2008 Lexus SC 430FACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. CHECK FOR DTC 
    1. Operate the driver door power window. Check if any DTC is output.

      Result 

      RESULT REFERENCE CHART

      Result Proceed to
      No DTC is output A
      DTC is output B

    B: GO TO DTC CHART 

    A: Go to Next Step 

  2. READ VALUE OF TECHSTREAM (POWER WINDOW SWITCH) 
    1. Check the Data List for proper functioning of the power window switch.

      Multiplex network door ECU front LH (driver door ECU) 

      ITEM MEASUREMENT NORMAL CONDITION CHART

      Item Measurement Item / Display (Range) Normal Condition Diagnostic Note
      P/W AUTO SW Driver door power window AUTO switch ON / OFF ON: Driver door power window
      AUTO switch operates
      OFF: Driver door power window
      AUTO switch does not operate
      -

      OK: ON (switch is operated) appears on screen. 

    NG: Go to step  4

    OK: Go to Next Step 

  3. PERFORM ACTIVE TEST BY TECHSTREAM (POWER WINDOW UP / DOWN) 
    1. Select the Active Test, use the Techstream to generate a control command, and then check the power window.

      Multiplex network door ECU front LH (driver door ECU) 

      MULTIPLEX NETWORK DOOR ECU FRONT LH (DRIVER DOOR ECU)

      Item Test Details Diagnostic Note
      P/W UP/DOWN Power Window UP/DOWN -

      OK: ON (power window is operating) appears on screen. 

      CAUTION: This test causes vehicle parts to move. Please watch your hands.

    NG: Go to step  6

    OK: REPLACE MULTIPLEX NETWORK DOOR ECU FRONT LH 

  4. INSPECT POWER WINDOW REGULATOR MASTER SWITCH ASSEMBLY 
    1. Remove the switch.
    2. Measure the resistance of the switch when the switch is operated.
      Fig 1: Identifying Power Window Regulator Master Switch Assembly Connector Terminals
      G05293438Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance: 

      for Driver switch 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Switch Condition Specified Condition
      6 (PW) - 16 (AUTO) AUTO UP Below 50 Ω
      6 (PW) - 20 (DUP)
      6 (PW) - 20 (DUP) UP Below 50 Ω
      - OFF -
      6 (PW) - 11 (DDN) DOWN Below 10 Ω
      6 (PW) - 16 (AUTO) AUTO DOWN Below 10 Ω
      6 (PW) - 11 (DDN) Below 50 Ω

    NG: REPLACE POWER WINDOW REGULATOR MASTER SWITCH ASSEMBLY 

    OK: Go to Next Step 

  5. CHECK WIRE HARNESS (MASTER SWITCH - DOOR ECU FRONT LH) 
    Fig 2: Identifying P14 And D17 Connector Terminals
    G05293439Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the P14 switch connector.
    2. Disconnect the D17 ECU connector.
    3. Measure the resistance of the wire harness side connectors.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      P14-6 (PW) - D17-21 (PWS) Below 1 Ω
      P14-10 (E) - D17-29 (PWE) Below 1 Ω
      P14-16 (AUTO) - D17-2 (AUTO) Below 1 Ω
      P14-20 (DUP) - D17-23 (MUP) Below 1 Ω
      P14-11 (DDN) - D17-25 (MDN) Below 1 Ω
      P14-6 (PW) or D17-21 (PWS) - Body ground 10 kΩ or higher
      P14-10 (E) or D17-29 (PWE) - Body ground 10 kΩ or higher
      P14-16 (AUTO) or D17-2 (AUTO) -Body ground 10 kΩ or higher
      P14-20 (DUP) or D17-23 (MUP) - Body ground 10 kΩ or higher
      P14-11 (DDN) or D17-25 (MDN) - Body ground 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: Go to Next Step 

  6. INSPECT FRONT POWER WINDOW REGULATOR MOTOR ASSEMBLY LH 
    1. Remove the motor.
    2. Inspect the operation of the power window regulator motor (for driver side door).
      Fig 3: Identifying Operation Of Power Window Regulator Motor (For Driver Side Door)
      G05293440Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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