LEXUS SC400 1991 Service Repair Manual

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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STANDARD BOLT TORQUE SPECIFICATIONS
HOW TO DETERMINE BOLT STRENGTH
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INTRODUCTION Standard Bolt Torque SpecificationsIN±35
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SPECIFIED TORQUE FOR STANDARD BOLTS
ClassDiameterPitchSpecified torqueClassmmmmHexagon head boltHexagon flange bolt
NVmkg Vcmft VlbN Vmkg Vcmft Vlb
6155548 in. Vlb66052 in. Vlb
81.2512.5130 9 14145 10
4T101.2526260 19 29290 21
121.2547480 35 53540 39
141.574760 55 84850 61
161.511 51,150 83 ±±±
616.56556 in. Vlb7.57565 in. Vlb
81.2515.5160 12 17.5175 13
5T101.2532330 24 36360 265T121.2559600 43 65670 48
141.591930 67 1001,050 76
161.51401,400 101 ±±±
6188069 in. Vlb99078 in. Vlb
81.2519195 14 21210 15
6T101.2539400 29 44440 326T121.2571730 53 80810 59
141.511 01,100 80 1251,250 90
161.51701,750 127 ±±±
6110.511 08121209
81.2525260 19 28290 21
7T101.2552530 38 58590 437T121.2595970 70 1051,050 76
141.51451,500 108 1651,700 123
161.52302,300 166 ±±±
81.2529300223333024
8T101.2561620 45 68690 50
121.2511 01,100 80 1201,250 90
81.2534340253738027
9T101.2570710 51 78790 57
121.251251,300 94 1401,450 105
81.2538390284243031
10T101.2578800 58 88890 64
121.251401,450 105 1551,600 116
81.2542430314748035
11 T101.2587890 64 97990 72
121.251551,60011 61751,800130
IN±36±
INTRODUCTION Standard Bolt Torque Specifications
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INTRODUCTION
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INTRODUCTIONIN±1
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HOW TO USE THIS MANUAL
INDEX
An INDEX is provided on the first page of each sec-
tion to guide you to the item to be repaired.
To assist you in finding your way through the manual,
the Section Title and major heading are given at the
top of every page.
ALPHABETICAL INDEX
An ALPHABETICAL INDEX is also provided at the
end of this manual so that you can rapidly find the
item and page you are searching for.
GENERAL DESCRIPTION
At the beginning of each section, a General Descrip-
tion (Precautions) is given that pertains to all repair
operations contained in that section.
Read these precautions before starting any
repair task.
REPAIR PROCEDURES
Most repair operations begin with an overview il-
lustration. It identifies the components and shows
how the parts fit together.
Example:
PREPARATION
Preparation lists the SST (Special Service Tools), rec-
ommended tools, equipment, lubricant and SSM
(Special Service Materials) which should be prepared
before beginning the operation and explains the pur-
pose of each one.
TROUBLESHOOTING
TROUBLESHOOTING tables are included for each
system to help you diagnose the problem and find the
cause.
The fundamentals of how to proceed with trouble±
shooting are described on page IN±15. Be sure to
read this before performing troubleshooting.
IN±2
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The procedures are presented in a step±by±step format:
wThe illustration shows what to do and where to do it.
w The task heading tells what to do.
w The detailed text tells how to perform the task and gives
other information such as specifications and warnings.
Example:
This format provides the experienced technician with a FAST
TRACK to the information needed. The upper case task
heading can be read at a glance when necessary, and the
text below it provides detailed information. Important specifi-
cations and warnings always stand out in bold type.
REFERENCES
References have been kept to a minimum. However, when
they are required you are given the page to refer to.
SPECIFICATIONS
Specifications are presented in bold type throughout the text
where needed. You never have to leave the procedure to look
up your specifications. They are also found at the end of each
section, for quick reference.
CAUTIONS, NOTICES, HINTS:
w CAUTIONS are presented in bold type, and indicate
there is a possibility of injury to you or other people.
w NOTICES are also presented in bold type, and indicate
the possibility of damage to the com ponent being
repaired.
w HINTS are separated from the text but do not appear in
bold. They provide additional information to help you
efficiently perform the repair.
SI UNIT
The UNIT given in this manual are primarily expressed with
the SI UNIT (International System of Unit), and alternately ex-
pressed in the metric system and in the yard/pound system.
Example:
Torque: 30 N Vm (310 kgf Vcm, 22 ft Vlbf)
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INTRODUCTION How to Use This ManualIN±3
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IDENTIFICATION INFORMATION
VEHICLE IDENTIFICATION NUMBER
This number is stamped on the vehicle identification number plate
at the top of the left instrument panel and is also on the certification
regulation label.A: Vehicle Identification Number
B: Vehicle Identification Number Plate
C: Certification Regulation Label
ENGINE SERIAL NUMBER
The engine serial number is stamped on the engine block as
shown.
GENERAL REPAIR INSTRUCTIONS
1. Use fender seat and floor covers to keep the vehicle clean
and prevent damage.
2. During disassembly, keep parts in the appropriate order to facilitate reassembly.
3. Observe the following:
(a) CAUTION: W ork must be started after approx. 20 seconds
or longer from the time the ignition switch is turned to the
ºLOCKº position and the negative (±) terminal cable is
disconnected from the battery (See page AB±2).
