1999 Lexus LS400 suspension

COMFORT ADJUSTMENT
172
Do not use accessories for the seats which
cover the parts where the side airbags should
inflate. Such accessories may prevent the side
airbags from activating correctly, causing
death or serious injury.
 Do not modify or remove any wiring. Do not
modify, remove, strike or open any
components, such as the steering wheel pad,
steering wheel, column cover, front passenger
airbag cover, front seats, airbag sensor
assembly or seat belt assemblies. Doing any of
these may cause sudden SRS operation or
disable the system, which could result in death
or serious injury.
 Do not modify or replace the seats or surface of
the front seats with side airbags. Such
changes may disable the system or cause the
side airbags to inflate, resulting in death or
serious injury. Consult your Lexus dealer.
Failure to follow these instructions can result in
death or serious injuries.NOTICE
Do not perform any of the following changes without consulting your Lexus dealer. Suchchanges can interfere with proper operation of the
SRS in some cases.
Installation of electronic items such as a mobile two±way radio, cassette tape player orcompact disc player.
Modification of the suspension system.
Modification of the front end structure and sidestructure of the passenger compartment.
Attachment of a grille guard (bull bar, kangaroobar, etc.), snow plow, winches or any otherequipment to the front end.
Repairs made on or near the front fenders, front
end structure, console, steering column, steering wheel, dashboard near the frontpassenger airbag, front seats or seat belt
assembly.

SECTION 3 ± 1
271
STARTING AND DRIVING
Starting and driving
Three±way catalytic converter271
. . . . . . . . . . . . . . . . . .
Engine exhaust caution 274
. . . . . . . . . . . . . . . . . . . . . . . .
Before starting the engine 275
. . . . . . . . . . . . . . . . . . . . . .
Ignition switch with steering lock 276
. . . . . . . . . . . . . . . .
Parking brake 279
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to start the engine 280
. . . . . . . . . . . . . . . . . . . . . . . .
Automatic transmission 281
. . . . . . . . . . . . . . . . . . . . . . . .
Electronic throttle control system 295
. . . . . . . . . . . . . . . .
Cruise control 297
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electronically modulated air suspension 301
. . . . . . . . . .
Traction control system 304
. . . . . . . . . . . . . . . . . . . . . . . .
Vehicle skid control system 307
. . . . . . . . . . . . . . . . . . . . .
Brake system 313
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Types of tires 319
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
THREE±WAY CATALYTIC
CONVERTER

STARTING AND DRIVING
301
Resuming the preset speed
If the preset speed is cancelled by pulling the control
lever or by depressing the brake pedal, pushing the lever
up in the ºRES/ACCº direction will restore the speed set
prior to cancellation. However, once the vehicle speed
falls below about 40 km/h (25 mph), the preset speed will
not be resumed.
Cruise control failure warning
If the ºCRUISEº indicator light in the instrument cluster
flashes when using the cruise control, push the main
switch to turn the system off and then push it again to
turn it on.
If any of the following conditions then occurs, there is
some trouble in the cruise control system.
 The indicator light does not come on.
 The indicator light flashes again.
 The indicator light goes out after it comes on.
If this is the case, contact your Lexus dealer and have
your Lexus inspected.
ELECTRONICALLY
MODULATED AIR SUSPENSION
(U.S.A. ONLY)
This electronically modulated air suspension
adjusts the damping effect on the shock absorbers
and the vehicle height. This adjustment is
automatically made in response to the driving
conditions to provide good riding comfort and
stability in all driving conditions.

