With the rapid development of science and technology, the modern automobile industry is changing with each passing day. The wide application of new technologies, new materials and new processes, especially the application of electronic technology and hydraulic technology in automobiles, makes today's automobiles a collection of advanced technologies and a novel and unique automobile that is constantly being refurbished. The fault diagnosis of modern automobile is no longer a matter of seeing, listening and touching, and the maintenance of automobile is no longer a skill of master with apprentice, but a process of applying various new technologies. With the rapid development of automobile technology, the high-tech characteristics of automobile maintenance are increasingly presented, and the concept of automobile maintenance is constantly updated. 1 features of modern automobile maintenance 1. 1 features of fault diagnosis Modern automobile is no longer a simple mechanical product, nor a primitive means of transportation, but has evolved from a primitive automobile into a high-tech crystallization. Especially with the rapid development of electronic technology and computer technology, the technical level of automobiles is constantly improving. Electronic fuel injection system engine (EFIE), ABS anti-lock braking system, SRS airbag system, electronically controlled automatic transmission system (AT), accelerated taxi control system (ASR), automatic air conditioning system (A/C), electronic suspension system (ECS), power steering system, automatic cruise system, central locking and anti-theft system, TCS power traction system and self-diagnosis system. These components are all composed of electronic control units. Through the decoder, the stored fault code can be read from the memory of the electronic control unit, so as to determine the fault location and provide online help for troubleshooting. 1.2 characteristics of maintenance tools with the development of automobile technology, maintenance equipment has also undergone qualitative changes. The production of automobile warranty equipment is no longer dominated by machines and tools. Since 1990s, batches of advanced imported automobile inspection equipment and instruments have flooded into China. The four-wheel locator, decoder, automobile oscilloscope, automobile ammeter, engine analyzer, exhaust gas tester and computer dynamic balancing machine, which people were unfamiliar with in the past, have become the necessary tools for modern maintenance enterprises [4]. These test equipments are high-tech products themselves, and they are the advanced integration of electronic test technology and computer technology. To skillfully operate and use these testing equipment, technicians need to undergo strict training and master foreign languages and computer technology, so as to master the correct use methods and give full play to the functions of testing equipment. This high-tech modern automobile inspection equipment greatly improves the scientific and technological content of modern automobile maintenance. 1.3 characteristics of maintenance information with the development of information, information and network technology, all walks of life are in a brand-new development period. The structure and control technology of automobiles are becoming increasingly high-tech, and new brands, new equipment and new functions of automobiles emerge one after another. It is impossible for a maintenance technician to keep thousands of models of maintenance data, data and procedures in mind. The knowledge, technology, experience and comprehensive mastery of information of automobile maintenance technicians are increasingly showing their limitations. The solution to this problem is the professional Internet of automobile maintenance, that is, the Internet. The appearance of the Internet has completely broken the space and time limitations of information dissemination, and it can spread information to every corner of the earth in the first time. Internet appeared in China's modern automobile maintenance industry. From the perspective of the international automobile maintenance industry, the networking of technical information inquiry, fault detection and diagnosis and technical training in the maintenance industry has been fully popularized. Take the automobile maintenance industry in America as an example. As early as the early 1990s, the comprehensive management of maintenance information, expert group consultation, online information inquiry, online troubleshooting, online technical training and online purchase of automobile maintenance materials have become the basic characteristics of the maintenance industry. The internet of automobile maintenance specialty started in China in the mid-1990s. Taking the professional website of Eurasia Dewei Automobile Maintenance as an example, starting from 1995, a remote communication BBS used by member units was established. 1996, and began to invest huge sums of money to build a large-scale internet website for automobile maintenance [6]. At present, it has developed into the most professional website, covering the basic maintenance, overhaul procedures, various data, various parts location diagrams, mechanical disassembly diagrams, electrical wiring diagrams, etc. of engines, gearboxes, air conditioners, suspension, steering, constant speed, airbags and anti-theft systems of various automobiles in Europe, America and Asia, and has realized the functions of online answering questions, online consultation, online shopping and online training. 