1991 LEXUS SC300 egr

ABBREVIATIONS USED IN THIS
MANUAL
ABS Anti±Lock Brake System J/B Junction Block
A/C Air Conditioner LED Light Emitting Diode
ALR Automatic Locking Retractor LH Left±Hand
APPROX. Approximation LHD Left±Hand Drive
A/T, ATM Automatic Transmission LLC Long Life Coolant (Year Around Coolant)
ATF Automatic Transmission Fluid Max. Maximum
BTDC Before Top Dead Center Min. Minimum
BVSV Bimetal Vacuum Switching Valve MP Multipurpose
CALIF. Vehicles Sold in California N Neutral
CB Circuit Breaker OD, O/D Overdrive
DOHC Double Over Head Cam O/S Oversize
DP Dash Pot P & BV Proportioning and Bypass Valve
ECT Electronic Controlled Transmission PCV Positive Crankcase Ventilation
ECU Electronic Controlled Unit PS Power Steering
EFI Electronic Fuel Injection RH Right±Hand
EGR Exhaust Gas Recirculation RL Rear Left
ELR Emergency Locking Retractor RR Rear Right
EPR Evaporator Pressure Regulator RR, Rr Rear
ESA Electronic Spark Advance SRS Supplemental Restraint System
EVAP Evaporative (Emission Control) SSM Special Service Materials
EX Exhaust (manifold, valve) SST Special Service Tools
Ex. Except STD Standard
FIPG Formed in Place Gasket SW Switch
FL Front Left TDC Top Dead Center
FL Fusible Link TDCL Total Diagnostic Communication Link
FPU Fuel Pressure Up Temp. Temperature
FR Front Right TRAC Traction Control System
FR, Fr Front TWC Three±Way Catalyst
HAC High Altitude Compensation VSV Vacuum Switching Valve
IG Ignition VTV Vacuum Transmitting Valve
IN Intake (manifold, valve) w/ With
INT Intermittent w/o Without
ISC Idle Speed Control
IN±34±
INTRODUCTION Abbreviations Used in This Manual
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3. Grease should not be applied to the steering wheel pad andthe pad should not be cleaned with detergents of any kind.
4. Store the steering wheel pad where the ambient temperature remains below 93
C (200
F), without high humidity and
away from electrical noise.
5. When using electric welding, first disconnect the airbag connector (yellow color and 2 pins) under the steering
column near the combination switch connector before
starting work.
6. When disposing of a vehicle or the steering wheel pad alone, the airbag should be deployed using an SST
before disposal (See page AB±91). Perform the
operation in a place away from electrical noise.
CENTER AIRBAG SENSOR ASSEMBLY
The connector to the center airbag sensor assembly should be
connected or disconnected with the sensor mounted on the floor.
If the connector is connected or disconnected while the center air-
bag sensor assembly is not mounted to the floor, it could cause un-
desired ignition of the airbag system.
WIRE HARNESS AND CONNECTOR
The airbag system's wire harness is integrated with the cowl wire
harness assembly. The wires for the airbag wire harness are en-
cased in a yellow corrugated tube. All the connectors for the sys-
tem are also a standard yellow color. If the airbag system wire har-
ness becomes disconnected or the connector becomes broken
due to an accident, etc., repair or replace it as shown on page
AB±22 .
±
INTRODUCTION Precautions for Vehicles Equipped with SRS AirbagIN±11
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R±12 AIR CONDITIONER SYSTEM RETROFIT ± AC001±98 April 3, 1998
Page 3 of 4
A. Refrigerant handling
1. Do not handle refrigerant in an enclosed area or near an open flame.
2. Always wear eye protection.
3. Avoid getting liquid refrigerant in your eyes or on your skin.
4. Never heat a container with an open flame.
5. Keep containers below 104 °F.
6. When heating a refrigerant can with water, keep the valve above water.
7. Never reuse empty service cans.
B. Replacing parts 1. Plug off any open connections to prevent the entry of moisture and dust.
2. Do not remove plugs from Receiver ports until it is ready for installati\
on.
C. Tightening connecting parts
1. Apply a few drops of ND±Oil 8 compressor oil to O±ring fittings be\
fore tightening.
2. Avoid twisting refrigerant piping when installing R134a service fitting a\
dapters.
3. Tighten all fittings to specified torque.
D. Recharging with A/C ªonº
1. Never open the high side valve with the engine running.
2. Never run the A/C system when low on refrigerant as compressor damage ma\
yoccur.
3. Never charge the system with liquid refrigerant with the engine running.\
4. Be careful not to overcharge the system.
NOTE:
Oil removed during R±12 evacuation should not be used with an R134a Syst\
