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Diagnosis System

  1. DESCRIPTION 
    1. Push-button start function data and the Diagnostic Trouble Codes (DTCs) can be read through the Data Link Connector 3 (DLC3) of the vehicle. When the function seems to be malfunctioning, use Techstream to check for malfunctions and perform repairs.
  2. CHECK DLC3 

    HINT:

    The ECU uses 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 Terminals
    G04828034Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    TERMINAL DESCRIPTION SPECIFIED CONDITION CHART

    Symbols (Terminal No.) Terminal Description Condition Specified Condition
    CG (4) - Body ground Chassis ground Always Below 1 Ω
    SG (5) - Body ground Signal ground Always Below 1 Ω
    SIL (7) - SG (5) Bus "+" line During transmission Pulse generation
    BAT (16) - Body ground Battery positive Always 10 to 14 V
    CANH (6) - CANL (14) CAN bus line Engine Switch OFF(1) 56 to 69 Ω
    CANH (6) - CG (4) HIGH-level CAN bus line Engine Switch OFF(1) 200 Ω or more
    CANL (14) - CG (4) LOW-level CAN bus line Engine Switch OFF(1) 200 Ω or more
    CANH (6) - BAT (16) HIGH-level CAN bus line Engine Switch OFF(1) 6 kΩ or more
    CANL (14) - BAT (16) LOW-level CAN bus line Engine Switch OFF(1) 6 kΩ or more
    (1) Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the engine switch, any other switches or the doors.

    If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.

    HINT:

    Connect the cable of Techstream to the DLC3, turn the engine switch on (IG) and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.

    • If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
    • If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual.
  3. INSPECT BATTERY VOLTAGE 

    Standard voltage: 11 to 14 V 

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