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Home >> Infiniti >> 2011 >> M37 x >> Repair and Diagnosis >> External Pages >> Different car >> Section 10 (Audio, Visual & Navigation System) >> DTC/Circuit Diagnosis >> Composite Image Signal Circuit (Video Distributor To Headrest Display Unit) >> Diagnosis Procedure
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Diagnosis Procedure

WARNING: This page is about a different car, the 2011 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK CONTINUITY COMPOSITE IMAGE SIGNAL CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect video distributor connector and headrest display unit connector.
    3. Check continuity between video distributor harness connector and headrest display unit harness connector.
      CONTINUITY SPECIFICATION

      Video distributor Headrest display unit Continuity
      Connector Terminal Connector Terminal
      M217 32 B554(1) 24 Existed
      28 B574(2) 24 Existed
      (1) Headrest display unit LH
      (2) Headrest display unit RH
    4. Check continuity between headrest display unit harness connector and ground.
      CONTINUITY SPECIFICATION

      Headrest display unit Ground Continuity
      Connector Terminal
      B554(1) 24 Not existed
      B574(2) 24
      (1) Headrest display unit LH
      (2) Headrest display unit RH

      Is the inspection result normal? 

      YES: Go to 2.

      NO: Repair harness or connector.

  2. CHECK COMPOSITE IMAGE SIGNAL
    1. Connect video distributor connector and rear display unit connector.
    2. Turn ignition switch ON.
    3. Check signal between rear display unit harness connector using an oscilloscope.
      SIGNAL REFERENCE

      (+) (-) Condition Reference value
      Headrest display unit
      Connector Terminal
      B554(1) 24 Ground When DVD, USB or front AUX image is displayed on headrest display unit LH or RH.
      G04890020Courtesy of NISSAN MOTOR CO., U.S.A.
      B574(2) 24
      (1) Headrest display unit LH
      (2) Headrest display unit RH

      Is the inspection result normal? 

      YES: Replace headrest display unit. Refer to "EXPLODED VIEW ".

      NO: Replace video distributor. Refer to "REMOVAL AND INSTALLATION ".