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Diagnosis System

  1. DESCRIPTION 
    1. The door ECUs control the power window control system functions on the vehicle. Power window control system data and the Diagnostic Trouble Codes (DTCs) can be read through the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform repairs.
  2. CHECK DLC3 
    Fig 1: Identifying DLC3 Connector Terminal
    GTY155785Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT: 

    The vehicle uses ISO 9141-2 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

    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 10 to 14 V
    • 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 the Techstream to the DLC3, turn the ignition switch ON and attempt to use the Techstream. If the screen displays the message UNABLE TO CONNECT TO VEHICLE, there is a problem either with the vehicle or with the Techstream.

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