2008 Lexus LX 570FACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. CHECK LIN COMMUNICATION SYSTEM 
    1. Check for LIN communication system DTCs related to the power window control system (See DTC CHECK / CLEAR ).

      OK: LIN communication system DTCs are not output. 

    NG: GO TO LIN COMMUNICATION SYSTEM  (See DIAGNOSTIC TROUBLE CODE CHART )

    OK: Go to next step 

  2. CHECK FOR DTC (B2312) 
    1. Check if DTC B2312 is output (See DTC CHECK / CLEAR  ).

      OK: DTC B2312 is not output. 

    NG: GO TO DTC B2312  (See DTC B2312 POWER WINDOW SWITCH MALFUNCTION  )

    OK: Go to next step 

  3. READ VALUE USING TECHSTREAM (FRONT POWER WINDOW REGULATOR MOTOR LH) 
    1. Use the Data List to check if the power window regulator motor is functioning properly (See DATA LIST / ACTIVE TEST  ).

      D-Door Motor 

      ITEM RANGE REFERENCE

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      D Door P/W Up SW Driver side power window manual up signal / ON or OFF ON: Driver side power window manual up switch operated
      OFF: Driver side power window switch not operated      		 -
      D Door P/W Down SW Driver side power window manual down signal / ON or OFF ON: Driver side power window manual down switch operated
      OFF: Driver side power window switch not operated      		 -

      OK: Techstream display changes according to operation of multiplex network master switch. 

    NG: Go to step 4 

    OK: REPLACE FRONT POWER WINDOW REGULATOR MOTOR ASSEMBLY LH  (See REMOVAL  )

  4. CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK MASTER SWITCH - BATTERY AND BODY GROUND) 
    1. Disconnect the I11 switch connector.
    2. Measure the voltage and resistance according to the value (s) in the table below.

      Standard Voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      I11-11 (B) - Body ground Always 11 to 14 V

      Standard Resistance 

      RESISTANCE REFERENCE

      Tester Connection Condition Specified Condition
      I11-12 (GND) - Body ground Always Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 1: Identifying I11 Connector Terminal
    G05636313Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  5. CHECK HARNESS AND CONNECTOR (FRONT POWER WINDOW REGULATOR MOTOR LH - BATTERY AND BODY GROUND) 
    1. Disconnect the I12 motor connector.
    2. Measure the voltage and resistance according to the value (s) in the table below.

      Standard Voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      I12-2 (B) - Body ground Always 11 to 14 V

      Standard Resistance 

      RESISTANCE REFERENCE

      Tester Connection Condition Specified Condition
      I12-1 (GND) - Body ground Always Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 2: Identifying I12 Connector Terminal
    G05636314Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  6. CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK MASTER SWITCH - FRONT POWER WINDOW REGULATOR MOTOR LH) 
    1. Disconnect the I11 switch connector.
    2. Disconnect the I12 motor connector.
    3. Measure the resistance according to the value (s) in the table below.

      Standard Resistance 

      RESISTANCE REFERENCE

      Tester Connection Condition Specified Condition
      I11-20 (UP) - I12-10 (UP) Always Below 1 Ω
      I11-15 (DOWN) - I12-7 (DOWN) Always Below 1 Ω
      I11-20 (UP) or I12-10 (UP) - Body ground Always 10 kΩ or higher
      I11-15 (DOWN) or I12-7 (DOWN) - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 3: Identifying I12 And I11 Connector Terminal
    G05636303Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  7. INSPECT FRONT POWER WINDOW REGULATOR MOTOR LH 
    1. Remove the motor (See REMOVAL  ).
    2. Apply positive (+) battery voltage to connector terminal 2 (B).
      NOTE:
      • Do not apply positive (+) battery voltage to any terminals, except terminal 2 (B), to avoid damaging the pulse sensor inside the motor.
      • Reset the power window regulator motor (initialize the pulse sensor) after installing the power window regulator motor and regulator assembly onto the door.
    3. Apply negative (-) battery voltage to connector terminals 1 (GND), and 7 (DOWN) or 10 (UP).
    4. Check that the motor gear rotates smoothly as follows.
      Fig 4: Inspecting Front Power Window Regulator Motor LH
      G05636316Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK 

      CONDITION CHART

      Measurement Condition Specified Condition
      1. Connect the positive (+) battery cable to terminal 2 (B), and connect the negative (-) battery cable to terminal 1 (GND), and keep them connected for 3 seconds or more.
      2. With terminals 2 (B) and 1 (GND) connected, connect the negative (-) battery cable to terminal 10 (UP).
      3. Disconnect and reconnect the negative (-) battery cable to terminal 10 (UP) within 1 second.
      		 Motor gear rotates clockwise (Up)
      1. Connect the positive (+) battery cable to terminal 2 (B), and connect the negative (-) battery cable to terminal 1 (GND), and keep them connected for 3 seconds or more.
      2. With terminals 2 (B) and 1 (GND) connected, connect the negative (-) battery cable to terminal 7 (DOWN).
      3. Disconnect and reconnect the negative (-) battery cable to terminal 7 (DOWN) within 1 second.
      		 Motor gear rotates counterclockwise (Down)

    NG: REPLACE FRONT POWER WINDOW REGULATOR MOTOR ASSEMBLY LH  (See REMOVAL  )

    OK: REPLACE MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY  (See REMOVAL  )

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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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