LEXUS GS400 2000 Service Repair Manual

IN±38
± INTRODUCTIONTERMS
38 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) H±FUSE
High Current Fuse
HIHigh
HIDHigh Intensity Discharge (Head Lamp)
HSGHousing
HTHard Top
HWSHeated Windshield System
IACIdle Air Control
ICIntegrated circuit
IDIIndirect Diesel Injection
IFSIndependent Front Suspension
IGIgnition
IIAIntegrated Ignition Assembly
INIntake (Manifold, Valve)
INTIntermittent
I/PInstrument Panel
IRSIndependent Rear Suspension
J/BJunction Block
J/CJunction Connector
KDKick±Down
LANLocal Area Network
LBLiftback
LCDLiquid Crystal Display
LEDLight Emitting Diode
LHLeft±Hand
LHDLeft±Hand Drive
L/H/WLength, Height, Width
LLCLong±Life Coolant
LNGLiquified Natural Gas
LOLow
LPGLiquified Petroleum Gas
LSDLimited Slip Differential
LSP & PVLoad Sensing Proportioning And Bypass Valve
LSPVLoad Sensing Proportioning Valve
MAX.Maximum
MICMicrophone
MILMalfunction Indicator Lamp
MIN.Minimum
MPMultipurpose
MPXMultiplex Communication System
M/TManual Transmission
MTMount
MTGMounting
NNeutral
NANatural Aspiration
No.Number
O/DOverdrive

± INTRODUCTIONTERMS
IN±39
39 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) OEM
Original Equipment Manufacturing
OHCOverhead Camshaft
OHVOverhead Valve
OPTOption
O/SOversize
P & BVProportioning And Bypass Valve
PCSPower Control System
PCVPositive Crankcase Ventilation
PKBParking Brake
PPSProgressive Power Steering
PSPower Steering
PTOPower Take±Off
R & PRack And Pinion
R/BRelay Block
RBSRecirculating Ball Type Steering
R/FReinforcement
RFSRigid Front Suspension
RHRight±Hand
RHDRight±Hand Drive
RLYRelay
ROMRead Only Memory
RrRear
RRRear±Engine Rear±Wheel Drive
RRSRigid Rear Suspension
RWDRear±Wheel Drive
SDNSedan
SENSensor
SICSStarting Injection Control System
SOCState Of Charge
SOHCSingle Overhead Camshaft
SPECSpecification
SPISingle Point Injection
SRSSupplemental Restraint System
SSMSpecial Service Materials
SSTSpecial Service Tools
STDStandard
STJCold±Start Fuel Injection
SWSwitch
SYSSystem
T/ATransaxle
TACHTachometer
TBIThrottle Body Electronic Fuel Injection
TCTurbocharger
TCCSTOYOTA Computer±Controlled System
TCVTiming Control Valve
TDCTop Dead Center

IN±40
± INTRODUCTIONTERMS
40 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) TEMP.
Temperature
TEMSTOYOTA Electronic Modulated Suspension
TISTotal Information System For Vehicle Development
T/MTransmission
TMCTOYOTA Motor Corporation
TMMKTOYOTA Motor Manufacturing Kentucky, Inc.
TRACTraction Control System
TURBOTurbocharge
U/DUnderdrive
U/SUndersize
VCVVacuum Control Valve
VENTVentilator
VINVehicle Identification Number
VPSVariable Power Steering
VSCVehicle Skid Control
VSVVacuum Switching Valve
VTVVacuum Transmitting Valve
w/With
WGNWagon
W/HWire Harness
w/oWithout
1stFirst
2ndSecond
2WDTwo Wheel Drive Vehicle (4x2)
4WDFour Wheel Drive Vehicle (4x4)

FI1066
IN0DC±01
Z11554
Seal Lock Adhesive
IN±4
± INTRODUCTIONREPAIR INSTRUCTIONS
4 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REPAIR INSTRUCTIONS
GENERAL INFORMATION
BASIC REPAIR HINT
(a) Use fender, seat and floor covers to keep the vehicle
clean and prevent damage.
(b) During disassembly, keep parts in the appropriate order
to facilitate reassembly.
(c) Installation and removal of battery terminal:
(1) Before performing electrical work, disconnect the
negative (±) terminal cable from the battery.
(2) If it is necessary to disconnect the battery for in-
spection or repair, first disconnect the negative (±)
terminal cable.
(3) When disconnecting the terminal cable, to prevent
damage to the battery terminal, loosen the cable
nut and raise the cable straight up without twisting
or prying it.
(4) Clean the battery terminals and cable ends with a
clean shop rag. Do not scrape them with a file or oth-
er abrasive objects.
(5) Install the cable ends to the battery terminals after
loosening the nut, and tighten the nut after installa-
tion. Do not use a hammer to tap the cable ends
onto the terminals.
(6) Be sure the cover for the positive (+) terminal is
properly in place.
(d) Check hose and wiring connectors to make sure that they
are connected securely and correctly.
(e) Non±reusable parts
(1) Always replace cotter pins, gaskets, O±rings, oil
seals, etc. with new ones.
(2) Non±reusable parts are indicated in the component
illustrations by the ºº symbol.
(f) Precoated parts
Precoated parts are bolts, nuts, etc. that are coated with
a seal lock adhesive at the factory.
(1) If a precoated part is retightened, loosened or
caused to move in any way, it must be recoated with
the specified adhesive.
(2) When reusing precoated parts, clean off the old
adhesive and dry with compressed air. Then apply
the specified seal lock adhesive to the bolt, nut or
threads.

