Lexus NX: Mute Signal Circuit between Stereo Component Amplifier and Telematics Transceiver
DESCRIPTION
This 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).
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:
When replacing the DCM (telematics transceiver), make sure to replace it with a new one.
HINT:
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.
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PROCEDURE
| 1. | INSPECT DCM (TELEMATICS TRANSCEIVER) |
| (a) Remove the DCM (telematics transceiver) with the connector(s) still connected. Click here |
|
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Switch Condition | Specified Condition |
|---|---|---|
| I183-14 (MUTE) - Body ground | Power switch on (IG), audio system playing → Emergency call mode | 3.0 to 5.0 V → Below 1 V |
| OK | .gif) | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
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| 2. | CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSEMBLY - DCM [TELEMATICS TRANSCEIVER]) |
(a) Disconnect the P22 stereo component amplifier assembly connector.
(b) Disconnect the I183 DCM (telematics transceiver) connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| P22-2 (TMUT) - I183-14 (MUTE) | Always | Below 1 Ω |
| P22-2 (TMUT) - Body ground | Always | 10 kΩ or higher |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 3. | CHECK STEREO COMPONENT AMPLIFIER ASSEMBLY |
(a) Disconnect the DCM (telematics transceiver) connector.
| (b) Measure the voltage according to the value(s) in the table below. Standard Voltage:
|
|
| OK | | REPLACE DCM (TELEMATICS TRANSCEIVER) |
| NG | | REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY |
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