NAVIGATION SYSTEM Mute Signal Circuit between Navigation Receiver Assembly and Stereo Component Amplifier

DESCRIPTION

This circuit sends a signal to the stereo component amplifier assembly to mute noise. Due to this, 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 stereo component amplifier assembly is functioning normally, no sound or only an extremely faint sound can be heard.

WIRING DIAGRAM

A005EA8E59
*a MUTE
*b Stereo Component Amplifier Assembly
*c Navigation ECU Sub-assembly

PROCEDURE


  1. INSPECT STEREO COMPONENT AMPLIFIER ASSEMBLY


    1. A005D3XE02
      Text in Illustration
      *a

      Component with harness connected

      (Stereo Component Amplifier Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L31-1 (MUTE) - Body ground

      Power switch on (ACC), audio system 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 (NAVIGATION ECU SUB-ASSEMBLY - STEREO COMPONENT AMPLIFIER ASSEMBLY)


    1. Disconnect the L38 navigation ECU sub-assembly connector.

    2. Disconnect the L31 stereo component amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L38-20 (MUT2) - L31-1 (MUTE) Always Below 1 Ω
      L38-20 (MUT2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT STEREO COMPONENT AMPLIFIER ASSEMBLY (OUTPUT SIGNAL)


    1. Reconnect the L31 stereo component amplifier assembly.

    2. A005C9XE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Navigation ECU Sub-assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L38-20 (MUT2) - Body ground Power switch on (ACC), audio system is playing Above 3.5 V

    OK

    REPLACE NAVIGATION ECU SUB-ASSEMBLY Click here

    NG

    REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY Click here