ABS LEXUS SC400 1991 Service Repair Manual

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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ECU TERMINALS
ABS & TRAC ECU:
BR0F7±05
BR±156±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)
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ECU TERMINALS STANDARD VALUE
ABS & TRAC ECU:
BR0F8±03
 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) 


Below 1.0\
 
\

\

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±158±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)
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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
 

10±14\
 
\

\
IG switch ON, Shift position in ªNº position
 
N
(A26±5) 
±
 
GND
(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 TRACTION CONTROL SYSTEM (TRAC)BR±159
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ABBREVIATIONS USED IN THIS MANUAL
For convenience, the following abbreviations are used in this
manual.
ABS Antilock Brake System
assy assembly
ECT Electronic Controlled Transmission
ECU Electronic Control Unit
e.g. Exempi Gratia (For Example)
Ex. Except
in. inch
LH Left-hand
MIG Metal Inert Gas
M/Y Model Year
PPS Progressive Power Steering
RH Right-hand
w/ with
w/o without
INTRODUCTIONIN-16
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CodeMaterial
name Heat *
resistant
temperature
limit
°C (°F) Resistance to
alcohol or gasoline Notes
AAS Acrylonitrile
Acrylic Styrene 80
(176) Alcohol is harmless if applied
only for short time in small
amounts (e.g., quick wiping to
remove grease). Avoid gasoline and or-
ganic or aromatic sol-
vents.
ABS Acrylonitrile
Butadiene Styrene 80
(176) Alcohol is harmless if applied
only for short time in small
amounts (e.g., quick wiping to
remove grease).
Avoid gasoline and or-
ganic or aromatic sol-
vents.
AES Acrylonitrile
Ethylene Styrene 80
(176) Alcohol is harmless if applied
only for short time in small
amounts (e.g., quick wiping to
remove grease). Avoid gasoline and or-
ganic or aromatic sol-
vents.
BMC Bulk
Moulding
Compound
150
(302) Alcohol and gasoline are
harmless. Most solvents are
harmless.
CAB Cellulose
Acetate 80
(176) Alcohol is harmless if applied
only for short time in small
amounts (e.g., quick wiping to
remove grease). Avoid gasoline and or-
ganic or aromatic sol-
vents.
EPDM Ethylene
Propylene 100
(212) Alcohol is harmless.
Gasoline is harmless if applied
only for short time in small
amounts. Most solvents are harm-
less but avoid dipping in
gasoline, solvents, etc.
PA Polyamide
(Nylon) 80
(176) Alcohol and gasoline are
harmless.
Avoid battery acid.
PBT Polybutylene
Terephthalate 160
(320) Alcohol and gasoline are
harmless. Most solvents are
harmless.
PC Polycarbonate 120
(248) Alcohol is harmless. Avoid gasoline, brake
fluid, wax, wax removers
and organic solvents.
PE Polyethylene 80
(176) Alcohol and gasoline are
harmless. Most solvents are
harmless.
PET Polyethylene
Terephthalate 75
(167) Alcohol and gasoline are
harmless.
Avoid dipping in water.
HANDLING PRECAUTIONS
1. The repair procedure for plastic body parts must conform with the type o\
f plastic material.
2. Plastic body parts are identified by the codes in the following chart.
3. When repairing metal body parts adjoining plastic body parts (by brazin\
g, frame cutting, welding, paint-
ing, etc.), consideration must given to the property of the plastic.
*Temperatures higher than those listed here may result in material deforma\
tion during repair.
PLASTIC BODY PARTSPP-2
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LOCATION OF PLASTIC BODY PARTS
Outside Rear View Mirror (ABS)
Instrument Panel Safety Pad (PVC/PUR) Rear Spoiler (SMC)
Front Turn Signal Light (PC/PP)
Center Stop Light (PC)
Mead Light (PC/PP)
Head Light (PC/PP)
Front Bumper Extension
Mounting Bracket (PP)
Quarter Panel
Mud Guard (TPO)
Outside Moulding
Front Fender Mud Guard (TPO)
Front Spoiler (PUR) Cowl Top Ventilation Louver (PP)
Front Bumper Cover (PUR) Side Turn Signal Light (PMMA/ABS)
Cornering Light (PC)
HINT:
wResin material differs with model.
/ Made up of 2 or more kinds of materials.
PLASTIC BODY PARTSPP-4
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