steering LEXUS SC400 1991 Service Manual PDF

5. USAINSPECT COMBINATION SWITCH CIRCUIT
(a) Pull the spool body to forward and separate spool bodyfrom steering column.
(b) C onnect the wire harness side connector to the
combination switch and inspect wire harness side
connector from the back side as shown.
(Light Control Switch Circuit)
Check forTester connectionConditionSpecified value
ContinuityB4±GroundConstantContinuity
(Dimmer Switch Circuit)
Check forTester connectionConditionSpecified value
*1B7 GroundLight Control Switch PositionOFF or TAILNo voltage*1B7±GroundLight Control Switch PositionHEADBattery voltage
VoltageLow beamNo voltage
*1B9±GroundDimmer Switch PositionFlash or High
beamBattery voltage
ContinuityB18±GroundConstantContinuity
*1: USA
(Turn Signal Switch Circuit)
Check forTester connectionConditionSpecified value
VoltageA3±GroundHazard Warning Switch ONBattery voltage
e 0 V
Ignition Switch ON and turn
signal switch positionRightBattery voltage
e 0 V
A4±GroundHazard Warning Switch ONBattery voltage
e 0 V
Ignition Switch ON and turn
signal switch positionLeftBattery voltage
e 0 V
ContinuityA12±GroundConstantContinuity
(Cornaring Light Control Switch Circuit)
Check forTester connectionConditionSpecified value
VoltageA8±GroundLight control switch HEAD andLOBattery voltagegg
dimmer switch positionHI or FLASHNo voltage
ContinuityA10±GroundConstant*2 Continuityy
A11±GroundConstant*2Continuity
*2 There is resistance because this circuit is grounded through the bulb.
If the circuit is not as specified, refer to BE±34 wiring diagram
and inspect the circuits connected to other parts.
±
BODY ELECTRICAL SYSTEM Lighting SystemBE±47
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Parts Inspection
(Combination Meter Assembly)
REMOVAL AND INSTALLATION OF
COMBINATION METER ASSEMBLY
1. REMOVE COMBINATION METER ASSEMBLY(a) Lower the steering wheel fully and set it in the far position.
(b) Turn the ignition switch to LOCK and disconnect battery terminals.
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and negative (±) terminal
cable is disconnected from the battery.
(c) Remove instrument cluster finish panel.
(d) Remove four screws and disconnect three connectors.
(e) Remove combination meter assembly.
2. INSTALL COMBINATION METER ASSEMBLY For installation, follow the removal procedure in reverse.
±
BODY ELECTRICAL SYSTEM Combination MeterBE±103
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TORQUE SPECIFICATIONS
BR03B±0G\
 
\

\
Part tightened
 

N
Vm
 

kgf
Vcm
 

ft
Vlbf
\
 \
Master cylinder x Piston stopper bolts 10 100 7
\
 \
Master cylinder x Reservoir 1.7 17.5 15.2 in. Vlbf
\
 
\

\
Master cylinder x Brake booster 

13 

130 

9
\
 \
Brake tube union nut 15 155 11
\
 \
Brake booster clevis lock nut 25 260 19
\
 \
Brake booster x Pedal bracket 15 150 11\
 
\

\
Bleeder plug (TRAC actuator and TRAC accumulator)
 

8.3
 

85
 

74 in.
Vlbf
\
 \
Bleeder plug 11 11 0 8
\
 \
Front disc brake torque plate x Steering knuckle 11 8 1,200 87
\
 \
Front disc brake cylinder installation bolt 34 350 25\
 
\

\
Front disc brake cylinder x Flexible hose bolt
 

30
 

310
 

22
\
 \
Rear disc brake torque plate x Axle carrier 104 1,065 77
\
 \
Rear disc brake cylinder installation bolt 34 350 25
\
 
\

\
Rear disc brake x Flexible hose union bolt 

30 

310 

22
\
 \
Parking brake lever x Floor 59 600 43
\
 \
Parking brake cable No.1 x Floor 9 80 69 in.
Vlbf
\
 \
Parking brake cable retainer x Floor 5.4 55 48 in. Vlbf\
 
