1991 LEXUS SC400 brake

NGOK
OKNG
INSPECTION PROCEDURE
1Check voltage between terminals Tc and E1 of DLC2 or DLC1.
C
OK
PTurn ignition switch ON.
Measure voltage between terminals Tc and E1 of DLC2
or DLC1.
Voltage: 10 ± 14 V
If ABS warning light does not blink even after Tc and E1
are connected,t he ECU may be defective.
2Check for open and short in harness and connector between ABS (& TRAC) ECU \
and DLC2 or
DLC1, DLC2 or DLC1 and body ground (See page IN±33).
Repair or replace harness or connector.
Check and replace ABS (& TRAC) ECU.
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±149
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IN±33 ).
WIRING DIAGRAM
Ts Terminal Circuit
CIRCUIT DESCRIPTION
The sensor check circuit detects abnormalities in the speed sensor signal w\
hich can not be detected with
the diagnostic trouble code check.Connecting terminals Ts and E1 of the DLC1 in the engine compartment
starts the check.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
BR±150±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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NGOK
OKNG
INSPECTION PROCEDURE
1Check voltage between terminal Ts and E1 of data link connector 1.
C
OK
PTurn ignition switch ON.
Measure voltage between terminals Ts and E1 of DLC1.
Voltage: 10 ± 14 V
If ABS warning light does not blink even after Ts and E1
are connected, the ECU may be defective.
2Check for open and short in harness and connector between ABS (& TRAC) ECU and D\
LC1,
DLC1 and body ground (See page IN±33).
Repair or replace harness or connector.
Check and replace ABS (& TRAC) ECU.
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±151
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Check for Fluid Leakage.
BR±152±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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TRACTION CONTROL SYSTEM (TRAC)
DESCRIPTION
BR0F3±01
The TRAC (Traction Control) system totally controls the engine torque and the braking of the driving wheels
(rear wheels). It helps avoid slippage of the driving wheels that tends to h\
appen during starting and accel-
eration and to maintain an optimal driving force according to the road surface conditions. The syst\
em elimi-
nates the need for a subtle accelerator pedal operation and improves veh\
icle stability when starting, accel-
erating or turning on slippery roads.
The TRAC system is an option.
SYSTEM PARTS LOCATION
BR0F4±01
±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)BR±153
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HYDRAULIC SYSTEM DIAGRAM
BR0F5±01
BR±154±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)
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WIRING DIAGRAM
BR0F6±01
±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)BR±155
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ECU TERMINALS
ABS & TRAC ECU:
BR0F7±05
BR±156±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)
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