LEXUS LS430 2003 Factory Repair Manual

Fig. 45: Identifying Power Source Circuit (Stereo Component Tuner) Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT STEREO COMPONENT TUNER (B, ACC, GND)
a. Disconnect the stereo component tuner connector S31.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION CONDITION CHART
Tester connectionConditionSpecified condition
GND - Body groundAlwaysBelow 1 ohms

c. Measure the voltage according to the value (s) in the table below.
TESTER CONNECTION CONDITION CHART
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE or DIAGNOSTIC TROUBLE CODE CHART
Fig. 46: Inspecting Stereo Component Tuner

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CIRCUIT DESCRIPTION
This circuit provides the power to the stereo component amplifier ass
y.
Tester connectionConditionSpecified condition
B - GNDAlways10 to 14V
ACC - GNDIgnition SW ACC10 to 14V

WIRING DIAGRAM
Fig. 47: Stereo Component Amplifier Assy Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT STEREO COMPONENT AMPLIFIER ASSY (+B, +B2, ACC, GND, E)
a. Disconnect the stereo component amplifier assy connector S29, S30.
b. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION CONDITION CHART
Tester connectionConditionSpecified condition
GND - Body groundAlwaysBelow 1 ohms
E - Body groundAlwaysBelow 1 ohms

c. Measure the voltage according to the value (s) in the table below.
TESTER CONNECTION CONDITION CHART
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE or DIAGNOSTIC TROUBLE CODE CHART
Fig. 48: Disconnecting Stereo Component Amplifier Assy Connector S29, S30

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Tester connectionConditionSpecified condition
B+ ((1)),+B ((2)) - GNDAlways10 to 14V
B+ ((1)), +B2 ((2)) -GNDAlways10 to 14V
ACC - GNDIgnition SW ACC10 to 14V
(1)Mark Levinson models
(2)Standard models

Fig. 49: Identifying Standard Model
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CIRCUIT DESCRIPTION
This circuit provides the power to the audio and rear A/C control switch.
WIRING DIAGRAM

Fig. 50: Identifying Audio And Rear A/C Control SW Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT AUDIO AND REAR A/C CONTROL SWITCH (+B, ACC, GND)
a. Disconnect the audio and rear A/C control switch connector A35.
b. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION CONDITION CHART
c. Measure the voltage according to the value (s) in the table below.
TESTER CONNECTION CONDITION CHART
Tester connectionConditionSpecified condition
GND - Body groundAlwaysBelow 1 ohms
Tester connectionConditionSpecified condition
+B - GNDAlways10 to 14V

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE or DIAGNOSTIC TROUBLE CODE CHART
Fig. 51: Inspecting Audio And Rear A/C Control Switch (+B, ACC, Gnd)

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CIRCUIT DESCRIPTION
The sound signal that has been amplified by the stereo component amplifier assy is sent to the speaker from the
stereo component amplifier ass
y through this circuit.
ACC - GNDIgnition SW ACC10 to 14V

If there is a short in this circuit, the stereo component amplifier assy detects it and stops output to the speakers.
Thus sound can not be heard from the speaker even if there is no malfunction in the stereo component amplifier
assy or speaker.
Standard System:
There are two circuits that detect a short circuit.
When a short in the woofer speaker circuit is detected, sound output from only the woofer speaker circuit
stops.
When a short in the other circuits is detected, sound output from the circuits other than the woofer
speaker circuit is stopped.
Mark Levinson System:
When a short in the speaker circuit is detected, all sound output is stopped.
WIRING DIAGRAM

Fig. 52: Speaker Circuit Wiring Diagram (1 Of 2)
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Fig. 53: Speaker Circuit Wiring Diagram (2 Of 2)

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INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSY -
SPEAKER ASSY)

a. Disconnect the connectors from the stereo component amplifier assy S28, S30 and speakers.
b. Measure resistance between terminals of stereo component amplifier assy and speakers.
Standard: Below 1 ohms
c. Measure resistance between terminals of stereo component amplifier assy and body ground.
Fig. 54: Stereo Component Amplifier Assy
- Speaker Assy (Levinson Model)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.