2003 LEXUS LS430 Identifying ac

Fig. 76: Identifying Radio Receiver Assy Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 77: Identifying Stereo Components Amplifier Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE RADIO RECEIVER ASSY (SEE REPLACEMENT
)

Fig. 78: Identifying Stereo Connector Amplifier Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
CIRCUIT DESCRIPTION
This circuit sends the signal to the stereo component amplifier to mute the noise. Because of that, the noise
produced by changing the sound source ceases.
In addition, this circuit is used to mute the sound when the navigation system performs voice guide.
If there is an open in the circuit, noise can be heard from the speaker when changing the sound source.
When the vehicle is equipped with the navigation system, audio sound keeps coming out from the speaker on
the driver's side while the voice navigation is in operation.
If there is a short in the circuit, even though the stereo component amplifier assy is normal, no sound or only
extremel
y small sound can be produced.

WIRING DIAGRAM
Fig. 79: Identifying Radio Receiver Assy
- Stereo Component Tuner Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT STEREO COMPONENT TUNER
a. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION CONDITION CHART
NG: Go to step 2
Tester connectionConditionSpecified condition
MUTE - Body
groundTurn ignition switch to ACC. Audio system is playing -->
ChangingAbove 3.5 V --> Below
1 V

Fig. 81: Identifying Radio Receiver Assy Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 82: Identifying Stereo Receiver Assy Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE RADIO RECEIVER ASSY (SEE REPLACEMENT
)
INSPECTION PROCEDURE
1.READ VALUE OF HAND-HELD TESTER
a. Connect the hand-held tester to DLC3.
b. Turn the ignition switch ON and push the hand-held tester main switch ON.
c. Select the items below in the DATA LIST, and read the displays on the hand-held tester.
SPAD:

Fig. 83: Identifying Steering Pad Switch Item Condition Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
NG: REPLACE STEERING PAD SWITCH (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
Each unit of the radio receiver system connected to AVC-LAN (communication bus) communicates by
transferring the signals from each switch.
When +B short and GND short occur in this AVC-LAN, radio receiver system will not function normally as
communication is discontinued.
In AVC-LAN, radio receiver assy becomes the communication master, and the radio receiver assy has enough
resistance necessary for transmitting the communication.
WIRING DIAGRAM

Fig. 84: Identifying Stereo Component Amplifier Assy - Stereo Component Tuner Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSY -
STEREO COMPONENT TUNER)
a. Disconnect the connector from the stereo component amplifier assy S29 and stereo component
tuner S31.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION CONDITION CHART
Tester connectionConditionSpecified condition
TX+(1), MTX+(2) - ATX+AlwaysBelow 1 ohms
TX-(1), MTX-(2) - ATX-AlwaysBelow 1 ohms
MTX+ - Body groundAlways10 kohms or higher