Diagnosis Procedure

WARNING: This page is about a different car, the 2008 Infiniti M45 and 2008 Infiniti M35. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CONTINUITY BETWEEN AV CONTROL UNIT AND MICROPHONE CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect AV control unit connector and microphone connector.
3. Check continuity between AV control unit harness connector terminals 26, 27, 28 and microphone harness connector terminals 4, 2, 1.
  26 - 4: Continuity should exist.
  
  27 - 2: Continuity should exist.
  
  28 - 1: Continuity should exist.
4. Check continuity between AV control unit harness connector terminals 26, 28 and ground.
  26, 28 - Ground: Continuity should not exist.
Is the inspection result normal?

Yes: GO TO 2.

No: Repair harness or connector.
CHECK VOLTAGE MICROPHONE VCC
1. Connect AV control unit connector.
2. Turn ignition switch ON.
3. Check voltage between AV control unit harness connector terminals 26 and 27.
  26 - 27: Approx. 5 V
Is the inspection result normal?

Yes: GO TO 3.

No: Replace AV control unit.

CHECK MICROPHONE SIGNAL

Connect microphone connector.

Check signal between AV control unit harness connector terminals 28 and 27.

SIGNAL REFERENCE TABLE

Terminal	Condition		Reference value
28 - 27	Ignition switch ON	Give a voice.	Courtesy of NISSAN MOTOR CO., U.S.A.

Is the inspection result normal?

Yes: Replace AV control unit.

No: Replace microphone.