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

WARNING: This page is about a different car, the 2006 Nissan Titan. 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

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.

CONTINUITY CONDITIONS

Terminals				Continuity
Display control unit		Audio unit
Connector	Terminal	Connector	Terminal
M95	40	M45	65	Yes
M95	42	M45	66	Yes

Check continuity between display control unit and ground.

CONTINUITY CONDITIONS

Terminals			Continuity
Display control unit		-
Connector	Terminal	-
M95	40	Ground	No
M95	42	Ground	No

Fig 1: Identifying Continuity Between Audio Unit And Display Control Unit Terminals And Ground

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 and ground.
  Approx. 3.5V or more.
OK or NG

OK : GO TO 4.

NG : Replace display control unit. Refer to "DISPLAY CONTROL UNIT ".

Fig 2: Identifying Voltage Between Display Control Unit Harness Connector M95 Terminal 42 And Ground
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 and ground.
  Approx. 3.5V or more.
OK or NG

OK : GO TO 5.

NG : Replace audio unit. Refer to "AUDIO UNIT ".

Fig 3: Identifying Voltage Between Audio Unit Harness Connector M45 Terminal 65 And Ground
CHECK 3: AUDIO-TX COMMUNICATION SIGNAL
Check signal between display control unit harness connector M95 terminal 40 and ground with CONSULT-II or oscilloscope.

40 - Ground : Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".

OK or NG

OK : GO TO 6.

NG : Replace display control unit. Refer to "DISPLAY CONTROL UNIT ".

Fig 4: Identifying Signal Between Display Control Unit Harness Connector M95 Terminal 40 And Ground
CHECK 4: AUDIO-RX COMMUNICATION SIGNAL
1. Turn ignition switch ON.
2. Check signal between display control unit harness connector M95 terminal 42 and ground with CONSULT-II or oscilloscope.
  42 - Ground : Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
OK or NG

OK : Inspection End.

NG : Replace audio unit. Refer to "AUDIO UNIT ".

Fig 5: Identifying Signal Between Display Control Unit Harness Connector M95 Terminal 42 And Ground