1991 LEXUS SC300 display

 
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Problem No.
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Radio not operating when power switch turned to ºONº 1
 


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Display indicates when power switch turned to ºONº, but no sound (\
including ºnoiseº)
is produced (except woofer). 


2
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Noise present, but AM±FM not operating 3
 
Radio
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Any speaker does not work (except woofer). 4
 Radio\
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Volume faint (except woofer). 5 \
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Woofer does not work. 6 


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Woofer volume faint. 

7
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Reception poor. 8
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Preset memory disappears. 9
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Volume remains at maximum level. 10
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Cassette tape cannot be inserted. 11
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Cassette tape will not eject. 12
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Display indicates, but no sound is produced (except woofer). 13 \
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Any speaker does not work (except woofer). 14 

Tape player
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Volume faint (except woofer). 

15
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Woofer does not work. 16
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Woofer volume faint. 17
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Sound quality poor. 18
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Volume remains at maximum level. 19
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Magazine cannot be inserted into auto changer. 20
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Magazine is inserted, but display does not indicate ºCDº. 21 \
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Display indicates, but no sound is produced (except woofer). 22 


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Any speaker does not work (except woofer). 

23
 CDplayer\
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Volume faint (except woofer). 24
 CD player\
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RH channel or LH channel speaker volume faint. 25
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Woofer does not work. 26
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Woofer volume faint. 27
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Sound quality poor. 28
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Volume remains at maximum level. 29 
Noise
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Noise produced by vibration or shock while driving. 30 


Noise\
 
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Noise produced when engine starts. 

31
 Antenna\
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Antenna±related. 32
±
BODY ELECTRICAL SYSTEM AUDIO SYSTEMBE±219
WhereEverybodyKnowsYourName

2Radio
DISPLAY INDICATES WHEN POWER SWITCH
TURNED TO ºONº, BUT NO SOUND (INCLUDING
ºNOISEº) IS PRODUCED (EXCEPT WOOFER)
A. without CD player type
Is there continuity between the following terminals
with connector disconnected?

Radio receiver assembly B1±Power switch 14

Radio receiver assembly B3±Power switch 11
Radio receiver assembly faulty.
Is tape player operating normally?
When the volume switch is turned from minimum
to maximum, does resistance between terminals
B1 ± B3 of radio receiver assembly change from
0 to 50 k .
Power switch faulty. Wire harness faulty.
Is resistance value approx. 50  between termi-
nals is B3±B6 of radio receiver assembly?
Radio receiver assembly faulty. Is there continuity between the following terminals
with connector disconnected?


Radio receiver assembly B6±Power switch 13
Power switch faulty. Wire harness faulty.
BE±222±
BODY ELECTRICAL SYSTEM AUDIO SYSTEM
WhereEverybodyKnowsYourName

13Tape playerDISPLAY INDICATES, BUT NO SOUND IS
PRODUCED (EXCEPT WOOFER)
A. without CD player type
Is radio operating normally?Radio receiver assembly faulty.
Radio receiver assembly faulty. Is there continuity between the following terminals
with connector disconnected?


Radio receiver amplifier B1 ± Power switch 14

Radio receiver amplifier B3 ± Power switch 11
When the volume switch is turned from minu-
mum to maximum, does resistance between
terminal B1±B3 of radio receiver assembly
change from 0 to 50 k
?
is resistance value approx. 50 k  between ter-
minals B3±B6 of radio receiver assembly? Is there continuity between the following terminals
with connector disconnected?


Radio receiver amplifier B6 ± Power switch 13
Power switch faulty. Wire harness faulty. Power switch faulty. Wire harness faulty.
BE±238±
BODY ELECTRICAL SYSTEM AUDIO SYSTEM
WhereEverybodyKnowsYourName

21CD playerMAGAZINE IS INSERTED, BUT DISPLAY DOES
NOT INDICATE ºCDº
Is radio operating normally?
Is there battery voltage between the following
terminals with connector connected?

Radio receiver assembly C12 ± ground
Wire harness faulty.Radio receiver assembly faulty.
Go to No. 1.
Is there battery voltage between the following
terminals with connector connected?

Radio receiver assembly C12 ± CD auto
changer A3
Is there battery voltage between the following
terminals with connector connected?

Radio receiver assembly C3 ± CD auto changer
B1

Radio receiver assembly C8 ± CD auto changer
B3

Radio receiver assembly C9 ± CD auto changer
B2

Radio receiver assembly C10 ± CD auto changer
B10
Is there battery voltage between the following
terminals with connector disconnected?

Radio receiver assembly C3 ± ground

Radio receiver assembly C8 ± ground

Radio receiver assembly C9 ± ground

Radio receiver assembly C10 ± ground
Temporarily install another CD auto changer.
Functions OK? CD auto changer faulty. Wire harness faulty.
Wire harness faulty.
Radio receiver assembly faulty
BE±250±
BODY ELECTRICAL SYSTEM AUDIO SYSTEM
WhereEverybodyKnowsYourName

22CD playerDISPLAY INDICATES, BUT NO SOUND IS
PRODUCED (EXCEPT WOOFER)
Is radio operating normally?Wire harness faulty.
Is there battery voltage between the following ter-
minals with connector connected?

