AUDIO AND VISUAL SYSTEM > Mute Signal Circuit between Navigation ECU and Stereo Component Amplifier

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DESCRIPTION

This circuit sends a mute signal to the stereo component amplifier to enable the voice on the phone to be heard clearly when the cellular phone is used.
If there is an open in the circuit, no sound can be produced from the speakers while the cellular phone is being used.
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


E110895E03


E110895E04


INSPECTION PROCEDURE

1.INSPECT STEREO COMPONENT AMPLIFIER


    E110893E05

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

    Standard voltage:
    Tester connection
    		Condition
    		Specified condition
    N-MU - Body ground
    		Turn ignition switch to ACC, Audio system is playing → Navigation voice is produced
    		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 (NAVIGATION ECU - STEREO COMPONENT AMPLIFIER)


    E110896E02

  1. Disconnect the connectors from the navigation ECU and stereo component amplifier.

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

    Standard resistance:
    Tester connection
    		Condition
    		Specified condition
    MUT2 - N-MU
    		Always
    		Below 1 Ω
    MUT2 - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT NAVIGATION ECU


    E112073E02

  1. Connect the connector to the stereo component amplifier.

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

    Standard voltage:
    Tester connection
    		Condition
    		Specified condition
    MUT2 - Body ground
    		Turn ignition switch to ACC
    		Above 3.5 V



NG
REPLACE STEREO COMPONENT AMPLIFIER (STANDARD SYSTEM)

NG
REPLACE STEREO COMPONENT AMPLIFIER (MARK LEVINSON SYSTEM)
OK

REPLACE NAVIGATION ECU