page_title: IEBus
section_title: Automotive manufacturers using IEBus
hierarchical_section_title: IEBus / Automotive manufacturers using IEBus
caption_attribution_description: English: Wire harness for adapting speaker wires in car audio to an aftermarket head unit. Русский: Связка проводов для подключения автомобильной аудиосистемы.
context_page_description: IEBus is a communication bus specification "between equipments within a vehicle or a chassis" of Renesas Electronics. It defines OSI model layer 1 and layer 2 specification. IEBus is mainly used for car audio and car navigations, which established de facto standard in Japan, though SAE J1850 is major in United States.
  IEBus is also used in some vending machines, which major customer is Fuji Electric.
  Each button on the vending machine has an IEBus ID, i.e. has a controller.
  Detailed specification is disclosed to licensees only, but protocol analyzers are provided from some test equipment vendors.
  Its modulation method is PWM with 6.00 MHz base clock originally, but most of automotive customers use 6.291 MHz, and physical layer is a pair of differential signalling harness. Its physical layer adopts half-duplex, asynchronous, and multi-master communication with CSMA/CD for access control. It allows for up to fifty units on one bus over a maximum length of 150 meters. Two differential signalling lines are used with Bus+ / Bus− naming, sometimes labeled as Data / Data.
  It is sometimes described as "IE-BUS", "IE-Bus," or "IE Bus," but these are incorrect. In formal, it is "IEBus."
context_section_description: Each manufacturer has its own name, but it is not an alias of IEBus. Those are specifications of wire harness which comprise control cables based on IEBus, OSI model layer 3 and above communication protocol, audio cables, interconnection couplers, and so on.
caption: A wire harness for a car audio headunit
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