LEXUS SC400 1991 Service Repair Manual
Manufacturer: LEXUS, Model Year: 1991,
Model line: SC400,
Model: LEXUS SC400 1991
Pages: 4087, PDF Size: 75.75 MB
LEXUS SC400 1991 Service Repair Manual
SC400 1991
LEXUS
LEXUS
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LEXUS SC400 1991 Service Repair Manual
Trending: fuel consumption, fog light, fog light bulb, headlight aiming, brake pads, coolant capacity, Parking Brake Boot
Page 1021 of 4087
ANTI±LOCK BRAKE SYSTEM (ABS)
BR0EU±04
DESCRIPTION
ABS is a brake system which controls the brake cylinder hydraulic pressure \
to all 4 wheels during sudden
braking and braking on slippery road surfaces, preventing the wheels from locki\
ng. ABS provides the
following benefits:
(1) Enables steering round an obstacle with a greater degree of certai\
nty even when panic braking.
(2) Enables stopping during panic braking while keeping the effect upon stability and steerability to a mini-
mum, even on curves.
In case a malfunction occurs, a diagnosis function and fail±safe system have been adopted for the ABS.
SYSTEM PARTS LOCATION
BR02L±05
BR±52±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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Page 1022 of 4087
BR0EV±04
HYDRAULIC SYSTEM DIAGRAM
w/o TRAC:
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±53
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w/ TRAC:
BR±54±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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Page 1024 of 4087
BR0EW±05
WIRING DIAGRAM
w/o TRAC:
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±55
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w/ TRAC:
BR±56±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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BR0EX±01
ECU TERMINALS
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±57
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Page 1027 of 4087
BR±58±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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Page 1028 of 4087
![LEXUS SC400 1991 Service Repair Manual
BR0EY±05
ECU TERMINALS STANDARD VALUE
w/o TRAC:
Symbols
(Terminals No.)
STD Voltage (V)\
\](/img/36/57051/w960_57051-1027.png "LEXUS SC400 1991 Service Repair Manual
BR0EY±05
ECU TERMINALS STANDARD VALUE
w/o TRAC:
Symbols
(Terminals No.)
STD Voltage (V)\
\")
BR0EY±05
ECU TERMINALS STANDARD VALUE
w/o TRAC:
Symbols
(Terminals No.)
STD Voltage (V)\
\
\
Condition
BAT
(A23±22)
±
GND
(A23±13)
10±14\
\
\
Always
IG
(A23±11) ± GND
(A23±2) 10±14\
\
IG switch ON
SR
(A22±5)
±
R±
(A22±4)
8.3±14
\
\
\
IG switch ON, ABS warning light OFF
MR
(A22±11)
±
R±
(A22±4)
Below 1.0
\
\
\
IG switch ON
SFR
(A23±1)
±
GND
(A23±2)
10±14
\
\
\
IG switch ON, ABS warning light OFF
SFL
(A22±6)
±
GND
(A23±13)
10±14\
\
\
IG switch ON, ABS warning light OFF
SRR
(A22±12)
±
GND
(A23±13)
10±14\
\
\
IG switch ON, ABS warning light OFF
AST
(A22±8) ± GND
(A23±13) 10±14\
\
IG switch ON, ABS warning light OFF
WA
±
GND
Below 2.0
\
\
\
IG switch ON, ABS warning light ON
WA
(A23±10)
±
GND
(A23±13) 10±14\
\
IG switch ON, ABS warning light OFF
PKB ± GND Below 1.5\
\
IG switch ON, PKB switch ON
PKB
(A23±16) ±
GND
(A23±13) 10±14\
\
IG switch ON, PKB switch OFF
STP
±
GND Below 1.5\
\
Stop light switch OFF
STP
(A23±7) ± GND
(A23±2) 8±14\
\
Stop light switch ON
D/G
(A23±21)
±
GND
(A23±13)
10±14
\
\
\
IG switch ON, ABS warning light OFF
Tc
(A23±17)
±
GND
(A23±13)
10±14
\
\
\
IG switch ON
Ts
(A23±6)
±
GND
(A23±2)
10±14\
\
\
IG switch ON
FR+
(A22±1)
±
FR±
(A22±7)
AC generation\
\
\
IG switch ON
Slowly turn right front wheel
FL+
(A22±3) ± FL±
(A22±10) AC generation\
\
IG switch ON
Slowly turn left front wheel
RR+
(A23±19)
±
RR±
(A23±20)
AC generation
\
\
\
IG switch ON
Slowly turn right rear wheel
RL+
(A23±14)
±
RL±
(A23±3)
AC generation
\
\
\
IG switch ON
Slowly turn left rear wheel
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±59
WhereEverybodyKnowsYourName
Page 1029 of 4087
![LEXUS SC400 1991 Service Repair Manual
w/TRAC:
Symbols
(Terminals No.)
STD Voltage (V)\
\
\
Condition](/img/36/57051/w960_57051-1028.png "LEXUS SC400 1991 Service Repair Manual
w/TRAC:
Symbols
(Terminals No.)
STD Voltage (V)\
\
\
Condition")
w/TRAC:
Symbols
(Terminals No.)
