LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2007 >> SC 430 >> Repair and Diagnosis >> Body & Frame >> Windows >> Windshield/WINDOWGLASS >> Window Defogger System >> Diagnosis System
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis System

  1. DESCRIPTION 
    1. The rear window defogger system data and the Diagnostic Trouble Code (DTCs) can be read through the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the intelligent tester to check for malfunctions and perform repairs.
      Fig 1: Identifying DLC3 Connector Terminal
      G05293506Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. CHECK DLC3 

    HINT:

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

    ECU CONNECTOR TERMINAL SPECIFIED CONDITION

    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 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 intelligent tester to the DLC3, turn the ignition switch ON and attempt to use the tester. If the screen displays the message UNABLE TO CONNECT TO VEHICLE, 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.
      Fig 2: Identifying Data Link Connector DLC3
      G05293507Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002