AUDIO AND VISUAL SYSTEM > Mute Signal Circuit between Radio Receiver and Stereo Component Amplifier

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DESCRIPTION

This circuit sends a signal to the stereo component amplifier 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 stereo component amplifier is normal, no sound, or only an extremely small sound, can be produced.

WIRING DIAGRAM


E110892E03


E110892E04


INSPECTION PROCEDURE

1.INSPECT STEREO COMPONENT AMPLIFIER


    E110893E04

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

    Standard voltage:
    Tester connection
    		Condition
    		Specified condition
    MUTE - Body ground
    		Turn ignition switch to ACC, Audio system is playing → Changing
    		Above 3.5 V → Below 1 V



NG
Go to step 2
OK

RETURN TO THE ORIGINAL INSPECTION FLOW BECAUSE THE CHECK RESULT IS NORMAL 

2.CHECK HARNESS AND CONNECTOR (RADIO RECEIVER - STEREO COMPONENT AMPLIFIER)


    E110933E02

  1. Disconnect the connectors from the radio receiver and stereo component amplifier.

  1. Measure the resistance according to the values in the table below.

    Standard resistance:
    Tester connection
    		Condition
    		Specified condition
    MUTE - MUTE
    		Always
    		Below 1 Ω
    MUTE - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT STEREO COMPONENT AMPLIFIER


    E110888E03

  1. Connect the connector to the radio receiver.

  1. Measure the voltage according to the value in the table below.

    Standard voltage:
    Tester connection
    		Condition
    		Specified condition
    MUTE - Body ground
    		Turn ignition switch to ACC
    		Above 3.5 V



OK
REPLACE STEREO COMPONENT AMPLIFIER (STANDARD SYSTEM)

OK
REPLACE STEREO COMPONENT AMPLIFIER (MARK LEVINSON SYSTEM)
NG

REPLACE RADIO RECEIVER