As the automotive industry enters the era of intelligence and connectivity, the wiring harness, serving as the "neural network" of vehicles, is undergoing revolutionary restructuring in its design logic and technical architecture. From the perspective of historical context, traditional automobiles emerged in the mechanical-dominated industrial era, with their wiring harness systems resembling a rudimentary vascular network, solely responsible for basic power distribution and signal transmission. Conversely, intelligent driving vehicles have grown up in the digital era of data explosion, where the wiring harness must transform into a high-speed information channel, carrying massive information flows such as LiDAR point clouds, high-precision map data, and V2X communication, with bandwidth demand growing exponentially.
In terms of design dimensions, traditional wiring harnesses adopt a "functional modularization" architecture, where subsystems such as powertrain and body control operate independently, and the wiring harness layout resembles a rigorous tree-like diagram. Smart vehicles, on the other hand, have shifted to a "service centralization" design, with domain controllers (such as autonomous driving domain and intelligent cockpit domain) becoming the core hubs. The wiring harness topology has evolved into a neural network combining star and ring structures. For example, the "Zonal Architecture" adopted by Tesla Model 3 has significantly reduced the length of the wiring harness by 1.5 kilometers and decreased its weight by 20%. This transformation not only optimizes space utilization but also significantly enhances reliability by reducing the number of connectors - it is worth noting that 90% of failures in traditional automotive wiring harnesses stem from poor contact of connectors.
At the technical level, there are three major transitions: Firstly, the transmission medium has evolved from the "unipolar world" of copper cables to a new era of "copper-fiber hybrid". The L3 auto drive system of the Audi A8 is the first to introduce fiber-optic transmission, which increases bandwidth by 4,000 times compared to traditional CAN bus and reduces latency to the microsecond level. Secondly, electromagnetic compatibility standards have risen from industrial level to military level. Intelligent driving wiring harnesses need to maintain signal purity in complex electromagnetic environments. The BMW iX adopts three-layer shielded coaxial cables, which can withstand strong electromagnetic interference of 200V/m. Thirdly, a material revolution is quietly taking place. BASF's polypropylene-based high-voltage cables retain elastic memory under operating conditions ranging from -40°C to 150°C, extending their lifespan by three times compared to traditional PVC materials.
Market demand differentiation has become more pronounced. Traditional automotive wiring harnesses prioritize "cost," with the value of a single main wiring harness being around 500-800 yuan; whereas smart driving wiring harnesses emphasize "performance premium," with the cost of wiring harnesses for L4-level vehicles reaching over 3,000 yuan. Consumer demand for OTA (Over-the-Air) upgrades has spurred the development of scalable wiring harness designs, such as the "bandwidth margin" interface reserved for NIO ET7, which supports subsequent LiDAR upgrades. More notably, smart wiring harnesses are moving from the background to the forefront, becoming a key carrier of user experience. The 48V low-voltage wiring harness of the Xiaopeng G9 supports millisecond-level power distribution switching, ensuring that the auto drive system can continue to operate for 8 minutes even when the 12V battery fails. This "functional safety redundancy" has become a core selling point for high-end models.
Amidst the flood of industrial transformation, wiring harnesses have evolved from auxiliary components to strategic resources. Suppliers like Bosch are developing "smart wiring harnesses" that integrate microsensors capable of real-time monitoring of parameters such as temperature rise and deformation. These "active cables" with self-diagnostic capabilities may redefine the neural system architecture of the next generation of smart cars.