BE1367
Medium Current Fuse and High Current Fuse
Equal Amperage Rating
V00076
Abbreviation Part Name Symbol Illustration
FUSE
MEDIUM CURRENT FUSE
HIGH CURRENT FUSE
FUSIBLE LINK
CIRCUIT BREAKERFUSE
M±FUSE
H±FUSE
FL
CB
± INTRODUCTIONREPAIR INSTRUCTIONS
IN±5
5 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(3) Precoated parts are indicated in the component il-
lustrations by the º
º symbol.
(g) When necessary, use a sealer on gaskets to prevent
leaks.
(h) Carefully observe all specifications for bolt tightening
torques. Always use a torque wrench.
(i) Use of special service tools (SST) and special service ma-
terials (SSM) may be required, depending on the nature
of the repair. Be sure to use SST and SSM where speci-
fied and follow the proper work procedure. A list of SST
and SSM can be found in Preparation section in this
manual.
(j) When replacing fuses, be sure the new fuse has the cor-
rect amperage rating. DO NOT exceed the rating or use
one with a lower rating.

IN0253
WRONG CORRECT
IN0252
WRONG CORRECT IN±6
± INTRODUCTIONREPAIR INSTRUCTIONS
6 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(k) Care must be taken when jacking up and supporting the
vehicle. Be sure to lift and support the vehicle at the prop-
er locations (See page IN±8).
Cancel the parking brake on the level place and
shift the transmission in Neutral (or N position).
When jacking up the front wheels of the vehicle, at
first place stoppers behind the rear wheels.
When jacking up the rear wheels of the vehicle, at
fitst place stoppers before the front wheels.
When either the front or rear wheels only should be
jacked up, set rigid racks and place stoppers in front
and behind the other wheels on the ground.
After the vehicle is jacked up, be sure to support it
on rigid racks. 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.
(l) Observe the following precautions to avoid damage to the
following parts:
(1) 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 electric-
ity.)
(2) To disconnect vacuum hoses, pull off the end, not
the middle of the hose.
(3) To pull apart electrical connectors, pull on the con-
nector itself, not the wires.
(4) Be careful not to drop electrical components, such
as sensors or relays. If they are dropped on a hard
floor, they should be replaced and not reused.
(5) When steam cleaning an engine, protect the elec-
tronic components, air filter and emission±related
components from water.
(6) Never use an impact wrench to remove or install
temperature switches or temperature sensors.
(7) When checking continuity at the wire connector, in-
sert the tester probe carefully to prevent terminals
from bending.
(8) When using a vacuum gauge, never force the hose
onto a connector that is too large. Use a step±down
adapter for adjustment. Once the hose has been
stretched, it may leak air.

IN0002
Example
± INTRODUCTIONREPAIR INSTRUCTIONS
IN±7
7 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(m) Installation and removal of vacuum hose:
(1) When disconnecting vacuum hoses, use tags to
identify where they should be reconnected to.
(2) After completing a job, double check that the vacu-
um hoses are properly connected. A label under the
hood shows the proper layout.
(n) Bleeding of hydraulic brake booster:
When repairing the hydraulic brake booster or ABS,
TRAC and VSC system, bleeding the air out of the hy-
draulic brake booster (See page BR±4).
(o) Unless otherwise stated, all resistance is measured at an
ambient temperature of 20°C (68°F). Because the resis-
tance may be outside specifications if measured at high
temperatures immediately after the vehicle has been run-
ning, measurement should be made when the engine has
cooled down.

