1991 LEXUS SC400 steering

LOWER SUSPENSION ARM REMOVAL
SA1A4±01
1. JACK UP VEHICLE AND REMOVE FRONT WHEEL
2. REMOVE ENGINE UNDER COVER
3. REMOVE FRONT BRAKE CALIPER
(b) Hang up the brake caliper using wire, etc.
4. DISCONNECT STABILIZER BAR LINK FROM LOWERSUSPENSION ARM
Remove the nut and disconnect the link from the arm.
5. DISCONNECT STEERING KNUCKLE
(a) Remove the clip and nut.
(b) Using SST, disconnect the steering knuckle from the lower suspension arm.
SST 09628±62011
6. REMOVE LOWER SUSPENSION ARM
(a) R e m o v e t h e b o l t a n d n u t a n d d i s c onnect the lower
suspension arm from the shock absorber.
±
SUSPENSION AND AXLE FRONT SUSPENSIONSA±41
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LOWER SUSPENSION ARM
INSTALLATION
SA1A5±01
1. INSTALL SHOCK ABSORBER BRACKET TO LOWERSUSPENSION ARM
Install the bracket to the arm with the 2 bolts.
Torque: 52 N Vm (530 kgf Vcm, 38 ft Vlbf)
2. INSTALL LOWER SUSPENSION ARM
(a) Install the lower suspension arm to the body and temporarily
install the adjusting cams and nut.
(b) Connect the lower suspension arm to the steering knuckle.
Torque: 125 N Vm (1,270 kgf Vcm, 92 ft Vlbf)
(c) Install a new clip.
(d) Connect the shock absorber to the lower suspension arm
with the bolt and nut.
Torque: 143 N Vm (1,460 kgf Vcm, 106 ft Vlbf)
2. CONNECT STABILIZER BAR LINK
(a) Connect the stabilizer bar link to the lower suspension arm
with the nut.
Torque: 74 N Vm (750 kgf Vcm, 54 ft Vlbf)
±
SUSPENSION AND AXLE FRONT SUSPENSIONSA±43
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3. INSTALL BRAKE CALIPERInstall the brake caliper to the steering cnuckle with the 2
bolts.
Torque: 118 N Vm (1,200 kgf Vcm, 87 ft Vlbf)
4. STABILIZE SUSPENSION
(a) Install the front wheel and jack down the vehicle.
Torque: 103 N Vm (1,050 kgf Vcm, 76 ft Vlbf)
(b) Bounce the vehicle up and down several times to stabilize the
suspension.
5. TORQUE ADJUSTING CAMS AND NUTS
(a) Jack up the vehicle and remove the front wheel.
(b) Support the lower arm with jack.
(c) Align the matchmarks and torque the adjusting cams and nuts with the vehicle weight on the suspension.
Torque: 226 N Vm (2,300 kgf Vcm, 166 ft Vlbf)
6. INSTALL ENGINE UNDER COVER
7. INSTALL FRONT WHEEL
Torque: 103 N Vm (1,050 kgf Vcm, 76 ft Vlbf)
8. CHECK FRONT WHEEL ALIGNMENT
(See page SA±5)
SA±44
±
SUSPENSION AND AXLE FRONT SUSPENSION
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27
Position of Parts in Engine Compartment
I 1 ISC Valve S 3Speed Sensor No. 1
I 2 Igniter S 4 Speed Sensor No. 2 (for ECT)
I 4 Ignition Coil S 6 Starter
I 6 Injector No. 1 S 7 Starter
I 7 Injector No. 2 S 8 Sub Throttle Actuator
I 8 Injector No. 3 S 9 Sub Throttle Position Sensor
I 9 Injector No. 4
I 10 Injector No. 5 T 1 Theft Deterrent Horn
I 11 Injector No. 6 T 2 Throttle Position Sensor T 3 Traction Brake Actuator
K 1 Knock Sensor No. 1 (on Front Side) T 4 Traction Brake Actuator
K 2 Knock Sensor No. 2 (on Rear Side) T 5 Traction pump and Motor
N 1 Neutral Start SW, Back±Up Light SW and A/T Indicator SW V 1 VSV (for EGR) (Exc. USA Spec) (for A/T) V 2 VSV (for EVAP)
N 2 Noise Filter (for Defogger System) V 4 VSV (for Water Valve)
N 3 Noise Filter (for Ignition System) V 7 VSV (for Intake Control Valve)
O 2 Oil Pressure SW W 1 Washer Level SW