STARTING AND DRIVING
307
VEHICLE SKID CONTROLSYSTEM
The vehicle skid control system helps to provide
comprehensive control of the systems such as an
anti±lock brake system, traction control, engine
control, electronically modulated air suspension,
etc. This system automatically controls the output
of the brakes or engine to help prevent the vehicle
from skidding when cornering on a slippery road
surface or abrupt steering wheel operation occurs.
31L052±1

DRIVING TIPS
332
Tires
Ensure that your vehicle's tires are properly inflated.
Adjust the tire pressure to the recommended cold tire
pressure indicated below:
Tire pressure, kPa (kgf/cm
2 or bar, psi)
Front 220 (2.2, 32)
Rear 220 (2.2, 32)
 The trailer tires should be inflated to the pressure
recommended by the trailer manufacturer in respect
to the total trailer weight.
Trailer lights
Trailer lights must comply with federal,
state/provincial and local regulations. See your local
recreational vehicle dealer or rental agency for the
correct type of wiring and relays for your trailer.
Check for correct operation of the turn signals and
stop lights each time you hitch up. Direct splicing may
damage your vehicle's electrical system and cause a
malfunction of your lights.
Break±in schedule
 Lexus recommends that you do not tow a trailer with
a new vehicle or a vehicle with any new power train
component (engine, transmission, differential, wheel
bearing, etc.) for the first 800 km (500 miles) of
driving.
Maintenance
If you tow a trailer, your vehicle will require more
frequent maintenance due to the additional load. For
this information, please refer to the scheduled
maintenance information in the ºOwner's Manual
Supplement/ Maintenance Scheduleº.
 Retighten all fixing bolts of the towing ball and bracket
after approximately 1000 km (600 miles) of trailer
driving.
Pre±towing safety check
 Check that your vehicle remains level when a loaded
or unloaded trailer is hitched. Do not drive if the
vehicle has an abnormal nose±up or nose±down
condition, and check for improper tongue load,
overload, worn suspension or other possible causes.
 Make sure the trailer cargo is securely loaded so that
it cannot shift.
 Check that your rear view mirrors conform to any
federal, state/provincial or local regulation. If they do
not, install required rear view mirrors appropriate for
towing purposes.

MAINTENANCE
384Engine oil level
Check
the level on the dipstick with the engine turned off
and the vehicle parked on a level spot. See page 405 for
additional information.
Power steering fluid level
Check the level on the dipstick. The level should be in
the ºHOTº or ºCOLDº range depending on the fluid
temperature. See page 419 for additional information.
Exhaust system
If you notice any change in the sound of the exhaust or
smell exhaust fumes, have the cause located and
corrected immediately. (See engine exhaust cautions in
Section 3±1.)
DOES YOUR VEHICLE NEED REPAIRING?
Be on the alert for changes in performance and sounds,
and visual tip±offs that indicate service is needed. Some
important clues are:

Engine missing, stumbling, or pinging

Appreciable loss of power

Strange engine noises

A fluid leak under the vehicle (However, water
dripping from the air conditioning after use is normal.)

Change in exhaust sound (This may indicate a
dangerous carbon monoxide leak. Drive with the
windows open and have the exhaust system checked
immediately.)

Flat±looking tires, excessive tire squeal when
cornering, uneven tire wear

Vehicle pulls to one side when driving straight on a
level road

Strange noises related to suspension movement

Loss of brake effectiveness, spongy feeling brake
pedal, pedal almost touches floors, vehicle pulls to
one side when braking

Engine coolant temperature continually higher than
normal

SECTION 6 ± 3
414
SERVICE PROCEDURES AND
SPECIFICATIONS
Chassis
Specifications415
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking brake fluid 417
. . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking power steering fluid 419
. . . . . . . . . . . . . . . . . .
Checking tire pressure 421
. . . . . . . . . . . . . . . . . . . . . . . . .
Rotating tires 423
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking and replacing tires 425
. . . . . . . . . . . . . . . . . . .
Installing snow tires and chains 429
. . . . . . . . . . . . . . . . .
Replacing wheels 431
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Aluminum wheel precautions 431
. . . . . . . . . . . . . . . . . . .
Suspension and chassis 432
. . . . . . . . . . . . . . . . . . . . . . .

CHASSIS
432
SUSPENSION AND CHASSIS
CAUTION
Do not modify the suspension/chassis with lift kits,
spacers, springs, etc. It can cause dangerous handling
characteristics, resulting in loss of control.