\

\
Parking brake cable clamp x Floor
 

19
 

190
 

14
\
 \
ABS actuator x Actuator bracket 5.4 55 48 in.
Vlbf
\
 \
ABS actuator bracket x Body 19 195 14
\
 
\

\
Front speed sensor installation bolt 

7.8 

80 

69 in.
Vlbf
\
 \
Rear speed sensor installation bolt 7.8 80 69 in. Vlbf
\
 \
TRAC pump bracket x Body 19 195 14
\
 \
TRAC pump or accumulator x Union bolt 46 465 34
BR±230±
BRAKE SYSTEM SERVICE SPECIFICATIONS
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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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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
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Steering Wheel Pad (PUR)A/C and Blower Unit (PP) Luggage Compartment Door
Striker Cover (PP)
Fuel Filler Opening
Lid (PBT)Rear Combination
Light (PMMA/PC/PP)
Door Scuff Outside Plate (PP) Door Scuff Inside Plate (PP)
Quarter Ventilation Duct (PP) License Plate
Light (PC/PP)
Rear Under Side Cover (PUR)
Rear Bumper Cover (PUR)
HINT:
wResin material differs with model.
/ Made up of 2 or more kinds of materials.
PLASTIC BODY PARTSPP-6
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mm (in.)
BO6850
BO6850
(Three-Dimensional Distance) (Three-Dimensional Distance)
SymbolName Hole dia. Symbol Name
Hole dia.
A, a Steering gear box installation hole
front 12 (0.47)
E, eLower arm installation hole-front
25
y16
(0.98 y0.63)
B, b Upper arm installation hole front 14 (0.55) F, f Lower arm installation hole rear25
y16
(0.98 y0.63)
C, c Suspension crossmember installation
hole front - lower
15 (0.59) G, g Upper arm installation hole rear
14 (0.55)
D, d Steering gear box installation hole-
lower 12 (0.47)
H, hSuspension crossmember installation
hole rear-lower
RH 15
y13 (0.59 y0.51)
LH 13 (0.51)
SUSPENSION CROSSMEMBER DIMENSION DRAWINGS
BODY DIMENSIONSDI-10

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Steering Wheel Pad (Airbag and Inflator)
Junction Block No. 1 Center Airbag
Front Airbag Sensor
Front Airbag Sensor
Warning Light Spiral Cable (in Combination Switch)
HANDLING PRECAUTIONS ON RELATED COMPONENTS
1. SRS AIRBAG
Locations of Airbag Components
This vehicle has an SRS AIRBAG (referred to as the airbag in the remain\
der of this manual).
When handling airbag components (removal, installation or inspection, e\
tc.), always follow the directions
given in the repair manual for the relevant model year to prevent the oc\
currence of accidents and airbag
malfunction.
Also take the following precautions when repairing the body:

Work must be started after 20 seconds or longer from the time the ignitio\
n switch is set to the LOCK
position and the negative (-) terminal cable is disconnected from the \
battery.
(The airbag system is equipped with a back-up power source so that if w\
ork is started within 20 seconds
of disconnecting the negative (-) terminal cable of the battery, the airbag may be deployed.)
When the negative (-) terminal cable is disconnected from the battery, memory of the clock and audio
systems will be cancelled. So before starting work, make a record of the\
contents memorized by each
memory system. Then when work is finished, reset the clock and audio sys\
tems as before.
When the vehicle has tilt and telescopic steering, power seat, and outsi\
de rear view mirror, which are all
equipped with memory function, it is not possible to make a record of th\
e memory contents.
So when the operation is finished, it will be necessary to explain this \
fact to the customer, and request
the customer to adjust the features and reset the memory.
To avoid erasing the memory of each memory system, never use back-up powe\
r supply from outside
the vehicle.

