1991 LEXUS SC400 wiring

WIRING DIAGRAM
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±107
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WIRING DIAGRAM
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BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±111
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WIRING DIAGRAM
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BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±115
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DIAGNOSTIC CHART
DIAGNOSTIC
CHART
WIRING DIAGRAM
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BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±119
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IN±33
WIRING DIAGRAM
DTC41IG Power Source Circuit
CIRCUIT DESCRIPTION
This is the power source for the ECU and becomes the power source for the CP\
U and actuators.
DTC No.DTC Detecting ConditionTrouble Area
41
Vehicle speed is 3 km/h (1.9 mph) or moreand voltage
of ECU terminal IG remains atmore than 17V or below
9.5V for more than 10 sec.
Battery

IC regulator

Open or short in power source circuit

ECU
Fail safe function: If trouble occurs in the power source circuit, the ECU cuts off current to the ABS
solenoid relay and prohibits ABS control.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
BR±122±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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OKNG
OKNG
3Check continuity between terminal GND of ABS (& TRAC) ECU connector and bod\
y ground.
C
OK
Measure resistance between terminals GND or ABS (&
TRAC) ECU connector and body ground.
Resistance: 1  or less
Repair or replace harness or connector.
4Check ECU±IG fuse.
C
OK
PRemove ECU±IG fuse from J/B No. 1.
Check continuity of ECU±IG fuse.
Continuity
Check for short in all the harness and components con-
nected to ECU±IG fuse (See attached wiring diagram).
Check for open in harness and connector between
ABS (& TRAC) ECU and battery (See page IN±33).
BR±124±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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WIRING DIAGRAM
DTC51ABS Pump Motor Lock
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
51Pump motor is not operating normally duringinitial
check.
ABS pump motor
Fail safe function: If trouble occurs in the ABS pump motor, the ECU cuts off the current to the solenoid
relay and prohibits ABS control.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
See inspection of ABS pump motor (See page BR±65 or BR±68 ).
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±125
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WIRING DIAGRAM
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±127
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