LEXUS SC400 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)
WhereEverybodyKnowsYourName

±MEMO±
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±83
WhereEverybodyKnowsYourName

LOCATION OF CONNECTORS
Location of Connectors in Engine Compartment
BR±84±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
WhereEverybodyKnowsYourName

SC400:
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±85
WhereEverybodyKnowsYourName

BR±86±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
WhereEverybodyKnowsYourName

Location of Connectors in Instrument Panel
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±87
WhereEverybodyKnowsYourName

BR±88±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
WhereEverybodyKnowsYourName

Location of Connectors in Instrument Panel
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±89
WhereEverybodyKnowsYourName

BR±90±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
WhereEverybodyKnowsYourName

±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±91
WhereEverybodyKnowsYourName