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

WARNING: This page is about a different car, the 2004 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.

CHECK HARNESS

Turn ignition switch OFF.
Disconnect display unit connector and display control unit connector.

Check continuity between display control unit and display unit.

DISPLAY CONTROL UNIT AND DISPLAY UNIT TERMINALS CONTINUITY

Terminals				Continuity
Display control unit		Display unit
Connector	Terminal (Wire color)	Connector	Terminal (Wire color)
M95	36 (B/W)	M93	11 (B/W)	Yes
	38 (L)		22 (L)

Check continuity between display control unit and ground.

DISPLAY CONTROL UNIT TERMINALS CONTINUITY

Terminals			Continuity
Display control unit		---
Connector	Terminal (Wire color)
M95	36 (B/W)	Ground	No
	38 (L)

Fig 1: Checking Continuity Between Display Control Unit And Display Unit Terminals

Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK : GO TO 2.
NG : Repair harness or connector.

CHECK 1: COMMUNICATION SIGNAL (DCU-DSP)
1. Connect display unit connector.
2. Turn ignition switch ON.
3. Check voltage between display unit harness connector M93 terminal 11 (B/W) and ground.
  Approx. 3.5 V or more.
  
  Fig 2: Checking Voltage Between Display Unit Harness Connector M93 Terminal 11 (B/W) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : GO TO 3.
2. NG : Replace display unit. Refer to , "REMOVAL AND INSTALLATION OF DISPLAY UNIT ".
CHECK 2: COMMUNICATION SIGNAL (DSP-DCU)
1. Turn ignition switch OFF.
2. Disconnect display control unit connector.
3. Connect display control unit connector.
4. Turn ignition switch ON.
5. Check voltage between display control unit harness connector M95 terminal 38 (L) and ground.
  Approx. 3.5 V or more.
  
  Fig 3: Checking Voltage Between Display Control Unit Harness Connector M95 Terminal 38 (L) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : GO TO 4.
2. NG : Replace display control unit. Refer to , "REMOVAL AND INSTALLATION OF DISPLAY CONTROL UNIT ".
CHECK 3: COMMUNICATION SIGNAL (DCU-DSP)
1. Turn ignition switch OFF.
2. Connect display unit connector.
3. Turn ignition switch ON.
4. Check signal between display control unit harness connector M95 terminal 36 (B/W) and ground with CONSULT-II or oscilloscope.
  36 (B/W) - Ground : Refer to , "TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
  
  Fig 4: Checking Signal Between Display Control Unit Harness Connector M95 Terminal 36 (B/W) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : GO TO 5.
2. NG : Replace display control unit. Refer to , "REMOVAL AND INSTALLATION OF DISPLAY CONTROL UNIT ".
CHECK 4: COMMUNICATION SIGNAL (DSP-DCU)
1. Turn ignition switch ON.
2. Check signal between display control unit harness connector M95 terminal 38 (L) and ground with CONSULT-II or oscilloscope.
  38 (L) - Ground : Refer to , "TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
  
  Fig 5: Checking Signal Between Display Control Unit Harness Connector M95 Terminal 38 (L) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : INSPECTION END.
2. NG : Replace display unit. Refer to , "REMOVAL AND INSTALLATION OF DISPLAY UNIT ".