LEXUS LS430 2003 Factory Repair Manual

Fig. 7: Identifying Phasing Area
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2. Multi-path
A radio signal can sometimes be reflected by an obstruction in its path. When this occurs, the
reflected signal may interfere with the direct signal sent from the transmitter. This phenomenon is
known as "Multi-path".

Fig. 8: Identifying Multi-Path Area
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3. Fade out
FM radio frequency is higher than AM. Therefore, it is more likely to be reflected by large
obstructions such as tall buildings or mountains. For this reason, the FM signal will gradually
weaken or disappear when the vehicle is behind such obstructions. This phenomenon is known as
"fade out".

Fig. 9: Identifying Fade Out Area
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3. Noise problem
It is very important for a technician to understand the specifics of the noise problem. To diagnose the
symptom, use the table below.
RADIO FREQUENCY CHART
Radio FrequencyNoise occurrence conditionPresumable cause
AMNoise occurs in a specified areaForeign noise
AMNoise occurs when listening to an
intermittent broadcastAn identical program transmitted from
multiple towers can cause noise where
the signals overlap
FMNoise occurs only at nightMusic beat from a far-off broadcast
FMNoise occurs while driving in a specified
areaMulti-path or phasing noise resulting
from a change in FM frequency

HINT:
If the noise does not fall into any category in the table above, determine the cause using "Radio reception
problems" above. Refer to the multi-path and phasing sections.
HINT:
Before performing verification listed in the table below, check the fuse and relay.
Methods used to verify the cause of the problem are listed in order of probability in the verification
column.
AUDIO FUNCTION

Fig. 10: Identifying Audio Function Chart
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REAR AUDIO AND REAR A/C CONTROL SW FUNCTION

Fig. 11: Identifying Rear Audio And Rear A/C Control SW Function Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
STEERING PAD FUNCTION
Fig. 12: Identifying Steering Pad Function Chart

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1.RADIO RECEIVER ASSY
Fig. 13: Radio Receiver Assy ECU Terminal Connector

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 14: TERMINAL DESCRIPTION CHART
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2.STEREO COMPONENT AMPLIFIER ASSY
Fig. 15: Stereo Component Amplifier Assy ECU Terminal Connector

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
TERMINAL DESCRIPTION CHART

Symbols (Terminal
No.)Wiring
Color
Terminal DescriptionConditionSpecification
WFL+ (S28-3) - GND
(S30-16)LG - W-BSound signal (Front
Left)Audio system is playing-
WFR+ (S28-4) - GND
(S30-16)Y - W-BSound signal (Front
Right)Audio system is playing-
WFL-(2) (S28-9) -
GND (S30-16)L - W-BSound signal (Front
Left)Audio system is playing-
WFR-(2) (S28-10) -
GND (S30-16)B - W-BSound signal (Front
Right)Audio system is playing-
MUTE (S29-1) - GND
(S30-16)Y - W-BMute signal from radio
receiverAudio system is
sounding --> ChangingAbove 3.5 V -->
Below 3.5 V
L- (S29-2) - GND
(S30-16)G - W-BSound signal from
radio receiver (Left)Audio system is playing-
L+ (S29-3) - GND
(S30-16)R - W-BSound signal from
radio receiver (Left)Audio system is playing-
R- (S29-4) - GND
(S30-16)W - W-BSound signal from
radio receiver (Right)Audio system is playing-
R+ (S29-5) - GND
(S30-16)B - W-BSound signal from
radio receiver (Right)Audio system is playing-
TX-(1), MTX-(2) (S29-
7) - GND (S30-16)LG - W-BAVC-LAN
communication signalTurn ignition switch to
ACC2 to 3 V
TX+(1), MTX+(2)
(S29-8) - GND (S30-
16)L - W-BAVC-LAN
communication signalTurn ignition switch to
ACC2 to 3 V
ACC (S29-12) - GND
(S30-16)GR - W-BAccessory (ON)Turn ignition switch to
OFF --> ACCBelow 1 V -->
10 to 14 V
SPD (S29-11) - GND
(S30-16)O - W-BSpeed signal from
combination meterVehicle is drivingPulse generation
TXD-(1), RTX-(2)
(S29-19) - GND (S30-
16)R - W-B ((5))AVC-LAN
communication signalTurn ignition switch to
ACC2 to 3 V
TXD+(1), RTX+(2)
(S29-20) - GND (S30-
16)G - W-B ((5))AVC-LAN
communication signalTurn ignition switch to
ACC2 to 3 V
N-MUT(1), N-MU(2)
(S29-21) - GND (S30-
16)SB - W-B
(
(3))
Mute signal from radio
receiverAudio system is
sounding --> ChangingAbove 3.5 V -->
Below 3.5 V
TMUT (S29-24) -
GND (S30-16)LG - W-BMute signal from radio
receiverAudio system is
sounding --> ChangingAbove 3.5 V -->
Below 3.5 V
B+(1), +B(2) (S30-1) -
GND (S30-16)L-R - W-BBatteryAlways10 to 14 V
FL+ (S30-4) - GND LG(3), P(4) - Sound signal (Front Audio system is playing-

