LEXUS GS400 2000 Service Repair Manual

Illustration:
what to do and where
21. CHECK PISTON STROKE OF OVERDRIVE BRAKE
(a)
Task heading : what to do
SST 09350±30020 (09350±06120)
Set part No. Component part No.
Detailed text : how to do task
(b)
Piston stroke: 1.40 1.70 mm (0.0551 0.0669 in.)
Specification
Place SST and a dial indicator onto the overdrive brake pis-
ton as shown in the illustration.
Measure the stroke applying and releasing the compressed
air (392 785 kPa, 4 8 kgf/cm
2 or 57 114 psi) as shown
in the illustration. IN±2
± INTRODUCTIONHOW TO USE THIS MANUAL
2 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
The procedures are presented in a step±by±step format:

The illustration shows what to do and where to do it.

The task heading tells what to do.

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 informa-
tion. Important specifications and warnings always stand out in bold type.
6. REFERENCES
References have been kept to a minimum. However, when they are required you are given the page to refer
to.
7. 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 in Service Specifications section for quick ref-
erence.
8. CAUTIONS, NOTICES, HINTS:

CAUTIONS are presented in bold type, and indicate there is a possibility of injury to you or other
people.

NOTICES are also presented in bold type, and indicate the possibility of damage to the components
being repaired.

HINTS are separated from the text but do not appear in bold. They provide additional information to
help you perform the repair efficiently.
9. SI UNIT
The UNITS given in this manual are primarily expressed according to the SI UNIT (International System of
Unit), and alternately expressed in the metric system and in the English System.
Example:
Torque: 30 N´m (310 kgf´cm, 22 ft´lbf)

IN0EI±01
BO4111
Negative Cable
IN±10
± INTRODUCTIONFOR ALL OF VEHICLES
10 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
FOR ALL OF VEHICLES
PRECAUTION
1. FOR VEHICLES EQUIPPED WITH SRS AIRBAG AND
SEAT BELT PRETENSIONER
(a) The LEXUS GS400/GS300 is equipped with an SRS
(Supplemental Restraint System), such as the driver air-
bag, front passenger airbag assembly, side airbag as-
sembly and seat belt pretensioners.
Failure to carry out service operations in the correct se-
quence could cause the supplemental restraint system to
unexpectedly deploy during servicing, possibly leading to
a serious accident.
Further, if a mistake is made in servicing the supplemental
restraint system, it is possible the SRS may fail to operate
when required. Before servicing (including removal or
installation of parts, inspection or replacement), be sure
to read the following items carefully, then follow the cor-
rect procedure described in this manual.
(b) GENERAL NOTICE
(1) Malfunction symptoms of the supplemental re-
straint system are difficult to confirm, so the diag-
nostic trouble codes become the most important
source of information when troubleshooting. When
troubleshooting the supplemental restraint system,
always inspect the diagnostic trouble codes before
disconnecting the battery (See page DI±552).
(2) Work must be started after 90 seconds from the
time the ignition switch is turned to the ºLOCKº posi-
tion and the negative (±) terminal cable is discon-
nected from the battery.
(The supplemental restraint system is equipped
with a back±up power source so that if work is
started within 90 seconds of disconnecting the neg-
ative (±) terminal cable from the battery, the SRS
may deploy.)
When the negative (±) terminal cable is discon-
nected 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
the each memory system. Then when work is fin-
ished, reset the clock and audio systems as before.
This vehicle has power tilt and power telescopic
steering, power seat and power outside rear view
mirror, which are all equipped with memory function,
it is not possible to make a record of the memory
contents. So when the work is finished, therefore it
will be necessary to explain this fact to the custom-
er, and ask the customer to adjust the features and

R11910Match Marks
± INTRODUCTIONFOR ALL OF VEHICLES
IN±11
11 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
reset the memory. To avoid erasing the memory of
each memory system, never use a back±up power
supply from another battery.
(3) Even in cases of a minor collision where the SRS
does not deploy, the steering wheel pad, front pas-
senger airbag assembly, side airbag assembly,
front airbag sensor, side airbag sensor and seat belt
pretensioner should be inspected
(See page RS±15, RS±29, RS±42, RS±60, RS±65
and BO±125).
(4) Never use SRS parts from another vehicle. When
replacing parts, replace them with new parts.
(5) Before repairs, remove the airbag sensor if shocks
are likely to be applied to the sensor during repairs.
(6) Never disassemble and repair the airbag sensor as-
sembly, side airbag sensor assembly, steering
wheel pad, front passenger airbag assembly, side
airbag assembly, front airbag sensor, side airbag
sensor or seat belt pretensioner.
(7) If the airbag sensor assembly, side airbag sensor
assembly, steering wheel pad, front passenger air-
bag assembly, side airbag assembly, front airbag
sensor, side airbag sensor or seat belt pretensioner
has been dropped, or if there are cracks, dents or
other defects in the case, bracket or connector, re-
place them with new ones.
(8) Do not directly expose the airbag sensor assembly,
side airbag sensor assembly, steering wheel pad,
front passenger airbag assembly, side airbag as-
sembly, front airbag sensor, side airbag sensor or
seat belt pretensioner to hot air or flames.
(9) Use a volt/ohmmeter with high impedance (10 kW/V
minimum) for troubleshooting of the electrical cir-
cuit.
(10) Information labels are attached to the periphery of
the SRS components. Follow the instructions on the
notices.
(11) After work on the supplemental restraint system is
completed, check the SRS warning light (See page
DI±552).
(c) SPIRAL CABLE (in Combination Switch)
The steering wheel must be fitted correctly to the steering
column with the spiral cable at the neutral position, other-
wise cable disconnection and other troubles may result.
Refer to SR±17 of this manual concerning correct steer-
ing wheel installation.