IN0D6±01
± INTRODUCTIONTERMS
IN±41
41 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
GLOSSARY OF SAE AND LEXUS TERMS
This glossary lists all SAE±J1930 terms and abbreviations used in this manual in compliance with SAE rec-
ommendations, as well as their LEXUS equivalents.
SAE
ABBREVIATIONSSAE TERMSLEXUS TERMS
( )±±ABBREVIATIONS
A/CAir ConditioningAir Conditioner
ACLAir CleanerAir Cleaner, A/CL
AIRSecondary Air InjectionAir Injection (AI)
APAccelerator Pedal±
B+Battery Positive Voltage+B, Battery Voltage
BAROBarometric PressureHAC
CACCharge Air CoolerIntercooler
CARBCarburetorCarburetor
CFIContinuous Fuel Injection±
CKPCrankshaft PositionCrank Angle
CLClosed LoopClosed Loop
CMPCamshaft PositionCam Angle
CPPClutch Pedal Position±
CTOXContinuous Trap Oxidizer±
CTPClosed Throttle PositionLL ON, Idle ON
DFIDirect Fuel Injection (Diesel)Direct Injection (DI)
DIDistributor Ignition±
DLC1
DLC2
DLC3Data Link Connector 1
Data Link Connector 2
Data Link Connector 31: Check Connector
2: Total Diagnosis Comunication Link (TDCL)
3: OBD II Diagnostic Connector
DTCDiagnostic Trouble CodeDiagnostic Code
DTMDiagnostic Test Mode±
ECLEngine Control Level±
ECMEngine Control ModuleEngine ECU (Electronic Control Unit)
ECTEngine Coolant TemperatureCoolant Temperature, Water Temperature (THW)
EEPROMElectrically Erasable Programmable Read Only Memory
Electrically Erasable Programmable Read Only Memory
(EEPROM),
Erasable Programmable Read Only Memory (EPROM)
EFEEarly Fuel EvaporationCold Mixture Heater (CMH), Heat Control Valve (HCV)
EGRExhaust Gas RecirculationExhaust Gas Recirculation (EGR)
EIElectronic IgnitionTOYOTA Distributorless Ignition (TDI)
EMEngine ModificationEngine Modification (EM)
EPROMErasable Programmable Read Only MemoryProgrammable Read Only Memory (PROM)
EVAPEvaporative EmissionEvaporative Emission Control (EVAP)
FCFan Control±
FEEPROMFlash Electrically Erasable Programmable Read Only
Memory±
FEPROMFlash Erasable Programmable Read Only Memory±
FFFlexible Fuel±
FPFuel PumpFuel Pump
GENGeneratorAlternator
GNDGroundGround (GND)

IN±42
± INTRODUCTIONTERMS
42 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) HO2S
Heated Oxygen SensorHeated Oxygen Sensor (HO2S)
IACIdle Air ControlIdle Speed Control (ISC)
IATIntake Air TemperatureIntake or Inlet Air Temperature
ICMIgnition Control Module±
IFIIndirect Fuel InjectionIndirect Injection (IDL)
IFSInertia Fuel±Shutoff±
ISCIdle Speed Control±
KSKnock SensorKnock Sensor
MAFMass Air FlowAir Flow Meter
MAPManifold Absolute PressureManifold Pressure
Intake Vacuum
MCMixture Control
Electric Bleed Air Control Valve (EBCV)
Mixture Control Valve (MCV)
Electric Air Control Valve (EACV)
MDPManifold Differential Pressure±
MFIMultiport Fuel InjectionElectronic Fuel Injection (EFI)
MILMalfunction Indicator LampCheck Engine Lamp
MSTManifold Surface Temperature±
MVZManifold Vacuum Zone±
NVRAMNon±Volatile Random Access Memory±
O2SOxygen SensorOxygen Sensor, O2 Sensor (O2S)
OBDOn±Board DiagnosticOn±Board Diagnostic System (OBD)
OCOxidation Catalytic ConverterOxidation Catalyst Convert (OC), CCo
OPOpen LoopOpen Loop
PAIRPulsed Secondary Air InjectionAir Suction (AS)
PCMPowertrain Control Module±
PNPPark/Neutral Position±
PROMProgrammable Read Only Memory±
PSPPower Steering Pressure±
PTOXPeriodic Trap OxidizerDiesel Particulate Filter (DPF)
Diesel Particulate Trap (DPT)
RAMRandom Access MemoryRandom Access Memory (RAM)
RMRelay Module±
ROMRead Only MemoryRead Only Memory (ROM)
RPMEngine SpeedEngine Speed
SCSuperchargerSupercharger
SCBSupercharger BypassE±ABV
SFISequential Multiport Fuel InjectionElectronic Fuel Injection (EFI), Sequential Injection
SPLSmoke Puff Limiter±
SRIService Reminder Indicator±
SRTSystem Readiness Test±
STScan Tool±
TBThrottle BodyThrottle Body
TBIThrottle Body Fuel InjectionSingle Point Injection
Central Fuel Injection (Ci)
TCTurbochargerTurbocharger
TCCTorque Converter ClutchTorque Converter

± INTRODUCTIONTERMS
IN±43
43 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) TCM
Transmission Control ModuleTransmission ECU, ECT ECU
TPThrottle PositionThrottle Position
TRTransmission Range±
TVVThermal Vacuum ValveBimetallic Vacuum Switching Valve (BVSV)
Thermostatic Vacuum Switching Valve (TVSV)
TWCThree±Way Catalytic Converter
Three±Way Catalytic (TWC)
Manifold Converter
CC
RO
TWC+OCThree±Way + Oxidation Catalytic ConverterCCR + CCo
VA FVolume Air FlowAir Flow Meter
VRVoltage RegulatorVoltage Regulator
VSSVehicle Speed SensorVehicle Speed Sensor
WOTWide Open ThrottleFull Throttle
WU±OCWarm Up Oxidation Catalytic Converter±
WU±TWCWarm Up Three±Way Catalytic Converter±
3GRThird Gear±
4GRFourth Gear±