2003 Nissan-Datsun Sentra SE-R, StandardFACTORY OEM SERVICE PROCEDURE

Audio Communication Line Check

WARNING: This page is about a different car, the 2004 Nissan Murano. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK HARNESS 
    1. Turn ignition switch OFF.
    2. Disconnect audio unit connector and display unit connector.
    3. Check continuity between audio unit and display unit.
      CONTINUITY CHECK CHART

      Terminals Continuity
      Display unit Audio unit
      Connector Terminal (Wire color) Connector Terminal (Wire color)
      M39 8 (R/G) M46 23 (R/G) Yes
      10 (R/Y) 21 (R/Y)
      9 25
      Fig 1: Checking Continuity Between Audio Unit And Display Unit
      G03492442Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check continuity between display unit and ground.
      CONTINUITY CHECK CHART

      Terminals Continuity
      Display unit Ground
      Connector Terminal (Wire color)
      M39 8 (R/G) No
      10 (R/Y)
      Fig 2: Checking Continuity Between Display Unit And Ground
      G03492443Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    1. OK: GO TO 2.
    2. NG: Repair harness.
  2. CHECK AUDIO TX COMMUNICATION SIGNAL 
    1. Connect audio unit connector.
    2. Turn ignition switch ON.
    3. Check voltage between audio unit harness connector M46 terminal 23 (R/G) and ground.

      Approx. 4V 

      Fig 3: Checking Voltage Between Audio Unit Harness Connector And Ground
      G03492444Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    1. OK: GO TO 3.
    2. NG: Replace audio unit.
  3. CHECK AUDIO RX COMMUNICATION SIGNAL 
    1. Turn ignition switch OFF.
    2. Disconnect audio unit connector, and connect display unit connector.
    3. Turn ignition switch ON.
    4. Check voltage between display unit harness connector M39 terminal 10 (R/Y) and ground.

      Approx. 4V 

      Fig 4: Checking Voltage Between Display Unit Harness Connector And Ground
      G03492445Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    1. OK: GO TO 4.
    2. NG: Replace display unit.
  4. CHECK AUDIO TX COMMUNICATION SIGNAL 
    1. Turn ignition switch OFF.
    2. Connect audio unit connector.
    3. Turn ignition switch ON.
    4. Check the signal between display unit harness connector M39 terminal 8 (R/G) and ground with CONSULT-II or oscilloscope.

      8 (R/G) - Ground: Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY UNIT   ". 

      Fig 5: Checking Signal Between Display Unit Harness Connector And Ground
      G03492446Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    1. OK: GO TO 5.
    2. NG: Replace display unit.
  5. CHECK AUDIO RX COMMUNICATION SIGNAL 
    1. Turn ignition switch ON.
    2. Check the signal between display unit harness connector M39 terminal 10 (R/Y) and ground with CONSULT-II or oscilloscope.

      10 (R/Y) - Ground: Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY UNIT   ". 

      Fig 6: Checking Signal Between Display Unit Harness Connector And Ground
      G03492447Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    1. OK: INSPECTION END.
    2. NG: Replace audio unit.
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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.