DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
INSPECT STEREO COMPONENT AMPLIFIER
CHECK HARNESS AND CONNECTOR (RADIO RECEIVER - STEREO COMPONENT AMPLIFIER)
INSPECT STEREO COMPONENT AMPLIFIER
AUDIO AND VISUAL SYSTEM - Mute Signal Circuit between Radio Receiver and Stereo Component Amplifier
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
INSPECTION PROCEDURE
| 1.INSPECT STEREO COMPONENT AMPLIFIER |
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
| Tester connection | Condition | Specified condition |
| MUTE - Body ground | Turn engine switch on (ACC), Audio system is playing → Changing | Above 3.5 V → Below 1 V |
| | PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
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| 2.CHECK HARNESS AND CONNECTOR (RADIO RECEIVER - STEREO COMPONENT AMPLIFIER) |
Disconnect the radio receiver connector J66 and stereo component amplifier connector P30.
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 |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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| 3.INSPECT STEREO COMPONENT AMPLIFIER |
Reconnect the stereo component amplifier connector P30.
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
| Tester connection | Condition | Specified condition |
| MUTE - Body ground | Turn engine switch on (ACC), Audio system is playing | Above 3.5 V |
| | REPLACE STEREO COMPONENT AMPLIFIER |
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LEXUS IS250, IS220d / GSE20 ALE20