em.
A. Vehicle Inspection:
Ensure the integrity of the A/C system before proceeding with retrofit.
B. Recover R±12 using R±12 recovery/recycling/recharging equipment: Follow Lexus recommended procedure.
C. Install R134a service fitting adapters: 1. Remove valve cores from R±12 service fittings and discard.
2. Clean external threads of the R±12 service fittings.
3. Apply adhesive to threads (Loctite 262 or equivalent), screw on R134a \
adapterfittings, and tighten to 13 ft±lb.
NOTE:
Vehicles with more than 2 service fittings will require the installation \
of additional
adaptors. All service fittings must have R134a adaptors installed.
D. Replace piping and hose O±rings:
1. Disconnect discharge hose from compressor.
2. Remove and discard old O±rings.
3. Lubricate with ND±Oil 8 and install new O±rings.
4. Disconnect discharge hose from condenser.
5. Lubricate and install retrofit O±rings with ND±Oil 8.
6. Reconnect hoses and torque to specification. (Specifications can be fou\
nd in applicable manuals/guides.)
Service
Precautions
Repair
Procedure
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3. Grease should not be applied to the steering wheel pad and the pad should not b\
e cleaned with detergents
of any kind.
4. Store the steering wheel pad where the ambient temperature remains below 93 °C (200 °F), without high
humidity and away from electrical noise.
5. When using electric welding, first disconnect the airbag connector (yellow \
color and 2 pins) under the steering column near the combination switch connector before starting work.
6. When disposing of a vehicle or the steering wheel pad alone, the airbag shou\
ld be deployed using an SST before disposal (See page AB±91). Perform the operation in a place away from electrical noise.
CENTER AIRBAG SENSOR ASSEMBLY
The connector of the center airbag sensor assembly should be connected or d\
isconnected with the sensor
mounted on the floor. It the connector is connected or disconnected while the center airbag \
sensor assem-
bly is not mounted to the floor, it could cause undesired ignition of the airbag system.
WIRE HARNESS AND CONNECTOR
The airbag system wire harness is integrated with the cowl wire harness ass\
embly. The wires for the airbag
wire harness are encased in a yellow corrugated tube. All the connectors\
for the system are also a standard
yellow color. If the airbag system wire harness becomes disconnected or the connecto\
r becomes broken
due to an accident, etc., repair or replace it as shown on page AB±20.
AB±4
SRS AIRBAG
± General Description
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INSTALLATION OF FRONT SEAT BELT
(See page BO±70)
1. INSTALL FRONT SEAT INNER BELT
Torque: 43 N Vm (440 kgf Vcm, 32 ft Vlbf)
2. INSTALL FRONT SEAT OUTER BELT
Torque:
Retractor bolt 43 N Vm (440 kgf Vcm, 32 ft Vlbf)
Anchor bolt 43 N Vm (440 kgf Vcm, 32 ft Vlbf)
HINT: After installing the anchor bolt, check that the an-
chor turns smoothly.
3. INSTALL FOLLOWING PARTS: (a) Quarter trim and roof side inner garnish
(b) Front pillar garnish
(c) Rear seat cushion and seat back
(d) Front seat
INSPECTION OF FRONT SEAT BELT
[Emergency Locking Retractor (ELR) Type]
1. RUNNING TEST (IN SAFE AREA)
(a) Fasten the front seat belt.
(b) Drive the car at 10 mph (16 km/h) and make a very hardstop.
(c) Check that the belt is locked and cannot be extended at this time.
HINT: Conduct this test in a safe area. If the belt does not
lock, remove the belt mechanism assembly and conduct the
following static check. Also, whenever installing a new belt
assembly, verify the proper operation before installation.
2. STATIC TEST (a) Remove the locking retractor assembly.
(b) Tilt the retractor slowly.
(c) Verify that the belt can be pulled out at a tilt of 15degrees or less, and cannot be pulled out at over 45
degrees of tilt.
If a problem is found, replace the assembly.
BO±72
±
BODY Seat Belt (Front Seat Belt)
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SRS AIRBAG
(See page AB±2)
The LEXUS SC300 is equipped with an SRS (Supplemental Restraint System)\
airbag.
Failure to carry out service operations in the correct sequence could cause the airbag system to deploy,
possibly leading to a serious accident.
When removal or installation of airbag parts and the yellow wire harness\
and connector for the airbag is
necessary, refer to the precautionary notices in the AB section before performing\
the operation.

