Audio Communication Line Check (Between Display Control Unit and Audio Unit)

WARNING: This page is about a different car, the 2005 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

CHECK POWER SUPPLY AND GROUND CIRCUIT
1. Check power supply and ground circuit for audio unit. Refer to "POWER SUPPLY CIRCUIT INSPECTION ".
OK or NG
1. OK: GO TO 2.
2. NG: Check the malfunctioning parts.
CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect audio unit connector M45 and display control unit connector M95.
3. Check continuity between audio unit and display control unit.
  
  Fig 1: Checking Continuity Between Audio Unit Terminal 65, 66 And Display Control Unit Terminals 40, 42 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 2: Connector Terminal (Wire Color) Specifications Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
4. Check continuity between display control unit and ground.
  
  Fig 3: Connector Terminal Continuity Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 3.
2. NG: Repair harness or connector.
CHECK 1: AUDIO-TX COMMUNICATION SIGNAL
1. Connect display control unit connector M95.
2. Turn ignition switch ON.
3. Check voltage between display control unit harness connector M95 terminal 42 (BR) and ground.
  
  Fig 4: Checking Voltage Between Display Control Unit Harness Connector M95 Terminal 42 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Approx. 3.5V or more.
OK or NG
1. OK: GO TO 4.
2. NG: Replace display control unit. Refer to "REMOVAL AND INSTALLATION OF DISPLAY CONTROL UNIT ".
CHECK 2: AUDIO-RX COMMUNICATION SIGNAL
1. Turn ignition switch OFF.
2. Disconnect display control unit connector M95.
3. Connect audio unit connector.
4. Turn ignition switch ON.
5. Check voltage between audio unit harness connector M45 terminal 65 (B/R) and ground.
  
  Fig 5: Checking Voltage Between Audio Unit Harness Connector M45 Terminal 65 (B/R) & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Approx. 3.5V or more.
OK or NG
1. OK: GO TO 5.
2. NG: Replace audio unit. Refer to "REMOVAL AND INSTALLATION FOR AUDIO UNIT ".
CHECK 3: AUDIO-TX COMMUNICATION SIGNAL
1. Turn ignition switch OFF.
2. Connect display control unit connector.
3. Turn ignition switch ON.
4. Check signal between display control unit harness connector M95 terminal 40 (B/R) and ground with CONSULT-II or oscilloscope.
  
  Fig 6: Checking Signal Between Display Control Unit Harness Connector M95 Terminal 40 (B/R) & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  40 (B/R) - Ground: Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
OK or NG
1. OK: GO TO 6.
2. NG: Replace display control unit. Refer to "REMOVAL AND INSTALLATION OF DISPLAY CONTROL UNIT ".
CHECK 4: AUDIO-RX COMMUNICATION SIGNAL
1. Turn ignition switch ON.
2. Check signal between display control unit harness connector M95 terminal 42 (BR) and ground with CONSULT-II or oscilloscope.
  
  Fig 7: Checking Signal Between Display Control Unit Harness Connector M95 Terminal 42 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  42 (BR) - Ground: Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
OK or NG
1. OK: Inspection End.
2. NG: Replace audio unit. Refer to "REMOVAL AND INSTALLATION FOR AUDIO UNIT ".