NAVIGATION SYSTEM Mute Signal Circuit between Radio Receiver and Extension Module

DESCRIPTION

The circuit sends a signal to the navigation ECU to mute noise. Because of that, the noise produced by changing the sound source ceases.

If there is an open in the circuit, noise can be heard from the speakers when changing the sound source.

If there is a short in the circuit, even though the navigation ECU is functioning, no sound, or only an extremely faint sound, can be heard.

WIRING DIAGRAM

B0047TGE01
*a MUTE
*b Navigation ECU
*c Radio Receiver Assembly

PROCEDURE


  1. INSPECT NAVIGATION ECU


    1. B0047YYE01
      Text in Illustration
      *a

      Component with harness connected

      (Navigation ECU)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      z8-1 (MUTE) - Body ground Ignition switch ACC, audio system is playing → Changing modes Above 3.5 V → Below 1 V

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - NAVIGATION ECU)


    1. Disconnect the z9 radio and display receiver assembly connector.

    2. Disconnect the z8 navigation ECU connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      z9-6 (MUTE) - z8-1 (MUTE) Always Below 1 Ω
      z9-6 (MUTE) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY (OUTPUT SIGNAL)


    1. Disconnect the navigation ECU connector.

    2. B00456SE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Navigation ECU)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      z8-1 (MUTE) - Body ground Ignition switch ACC, audio system is playing → Changing modes Above 3.5 V

    OK

    REPLACE NAVIGATION ECU Click here

    NG

    REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY Click here