B02398
Example:
Correct Wrong
Z13950
Example: IN±12
± INTRODUCTIONFOR ALL OF VEHICLES
12 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(d) STEERING WHEEL PAD (with Airbag)
(1) When removing the steering wheel pad or handling
a new steering wheel pad, it should be placed with
the pad top surface facing up.
Storing the pad with its metallic surface facing up-
ward may lead to a serious accident if the airbag de-
ploys for some reason. In addition do not store a
steering wheel pad on top of another one.
(2) Never measure the resistance of the airbag squib.
(This may cause the airbag to deploy, which is very
dangerous.)
(3) Grease should not be applied to the steering wheel
pad and the pad should not be cleaned with deter-
gents 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 air-
bag connector (yellow color and 2 pins) under the
steering column near the combination switch con-
nector 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 RS±17).
Carry out the operation in a safe place away from
electrical noise.

B00696
Example:
Correct
Wrong
Z13951
Example:
± INTRODUCTIONFOR ALL OF VEHICLES
IN±13
13 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(e) FRONT PASSENGER AIRBAG ASSEMBLY
(1) Always store a removed or new front passenger air-
bag assembly with the airbag deployment direction
facing up.
Storing the airbag assembly with the airbag deploy-
ment direction facing down could cause a serious
accident if the airbag deploys.
(2) Never measure the resistance of the airbag squib.
(This may cause the airbag to deploy, which is very
dangerous.)
(3) Grease should not be applied to the front passen-
ger airbag assembly and the airbag door should not
be cleaned with detergents of any kind.
(4) Store the airbag assembly where the ambient tem-
perature remains below 93°C (200°F), without high
humidity and away from electrical noise.
(5) When using electric welding, first disconnect the air-
bag connector (yellow color and 2 pins) installed on
the assembly before starting work.
(6) When disposing of a vehicle or the airbag assembly
alone, the airbag should be deployed using an SST
before disposal (See page RS±31).
Perform the operation in a safe place away from
electrical noise.

B02129
Example:
Correct Wrong
B01546
Example: IN±14
± INTRODUCTIONFOR ALL OF VEHICLES
14 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(f) SIDE AIRBAG ASSEMBLY
(1) Always store a removed or new side airbag assem-
bly with the airbag deployment direction facing up.
Storing the airbag assembly with the airbag deploy-
ment direction facing down could cause a serious
accident if the airbag deploys.
(2) Never measure the resistance of the airbag squib.
(This may cause the airbag to deploy, which is very
dangerous.)
(3) Grease should not be applied to the side airbag as-
sembly and the surface should not be cleaned with
detergents of any kind.
(4) Store the airbag assembly where the ambient tem-
perature remains below 93°C (200°F), without high
humidity and away from electrical noise.
(5) When using electric welding, first disconnect the air-
bag connector (yellow color and 2 pins) under the
seat before starting work.
(6) When disposing of a vehicle or the side airbag as-
sembly alone, the airbag should be deployed using
an SST before disposal (See page RS±43).
Perform the operation in a safe place away from
electrical noise.

B02121
Example:
± INTRODUCTIONFOR ALL OF VEHICLES
IN±15
15 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(g) SEAT BELT PRETENSIONER
(1) Never measure the resistance of the seat belt pre-
tensioner. (This may cause the seat belt pretension-
er to activate, which is very dangerous.)
(2) Never disassemble the seat belt pretensioner.
(3) Never install the seat belt pretensioner in another
vehicle.
(4) Store the seat belt pretensioner where the ambient
temperature remains below 80°C (176°F) and
away from electrical noise without high humidity.
(5) When using electric welding, first disconnect the
connector (yellow color and 2 pins) before starting
work.
(6) When disposing of a vehicle or the seat belt preten-
sioner alone, the seat belt pretensioner should be
activated before disposal (See page BO±130). Per-
form the operation in a safe place away from electri-
cal noise.
(7) The seat belt pretensioner is hot after activation, so
let it cool down sufficiently before the disposal.
However never apply water to the seat belt preten-
sioner.
(8) Oil or water should not be put on the front seat outer
belt and the front seat outer belt should not be
cleaned with detergents of any kind.