Work must be started after 20 seconds or longer from the time the ignition switch is set to the LOCK
position and the negative (±) terminal cable is disconnected from the batte\
ry.
(The airbag system is equipped with a back±up power source so that if wor\
k is started within 20 se-
conds of disconnecting the negative (±) terminal cable of the batte\
ry, the airbag may be deployed.

To avoid erasing the memory of each memory system, never use a back±up power supply from
outside the vehicle.

Before repairs, remove the airbag sensors if shocks are likely to be applied t\
o the sensors during
repaires.

The front airbag sensor set bolt has been anti±rust treated. When the\
sensor is removed, always
replace the set bolt with a new one.

If the front airbag sensors, center airbag sensor or steering wheel pad ha\
ve been dropped, or if there
are cracks, dents or other defects in the case, bracket or connector, replace them with new ones.

Never use airbag parts from another vehicle. When replacing parts, repla\
ce them with new parts.

Do not expose the front airbag sensors, center airbag sensor or steering w\
heel pad directly to hot air
or flames.

The airbag system's wire harness is integrated with the cowl wire harness assembly. The wires for the
airbag wire harness are encased in a yellow corrugated tube. All the connector\
s for the system are
also a standard yellow color. If the airbag system wire harness becomes disconnected or the
connector becomes broken due to an accident, etc., repair or replace it as shown \
on page AB±20.

The steering wheel must be fitted correctly to the steering column with the\
spiral cable at the neutral
position; otherwise, cable disconnection and other troubles may result. \
Refer to page AB±14 of this
manual concerning correct steering wheel installation.

When removing the steering wheel pad or handling a new steering wheel pad, i\
t should be placed with
the pad top surface facing up. In this case, the twin±lock type connector lock lever should be in the
locked state and care should be taken to place it so the connector will not be damaged. (\
Storing the
pad with its metallic surface up may lead to a serious accident if the a\
irbag inflates for some reason.)

Grease should not be applied to the steering wheel pad and the pad should not \
be cleaned with
detergents of any kind.

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

Information labels are attached to the periphery of the airbag component\
s. Follow the notices.

When the ignition switch is at ACC or ON and the airbag warning light remains on, the cent\
er airbag
sensor assembly has detected a malfunction code. (See page AB±30).
BO±8
±
BODY General Information
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(c) Pull the cable from front wheel housing to remove it.
INSTALLATION OF HOOD LOCK
CONTROL
(See page BO±24)
1. BEFORE INSTALLING PARTS, COAT LOCK WITH MP GREASE
Apply MP grease to the sliding surface of the lock.
2. INSTALL HOOD LOCK CONTROL CABLE (a) Push the rear side cable through the grommet.
(b) Using the screwdriver, push the cable stopper into thegrommet.
HINT: Do not damage the grommet with the screwdriver.
(c) Clamp the cable to the junction block.
(d) Pass the front side cable through the upper radiator
support.
3. INSTALL HOOD RELEASE LEVER
4. INSTALL HOOD LOCK TEMPORARILY
5. CHECK HOOD LOCK CONTROL FOR PROPER OPERATION
After checking for proper operation, tighten the nut and two
bolts to install the lock.
6. INSTALL FOLLOWING PARTS: (a) Hood release lever
(b) Fender splash shield
(c) LH fender liner
(d) LH front fender wheel opening moulding
(e) Front bumper
BO±26
±
BODY Hood (Hood Lock Control)
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Terminals of ECU
WIRING DIAGRAM
No.SymbolTerminal NameNo.SymbolTerminal Name
W8±1+BPower SourceW8±6KSWKey Unlock Warning Switch
W8±2LSWD1Door Unlock Detection Switch LHW8±7EGround
W8±3LSWPDoor Unlock Detection Switch RHW8±8
W8±4UL1Door Key Lock and Unlock SwitchW8±9LSWD2Door Lock Motor LH
W8±5L1Door Key Lock and Unlock SwitchW8±10DSWDDoor Open Detection Switch
BE±452±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
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