2003 LEXUS LS430 Diagram AC

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)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Fig. 53: Speaker Circuit Wiring Diagram (2 Of 2)

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSY -
SPEAKER ASSY)

Fig. 59: Measuring Resistance Between Terminals Of Speaker
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
The radio receiver assy sends a sound signal to the stereo component amplifier assy through this circuit. The
sound signal that has been sent is amplified by the stereo component amplifier assy, and then is sent to the
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malfunction in the stereo component amplifier assy or speaker.
WIRING DIAGRAM

Fig. 60: Identifying Radio Receiver Assy - Amp Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSY - STEREO COMPONENT
AMPLIFIER ASSY)
a. Disconnect the connectors from the radio receiver assy R2 and stereo component amplifier assy
S29.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION CONDITION CHART
Tester connectionSpecified condition
L+ (R2) - L+ (S29)Below 1 ohms
L- (R2) - L- (S29)Below 1 ohms
R+ (R2) - R+ (S29)Below 1 ohms
R- (R2) - R- (S29)Below 1 ohms
L+ (R2 or S29) - Body ground10 kohms or higher
L- (R2 or S29) - Body ground10 kohms or higher
R+ (R2 or S29) - Body ground10 kohms or higher
R- (R2 or S29) - Body ground10 kohms or higher

Fig. 63: Identifying Stereo Components Amplifier
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
The stereo component tuner sends a sound signal to the radio receiver assy through this circuit.
WIRING DIAGRAM

Fig. 64: Identifying Radio Receiver Assy - Stereo Component Tuner Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSY - STEREO COMPONENT
TUNER)
a. Disconnect the connectors from the radio receiver assy R3 and stereo component tuner S31.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION CONDITION CHART
Tester connectionSpecified condition
RR+ - FR+Below 1 ohms
RR- - FR-Below 1 ohms
RL+ - FL+Below 1 ohms
RL- - FL-Below 1 ohms
RR+ - Body ground10 kohms or higher
RR- - Body ground10 kohms or higher
RL+ - Body ground10 kohms or higher
RL- - Body ground10 kohms or higher

WIRING DIAGRAM
Fig. 67: Identifying Stereo Component Amplifier Assy Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSY -
COMBINATION METER ASSY)
a. Disconnect the connectors from the stereo component amplifier assy S29 and combination meter
assy C12.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION CONDITION CHART
Tester connectionConditionSpecified condition
SPD - +SAlwaysBelow 1 ohms
SPD - Body groundAlways10 kohms or higher

Fig. 72: Identifying Blinking Pattern
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: GO TO COMBINATION METER SYSTEM (SEE PRECAUTION
)
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
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
extremely small sound can be produced.
WIRING DIAGRAM