Abstract: With the improvement of people's requirements for car ride comfort and the integration of electronic technology, sensor technology, computer control and network technology, automatic air conditioning system has been widely used in some middle and high-end passenger cars, and its control principle has great changes compared with traditional manual air conditioning. Taking the Great Wall Harvard M6 as an example, this paper introduces the composition, basic refrigeration principle and control circuit principle of automatic air conditioning and refrigeration system, combined with typical fault cases such as automatic air conditioning system not cooling, and demonstrates from the aspects of fault phenomenon, fault cause analysis, fault diagnosis, principle hypothesis, principle verification, fault troubleshooting, summary reflection and so on. Through typical fault cases, the control principle of automatic air conditioning and refrigeration system is verified, the theoretical application ability is improved, the diagnostic ideas are established, and certain references are provided for teachers, students and maintenance technicians of automotive majors in vocational colleges.

Key words: Great Wall Harvard M6; automatic air conditioning refrigeration system; compressor; blower; cooling fan; fault case

摘要： 随着人们对汽车乘坐舒适性要求的提高以及电子技术、传感器技术、计算机控制与网 络技术的融入，自动空调系统已大量应用在一些中高档乘用车上，其控制原理与传统手动空 调相比有较大变化。文章以长城哈弗 M6 为例，介绍自动空调制冷系统组成、基本制冷原理 和控制电路原理，结合自动空调系统典型故障案例，从故障现象、故障原因分析、故障诊断、 原理假设、原理验证、故障排除、总结反思等方面进行论证。通过典型故障案例验证自动空 调制冷系统控制原理，提高理论应用能力，建立诊断思路，为职业院校汽车专业师生及维修 技术人员提供一定参考。

关键词: 长城哈弗 M6；自动空调制冷系统；压缩机；鼓风机；散热风扇；故障案例