Vehicle wiring harness under the trend of automobile lightweighting

Lightweighting of automobiles is a major trend, but many people overlook a very important link, that is, the automobile wiring harness. According to the data, the length of a vehicle's entire wiring harness is often several kilometers and weighs tens of kilograms.

You can imagine that if the length of the wiring harness can be greatly reduced, it will not only reduce the weight of the vehicle and reduce driving energy consumption, but also the difficulty of assembling the vehicle will be greatly reduced and the assembly speed will be greatly improved.

In 2019, Tesla founder Musk made a high-profile announcement that the wiring harness of the entire Model Y vehicle would be shortened to less than 100m. At that time, Tesla also announced a patent related to wiring harnesses, which adjusted the domain control and combined multiple wiring harness components into one component. For example, one controller for one door can control multiple devices, including door locks, lighting, audio, etc.

At that time, the automotive industry was quite a sensation. You know, reducing the length of automotive wiring harnesses is something that the automotive industry is exploring. So Musk personally stood up to set this flag, which is enough to show the importance of this link. Among Tesla's models, the length of the entire vehicle wiring harness of Model S is 3km, and the length of the entire vehicle wiring harness of Model 3 is 1.5km. The length of the wiring harness is shortening at a speed visible to the naked eye. Coupled with Musk's influence and almost paranoid technology enthusiasm, everyone basically believed it and was looking forward to whether there would be any black technology in the field of wiring harnesses. Some people also said that SpaceX's technology would also be used in Model Y.

However, as Model Y began to be delivered in 2021, the eager dismantling teams could not wait to pick up wrenches and screwdrivers to explore this big toy, but the result was a slap in Musk's face. The wiring harness length of the Model Y vehicle did not decrease, reaching 1.9km, far exceeding the declared 100m, and even exceeding the 1.5km of Model 3. However, although the Model Y's Flag fell, it also embedded many new attempts of Tesla, such as the introduction of flexible circuit board FPC technology, which can have multiple transmission channels of the same length to shorten the wiring harness length.

In summary, with the trend of automobile electrification, intelligence, and networking, the electronic and electrical architecture of automobiles has also changed, and the wiring harnesses inside the car have become more and more complex. The functional complexity of cars in the 1950s and today's cars in the 21st century is no longer the same. In the past, the core of a car may have been the power system, but now the core of a car has gradually shifted to various domain controls of automotive electronics.

Automotive wiring harnesses are becoming more and more complex, and the complexity of the lines conflicts with the stability of the electronic system. How to streamline the wiring harness has become a headache for the industry.

So what is the solution?

Tesla's domain control reorganization is a solution that no longer divides domains according to single functions, but uniformly controls the same area, which can reduce duplicate wiring;

Flexible printed circuit (FPC) is also a solution. It uses a more sophisticated wiring harness manufacturing process and can significantly reduce the complexity of wiring for information transmission.

At the same time, some organizations, such as the domestic Star Flash Alliance, are also exploring whether wireless technology can be used instead of wired technology for internal communications within the vehicle. However, considering the robustness and susceptibility to interference of wireless technology, many problems also need to be addressed.

About the author: Bu Rixin

Founder of Chuangdao Consulting, entrepreneurship mentor of Beijing University of Posts and Telecommunications, distinguished mentor of School of Economics and Management, and consultant of Tianjin Integrated Circuit Industry Association. He holds a bachelor's degree in electronic engineering and a master's degree in computer science. He has securities practitioner qualifications, fund practitioner qualifications, and has passed the CFA LII exam. He has worked for AsiaInfo Consulting, Chinese Academy of Sciences Saixin Capital, Dongxu Financial Holding Group, etc. He has more than 15 years of experience in IT R&D, consulting, investment and financing, and focuses on investment areas such as semiconductors, intelligent manufacturing, Internet of Things, and information technology innovation.