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Home › Lexus › 2007 › GS 430 › Repair and Diagnosis › Accessories & Equipment › Headlights › Lighting › System Description › Back-up Light Circuit › Inspection Procedure

Inspection Procedure

  1. PERFORM ACTIVE TEST BY INTELLIGENT TESTER 
    1. Select the ACTIVE TEST, use the intelligent tester to generate a control command, and then check that the back-up light illuminates.

      Multiplex network rear ECU 

      ACTIVE TEST DETAIL - MULTIPLEX NETWORK REAR ECU

      Item Test Details Diagnostic Note
      BACK-UP LIGHT Back-up light ON / OFF -

      OK: 

      Back-up light illuminates. 

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

    NG: Go to next step 

  2. READ VALUE OF INTELLIGENT TESTER 
    1. Check the DATA LIST for proper functioning of the park / neutral position switch.

    Multiplex network rear ECU 

    DATA LIST - MULTIPLEX NETWORK REAR ECU

    Item Measurement Item / Display (Range) Normal Condition Diagnostic Note
    SHIFT POSTION-R Transmission position R signal / ON or OFF ON: Shift position is R
    OFF: Shift position is not R    		 -

    OK: Go to step 3 

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

  3. REPLACE BACK-UP LIGHT BULB 
    1. Temporarily replace the back-up light bulb with a new or normally functioning one.
    2. Check that light bulb illuminates.

      OK: 

      Back-up light bulb illuminates. 

    OK: END 

    NG: Go to next step 

  4. CHECK WIRE HARNESS (NO. 1 JUNCTION BLOCK - REAR COMBINATION LIGHT (BACK-UP LH OR BACK-UP RH) - BODY GROUND) 
    1. Check the wire harness between the rear combination light (back-up LH) and No. 1 junction block, and the rear combination light (back-up LH) and body ground.
      1. Disconnect the Y2 light connector.
      2. Disconnect the LA junction block connector.
      3. Measure the resistance of the wire harness side connectors.

        Standard resistance 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        LA-2 (BCK1) - Y2-1 Below 1 Ω
        LA-2 (BCK1) or Y2-1 - Body ground 10 kΩ or higher
      4. Connect the LA junction block connector.
      5. Measure the resistance of the wire harness side connector.

        Standard resistance 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Y2-4 - Body ground Below 1 Ω
      Fig 1: Identifying Y2 Light Connector And LA Junction Block Connector
      G05298853Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the wire harness between the rear combination light (back-up RH) and No. 1 junction block, and the rear combination light (back-up RH) and body ground.
      1. Disconnect the Y9 light connector.
      2. Disconnect the LA junction block connector.
      3. Measure the resistance of the wire harness side connectors.

        Standard resistance 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        LA-2 (BCK1) - Y9-1 Below 1 Ω
        LA-2 (BCK1) or Y9-1 - Body ground 10 kΩ or higher
      4. Connect the LA junction block connector.
      5. Measure the resistance of the wire harness side connector.

        Standard resistance 

        RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Y9-4 - Body ground Below 1 Ω
    Fig 2: Identifying Y9 Light Connector And LA Junction Block Connector
    G05298854Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

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

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