As Vehicles Add Sensors and Data Links, Connectors Are Getting Smaller

Source: tanakorn/stock.adobe.com

Published March 30, 2026

When the first Model T rolled off Mr. Ford’s production line, vehicle manufacturing was still largely mechanical and labor intensive. Today’s automotive factories are different, relying on robotics, automation, advanced quality control, and digitally coordinated production systems.

While the vehicles rolling off today’s assembly lines still share the core elements of a vehicle platform, they now also contain a vast network of electronic subsystems for advanced driver assistance systems (ADAS), emissions compliance, and infotainment. Traditionally, many new features have been introduced as separate electronic control units (ECUs) connected through the wiring harness. As a result, modern vehicles can contain more than 150 ECUs, and onboard electronics can account for nearly half of a vehicle’s total cost.^[1] Wiring harnesses have grown alongside this electronic expansion, both in size and complexity, and are now among the heaviest and most expensive subsystems in a vehicle.^[2]

This blog explores how the growing demand for more sensors, ECUs, and high-speed data links—driven by increasing vehicle connectivity—adds complexity to wiring harnesses. It also examines why designers now rely on miniaturized connectors to reduce harness size while still meeting the high-bandwidth, power-delivery, safety, and performance requirements of modern automotive electronics.

The Need for Miniaturization

With this explosion of technology, vehicle designers are beginning to run out of room inside modern cars and trucks. In addition to the challenge of finding space for all these systems, the complexity of the wiring harness itself has become a significant obstacle. Managing the growing web of cables required to power and connect modern vehicle electronics is now a bottleneck in automotive design and production. As a result, miniaturization has become one of the most important goals in modern automotive connector design.

Modern vehicle wiring harnesses can contain many kilometers of cable and hundreds of connectors.^[3] Their irregular shapes make them difficult to manufacture using conventional automotive processes, which means they are still largely assembled by hand. This increases production costs and raises the potential for installation errors. Harness weight is also significant, particularly for electric vehicles, where additional mass directly affects driving range.

Modern vehicles have become more-connected systems, using cameras, radar, and lidar sensors to gather information about their surroundings and transmit it to onboard computing systems that support ADAS and emerging autonomous driving functions.

The wiring harness that links these systems together must now do more than simply distribute electrical power. It must also support the transfer of large data streams, often at speeds of several gigabits per second. Requirements like this are changing how vehicle electronics are organized. Instead of relying solely on complex harnesses, emerging vehicle architectures treat the car more like a distributed computing platform. Local processing nodes communicate with central systems through high-speed links.

As vehicles start to resemble networked computing systems, the connectors within them must deliver higher performance while occupying less space and maintaining reliability in harsh automotive environments. Sensors reflect this change in electrical architecture. Earlier vehicles might have used a single rear-view camera, but many modern designs incorporate multiple vision systems that provide a surround view of the vehicle’s environment. Each sensor generates continuous data streams that must be carried reliably within the vehicle.

However, coaxial cables and connectors can also be bulkier than simpler discrete wire connections used elsewhere in the vehicle. Without careful design, this can increase both the weight and the complexity of the wiring harness.

Compact Solutions for Vehicle Harnessing

To address this challenge, Molex developed the High-Speed FAKRA-Mini (HFM) Interconnect System. The HFM system supports automotive data transmission in a much smaller form factor than conventional FAKRA connectors. The reduced connector size helps limit wiring harness growth as vehicles add more links while still supporting high-frequency data signals.

The HFM platform supports data rates of up to 28Gbps while offering up to 80 percent space savings compared with traditional FAKRA connectors. Providing high bandwidth in a much smaller connector makes it far easier to integrate links for camera systems, ADAS modules, and infotainment systems without increasing harness bulk. By shrinking the interconnect size, designers gain valuable flexibility when routing high-speed data links through crowded vehicle architectures.

Sensor modules also present space challenges. Camera and lighting systems often contain densely packed printed circuit boards (PCBs) that must communicate within extremely confined spaces. Automakers carefully design modules to be used across different vehicle models, meaning the smallest chassis in the lineup determines size constraints.

Conventional pin-and-socket connectors are often too large for these applications. Instead, flexible printed circuits (FPCs) are frequently used to link components because they allow designers to route signals through very tight mechanical spaces. However, FPCs require connectors that can deliver reliable electrical performance while occupying a very small profile above the circuit board.

Molex Easy-On Flat Flexible Cable (FFC) and FPC Connectors are designed to address this requirement by providing low-profile alternatives to conventional wire-to-board connections for the complex electronic assemblies commonly found within vehicle sensor modules. These connectors support FFCs and FPCs while providing secure mechanical retention.

They are available with secure locking systems, including push-style and flip-style actuators, which help ensure that the cable-to-terminal connections remain reliable even in the high-vibration environment of a moving vehicle. Their low-profile geometry allows designers to integrate high-density interconnects within miniature sensor modules, making them suitable for applications such as cameras, displays, and other compact automotive electronics.

Delivering Power and Data

Wiring harnesses must provide both electrical power and data to vehicle systems. Interior lighting, power mirrors, infotainment displays, and windscreen wipers all need dependable power connections that coexist with high-speed computing and sensing links.

Power connectors bring additional challenges because of safety-driven isolation requirements. Maintaining adequate electrical isolation often requires greater spacing between power contacts and surrounding conductors, which increases connector size. As vehicles incorporate more electrical functions—electronic turbochargers, advanced infotainment, and other loads—the legacy 12V architecture is reaching its limits. Designers are increasingly adopting 48V architectures to meet higher power demands, and these systems must also coexist with the high-current wiring used in electric vehicles. All of this places extra demands on connector design and harness packaging.

Higher power requirements can increase connector size and harness complexity, which makes compact, high-current interconnect solutions important. The Molex Nano-Fit Power Connector family is an example of a compact power connector that is often used inside control or distribution boxes rather than being an integral part of the external wiring harness. Housing Nano-Fit connectors inside a box allows the harness to interface with a protected, compact power distribution module while keeping the harness routing simpler and safer.

Placing Nano-Fit connectors inside enclosure modules is a common design approach to balance safety, space efficiency, and harness complexity: the harness terminates to the box, and internal Nano-Fit connections handle compact, isolated power distribution within the enclosure.

Conclusion

Modern vehicles are self-contained, distributed computing networks on wheels. Large volumes of data must move through the vehicle, along with the power needed to operate sensors, safety systems, and computing systems.

The connectors that support these systems must provide high performance without adding weight or occupying valuable space. Miniaturized connector systems help manage these constraints. Compact high-speed data links, dense board-level interfaces, and efficient power distribution enable engineers to provide the growing levels of functionality that modern drivers demand.

[1]https://www.molex.com/en-us/blog/unleashing-the-power-of-connected-cars; https://eden-boites.com/blog/en/prix-de-lelectronique-dans-une-voiture-ce-quil-faut-savoir/; https://www.statista.com/statistics/277931/automotive-electronics-cost-as-a-share-of-total-car-cost-worldwide/
[2]https://chargedevs.com/newswire/siemens-acquires-electrical-systems-and-wire-harness-software-specialist-comsa/
[3]https://wiringharnessnews.com/wired-to-drive-exploring-the-automotive-wires-and-cables-market/

David Pike is well known across the interconnect industry for his passion and general geekiness. His online name is Connector Geek.