AUDIO AND VISUAL SYSTEM (w/o Navigation 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 assembly.

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

WIRING DIAGRAM

A0158QSE20

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT RADIO RECEIVER ASSEMBLY


    1. A0159C5E29
      Text in Illustration
      *1

      Component with harness connected

      (Radio Receiver Assembly)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      F55-6 (MUTE) - Body ground Engine switch on (ACC), USB audio system is playing → Mode is changing Above 2.5 V → Below 0.5 V

    NG

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


    1. Disconnect the F55 radio receiver assembly and L40 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
      F55-6 (MUTE) - L40-6 (MUTI) Always Below 1 Ω
      F55-6 (MUTE) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT MULTI-MEDIA INTERFACE ECU


    1. A0159C5E30
      Text in Illustration
      *1

      Component with harness connected

      (Multi-media Interface ECU)

      Reconnect the L40 multi-media interface ECU connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      L40-6 (MUTI) - Body ground Engine switch on (ACC) Above 2.5 V

    NG

    REPLACE MULTI-MEDIA INTERFACE ECU Click here

    OK

    REPLACE RADIO RECEIVER ASSEMBLY Click here