3.STEREO COMPONENT TUNER
(S30-16)W-BLeft)
FR+ (S30-5) - GND
(S30-16)LG - W-BSound signal (Front
Right)Audio system is playing-
RL+ (S30-6) - GND
(S30-16)B - W-BSound signal (Rear
Left)Audio system is playing-
RR+ (S30-7) - GND
(S30-16)W - W-BSound signal (Rear
Right)Audio system is playing-
TFL+(1), FL+(2) (S30-
8) - GND (S30-16)GR - W-BSound signal (Front
Left)Audio system is playing-
TFR+(1), FR+(2) (S30-
9) - GND (S30-16)SB - W-BSound signal (Front
Right)Audio system is playing-
B+(1), +B2(2) (S30-10)
- GND (S30-16)L-R - W-BBatteryAlways10 to 14 V
FL- (S30-13) - GND
(S30-16)L(3), V(4) -
W-BSound signal (Front
Left)Audio system is playing-
FR- (S30-14) - GND
(S30-16)L - W-BSound signal (Front
Right)Audio system is playing-
E (S30-15) - Body
groundW-B - Body
groundGroundAlwaysBelow 1 ohms
GND (S30-16) - Body
groundW-B - Body
groundGroundAlwaysBelow 1 ohms
RL- (S30-17) - GND
(S30-16)Y - W-BSound signal (Rear
Left)Audio system is playing-
RR- (S30-18) - GND
(S30-16)R - W-BSound signal (Rear
Right)Audio system is playing-
TFL-(1), FL-(2) (S30-
19) - GND (S30-16)G - W-BSound signal (Front
Left)Audio system is playing-
TFR-(1), FR-(2) (S30-
20) - GND (S30-16)BR - W-BSound signal (Front
Right)Audio system is playing-
(1)Mark Levinson Models
(2)Standard Models
(3)w/ LEXUS Navigation System
(4)w/o LEXUS Navigation System
(5)w/ Rear Audio Controller

Fig. 16: Stereo Component Tuner ECU Terminal Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
TERMINAL DESCRIPTION CHART
Symbols (Terminal
No.)Wiring ColorTerminal DescriptionConditionSpecification
B (S31-1) - GND
(S31-25)L - W-BBatteryAlways10 to 14 V
SG (S31-2) - Body
groundShielded -
Body groundGroundAlwaysBelow 1 ohms
FR+ (S31-3) - GND
(S31-25)G - W-BSound signal (Front
Right)Audio system is
playing-
FL+ (S31-4) - GND
(S31-25)W - W-BSound signal (Front
Left)Audio system is
playing-
ATX+ (S31-8) -
GND (S31-25)G - W-BAVC-LAN
communication signalTurn ignition switch to
ACC2 to 3 V
MTX+ (S31-9) -
GND (S31-25)Y - W-BAVC-LAN
communication signalTurn ignition switch to
ACC2 to 3 V
UTX+ (S31-10) -
GND (S31-25)
(1)L - W-BAVC-LAN
communication signalTurn ignition switch to
ACC2 to 3 V
MUTE (S31-11) -
GND (S31-25)P - W-BMute signal from radio
receiverAudio system is
sounding -->
ChangingAbove 3.5 V -->
Below 3.5 V
ACC (S31-14) -
GND (S31-25)GR - W-BAccessory (ON)Turn ignition switch to
OFF --> ACCBelow 1 V 10 to 14
V
FR- (S31-16) - GND
(S31-25)R - W-BSound signal (Rear
Right)Audio system is
playing-
FL- (S31-17) - GND
(S31-25)B - W-BSound signal (Rear
Left)Audio system is
playing-
UTX- (S31-22) -
GND (S31-25)
(1)LG - W-BAVC-LAN
communication signalTurn ignition switch to
ACC2 to 3 V