LEXUS LS430 2003 Factory Repair Manual

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

Fig. 85: Disconnecting Connector From Stereo Component Amplifier Assy S29
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MTX- - Body groundAlways10 kohms or higher
(1)Mark Levinson Models
(2)Standard Models

Fig. 86: Identifying Stereo Amplifier Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 87: Identifying Stereo Components Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN DIAGNOSTIC TROUBLE
CODE CHART
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. 88: Identifying Stereo Component Amplifier Assy
- Audio And Rear A/C Control SW Wiring
Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSY - AUDIO
AND REAR A/C CONTROL SW)
a. Disconnect the connector from the stereo component amplifier assy S29 and audio and rear A/C
control SW A35.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION CONDITION CHART
Tester connectionConditionSpecified condition
TX+ - TXD+(1), RTX+(2)AlwaysBelow 1 ohms
TX- - TXD-(1), RTX-(2)AlwaysBelow 1 ohms
TX+ - Body groundAlways10 kohms or higher
TX- - Body groundAlways10 kohms or higher
(1)Mark Levinson Models
(2)Standard Models

Fig. 89: Identifying Stereo Component Amplifier Assy - Audio And Rear A/C Control SW
Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 90: Identifying Stereo Components Amplifier Assy Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN DIAGNOSTIC TROUBLE
CODE CHART
CIRCUIT DESCRIPTION
Each unit of the radio receiver assy 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 assy 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. 92: Identifying Radio Receiver Assy
- Gateway ECU Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT RADIO RECEIVER ASSY
a. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION CONDITION CHART
Tester connectionConditionSpecified condition
TX+ - TX-Always60 to 80 ohms