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Home >> Infiniti >> 2011 >> M56 Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 249 (Audio, Visual & Navigation System (BOSE Audio With Navigation)) >> DTC/Circuit Diagnosis >> DTC U190C: Front/Rear Microphone >> Diagnosis Procedure
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Diagnosis Procedure

WARNING: This page is about a different car, the 2013 Infiniti M56 and 2013 Infiniti M37. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK ON BOARD SELF-DIAGNOSIS 

    Perform on board self-diagnosis. Refer to "ON BOARD DIAGNOSIS FUNCTION ".

    Is the inspection result normal? 

    YES: INSPECTION END

    NO: GO TO 2.

  2. CHECK CONTINUITY BETWEEN BOSE AMP. AND FRONT/REAR MICROPHONE CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect BOSE amp. connector and front/rear microphone connector.
    3. Check continuity between BOSE amp. harness connector and front/rear microphone harness connector.
      BOSE amp. Front microphone Continuity
      Connector Terminals Connector Terminals
      B43 72 R19 2 Existed
      52 1
      BOSE amp. Rear microphone Continuity
      Connector Terminals Connector Terminals
      B43 63 R21 2 Existed
      43 1
    4. Check continuity between BOSE amp. harness connector and ground.
      BOSE amp. Ground Continuity
      Connector Terminals
      B43 72 Not existed
      52
      63
      43

      Is the inspection result normal? 

      YES: GO TO 3.

      NO: Repair harness or connector.

  3. CHECK MICROPHONE SIGNAL 
    1. Connect BOSE amp. connector and front/rear microphone connector.
    2. Check signal between BOSE amp. harness connector.
      (+) (-) Condition Reference value
      BOSE amp. BOSE amp.
      Connector Terminal Connector Terminal
      B43 72 B43 52 When inputting interior sound.
      G08893443
      63 43 When inputting interior sound.
      G08893444

      Is the inspection result normal? 

      YES: Replace BOSE amp. Refer to "REMOVAL AND INSTALLATION ".

      NO: Replace front/rear microphone. Refer to "REMOVAL AND INSTALLATION " (front microphone), "REMOVAL AND INSTALLATION "(rear microphone).