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Home >> Lexus >> 2007 >> LS 460L >> Repair and Diagnosis (Single Page) >> External Pages >> Different car >> Section 614 (Audio, Visual, Navigation System) >> Base Audio >> Component Diagnosis >> Microphone Signal Circuit >> Diagnosis Procedure
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Diagnosis Procedure

WARNING: This page is about a different car, the 2009 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK HARNESS BETWEEN BLUETOOTH CONTROL UNIT AND MICROPHONE
    1. Turn ignition switch OFF.
    2. Disconnect Bluetooth control unit connector and microphone connector.
    3. Check continuity between Bluetooth control unit harness connector B126 (A) and microphone harness connector R7 (B).
      CONNECTOR TERMINAL CONTINUITY CHART

      A B Continuity
      Connector Terminal Connector Terminal
      B126 7 R7 1 Yes
      8 2
      29 4
      Fig 1: Checking Continuity Between Bluetooth Control Unit Connector B126 And Microphone Harness Connector R7
      G05885687Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check continuity between Bluetooth control unit harness connector B126 (A) and ground.
    CONNECTOR TERMINAL CONTINUITY CHART

    A - Continuity
    Connector Terminal
    B126 7 Ground No
    8
    29

    Are the continuity test results as specified? 

    YES: GO TO 2.

    NO: Repair harness or connector.

  2. CHECK MICROPHONE POWER SUPPLY
    1. Connect Bluetooth control unit connector and microphone connector.
    2. Turn ignition switch ON.
    3. Check voltage between microphone harness connector R7 terminal 4 and ground.
    CONNECTOR TERMINAL VOLTAGE CHART

    (+) (-) Voltage (approx.)
    Connector Terminal
    R7 4 Ground 5V
    Fig 2: Checking Voltage Between Microphone Harness Connector R7 Terminal 4 And Ground
    G05885688Courtesy of NISSAN MOTOR CO., U.S.A.

    Is voltage reading approx. 5 volts? 

    YES: GO TO 3.

    NO: Replace Bluetooth control unit. Refer to "REMOVAL AND INSTALLATION ".

  3. CHECK MICROPHONE SIGNAL

    Check signal between Bluetooth control unit harness connector B126 terminals 7 and 8.

    CONNECTOR TERMINAL SIGNAL CHART

    Connector (+) (-) Reference signal
    Terminal Terminal
    B126 7 8 While talking into microphone
    G05885689Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 3: Checking Signal Between Bluetooth Control Unit Harness Connector B126 Terminals 7 And 8
    G05885690Courtesy of NISSAN MOTOR CO., U.S.A.

    Are voltage readings as specified? 

    YES: Replace Bluetooth control unit. Refer to "REMOVAL AND INSTALLATION ".

    NO: Replace microphone. Refer to "REMOVAL AND INSTALLATION ".