Power amplifier A14 ± ground

Power amplifier A10 ± ground
Wire harness faulty.
Is there battery voltage between the following ter-
minals with connector connected?


Power amplifier A6 ± ground
Is there battery voltage between the following ter-
minals with connector connected?

Power amplifier A7 ± ground Is there battery voltage between the following ter-
minals with connector disconnected?


Radio receiver assembly B6 ± Power switch 13.
Is there battery voltage between the following ter-
minals with connector disconnected?


Radio receiver assembly B1±Power switch 14

Radio receiver assembly B3±Power switch 11
Wire harness faulty.
Power switch faulty.
Wire harness faulty.
Radio receiver assem-
bly faulty. Wire harness faulty.
Power switch faulty.
Is resistance value about 50 k  between terminals
B3±B6 of radio receiver assembly?
Temporarily install another CD auto changer.
Functions OK? CD auto changer faulty.Is there continuity between the following terminals
with connector disconnected?


Radio receiver assembly A1±Power amplifier A6.
When the volume switch is turned from minimum to
maximum, does resistance between terminals
B1±B3 of radio receiver assembly changer from 0
to 50 k

Radio receiver assembly faulty.
Radio receiver assembly faulty.
±
BODY ELECTRICAL SYSTEM AUDIO SYSTEMBE±251
WhereEverybodyKnowsYourName

DIAGNOSIS SYSTEM
INDICATOR CHECK
When the ignition switch is turned on, check that the TRAC
indicator light goes on for 3 seconds.
HINT: If the indicator check result is not normal, proceed to
troubleshooting for the TRAC indicator light circuit (see page
BR±225 ).
DIAGNOSTIC TROUBLE CODE CHECK
1. Turn the ignition switch ON.
2. Using SST, connect terminals Tc and E1 of DLC2 or DLC 1.
SST 09843±18020
3. Read the diagnostic trouble code from the TRAC indicator light on the combination meter.
HINT: If no code appears, inspect the diagnostic circuit or
TRAC indicator light circuit ( BR±226 orBR±225 ).
As an example, the blinking patterns for normal code and
codes 11 and 21 are shown on the left.
4. Codes are explained in the code table on the next page.
5. After completing the check, disconnect terminals Tc and
E1, and turn off the display.
If two or more malfunctions are indicated at the same time,
the lowest numbered diagnostic trouble code will be dis-
played 1st.
ECU DATA MONITOR USING LEXUS
HAND±HELD TESTER
1. Hook up the LEXUS hand±held tester to the DLC2.
2. Monitor the ECU data by following the prompts on thetester screen.
HINT: LEXUS hand±held tester has a ªSnapshotº function
which records the monitored data.
Please refer to the LEXUS hand±held tester operator's
manual for further details.
BR±170
±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)
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DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is displayed during the diagnostic trouble code chec\
k, check the circuit listed for that code
in the table below and proceed to the page given.
HINT: If the TRAC indicator light lights up and the TRAC indicator light doe\
s not blink when the Diag. code is
checked, check the blinking pattern of the ABS warning light and perform trouble\
shooting of the ABS system.
BR±186BR±189
BR±190
BR±192
BR±196 BR±198
BR±200
BR±208
BR±216
BR±218
BR±220BR±189
BR±189
BR±190
BR±190
BR±190
BR±200 BR±208
*1: If a malfunction is detected, the TRAC OFF indicator light lights up.
*2: Indicator light does not lights up even if an error is detected.
*3: If a malfunction is detected, the TRAC OFF indicator light or TRAC i\
ndicator light light up.
BR±172
±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)
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PROBLEM SYMPTOMS CHART
If a normal code is displayed during the diagnostic trouble code check but\
the problem still occurs, check
the circuits for each problem symptom in the order given in the table below\
and proceed to the page for
troubleshooting.
 Symptoms\
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Inspection Circuit See page
 


TRAC does not oper-
ate.\
 
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Only when 1.~5. are all normal and the problem is still occurring, repla\
ce
the TRAC ECU. 

BR±170
 


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1. Check the diagnostic trouble code, reconfirming that the normal code \
is
output. 


BR±192
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2. IG Power Source Circuit. BR±228
 


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3. Check the hydraulic circuit for leakage. 

BR±190
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4. Speed Sensor Circuit. 
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5. Park/neutral position switch circuit. 
 




TRAC indicator light
abnormal.\
 
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1. TRAC Indicator Light Circuit.
2. TRAC ECU. 




BR±224
 


TRAC OFF indicator
light abnormal.\
 
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Only when 1. and 2. are all normal and the problem is still occurring, r\
e-
place the TRAC ECU. 


BR±222
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1. TRAC OFF indicator Light Circuit. 
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2. TRAC cut switch circuit. 
 








Diagnostic trouble
code check cannot
be performed.\
 
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Only when 1. and 2. are all normal and the problem is still occurring, r\
e-
place the TRAC ECU.
1. TRAC Indicator Light Circuit.
2. Tc terminal Circuit. 








BR±224
BR±226
±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)BR±173
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