1.4 characteristics of maintenance personnel training in traditional automobile maintenance enterprises in China, the maintenance personnel's cultural level, theoretical basis and foreign language level are low. Most of the traditional training methods adopt the mentoring mode, which makes it difficult to reach the level of modern maintenance technicians who are mechatronic, computer-literate and foreign-literate. With the development of automobile high technology, technicians engaged in automobile maintenance service must have high-tech quality. In addition to having a solid professional theory of automobiles, they also need to master all kinds of automobile testing equipment and instruments, master a foreign language, skillfully use computer analysis and the professional Internet of automobile maintenance to inquire about automobile maintenance information, analyze all kinds of intractable diseases, make accurate judgments, be skilled in troubleshooting, and eliminate all kinds of automobile failures with the lowest cost, shortest working hours and best service. In addition to professional teaching in school, automobile maintenance technicians should also strengthen their own learning, and constantly update their maintenance concepts, knowledge and skills with the help of various technical trainings, especially audio-visual education and online training, so as to improve their own quality, thus maintaining modern automobiles. Supplement: Foreign automobile maintenance education circles have also launched multimedia computer operation animation and object teaching CD-ROM database, which can be applied to distance teaching and online teaching. Teachers can automatically arrange the content, sequence and time of teaching films according to students' level and teaching courses, adjust different evaluation contents and standards at any time, stimulate students' enthusiasm for learning, improve students' willingness to learn actively, establish a heuristic and interactive learning environment for computer teaching, and improve learning effect. This computer teaching method constitutes a new feature of modern automobile maintenance training. 1.5 characteristics of maintenance management with the development of computers and related systems, computer management has been widely used in automobile maintenance industry in many countries, and this trend will continue to expand. In China, computerized management has just started. For most automobile maintenance enterprises, whoever has the most perfect management system, the most modern management methods, the most accurate management data analysis and the most perfect service will win the most customers and be invincible in the competition. Through computerized management, the general managers of the business department, parts department, workshop, cashier and repair department can be comprehensively managed by network, which makes the business activities clear at a glance, overcomes the chaotic management situation in the past, liberates managers from daily chores, improves work efficiency and gains the recognition of customers. Senior managers can also know the dynamic situation of automobile maintenance in time through the computer management network system, which is convenient for overall arrangement. It can make the maintenance industry change the traditional manual operation mode and realize a qualitative leap. It can free the factory director from complicated affairs and strive for more benefits. Standardized computerized management can automatically establish complete and accurate customer and vehicle files, laying the foundation for long-term flexible customer service, and perfect maintenance tracking service function can increase customer satisfaction. It can eliminate some mistakes in work and improve work efficiency. Dynamic tracking of vehicles and customers can make business departments know the details of vehicles and each customer, remind customers to repair, maintain and replace parts at any time, and reflect the integrity, timeliness and hierarchy of services. Compared with the traditional way, modern automobile maintenance has made a qualitative leap in concept, maintenance system, maintenance enterprise management and intelligent fault diagnosis. 3. quality of enterprise's Supplement to Modern Automobile Maintenance: 3. 1 Enterprise's Characteristic Quality Modern automobile maintenance enterprises must pay attention to the improvement of their own quality in order to win the space for survival and development. Quality of enterprise elements mainly include: ① Modernization of enterprise management. ② Construction of enterprise technical management team. (3) the technical business level of the enterprise. ④ Maintain the use of technical data and information. ⑤ Quality level of maintenance vehicles. ⑥ Management concept and service consciousness. ⑦ Enterprise reputation and service reputation. (8) the operating efficiency of the enterprise, the income of employees and the price advantage of participating in market competition. Pet-name ruby maintain market share. 10 corporate social image, popularity and social recognition. The proportion of enterprise development factors is a quantitative index to measure the comprehensive quality of enterprises. The mathematical expression is q = [f1x1+f2x2+…+fnxn] [f1y/+f2y2+…+fnyn] = ∑ fixi/fiyi (1), where q That is, the social average statistical fi- analysis coefficient of this factor, to determine the importance of each factor, the leading factor is 1, and the rest is 0 ~ 0~ 13.2 WTO. The entry of automobile maintenance into WTO has great influence on the automobile maintenance industry in China. In order to meet the requirements of after-sales service, foreign automobile maintenance industry will enter the China market one after another. The intervention of foreign automobile maintenance industry provides a more advanced and efficient international technical environment for China automobile maintenance market, which will play a good role in promoting the innovation of domestic automobile maintenance industry and accelerating the technological progress of automobile maintenance industry. At present, there is still a big gap between domestic automobile maintenance and developed countries in terms of technical level, management ability, management mode, production scale, comprehensive quality and service consciousness, such as realizing parts distribution and all-round zero inventory in automobile maintenance industry. China's automobile maintenance management mode will gradually be in line with international standards, and various management modes such as special maintenance, agency maintenance, on-site maintenance and special assembly maintenance will be fully launched, and chain operation maintenance, fixed-point maintenance, member maintenance and club maintenance will also be realized. Fully reflect the superiority of low cost to ensure quality and service. Supplement: 4 Conclusion The traditional automobile maintenance mode, maintenance system and business model will inevitably be replaced by modern automobile maintenance mode.