(b) B e fo re pe rfo rmin g ele ctrica l wo rk, disc onnect the
negative cable from the battery terminal.
(c) If it is necessary to disconnect the battery for inspection or repair, always disconnect the cable from the negative
(±) terminal which is grounded to the vehicle body.
(d) To prevent damage to the battery terminal post, loosen the terminal nut and raise the cable straight up without
twisting or prying it.
(e) Clean the battery terminal posts and cable terminals with a shop rag. Do not scrape them with a file or other
abrasive object.
(f) Install the cable terminal to the battery post with the nut loose, and tighten the nut after installation. Do not use
a hammer to tap the terminal onto the post.
(g) Be sure the covers for the positive (+) terminal and negative (±) terminal are properly in place.
4. Check hose and wiring connectors to make sure that they are
secure and correct.
IN±4
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INTRODUCTION Identification Information, General Repair Instructions
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5. Non±reusable parts(a) Always replace cotter pins, gaskets, O±rings and oilseals etc. with new ones.
(b) Non±reusable parts are indicated in the component
illustrations by the º º symbol.
6. Precoated parts Precoated parts are bolts and nuts, etc. that are coated with
a seal lock adhesive at the factory.
(a) If a precoated part is retightened, loosened or causedto move in any way, it must be recoated with the
specified adhesive.
(b) Recoating of precoated parts
(1) Clean off the old adhesive from the bolt, nut or threads.
(2) Dry with compressed air.
(3) Apply the specified seal lock adhesive to the bolt or nut threads.
(c) P re co a te d pa rts are in d ica te d in th e co m ponent
illustrations by the º
º symbol.
7. When necessary, use a sealer on gaskets to prevent leaks.
8. Carefully observe all specifications for bolt tightening
torques. Always use a torque wrench.
9. Use of special service tools (SST) and special service materials (SSM) may be required, depending on the nature
of the repair. Be sure to use SST and SSM where specified
and follow the proper work procedure. A list of SST and SSM
can be found in the preparation part at the front of each
section in this manual.
10. When replacing fuses, be sure the new fuse has the correct
amperage rating. DO NOT exceed the rating or use one with
a lower rating.
11. Care must be taken when jacking up and supporting the vehicle. Be sure to lift and support the vehicle at the proper
locations (See page IN±33).
(a) If the vehicle is to be jacked up only at the front or rear end, be sure to block the wheels at the opposite end in
order to ensure safety.
(b) After the vehicle is jacked up, be sure to support it on
stands. It is extremely dangerous to do any work on a
vehicle raised on a jack alone, even for a small job that
can be finished quickly.
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INTRODUCTION General Repair InstructionsIN±5
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12. Observe the following precautions to avoid damage to theparts:
(a) Do not open the cover or case of the ECU unless
absolutely necessary (If the IC terminals are touched, the
IC may be destroyed by static electricity.).
(b) To pull apart electrical connectors, pull on the connectoritself, not the wires (See page BE±2).
(c) Be careful not to drop electrical components, such as sensors or relays. It they are dropped on a hard floor,
they should be replaced and not reused.
(d) When checking continuity at the wire connector, insert the tester probe carefully to prevent terminals from
bending.
(e) To disconnect vacuum hoses, pull on the end, not the middle of the hose.
(f) When steam cleaning an engine, protect the distributor,
coil and air filter from water.
(g) Ne ve r use an imp a ct wre n ch to re mo ve or in sta ll temperature switches or temperature sensors.
(h) When using a vacuum gauge, never force the hose onto
a connector that is too large. Use a step±down adapter
instead. Once the hose has been stretched, it may leak.
13. Tag hoses before disconnecting them: (a) When disconnecting vacuum hoses, use tags to identify
how they should be reconnected.
(b) After completing a job, double check that the vacuum hoses are properly connected. A label under the hood
shows the proper layout.
14. Installation of wheels The wheel assemblies are of the uni±directional type and
must be rotated only between the front and rear as illustrated.
Wheels are marked with turning direction indicators.
When installing the wheels, check the marks carefully and
install the wheel correctly.
15. Bleeding of traction control system When repairing the brake master cylinder or TRAC system,
bleed the air out of the TRAC system (See page BR±7).
CAUTION: Since the fluid is under high pressure, it could
spray out with great force, so be careful.
IN±6
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TOTAL DIAGNOSTIC
COMMUNICATION LINK (TDCL)
The TDCL is provided inside the cabin (located under the left side
instrument panel) as a connector exclusively for diagnosis of data
from the engine, ECT, ABS, A/C, Airbag and Cruise Control Sys-
tem to improve serviceability. The check connector inside the en-
gine compartment is used for engine adjustment.
Connecting the following terminals of the TDCL to terminal E1 se-
lects the diagnosis mode shown.
NOTICE: Never make a mistake with the terminal connection
position as this will cause a malfunction.
TerminalSystem
TE1Engine and ECT (Normal mode)
TE2 and TE1Engine and ECT (Test mode)
TcABS, A/C, Airbag, Traction Control and Cruise
Control System
TTECT
Refer to the respective system for the inspection method.
HINT: By connecting the TDCL up to a monitor specifically de-
signed for use with the TDCL, the diagnosis result for each system
can be read easily.
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INTRODUCTION Total Diagnostic Communication Link (TDCL)IN±7
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