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

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

CHECK POWER SUPPLY AND GROUND CIRCUIT
Check power supply and ground circuit for audio unit. Refer to "POWER SUPPLY CIRCUIT INSPECTION ".

OK or NG
- OK: GO TO 2.
- NG: Check the malfunctioning parts.

CHECK HARNESS

Turn ignition switch OFF.
Disconnect audio unit connector M45 and display control unit connector M95.

Check continuity between audio unit and display control unit.

Fig 1: Checking Continuity Between Audio Unit & Display Control Unit

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

CONTINUITY BETWEEN AUDIO UNIT & DISPLAY CONTROL UNIT

Terminals				Continuity
Display control unit		Audio unit
Connector	Terminal (Wire color)	Connector	Terminal (Wire color)
M95	40 (O/L)	M45	65 (O/L)	Yes
M95	42 (W/L)	M45	66 (W/L)	Yes

Check continuity between display control unit and ground.

CONTINUITY BETWEEN DISPLAY CONTROL UNIT AND GROUND

Terminals			Continuity
Display control unit		-
Connector	Terminal (Wire color)	-
M95	40 (O/L)	Ground	No
M95	42 (W/L)	Ground	No

OK or NG

OK: GO TO 3.
NG: Repair harness or connector.

CHECK 1: AUDIO-TX COMMUNICATION SIGNAL
1. Connect display control unit connector.
2. Turn ignition switch ON.
3. Check voltage between display control unit harness connector M95 terminal 42 (W/L) and ground.
  Approx. 3.5V or more .
  
  Fig 2: Checking Voltage Between Display Control Unit Harness Connector M95 Terminal 42 (W/L) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: GO TO 4.
- 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 M45.
4. Turn ignition switch ON.
5. Check voltage between audio unit harness connector M45 terminal 65 (O/L) and ground.
  Approx. 3.5V or more .
  
  Fig 3: Checking Voltage Between Audio Unit Harness Connector M45 Terminal 65 (O/L) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: GO TO 5.
- 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 M95.
3. Turn ignition switch ON.
4. Check signal between display control unit harness connector M95 terminal 40 (O/L) and ground with CONSULT-II or oscilloscope.
  40 (O/L) - Ground: Refer to "TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
  
  Fig 4: Checking Signal Between Display Control Unit Harness Connector M95 Terminal 40 (O/L) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: GO TO 6.
- 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 (W/L) and ground with CONSULT-II or oscilloscope.
  42 (W/L) - Ground: Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
  
  Fig 5: Checking Signal Between Display Control Unit Harness Connector M95 Terminal 42 (W/L) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: Inspection End.
- NG: Replace audio unit. Refer to "REMOVAL AND INSTALLATION FOR AUDIO UNIT ".