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Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus GX 470. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

Start the inspection from step  1 in the case of using the intelligent tester, and start from step  2 in the case of not using the intelligent tester.

  1. READ VALUE OF INTELLIGENT TESTER 
    1. Connect the intelligent tester to DLC3.
    2. Turn the ignition switch to ON and push the intelligent tester main switch ON.
    3. Select the items in the DATA LIST, and read the displays on the intelligent tester.

    Multiplex body ECU: 

    DATA LIST TABLE

    Item Measurement Item/Display (Range) Normal Condition Diagnostic Note
    AUTO LIGHT SW Head light control SW signal/ON or OFF ON: Light control switch is in AUTO position
    OFF: Light control switch is in except AUTO position    		 -
    HEAD LIGHT SW Head light control SW signal/ON or OFF ON: Light control switch is in HEAD position
    OFF: Light control switch is in except HEAD position    		 -
    TAIL LIGHT SW Taillight SW signal/ON or OFF ON: Light control switch is in TAIL or HEAD position
    OFF: Light control switch is in OFF position    		 -
    HIGH FLASHER SW Headlight dimmer SW signal/ON or OFF ON: Headlight dimmer switch is in FLASH position
    OFF: Headlight dimmer switch is in except FLASH position    		 -

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

    NG: Go to next step. 

  2. INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY (HEAD, TAIL, A) 
    1. Inspect the headlight dimmer switch continuity.
      1. Check continuity between terminals at each switch position as shown in the table.

        Standard resistance 

        TESTER CONNECTION SPECIFIED CONDITION TABLE

        Switch operation Tester connection Specified condition
        OFF - 10 kΩ or higher
        TAIL 14 - 16 Below 1 Ω
        HEAD 13 - 16 - 14 Below 1 Ω
        AUTO 16 - 12 Below 1 Ω
        FLASH 7 - 8 - 16 Below 1 Ω
        LOW BEAM 16 - 17 Below 1 Ω
        HI BEAM 7 - 16 Below 1 Ω
    Fig 1: Identifying Headlight Dimmer Switch Assembly Connector Terminals (HEAD, TAIL, A)
    G05243157Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY 

    OK: Go to next step. 

  3. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (HEAD, TAIL, A, HF) 
    1. Measure the voltage between terminal HEAD, TAIL, A and HF of the instrument panel J/B assembly (driver side J/B assembly) and body ground.
    Fig 2: Identifying Instrument Panel Junction Block Assembly Connector Terminals (HEAD, TAIL, A, HF)
    G05265724Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Standard voltage 

    TERMINAL SPECIFIED CONDITION

    Terminal No. (Symbols) Condition Specified Condition
    B5-1 - Body ground (HEAD Body ground) Turn IG switch ON 10 to 14 V
    B5-3 - Body ground (A - Body ground) Turn IG switch ON 10 to 14 V
    B5-8 - Body ground (TAIL - Body ground) Turn IG switch ON 10 to 14 V
    B5-7 - Body ground (HF - Body ground) Turn IG switch ON 10 to 14 V

    NG: CHECK AND REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

    OK: Go to next step. 

  4. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (HEAD, TAIL, A, HF) 
    1. Disconnect the connector from the instrument panel J/B assembly (driver side J/B assembly).
    2. Check continuity between terminal HEAD, TAIL, A and HF of the instrument panel J/B assembly (driver side J/B assembly) on the wire harness side and body ground.

      Standard resistance 

      TERMINAL SPECIFIED CONDITION

      Terminal No. (Symbols) Condition Specified Condition
      B5-1 - Body ground (HEAD - Body ground) Turn headlight dimmer switch OFF → HEAD 10 kΩ or higher → Below 1 Ω
      B5-3 - Body ground (A - Body ground) Turn headlight dimmer switch OFF → AUTO 10 kΩ or higher → Below 1 Ω
      B5-8 - Body ground (TAIL - Body ground) Turn headlight dimmer switch OFF → TAIL or HEAD 10 kΩ or higher → Below 1 Ω
      B5-7 - Body ground (HF - Body ground) Turn headlight dimmer switch LO → FLASH 10 kΩ or higher → Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

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