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Home › Lexus › 2008 › GS 450h › Repair and Diagnosis › Accessories & Equipment › Infotainment › Navigation › Navigation System › Microphone Circuit between Overhead Junction Block and Multi-display › Inspection Procedure

Inspection Procedure

  1. CHECK MULTI-DISPLAY 
    1. Check the waveform of the microphone using an oscilloscope.

      OK: 

      Waveform that matches sound spoken into microphone is output. 

      WAVEFORM REFERENCE

      Item Content
      Tester Connection K47-11 (MIN+) - K47-10 (MIN-)
      Tool Setting 0.2 V/DIV., 0.2 μs/DIV.
      Condition w/ LEXUS Link System:
      Power switch ON (ACC) and overhead junction block's "PHONE" button pressed
      w/o LEXUS Link System:
      Power switch is ON (ACC) and steering pad switch's "Voice" switch is pressed
      2. Fig 1: Identifying K47 Multi-Display Connector
      G05820058Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE MULTI-DISPLAY 

    NG: Go to Next Step 

  2. CHECK LEXUS LINK SYSTEM 
    1. Check if the vehicle is equipped with the LEXUS link system.

      Result: 

      RESULT REFERENCE

      Result Proceed to
      w/ LEXUS Link System A
      w/o LEXUS Link System B

    B:  Go to step  7

    A: Go to Next Step 

  3. CHECK WIRE HARNESS (MAYDAY ECU - OVERHEAD JUNCTION BLOCK AND MULTI-DISPLAY) 
    1. Disconnect the U45 ECU connector.
    2. Disconnect the W6 junction block connector.
    3. Disconnect the K47 display connector.
    4. Measure the resistance of the wire harness side connectors.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      U45-7 (MCVD) - W6-19 (ACC) Below 1 Ω
      U45-8 (MCI+) - W6-3 (MI1+) Below 1 Ω
      U45-9 (MCI-) - W6-2 (MIC-) Below 1 Ω
      U45-17 (MCO+) - K47-11 (MIN+) Below 1 Ω
      U45-18 (MCO-) - K47-10 (MIN-) Below 1 Ω
      U45-19 (SG) - Body ground 10 kΩ or higher
      U45-7 (MCVD) - Body ground 10 kΩ or higher
      U45-8 (MCI+) - Body ground 10 kΩ or higher
      U4S-9 (MCI-) - Body ground 10 kΩ or higher
      U4S-17 (MCO+) - Body ground 10 kΩ or higher
      U45-18 (MCO-) - Body ground 10 kΩ or higher
      5. Fig 2: Identifying U45 Mayday ECU, W6 Overhead Junction Block And K47 Multi-Display Connectors
      G05820059Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  4. CHECK MAYDAY ECU (MCVD VOLTAGE) 
    1. Reconnect the U45 ECU connector.
    2. Measure the voltage of the ECU.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      U45-7 (MCVD) - Body ground Power switch ON (ACC) 4 to 6V
      3. Fig 3: Identifying U45 Mayday ECU Connector
      G05820060Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE MAYDAY ECU 

    OK: Go to Next Step 

  5. CHECK MAYDAY ECU 
    1. Reconnect the W6 junction block connector.
    2. Check the waveform of the mayday ECU using an oscilloscope.

      OK: 

      Waveform that matches sound spoken into microphone is output. 

      WAVEFORM REFERENCE

      Item Content
      Tester Connection U45-8 (MCI+) - U45-9 (MCI-)
      Tool Setting 0.2 V/DIV., 0.2 μs/DIV.
      Condition Power switch ON (ACC) and overhead junction block's "PHONE" button pressed
      3. Fig 4: Identifying U45 Mayday ECU Connector
      G05820061Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE MAYDAY ECU 

    NG: Go to Next Step 

  6. CHECK MICROPHONE ASSEMBLY 
    1. Remove the microphone from the overhead junction block.
    2. Measure the resistance of the microphone.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      1 (MIC+) - 3 (MIC-) 1.9 to 2.2 kΩ
      3. Fig 5: Identifying Microphone Assembly Connector
      G05820062Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE MICROPHONE ASSEMBLY 

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

  7. CHECK WIRE HARNESS (OVERHEAD JUNCTION BLOCK - MULTI-DISPLAY) 
    1. Disconnect the W6 junction block connector.
    2. Disconnect the K47 display connector.
    3. Measure the resistance of the wire harness side connectors.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      K47-9 (MACC) - W6-19 (ACC) Below 1 Ω
      K47-11 (MIN+) - W6-3 (MI1+) Below 1 Ω
      K47-10 (MIN-) - W6-2 (MIC-) Below 1 Ω
      K47-9 (MACC) - Body ground 10 kΩ or higher
      K47-11 (MIN+) - Body ground 10 kΩ or higher
      K47-10 (MIN-) - Body ground 10 kΩ or higher
      4. Fig 6: Identifying W6 Junction Block And K47 Display Connectors
      G05820063Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  8. CHECK MULTI-DISPLAY (MACC VOLTAGE) 
    1. Reconnect the K47 display connector.
    2. Measure the voltage according to the value (s) in the table below.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      K47-9 (MACC) - Body ground Power switch ON (ACC) 4 to 6 V
      3. Fig 7: Identifying K47 Display Connector
      G05820064Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE MULTI-DISPLAY 

    OK: Go to Next Step 

  9. CHECK MICROPHONE ASSEMBLY 
    1. Remove the microphone from the overhead junction block.
    2. Measure the resistance of the microphone.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      1 (MIC+) - 3 (MIC-) 1.9 to 2.2 kΩ
      3. Fig 8: Identifying Microphone Assembly Connector
      G05820065Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE MICROPHONE ASSEMBLY 

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

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