When using electric welding, first disconnect the airbag connector (yel\
low color and 2 pins) under the
steering column near the combination switch connector before starting wo\
rk.
Sensor Assembly
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Front
Fender Area
Area from the Front Fender Apron
to the Cowl Side Member


Before repairing the body, remove the airbag sensors if, during repair, shocks are likely to, be applied
to the sensors due to vibrations of the body or direct tapping with tool\
s or other parts.

Do not expose the airbag sensors or the steering wheel pad directly to h\
ot air or flames.
NOTICE:
1) The maximum ambient temperature tolerance is 120
°C (248°F) for the front airbag sensor, 105°C
(221
°F) for the center airbag sensor assembly and 93°C (200°F) for the steering wheel pad. If it is
possible that the ambient temperature may reach or exceed the temperatur\
e limit, remove the sen- sors and the steering wheel pad from the vehicle or protect them with a \
hot insulation material be-fore starting work.
2) Prior to welding, remove adjacent airbag sensors or the steering wheel p\
ad from the vehicle or protect them with fire-proof covers.

If the front fender or periphery of the vehicle is damaged, visually ins\
pect for damage to the front air-
bag sensor using the inspection procedures described in section AB of th\
e repair manual for the rele-
vant model year.
Also check that the dimensions of the body where the front airbag sensor\
is installed match those in
the body dimension drawings.
(The airbag may malfunction; or may not work, if the mounting angle or \
dimensions of the sensor
mount are not correct.)

If the vehicle is damaged, visually inspect for damage to the steering w\
heel pad using the inspection
procedures described in section AB of the repair manual for the relevant\
model year.

When removing the steering wheel pad or handling a new steering wheel pa\
d, keep the pad upper
surface facing upward. Also, lock the lock lever of the twin lock type c\
onnector at the rear of the pad
and take care not to damage the connector.
(Storing the pad with its metallic surface up may lead to a serious acc\
ident if the airbag inflates for
some reason.)

Store the steering wheel pad where the ambient temperature remains below\
93 °C (200 °F), without
high humidity and away from electrical noise.

Be careful not to let painting materials contact the airbag sensors.

Information labels are attached to the periphery of the airbag component\
s. Follow the NOTICES.
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Fuel Pump ECUAuto Antenna Motor and Relay
Power Seat ECU
(For Passenger's Seat)
Power Seat ECU
(For Driver's Seat) CD Automatic Changer
Wireless Door Lock ECU
Moon Roof Control Relay
Locations of ECUs (Cont'd)
Many ECUs are mounted in this vehicle.
Take the following precautions during body repair to prevent damage to th\
e ECUs.


Before starting electric welding operations, disconnect the negative (-\
) terminal cable from the battery.
When the negative (-) terminal cable is disconnected from the battery, memory of the clock and audio
systems will be cancelled. So before starting work, make a record of the\
contents memorized by each
memory system. Then when work is finished, reset the clock and audio sys\
tems as before.
When the vehicle has tilt and telescopic steering, power seat and outsid\
e rear view mirror, which are all
equipped with memory function, it is not possible to make a record of th\
e memory contents.
So when the operation is finished, it will be necessary to explain this \
fact to the customer, and request
the customer to adjust the features and reset the memory.

Do not expose the ECUs to ambient temperatures above 80 °C (176 °F).
NOTICE: If it is possible the ambient temperature may reach 80°C (176°F) or, more, remove the ECUs
from the vehicle before starting work.

Be careful not to drop the ECUs and not to apply physical shocks to them\
.
5. COMPONENTS ADJACENT TO THE BODY PANELS
Various types of component parts are mounted directly on or adjacently to\
the body panels.
Strictly observe the following precautions to prevent damaging these com\
ponents and the body panels
during handling.

Before repairing the body panels, remove their adjacent components or ap\
ply protective covers over
the components.

Before prying components off using a screwdriver or a scraper, etc., attach protective tape to the tool
tip or blade to prevent damaging the components and the body paint.

Before removing components from the outer surface of the body, attach protective tape to the body to
ensure no damage to painted areas.
HINT: Apply touch-up paint to any damaged paint surfaces.

Before drilling or cutting sections, make sure that there are no wires, \
hoses, etc., on the reverse side.
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