Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Mute Signal Circuit between Radio Receiver 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

CAUTION / NOTICE / HINT

NOTICE:

Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed. Refer to Precaution for Audio and Visual System.

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PROCEDURE

(a) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Condition Specified Condition J156-1 (MUTE) - Body ground Engine switch on (ACC) Audio system playing → Audio system changing modes 2.0 V or higher → Below 1 V

*a Component with harness connected (Stereo Component Amplifier Assembly)

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

(a) Disconnect the J148 radio receiver assembly connector.

(b) Disconnect the J156 stereo component amplifier assembly connector.

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

Standard Resistance:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Reconnect the J156 stereo component amplifier assembly connector.

(b) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Condition Specified Condition J148-25 (MUT1) - Body ground Engine switch on (ACC) Audio system playing 2.0 V or higher

*a Front view of wire harness connector (to Radio Receiver Assembly)

OK

REPLACE RADIO RECEIVER ASSEMBLY

NG

REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY