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

WARNING: This page is about a different car, the 2005 Infiniti FX45 and 2005 Infiniti FX35. However, it is still accessible from the selected car via links, so may be relevant.

CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect display connector and display control unit connector.
3. Check continuity between display control unit and Display.
  
  Fig 1: Terminal Continuity Specification
  Courtesy of NISSAN MOTOR CO., U.S.A.
4. Check continuity between display control unit and ground.
  
  Fig 2: Checking Continuity Between Display Control Unit And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 3: Terminal Continuity Specification
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : GO TO 2.
2. NG : Repair harness or connector.
CHECK 1: COMMUNICATION SIGNAL (DCU-DSP)
1. Connect display connector.
2. Turn ignition switch ON.
3. Check voltage between display control unit harness connector M76 terminal 36 (PU) and ground.
  1. Approx. 4.2V
OK or NG
1. OK : GO TO 3.
2. NG : Replace display control unit.
Fig 4: Checking Voltage Between Display Control Unit Harness Connector M76 Terminal 36 (PU) And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK 2: COMMUNICATION SIGNAL (DSP-DCU)
1. Turn ignition switch OFF.
2. Disconnect display connector.
3. Connect display control unit connector.
4. Turn ignition switch ON.
5. Check voltage between display control unit harness connector M76 terminal 38 (LG) and ground.
  1. Approx. 4.2V
Fig 5: Checking Voltage Between Display Control Unit Harness Connector M76 Terminal 38 (LG) And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK : GO TO 4.
2. NG : Replace display control unit.
CHECK 3: COMMUNICATION SIGNAL (DCU-DSP)
1. Turn ignition switch OFF.
2. Connect display connector.
3. Turn ignition switch ON.
4. Check signal between display control unit harness connector M76 terminal 36 (PU) and ground with CONSULT-II or oscilloscope.
  1. 36 (PU) - Ground : Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
Fig 6: Checking Signal Between Display Control Unit Harness Connector M76 Terminal 36 (PU) And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK : GO TO 5.
2. NG : Replace display control unit.
CHECK 4: COMMUNICATION SIGNAL (DSP-DCU)
Check signal between display control unit harness connector M76 terminal 38 (LG) and ground with CONSULT-II or oscilloscope.
1. 38 (LG) - Ground : Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
OK or NG
1. OK : Replace display control unit.
2. NG : Replace display.
Fig 7: Checking Signal Between Display Control Unit Harness Connector M76 Terminal 38 (LG) And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.