Construction And Operation System Description

The vehicle ECUs on the BEAN on the control the systems described below.

Fig 1: Construction & Operation System Description General Table (1 Of 2)

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Fig 2: Construction & Operation System Description General Table (2 Of 2)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

• The network gateway ECU'S function to relay the signals that are exchanged among the buses (Door Bus, Instrument Panel Bus, and Light Bus), the AVC-LAN, and the diagnosis system. It carries out an integrated management of these communication functions.
• If a malfunction occurs in BEAN communication, DTCs (Diagnostic Trouble Codes) are stored in its memory.
  Fig 3: Gateway ECU Networking Wiring Diagram

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

• Even if a malfunction occurs in another bus or in the network gateway ECU, the basis controls within the same bus will still function.
• Because the communication line of the BEAN forms a loop, communication remains intact even if an open circuit occurs in one area.
• To protect lighting operations when a malfunction disrupts communication, a back-up bus is provided.
• To ensure low-beam headlight and wiper HI operations, a fail-safe line is provided.
  Fig 4: Fail-Safe System Diagram

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

• If a malfunction occurs in the BEAN communication, the network gateway ECU stores DTCs in its memory.
• The DTCs can be read by connecting a hand-held tester to the DLC3.
• The Active Test can be performed and the Data List can be monitored by connecting a hand-held tester to the DLC3 and establishing communication with the network gateway ECU.