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Diagnosis System

  1. DESCRIPTION 
    1. The driver side J/B ECU controls the function of the seat belt warning system on the vehicle. Data of the seat belt warning system can be read in the Data Link Connector 3 (DLC3) of the vehicle.

      When the system seems to be malfunctioning, use the hand-held tester to check for malfunctions and perform repairs.

  2. CHECK DLC3 

    HINT:

    The vehicle's ECU uses the ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.

    Fig 1: Identifying DLC3 Connector
    G03001913Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    TERMINAL DESCRIPTION CHART

    Symbols (Terminal No.) Terminal Description Condition Specified Condition
    SIL (7) - SG (5) Bus "+" line During transmission Pulse generation
    CG (4) - Body ground Chassis ground Always Below 1 Ω
    SG (5) - Body ground Signal ground Always Below 1 Ω
    BAT (16) - Body ground Battery positive Always 11 to 14V

    HINT:

    Connect the cable of the hand-held tester (with CAN VIM) to the DLC3, turn the ignition switch ON and attempt to use the hand-held tester. If the screen displays UNABLE TO CONNECT TO VEHICLE, a problem exists in the vehicle side or the tester side.

    • If communication is normal when the tester is connected to another vehicle, inspect the DLC3 on the original vehicle.
    • If communication is still impossible when the tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the taster's instruction manual.
      Fig 2: Connecting Cable Of Hand-Held Tester (With CAN VIM) To DLC3
      G03001914Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. INSPECT BATTERY VOLTAGE 
    1. Standard: 11 to 14 V 

    If voltage is below 11 V, recharge the battery before proceeding.