Electronic Products

Electronic Components for Sending Commands to Onboard Devices

We have developed a wide variety of electronic parts to control vehicles electronically.
We continually strive to create smaller, lighter parts, such as integrated parts that combine the functions of multiple components.

Central Gateways

Through the use of onboard computers (ECU) with "cooperative control", it has become possible to achieve unusually high levels of control over a car. With ECUs communicating in parallel to achieve this cooperative control,  the design of the onboard network has become highly important. Gateway Unit, as a part of the onboard network, has responsibility for relaying communications through focusing on complex cooperative control.

Properties of Sumitomo Wiring System, Ltd. Gateway Unit

Our gateway for vehicles has been developed and mass produced for more than 10 years, and we achieved to reduce thickness and weight of the product at the highest level. Having over 50 types of gateway-installed cars, we support the in-vehicle network infrastructure of recent years.


We have various channels such as the CAN (Controller Area Network) installed in many cars, and control the relay between the channels. It is manufactured to have the best component and software structure so any relays will not be leaked or communications to be delayed, since it relays the communications that control the whole vehicle.

Body ECUs

"Door Lock, Keyless Entry, Head Lamp, Room Lamp, and others are a part of the electrical unit which controls the functions that are active inside the car. You can customize the controlling system depending on the model of car."


It is possible to offer products (such as Junction BOX and PKE function integration for customer needs) based on various system configurations, which adapt to the structure changes based upon function.* The PKE function system integration ECU can start the engine and lock/unlock the door while the remote control is inside a pocket, bag, etc.


PKE function and system integrated product

Integration of the Body ECU to the PKE function used in conventional products.

・Ensures security and space saving through dual microcomputers
・Space Saving
・Cost reduction
・Reducing harness

Junction Box integrated product

Integrate by installing the body ECU to the junction box

・Reducing harness
・Reducing cost
・Improving the efficiency of circuit wiring

JBs(Junction Blocks)

Through incorporating parts such as relays and fuses, and by means of parts with electrical circuit integrated connection function, it provide total support to electronics control.


We aim for easily manufactured structure by modulizing components of the junction box.  The high quality junction box will be globally offered as part of the process of commonalizing vehicle components.


With the recent trend towards requiring more systems and feature for vehicles, demand for low fuel consumption and weight reduction has been increasing.  As functions required for the junction box have been increasing, weight reduction is achieved by employing the substrate for the wiring material to conduct high-density routing of the required circuit.

RBs(Relay Boxes)

We have reduced the thickness and weight of the relay box that is to be installed in the engine room, by developing a semiconductor relay module by means of the semiconductor switch which enables the relay and the FUSE function.


We are contributing to weight and thickness reduction of the electrical wires connecting to the relay box, by 50% in volume and 60% in weight in comparison with the conventional product, by converting the relays and FUSE functions into semiconductors.


The FUSE function has a control algorithm unique to the Sumitomo Wiring Systems Group, by which an exclusive custom IC automatically calculates the increase in temperature of the wires by the electricity running in the semiconductor switch, and also shuts off the electricity before it emits smoke. 

Compact And Lightweight Intelligent Power Distribution Module

Product for controlling startup of engine, headlamp relay, and wiper relay


Compact and light-weight product with interior LAN (CAN) connection function designed to make the engine compartment compact, reduce weight of the vehicle, and simplify the harness system.


・Covering to protect the part connected to wiring harnesses, and the main body
・Reducing weight through power distribution by eliminating bus bar
・Miniaturizing the structure by mounting terminals, relays and surface mounting components on the same substrate
 (compared to our old product : reduced by 20%)