关键词: 帝豪 EV300；高压系统；车辆故障；故障诊断与排除

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