LEXUS LS430 2003 Factory Repair Manual

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

Fig. 65: Radio Receiver Assy - Stereo Component Tuner Terminal Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig. 66: Identifying Stereo Components Tuner Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
This circuit is necessary for the stereo component amplifier assy for the ASL (Auto Sound Leveliser). Speed
signals are received from the combination meter.
The ASL function automatically adjusts the sound data in order to enable to hear the clear audio sound even
when the vehicle noise is increased (as vehicle noise increased, the volume is turned up etc.)
Standard System: Using speed signals and a microphone for the ASL built into the stereo component amplifier
assy.
Mark Levinson System: Using speed signals.

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. 68: Identifying Stereo Components Amplifier Terminal Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 69: Identifying Stereo Components Amplifier Terminal Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig. 70: Identifying Combination Meter Assembly Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
2.INSPECT COMBINATION METER ASSY
a. Check the voltage.
1. Jack up either of the front wheels.
2. Adjust the shift lever to the neutral position.
3. Measure the voltage between the terminals +S and body ground while turning the front wheel
slowly.
Standard:

TESTER CONNECTION CONDITION CHART
Fig. 71: Inspecting Combination Meter Assy

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Tester connectionConditionSpecification
+S - Body groundIgnition switch ONVoltage is pulsed

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