Sumitomo Wiring Systems, Ltd.

Company Profile



5-28, Hamadacho, Yokkaichi-shi, Mie-ken, 510-8528 Japan

Business Overview

-A wholly owned subsidiary of Sumitomo Electric Industries, engaged in the manufacturing and sales of automotive wire harnesses.

-The Sumitomo Group conducts its wire harness business at the following companies:

Company Scope of business
Sumitomo Electric Industries Ltd. Business Strategy and Sales
Sumitomo Wiring Systems, Ltd. Development, Design and Manufacturing
Autonetworks Technologies, Ltd. Research and Development


-Unlisted company
Name or Company Name Investment ratio (%)
Sumitomo Electric Industries Ltd. 100.0


Wiring harnesses for automobiles
-Aluminum wiring harnesses
-Harnesses for sliding doors
-EPB Harness Integrated with Wheel Speed Sensor

Wiring harness components

  • Sealed connectors
  • High-frequency connectors
  • Sealed connector for Engine ECU

-Electric wires

  • High-Voltage Wires
  • Shielded Cables
  • Aluminum wires

-Exterior equipments

  • Sound Absorbing Part
  • Grommets

Products for Electric Vehicles, Hybrid Vehicles, Plug-in Hybrid Vehicles
-Under-floor pipe harnesses
-Charger connectors
-Battery Wire Module
-Power Supply BOX
-Terminal Block ,Power Cable
-Charging-Discharging Controller for System
-High-Voltage Connectors

Electronics components
-Electronics Control Unit
-Junction blocks
-Relay boxes
-Power distributors


Feb. 1917 Tokai Densen Seizosyo was established to manufacture and sell sheathed electric wires.
Dec. 1917 Tokai Densen Seizosyo was transformed into a publicly-traded company named Tokai Densen K.K., headquartered in Yokkaichi City, Mie Pref.
July, 1932 Established technical and equity tie-ups with Sumitomo Electric Industries
July, 1959 Started wiring harness business.
July, 1965 Established the Sayama Plant in Sayama, Saitama Pref.
Feb. 1967 Completed a 50-50 merger with Izumi Densen Co., Ltd. (Osaka). Tokai Densen Co., Ltd. became the surviving company.  Named Izumi Densen's headquarters plant Sakai Seisakusho.
Established Suzuka Seisakusho in Suzuka, Mie Pref.
Established the Tokyo branch in Minato-ku, Tokyo.
Established the Osaka branch in Osaka.
Mar. 1969 Established Toyo Harness Co., Ltd. a wire harness manufacturing company, in Yokkaichi, Mie Pref. (currently headquarters is located in Matsusakashi, Mie Pref.)
Mar. 1970 Transferred Sakai Seisakusho to Izumishi, Osaka, and renamed it as Osaka Seisakusho.
Dec. 1972 Established the Yuuki Plant in Yuuki, Ibaraki Pref.
Feb. 1973 Established the Shiga Plant in Kousei-cho, Kouka-gun, Shiga Pref.
Jun. 1973 Established Hokuriku Harness Co., Ltd., a wire harness manufacturing company, in Kanazawa, Ishikawa Pref.
Sep. 1973 Established the Nagoya branch  (currently the Nagoya office) in Nagoya.
Apr. 1975 Established the Hokuriku Sales Office in Kanazawa, Ishikawa Pref.
Feb. 1980 Established Tohoku Harness Co., Ltd. (currently Tohoku SWS, a wire harness manufacturing company, in Iwate, Iwate Pref.
Mar. 1980 Bought into YAMAPlA (currently Sumidenso Pla-tech), a harness parts manufacturing and sales company in Gotenbashi, Shizuoka Pref.
Apr. 1984 Completed construction of the headquarters office.
Aug. 1984 Established the Yokkaichi Distribution Center in Yokkaichi, Mie Pref.
Nov. 1984 Established the Yachiyo office in Yachiyomachi, Yuukigun, Ibaraki Pref.
Apr. 1985 Changed Company name from Tokai Densen Co., Ltd. to Sumitomo Wiring Systems, Ltd.
Nov. 1986 Listed on the Second Section of the Nagoya Stock Exchange.
Sep. 1988 Established Sumitomo Wiring Systems (USA) Inc., a wire harness sales company in the US.
Nov. 1989 Established Sumitomo Wiring Systems Europe Limited, a wire harness sales company in the UK.
Apr. 1990 Established Yamagata Sumidensei Co., Ltd., a wire harness manufacturing company, in Nanyoushi, Yamagata Pref.
Aug. 1990 Established Sumitomo Densei Computer System Co, Ltd., a software company, in Yokkaichi, Mie Pref.
Oct. 1990 Established International Wiring Systems (Philippines) Corporation, a wire harness manufacturing and sales company in the Philippines.
Nov. 1990 Established Kyushu Sumidensei Co., Ltd. a wire harness manufacturing company in Hitashi, Oita Pref.
Nov. 1990 Established the Misono office in Suzukashi, Mie Pref.
Dec. 1990 Established P.T. Sumitomo Wiring Systems Batam Indonesia, a wire harness manufacturing company in Indonesia.
Sep. 1994 Established Sumidenso Logistics Network Co., Ltd., a delivery services company in Yokkaichi, Mie Pref.