O 3 Oxygen Sensor Main No. 1 (on Front Side) W 2 Washer Motor
O 4 Oxygen Sensor Main No. 2 (on Rear Side) W 3 Water Temp. Sender W 5 Wiper Motor
P 1 PPS Solenoid
P 20 Power Steering Pressure SW
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567 8
EB1
EC ED D DCCCCD
CCCC
C IJ2 IJ2
IG2
EB1
C D C DC C CCC
DDCDDDDDCCCCC
ED
1 2
1
2 23
1 23
14
4 234 51
25
1346
2
B±O
B±W B±OB±Y
B± R
B± R
W
R± LBR
B± R B±Y W
L±R
B±Y LG
GR±Y B Y B
G±W L±Y
R± G P B± R
B± R
18 19 17 16 15 46 23 44 34
31 32 34 32 35 33 33 24 2 76 1 37B
B± Y
B±R W
L±R
W± B
W± B
BR
LG±BL±WV±R
G± YB± Y
B± O P
B±W B± O
BR
W
L±R
B±R
P
B±O
BR
BR
#30 #20 #40 #50 #60 THG ACMG THW A/C
B±R
B±R
B±R
EB1
Fro m
Spe ed Sen sor
< 21±7>
P± L
Y± L
V± Y
Y± G
W± Y Y±R
L±R
Y± B
Y± G L±R
L±R
BR
BR
65 63 42 64 43 38 39 40 58 57 41 45 66 A9
AIR FLOW METER
From Trac tion ECU
< 8±8>
From I gniter
< 1±6>
7P
E2 IDL2 VTA2
IDL1
VTA1
THA
VC KS
IGT
IGF
VT 01
VT 02
NEO
TR
IGSW
NS W
SP1
M±REL
BATT
ISC3
ISC1
ISC4
ISC2
+B1
+B I1
ISC
VALVEBR
R±BBR
Y± L
L±R
R
Y
L±R
L±R
L±R
BR
L±R
BR
BR
BR
BR
BR W
G
From Magnet ic
Cl ut ch Rel ay
< 22±1>
To A/ C Amp lif ie r
< 22±7>
E3
EGR GAS TEMP. SENSOR
E2
EFI WATER TEMP. SENSOR
S9
SUB THROTTL E
POSITI ON SENSOR T2
THROTTLE
POSITI ON SENSOR
BR
Engine Control
2LEXUSSC300
(
Cont ' d )
ENGI NE AND ECT ECU, ENGI NE ECU *
1: (
w/ Trac tion Control )
(
* 1)
( * 2)
( * 1)
( * 2)
(
* 1 ) *
2:
(
w/ o Tr a ct i o n Co nt r ol )
(
* 1 ) To Trac ti on
ECU< 8±8>
R±B
R
4311 8
B±O
BR (
* 3)
(
* 3) *
3: (
US A S pe c. )
* 4:
(
Ex . USA Spe c. )
E9 , E10 DC
BR
Front side of
intake manifold Rear side of
c ylinder head RH Rear side of
c ylinder head RH
C
C
C 1 2
1
2
2
1
C
C
C
C
C
C
D
D
C
C
C
C
D
D
C
D
C
D
D
20
77
27
7
25
26
22
21
80
79
4
69
4
6
29
20
28
19
17
V7
VSV (
for Int ake
Contr ol Valve )
V2
VSV
(
for EVAP )
V1
VSV
(
for EGR )
BY1
BY1
BY1 BY1
BR
R±B
(
* 4 )
W
(
* 4 )
B±R
BR±W
(
* 3 )
R±L
(
* 3
)
3142 1256
IK2
IK2
12
22
C
C
1
O3
OXYGEN SENSOR
MAIN No. 1
(
ON Front Side )
C48 71 61 75 74
1
O4
OXYGEN SENSOR
MAIN No. 2
(
ON Rear Side )
C
D
1 2
35 47
P2 0
POWER STEERING
PRESSURE SW
IK11
IJ1
IJ1
(SHIELDED )2341 C
C
1
1 49
50
D1 3
DI ST RI B UTOR
( SHIELDED )
EC
Front side of
intake manifold
G±Y G± R
8
14
K1
No. 1(
ON Fr ont Side )
KNOCK SENSOR
K2
No. 2 (
ON Rear Side ) BR BR
BR
W
W L
B Y
R R±G
P
W± B
W± B G±W
L±Y
GR±Y LG
B±Y
G±Y
BR
BR
BR
G1 G2 G± NE
#10
TT TE2 VF2 TE1 VF1 W STP E1 E1 1 E0 2 E01 DI FPC G1 G2 G± NE KNK1 KNK2 STA ACI S
PS OX2 OX1 HT OX3 EGR EVAP 39
G± R G±B
B±W BR± W
BR± W
BR
B±R
B±R
B±R
B±R
W
BR± W
W
R±L
BR BR
BR
R±L W
LG±B BR
BR
(
SHI ELDED )
(
SHI EL DED )
(
SHI ELDED )
( SHIELDED )
O8
OXYGEN SENSOR SUB
(
for California )
BR
BR
Y B
R± L
BR
(* 4)
(
* 4)
(A/ T )
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244
Rear Window Defogger
and Mirror Heater
Remote Control Mirror
Seat Heater
Shift Lock
SRS AIRBAG
Starting
Taillight and
Stop Light
Theft Deterrent and
Door Lock Control
Turn Signal and Hazard
Warning Light
Wiper and Washer
Wireless Door Lock
Remote Control
Horn
Ignition
Illumination
Interior Light
Liquid Crystal Inner
Rear View Mirror
Moon Roof
Power Seat
(Driver's)
Power Source
Power Window
PPS (Progressive
Power Steering
Radio and Player
ABS and
Traction Control
Automatic
Air Conditioner
Auto Antenna
Back±Up Light
Cellular Mobile
Telephone
Charging
Cigarette Lighter
Combination Meter
