fault diagnosis and troubleshooting are conducted through fault recurrence. According to the idea of "fault phenomenon—fault analysis— fault diagnosis—fault summary", summarize the diagnosis and troubleshooting ideas for pure electric vehicles. Pure electric vehicle faults can be divided into two categories: "high-voltage system faults" and "AC slow charging faults". The high-voltage system involves many modules, such as the vehicle control unit (VCU) module, the positive temperature coefficient (PTC) thermistor module of the air conditioner, and the high-voltage wiring harness connection (high-voltage interlock). The failure of modules such as the power control unit local area network (P-CAN) affects high-voltage power on. The charging system involves an auxiliary control module (ACM) and a charging gun. Taking the Geely Emgrand EV300 (2017 model) as an example, this article analyzes the working principles of the low-voltage power supply system and high-voltage power-on system of pure electric vehicles, conducts a vehicle case study, and provides maintenance technicians with certain fault diagnosis solutions by analyzing common faults of pure electric vehicles.

Key words: Emgrand EV300; High-pressure system; Vehicle failure; Fault diagnosis and troubleshooting

摘要： 针对纯电动汽车常见的故障，通过故障重现，进行故障诊断与排除。按“故障现象— 故障分析—故障诊断—故障总结”思路，对纯电动汽车故障进行诊断排除思路总结。纯电动 汽车故障可分为“高压系统故障”和“交流慢充故障”两大类，高压系统涉及模块众多，如 整车控制单元（VCU）模块，空调正温度系数热敏电阻模块（PTC），高压线束连接（高压互 锁），动力控制单元局域网（P-CAN）等模块出现故障影响高压上电；充电系统涉及辅助控制 模块（ACM）及充电枪。文章以吉利帝豪 EV300（2017 款）为例，分析纯电动汽车低压供电 系统、高压上电系统工作原理，进行车辆案例分析，通过分析纯电动汽车常见故障给维修技 术人员提供一定的故障诊断解决方案。

关键词: 帝豪 EV300；高压系统；车辆故障；故障诊断与排除