STD Voltage (V)\
\
\
Condition
BAT
(A25±21)
±
GND
(A25±22)
10±14\
\
\
Always
IG
(A24±24)
±
GND
(A25±22)
10±14\
\
\
IG switch ON
SR
(A24±22) ± R±
(A24±25) 8.3±14\
\
IG switch ON, ABS warning light OFF
MR
(A25±16)
±
R±
(A24±25)
Below 1.0
\
\
\
IG switch ON
TSR
(A24±1)
±
R±
(A24±25)
8.3±14
\
\
\
IG switch ON, TRAC indicator light OFF
TMR
(A24±9)
±
R±
(A24±25)
Below1.0
\
\
\
IG switch ON
SFR
(A25±1)
±
GND
(A25±2)
10±14\
\
\
IG switch ON, ABS warning light OFF
SFL
(A24±13)
±
GND
(A25±22)
10±14\
\
\
IG switch ON, ABS warning light OFF
SRR
(A24±26) ±
GND
(A25±22)
10±14\
\
IG switch ON, ABS warning light OFF
SRL
(A25±12)
±
GND
(A25±13)
10±14
\
\
\
IG switch ON, ABS warning light OFF
AST
(A24±8)
±
GND
(A25±22)
10±14
\
\
\
IG switch ON, ABS warning light OFF
SAC
(A24±12)
±
GND
(A25±22)
10±14
\
\
\
IG switch ON, TRAC indicator light OFF
SMC
(A24±2)
±
GND
(A25±22)
10±14\
\
\
IG switch ON, TRAC indicator light OFF
SRC
(A24±15)
±
GND
(A25±22)
10±14\
\
\
IG switch ON, TRAC indicator light OFF
PR
(A24±10)
±
E2
(A24±20)
5±7\
\
\
IG switch ON
VC
(A24±19) ± E2
(A24±20) 4±6\
\
IG switch ON
ALT
±
GND
Below 1.0\
\
\
IG switch ON
ALT
(A25±8)
±
GND
(A25±22) 10±14\
\
Idling
WA ± GND Below 2.0\
\
IG switch ON, ABS warning light ON
WA
(A25±9) ±
GND
(A25±22) 10±14\
\
IG switch ON, ABS warning light OFF
PKB
±
GND
Below 1.5\
\
\
IG switch ON, PKB switch ON,
Fluid in M/C reservoir above MIN level
PKB
(A25±17)
±
GND
(A25±22)
10±14\
\
\
IG switch ON, PKB switch OFF,
Fluid in M/C reservoir above MIN level
BR±60±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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Page 1030 of 4087
![LEXUS SC400 1991 Service Repair Manual
Symbols
(Terminals No.)
STD Voltage (V)\
\
\
Condition
LBL
(A25Â](/img/36/57051/w960_57051-1029.png "LEXUS SC400 1991 Service Repair Manual
Symbols
(Terminals No.)
STD Voltage (V)\
\
\
Condition
LBL
(A25Â")
Symbols
(Terminals No.)
STD Voltage (V)\
\
\
Condition
LBL
(A25±6) ± GND
(A25±22) 10±14\
\
IG switch ON
Fluid in M/C reservoir tank above MIN level.
STP
±
GND
Below 1.5\
\
\
Stop light switch OFF
STP
(A25±10)
±
GND
(A25±22)
8±14
\
\
\
Stop light switch ON
D/G
(A25±20) ± GND
(A25±22) 10±14\
\
IG switch ON, ABS warning light OFF
Tc
(A26±3)
±
GND
(A25±22)
10±14
\
\
\
IG switch ON
Ts
(A26±1)
±
GND
(A25±22)
10±14
\
\
\
IG switch ON
P
±
GND 10±14\
\
IG switch ON, Shift position in ªPº position P
(A26±10) ± GND
(A25±22) Below 1.5\
\
IG switch ON, Other shift position in ªPº position
N
±
GND
(A25±22)
10±14
\
\
\
IG switch ON, Shift position in ªNº position
N
(A26±5) ± (A25±22) Below 1.5\
\
IG switch ON, Other shift position in ªNº position
FR+
(A24±17)
±
FR±
(A24±4)
AC generation\
\
\
IG switch ON
Slowly turn right front wheel.
FL+
(A24±5)
±
FL±
(A24±18)
AC generation\
\
\
IG switch ON
Slowly turn left front wheel.
RR+
(A25±14)
±
RR±
(A25±3)
AC generation\
\
\
IG switch ON
Slowly turn right rear wheel.
RL+
(A25±4) ± RL±
(A25±15) AC generation\
\
IG switch ON
Slowly turn left rear wheel.
FRO
(A26±15)
±
GND
(A25±22)
Pulse generation
\
\
\
IG switch ON
Slowly turn right front wheel.
FLO
(A26±6)
±
GND
(A25±22)
Pulse generation
\
\
\
IG switch ON
Slowly turn left front wheel.
RRO
(A26±13)
±
GND
(A25±22)
Pulse generation
\
\
\
IG switch ON
Slowly turn right rear wheel.
RLO
(A26±4)
±
GND
(A25±22)
Pulse generation\
\
\
IG switch ON
Slowly turn left rear wheel.
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±61
WhereEverybodyKnowsYourName
Trending: low oil pressure, seat adjustment, tires, maintenance schedule, phone, air filter, tow
![LEXUS SC400 1991 Service Repair Manual
ANTI±LOCK BRAKE SYSTEM (ABS)
BR0EU±04
DESCRIPTION
ABS is a brake system which controls the brake cylinder hydraulic pressure \
to all 4 wheels during sudden
braking and braking on slippery road su](/img/36/57051/w960_57051-1020.png "LEXUS SC400 1991 Service Repair Manual
ANTI±LOCK BRAKE SYSTEM (ABS)
BR0EU±04
DESCRIPTION
ABS is a brake system which controls the brake cylinder hydraulic pressure \
to all 4 wheels during sudden
braking and braking on slippery road su")
