code 32 LEXUS SC300 1991 Service Repair Manual

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\
 \
Inspection Circuit See page
 


ABS does not oper-
ate.\
 
\

\

Only when 1.±4. are all normal and the problem is still occurring,
replace the ABS (& TRAC) ECU. 


BR±76
 


\
 
\

\

1. Check the diagnostic trouble code, reconfirming that the nor-
mal code is output. 

BR±122
BR±118
 \
 \
2. IG Power Source Circuit. BR±65 or 68 


\
 
\

\
3. Speed sensor circuit.
 


 




\
 
\


\

\

4. Check the ABS actuator with a checker.
If abnormal, check the hydraulic circuit for leakage (see page
BR±138). 




 


ABS does not oper-
ate efficiently.\
 
\

\

Only when 1.±4. are all normal and the problem is still occurring,
replace the ABS (& TRAC) ECU. 


BR±76
 


\
 
\

\

1. Check the diagnostic trouble code, reconfirming that the nor-
mal code is output. 


BR±118
BR±142
 \
 \
2. Speed sensor circuit. BR±65
or 68
 \
 \
3. Stop light switch circuit 
 




\
 
\


\

\

4. Check the ABS actuator with a checker.
If abnormal, check the hydraulic circuit for leakage (see page
BR±138). 




 


ABS warning light ab-
normal.\
 
\

\

1. ABS warning light circuit. 

BR±144
 \
 \
2. ABS (& TRAC) ECU. 
 




Diagnostic trouble
code check cannot
be performed.\
 
\


\

\

Only when 1. and 2. are all normal and the problem is still occur-
ring, replace the ABS (& TRAC) ECU. 




BR±144
 \
 \
1. ABS warning light circuit BR±148 


\
 
\

\
2. To terminal circuit.
 


 


Speed sensor signal
check cannot be per-
formed.\
 
\

\

1. Ts terminal circuit. 


BR±150
 


\
 
\

\
2. ABS (& TRAC) ECU.
 


BR±82±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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OKNG
OKNG
3Check ABS solenoid relay.
C
OK
P
C
OK
Remove solenoid relay from R/B No. 6.
Check continuity between each terminal of ABS sole-
noid relay shown below.
1. Apply battery voltage between terminals 4 and 6.
2. Check continuity between each terminal of ABS so-
lenoid relay shown below.
Replace ABS solenoid relay.
4Check for open and short in harness and connector between ABS solenoid r\
elay and ABS (&
TRAC) ECU (See page IN±33).
Repair or replace harness or connector.
If the same code is still output after the diagnostic trouble code is dele\
ted, check the contact condition
of each connection.
If the connections are normal, the ECU may be defective.
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±97
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OKNG
OKNG
3Check ABS solenoid relay.
C
OK
P
OK
C
Remove solenoid relay from R/B No. 6
Check continuity between each pair of terminal of motor
relay shown below.
1. Apply battery voltage between terminals 3 and 4.
2. Check continuity between terminals shown below.
Replace ABS motor relay.
4Check for open and short in harness and connector between ABS motor relay and ABS (&
TRAC) ECU (See page IN±33).
Repair or replace harness or connector.
If the same code is still output after the diagnostic trouble code is dele\
ted, check the contact condition
of each connection.
If the connections are normal, the ECU may be defective.
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±101
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OKNG
OKNG
3Check TRAC solenoid relay.
C
OK
P
OK
C
Remove solenoid relay from R/B NO. 6.
Check continuity between each terminal of TRAC sole-
noid relay shown below.
1. Apply battery voltage between terminals 4 and 6.
2. Check continuity between terminals shown below.
Replace TRAC solenoid relay.
4Check for open and short in harness and connector between TRAC solenoid relay\
and ABS &
TRAC ECU (See page IN±33).
Repair or replace harness or connector.
If the same code is still output after the diagnostic trouble code is dele\
ted, check the contact condition
of each connection.
If the connections are normal, the ECU may be defective.
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±105
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OKNG
OKNG
3Check TRAC motor relay.
C
OK
P
OK
C
Remove motor relay from R/B No. 6.
Check continuity between each pair of terminal of motor
relay shown below.
1. Apply battery voltage between terminals 3 and 4.
2. Check continuity between terminals shown below.
Replace TRAC motor relay.
4Check for open and short in harness and connector between TRAC motor relay and ABS &
TRAC ECU (See page IN±33).
Repair or replace harness or connector.
If the same code is still output after the diagnostic trouble code is dele\
ted, check the contact condition
of each connection.
If the connections are normal, the ECU may be defective.
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±109
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OKNG
OKNG
INSPECTION PROCEDURE
1Check ABS actuator solenoid.
C
OK
Hint
Hint
OK
C
Check continuity between terminal 4 and 1, 3, 4, 6 of the ABS actuator connector.
Continuity
Resistance of each solenoid coil is 1.2
.
Check continuity between terminal 2 and 1, 4, 5, 6 of the ABS actuator connector.
Continuity
Resistance of each solenoid coil is 1.2
.
Replace ABS actuator.
2Check for open and short in harness and connector between ABS (& TRAC) ECU \
and actuator
(See page IN±33).
Repair or replace harness or connector.
If the same code is still output after the diagnostic trouble code is dele\
ted, check the contact condition
of each connection.
If the connections are normal, the ECU may be defective.
BR±112±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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OKNG
OKNG
OKNG
INSPECTION PROCEDURE
1Check TRAC actuator solenoid.
C
OK
PDisconnect TRAC actuator connector.
Check continuity between each terminal of TRAC ac-
tuator shown below.
Replace TRAC actuator.
2Check for open and short in harness and connector between solenoid relay and E\
CU (See page
IN±33 ).
Repair or replace harness or connector.
3Check for short in harness and connector between SMC and SRC, SAC and SMC, an\
d SAC and
SRC terminals with TRAC actuator and ECU connectors are disconnected.
Repair or replace harness or connector.
If the same code is still output after the diagnostic trouble code is dele\
ted, check the contact condition
of each connection. If the connections are normal, the ECU may be defectiv\
e.
BR±116±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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WIRING DIAGRAM
ABS Warning Light Circuit
CIRCUIT DESCRIPTION
If the ECU detects trouble, it lights the ABS warning light while at the s\
ame time prohibiting ABS control.
At this time, the ECU records a diagnostic trouble code in memory.After removing the short pin of the DLC1,
connect a DLC1 or connect terminals Tc and E1 of the DLC2 to make the ABS warning light to blink and
output the diagnostic trouble code.DIAGNOSTIC CHARTPerform troubleshooting in accordance with the
chart below for each trouble symptom.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
Perform troubleshooting in accordance with the chart below for each trouble sym\
ptom.
 


ABS warning light does not light up 


Go to step
 

ABS warning light remains on 

Go to step
BR±144±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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NOYES
YESNO
OKNG
INSPECTION PROCEDURE
3Is diagnosis trouble code output?
Perform diagnostic trouble code check on page BR±76.
Repair circuit indicated by the code output.
4Does ABS warning light go off if short pin is removed?
Check for short in harness and connector between warn-
ing light and data link connector 1 and ECU (See page
IN±33 ).
5Check ABS solenoid relay (See step No. ).
Replace ABS solenoid relay.
Repair or replace and check for short in harness
and connector between data link connector 1 and
ABS solenoid relay (See page IN±33).
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±147
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IN±33).
WIRING DIAGRAM
Tc Terminal Circuit
CIRCUIT DESCRIPTION
Connecting between terminals Tc and E1 of the DLC1 or the DLC2 causes the ECU to display the diagnos-
tic trouble code by flashing the ABS warning light.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
BR±148±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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