Toyota Avalon (XX50): Mute Signal Circuit between Radio Receiver and Stereo Component Amplifier. Mute Signal Circuit between Stereo Component Amplifier and Telematics Transceiver. No Sound can be Heard from Speakers
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.
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 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 Navigation System.
Click here 
- When replacing the radio and display receiver assembly, always replace
it with a new one. If a radio and display receiver assembly which was
installed to another vehicle is used, the following may occur:
- A communication malfunction DTC may be stored.
- The radio and display receiver assembly may not operate normally.
PROCEDURE
|
1. | INSPECT STEREO COMPONENT AMPLIFIER ASSEMBLY |
| (a) Measure the voltage according to the value(s) in the table below.
Standard Voltage: |
Tester Connection | Condition |
Specified Condition | |
G8-1 (MUTE) - Body ground |
Engine switch on (ACC), audio system playing → 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 |
 | |
| 2. |
CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - STEREO COMPONENT AMPLIFIER ASSEMBLY) |
(a) Disconnect the G3 radio and display receiver assembly connector.
(b) Disconnect the G8 stereo component amplifier assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|
G3-25 (MUT1) - G8-1 (MUTE) |
Always | Below 1 Ω |
|
G3-25 (MUT1) or G8-1 (MUTE) - Body ground |
Always | 10 kΩ or higher |
| NG |
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
OK | |
| |
| 3. |
INSPECT STEREO COMPONENT AMPLIFIER ASSEMBLY (OUTPUT SIGNAL) |
(a) Reconnect the G8 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 | |
G3-25 (MUT1) - Body ground |
Engine switch on (ACC), audio system is playing |
2.0 V or higher | |
 |
|
*a | Front view of wire harness connector
(to Radio and Display Receiver Assembly) | | |
| OK |
| REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY |
| NG |
| REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY |
Mute Signal Circuit between Stereo Component Amplifier and Telematics Transceiver
DESCRIPTION
The DCM (telematics transceiver) sends a mute signal to the stereo component amplifier assembly.
The stereo component amplifier assembly controls the volume according to the mute signal from the DCM (telematics transceiver).
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 Navigation System.
Click here 
- Before replacing the DCM (telematics transceiver), refer to Registration.
Click here
PROCEDURE
|
1. | INSPECT DCM (TELEMATICS TRANSCEIVER) |
| (a) Measure the voltage according to the value(s) in the table below.
Standard Voltage: |
Tester Connection | Condition |
Specified Condition | |
G9-17 (MUTE) - Body ground |
Engine switch on (ACC) Audio system playing → Emergency call mode |
2.0 V or higher → Below 1 V | |
 |
|
*a | Component with harness connected
(DCM (Telematics Transceiver)) | | |
| OK |
 | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
NG |
 | |
| 2. |
CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSEMBLY - DCM (TELEMATICS TRANSCEIVER)) |
(a) Disconnect the G8 stereo component amplifier assembly connector.
(b) Disconnect the G9 DCM (telematics transceiver) connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|
G8-24 (TMUT) - G9-17 (MUTE) |
Always | Below 1 Ω |
|
G8-24 (TMUT) or G9-17 (MUTE) - Body ground |
Always | 10 kΩ or higher |
| NG |
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
OK | |
| |
| 3. |
INSPECT STEREO COMPONENT AMPLIFIER ASSEMBLY |
(a) Disconnect the G9 DCM (telematics transceiver) connector.
| (b) Measure the voltage according to the value(s) in the table below.
Standard Voltage: |
Tester Connection | Condition |
Specified Condition | |
G9-17 (MUTE) - Body ground |
Engine switch on (ACC) |
2.0 V or higher | |
 |
|
*a | Front view of wire harness connector
(to DCM (Telematics Transceiver)) | | |
| OK |
| REPLACE DCM (TELEMATICS TRANSCEIVER) |
| NG |
| REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY |
No Sound can be Heard from Speakers
PROCEDURE
(a) In sound output setting mode, set volume, fader and balance to the initial values and check that the sound is normal.
OK:
Audio system returns to normal.
HINT:
Sound quality adjustment measures vary according to the type of amplifier.
| OK |
 | END |
| NG |
| PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