Jul. 1995

Established Huizhou Zhurun Wiring Systems Co., Ltd.. in China to manufacture wiring harnesses.
Feb. 1996 Established Sumi Motherson Innovative Engineering, Ltd. in India to manufacture and sell components.
Mar. 1997 Established a holding company, SWS India Holdings Ltd. in India.
Jul. 1998 Established Sumidenso do Brasil Industrias Eletricas Ltda in Brazil to manufacture and sell wiring harnesses.
Sep. 1999 Established SWS America, Inc. in the U.S. to provide loan, investment, and fund management services for the group companies.
Oct. 2000 Developed the IEEE1394-Ready, the world's highest speed in-vehicle fiber optic link. IEEE1394 is a leading candidate to become the standard interface for in-vehicle multimedia LANs and is expected to make possible "information sharing" between home and car. 
Dec. 2000 Established a joint venture company in the U.S. to manufacture wiring harnesses for automobile equipment with SWS America, Inc. and Sumidenso Logistics Network Co., Ltd.
Feb. 2001 Closed the Osaka Plant in Izumi City, Osaka.
Jul. 2002 Acquired shares of Kyohritsu Hiparts Co., Ltd. in Saitama-city, Saitama prefecture.
Feb. 2003 Established Sumidenso Administration and Finance (Europe) B.V. in Holland.
Mar. 2003 Closed down the Shiga plant (Koga-gun, Shiga prefecture).
Apr. 2003 Toyo Harness, Ltd.,; Tohoku Sumidenso, Ltd.; and Kyushu Sumidenso, Ltd. were merged into Gifu Harness, Ltd.,; Shinshu Harness Ltd.; and Chugoku Harness Ltd. respectively.
May 2003 Subsidiary companies in India, Sumi Motherson Innovative Engineering Limited and Sumi Motherson Integrated Technologies Limited were merged into SWS India Holdings Limited, which changed its name to Sumi Motherson Innovative Engineering Limited.
Jul. 2004 The company's wiring business withdrew from the electric power-line business to specialize in wiring for automotive applications.
Feb. 2005 Opened its Tokyo headquarters in Minato Ward.

Apr. 2005

Established Huizhou Zhurun Automotive Wire Co., Ltd. to manufacture and sell wire harnesses in China. 
May, 2005 Established Fuzhou Zhu Wiring Systems Co., Ltd. to manufacture wire harnesses in China
Oct. 2005 Merged Tohoku Sumidenso Ltd. and Yamagata Sumidenso Ltd. The surviving company was named Tohoku Sumideonso Ltd.
Mar. 2006 Acquired Volkswagen Bordnetze in Germany
May 2006 Completed the technical center at the Yokkaichi Headquarters
Sep. 2006 Closed Kanto Sesakusyo in Yuki-City, Ibaraki Pref.
Aug. 2007 Delisted stocks from the Nagoya Stock Exchange through a stock swap with Sumitomo Electric Industries, Ltd.
Jul. 2008 Established SE Wiring System Egypt S.A.E. in Egypt.
Sep. 2008 Established SE Bordnetze Tunisia S.A.R.L. in Tunisia.
Jun. 2009 Moved its Tokyo headquarters to Shibaura.
Nov. 2010 Developed a low-voltage automotive harness, in which aluminum wires are used.
2012 Established Sumi-Rema EV Solutions, a joint-venture company, together with Sumitomo Electric Industries and Rema, a German company engaged in the business of charge connectors; to develop and design connectors for electric vehicles.
Jan. 2013 Moved its Tokyo headquarters to Akasaka.
May 2013 Moved its headquarters function to front of Yokkaichi Station on the Kintetsu Line.

Supplemental Information 1