IN±16
± INTRODUCTIONFOR ALL OF VEHICLES
16 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(h) AIRBAG SENSOR ASSEMBLY
(1) Never reuse the airbag sensor assembly involved
in a collision when the SRS has deployed.
(2) The connectors to the airbag sensor assembly
should be connected or disconnected with the sen-
sor mounted on the floor. If the connectors are con-
nected or disconnected while the airbag sensor as-
sembly is not mounted to the floor, it could cause
undesired ignition of the supplemental restraint sys-
tem.
(3) Work must be started after 90 seconds from the
time the ignition switch is turned to the ºLOCKº posi-
tion and the negative (±) terminal cable is discon-
nected from the battery, even if only loosing the set
bolts of the airbag sensor assembly.
(i) WIRE HARNESS AND CONNECTOR
The SRS wire harness is integrated with the instrument
panel wire harness assembly. All the connectors in the
system are a standard yellow color. If the SRS wire har-
ness becomes disconnected or the connector becomes
broken due to an accident, etc., repair or replace it as
shown on page RS±68.

± INTRODUCTIONFOR ALL OF VEHICLES
IN±17
17 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
2. FOR VEHICLES EQUIPPED WITH A CATALYTIC CONVERTER
CAUTION:
If large amount of unburned gasoline flows into the converter, it may overheat and create a fire haz-
ard. To prevent this, observe the following precautions and explain them to your customer.
(a) Use only unleaded gasoline.
(b) Avoid prolonged idling.
Avoid running the engine at idle speed for more than 20 minutes.
(c) Avoid spark jump test.
(1) Perform spark jump test only when absolutely necessary. Perform this test as rapidly as possible.
(2) While testing, never race the engine.
(d) Avoid prolonged engine compression measurement.
Engine compression tests must be done as rapidly as possible.
(e) Do not run engine when fuel tank is nearly empty.
This may cause the engine to misfire and create an extra load on the converter.
(f) Avoid coasting with ignition turned off.
(g) Do not dispose of used catalyst along with parts contaminated with gasoline or oil.
3. IF VEHICLE IS EQUIPPED WITH MOBILE COMMUNICATION SYSTEM
For vehicles with mobile communication systems such as two±way radios and cellular telephones, observe
the following precautions.
(1) Install the antenna as far as possible away from the ECU and sensors of the vehicle's electronic
system.
(2) Install the antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the ve-
hicle's electronic systems. For details about ECU and sensors locations, refer to the section on
the applicable component.
(3) Avoid winding the antenna feeder together with other wiring as much as possible, and also avoid
running the antenna feeder parallel with other wire harnesses.
(4) Check that the antenna and feeder are correctly adjusted.
(5) Do not install powerful mobile communications system.
4. FOR USING OBD II SCAN TOOL OR LEXUS HAND±HELD TESTER
CAUTION:
Observe the following items for safety reasons:

Before using the OBD II scan tool or LEXUS hand±held tester, the OBD II scan tool's instruction
book or LEXUS hand±held tester's operator manual should be read thoroughly.

Be sure to route all cables securely when driving with the OBD II scan tool or LEXUS hand±held
tester connected to the vehicle. (i.e. Keep cables away from feet, pedals, steering wheel and
shift lever.)

Two persons are required when test driving with the OBD II scan tool or LEXUS hand±held tes-
ter, one person to drive the vehicle and the other person to operate the OBD II scan tool or LEX-
US hand±held tester.

F02853
B01549
F02853
IN±18
± INTRODUCTIONFOR ALL OF VEHICLES
18 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. FOR VEHICLES EQUIPPED WITH VEHICLE SKID
CONTROL (VSC) SYSTEM
NOTICE:
When using a 2±wheel drum tester such as a speedometer
tester or chassis dynamometer, etc., or jacking up the rear
wheels and driving the wheels, always push in the TRAC &
VSC cut switch and turn the TRAC & VSC system OFF.
(a) Press the VSC OFF switch.
(b) Check that the VSC OFF indicator light comes ON.
HINT:
The VSC OFF indicator light should be always OFF when the
engine is restarted.
(c) Begin measurements.
(d) Press the VSC OFF switch again to change the TRAC &
VSC system to operational condition and check that the
VSC OFF indicator light goes off.
HINT:
The SLIP indicator light blinks when the TRAC system is opera-
tional.