Cruise Control
Headlight and Light Auto
Turn Off (for USA)
Headlight
(for Canada) ECT and
A/T Indicator
4±2 16±2 7±2
3±2 21±2 3±8
14±4
18±2 19±4 (w/o CD Player)
20±8 (w/ CD Player)9±2 8±2
4±7 (for USA)
5±7 (for Canada)11±2
12±311±5 (w/ Driving
Position Memory)11±7 12±1 1±5 13±2
6±2 15±2 14±2
13±2
17±7 7±3 17±2 15±3
1±315±2
Power Tilt and
Power Telescopic12±2
Power Seat (Passengerºs
and Electric Tension Header
5±2 2±2
Cornering Light ABS (Anti±Lock
Brake System)
22±2
Engine Control Unlock and Seat
Belt Warning
1±2
23±2 (w/o Driving
Position Memory)
1 23±119±2 (w/o CD Player
20±2 (w/ CD Player
14±310±2 (w/ Memory)
5±7 (w/o Memory)
4±3 (for USA)
5±3 (for Canada) 4±5 (for USA)
5±5 (for Canada)
OVERALL ELECTRICAL WIRING DIAGRAM
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186
PPS (PROGRESSIVE POWER STEERING)
1H
12 1E 12 1I
9
IJ1
10
IK1
7IK1 6IG2
7
IJ2
6IJ2 16
12
10A
GAUGE
15A
E CU±IG
COMBINATION METER SPEED
SENSOR
NO. 1 PPS SOLENOID
PPS ECU
321 5 4
2
3
1 OUT
VCC GN D
Y SPD E SOL+ SOL±
+B
B±RY Y
PP W±BLG±B
LG±R
LG±B
LG±R
W±B
R
R L±R
Y
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
S3 P1
P2
C14
BR
13 15 10 1143D
13 3A
4
Y
IH IJ
B
2
A
2 SHORT
CONNECTOR
L±R L±R
S22 , S 2 3
BA
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11015
14
13 12
12345 123
GRAY GRAY
C14 P 1 P 2 S 3
X
2 2
BA
S22 S23
187
THE PPS (HYDRAULIC REACTION TYPE) CONTROLS THE HYDRAULIC PRESSURE APPLIED\
TO THE HYDRAULIC REACTION
CHAMBER IN THE GEAR BOX CONTROL UNIT USING THE PPS ECU, TO CHANGE THE STEERING FORCE AND PROVIDE OPTIMUM
STEERING FEELING AT ANY VEHICLE SPEED AND UNDER ANY STEERING CONDITIONS.
(PPS OPERATION)
WHEN THE IGNITION SW IS TURNED ON THE STARTING CURRENT FLOWS FROM THE ECU±IG FUSE TO TERMINAL 4 OF THE PPS
ECU. THE SPEED SENSOR MONITORS THE VEHICLE SPEED AND TRANSMITS CONTROL SIGNALS TO TERMINAL 3 OF THE ECU.
WHEN THE VEHICLE SPEED IS LOW, THE PPS ECU SENDS A HIGHER±VOLTAGE FROM TERMINAL 1 OF THE ECU " TERMINAL 1 OF
THE SOLENOID VALVE " TERMINAL 2 " TERMINAL 5 OF THE ECU " TERMINAL 2 " GROUND, INCREASING THE SOLENOID VALVE
OPENING ANGLE TO PROVIDE COMFORTABLE STEERING OPERATION. WHEN THE VEHICLE SPEED IS HIGH, THE PPS ECU
DECREASES THE SOLENOID VALVE OPENING ANGLE BY REDUCING THE VOLTAGE TO THE VALVE TO PROVIDE RESPONSIVE
STEERING FEELING.
P 1 PPS SOLENOID
1±2 : APPROX. 7.7
(25 °C, 77°F)
P 2 PPS ECU
4±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
2±GROUND : ALWAYS CONTINUITY
1±5 : APPROX. 0.8A WITH VEHICLE SPEED BELOW 20 KM/H ( 12 MPH)
APPROX. 0.45A WITH VEHICLE SPEED AT 80 KM/H ( 48 MPH)
APPROX. 0.2A WITH VEHICLE SPEED ABOVE 160 KM/H ( 96 MPH)
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C1428P 229S22B29
P 127S 327S23A29
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1E20INSTRUMENT PANEL WIRE
1H20COWL WIRE1I20COWL WIRE
3A22INSTRUMENT PANEL WIRE3D22INSTRUMENT PANEL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IG236INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO. 5)
IJ136ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)IJ236ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)
IK136ENGINE WIRE AND INSTRUMENT PANEL WIRE (RIGHT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IH36UNDER THE ASHTRAY LH
IJ36RIGHT KICK PANEL
SYSTEM OUTLINE
SERVICE HINTS
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