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.

CHECK HARNESS

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

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

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

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

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

OK or NG

OK: GO TO 2.
NG: Repair harness.

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
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 3.
2. NG: Replace audio unit.
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
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 4.
2. NG: Replace display unit.
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
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 5.
2. NG: Replace display unit.
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
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: INSPECTION END.
2. NG: Replace audio unit.