AUDIO AND VISUAL SYSTEM Mute Signal Circuit between Radio Receiver and Multi-media Interface ECU

DESCRIPTION

The multi-media interface ECU sends a mute signal to the radio receiver.

The radio receiver controls the volume according to the mute signal from the multi-media interface ECU.

The mute signal is sent to reduce noise and popping sounds generated when switching modes.

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 radio receiver is functioning, no sound, or only an extremely faint sound, can be heard.

WIRING DIAGRAM

A017C9OE64

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT RADIO RECEIVER


    1. A017BFFE61
      Text in Illustration
      *a

      Component with harness connected

      (Radio Receiver)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E24-6 (MUTE) - Body ground Ignition switch ACC, USB audio system is playing → Changing modes Above 3.5 V → Below 1 V

    NG

    CHECK HARNESS AND CONNECTOR (RADIO RECEIVER - MULTI-MEDIA INTERFACE ECU) Click here

    OK

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

  2. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER - MULTI-MEDIA INTERFACE ECU)


    1. Disconnect the radio receiver and multi-media interface ECU connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E24-6 (MUTE) - E25-6 (MUT1) Always Below 1 Ω
      E24-6 (MUTE) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT MULTI-MEDIA INTERFACE ECU


    1. A017BFFE62
      Text in Illustration
      *a

      Component with harness connected

      (Multi-media Interface ECU)

      Reconnect the multi-media interface ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E25-6 (MUT1) - Body ground Ignition switch ACC Above 3.5 V

    NG

    REPLACE MULTI-MEDIA INTERFACE ECU Click here

    OK

    REPLACE RADIO RECEIVER Click here