tires Lexus GX470 2003 Basic Functions / LEXUS 2003 GX470 OWNER'S MANUAL (OM60A45U)

SECTION 3 – 1
296
STARTING AND DRIVING
Starting and driving
Three−way catalytic converters297
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Engine exhaust caution 298
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Before starting the engine 299
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Ignition switch with steering lock 300
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Parking brake 301
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How to start the engine 302
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Automatic transmission 303
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Four−wheel drive system 309
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Cruise control 312
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Rear height control air suspension 315
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Electronic modulated suspension 320
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Active traction control system 321
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Vehicle skid control system 323
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Downhill assist control system 326
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Hill −start assist control system 329
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Brake system 331
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Brake pad wear limit indicators 335
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Limited −slip differential 336
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Types of tires 336
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STARTING AND DRIVING
321
When your vehicle is loaded heavily or you are driving in an
unpaved road, the mode

3
or 4
will be recommended. To
provide good vehicle stability, the damping effect will be harder
than for ordinary driving mode.
With the four−wheel drive control lever at “L”, the damping
effect suitable for off −road driving will be harder in any mode.ACTIVE TRACTION CONTROL
SYSTEM
The active traction control system automatically helps
prevent the spinning of 4 wheels when the vehicle is
started or accelerated on slippery road surfaces.
When the ignition key is turned to “ON”, the system
automatically turns on.
CAUTION
Under certain slippery road conditions, full traction of
the vehicle and power to the 4 wheels cannot be
maintained, even though the traction control system is
in operation. Do not drive the vehicle under any speed
or maneuvering conditions which may cause the
vehicle to lose traction control. In situations where the
road surface is covered with ice or snow, your vehicle
should be fitted with snow tires or tire chains. Always
drive at an appropriate and cautious speed for the
present road conditions.

STARTING AND DRIVING
324
Only use tires of specified size. The size,
manufacturer, brand and tread pattern for all 4 tires
should be the same. If you use the tires other than
specified, or different type or size, the vehicle skid
control system may not function correctly. When
replacing the tires or wheels, contact your Lexus
dealer.
 In situations where the road surface is covered with
ice or snow, your vehicle should be fitted with snow
tires or tire chains.
 Slip indicator light
If the vehicle is going to skid during driving, the slip indicator
light blinks and an alarm sounds intermittently. Special care
should be taken while driving. The slip indicator light comes on for a few seconds when the
ignition key is turned to “ON”. If the indicator light does not
come on when the ignition is turned on, contact your Lexus
dealer.
Pushing the center differential lock switch automatically
turns
the vehicle skid control system off. At this time, the
“VSC OFF” indicator comes on with the center differential
lock indicator light.
“VSC OFF” indicator light comes on for a few seconds when
the ignition key is turned to “ON”. It will come on again when
you push the center differential lock switch to turn off the
system.
In the following cases, contact your Lexus dealer:
 The indicator light does not come on when the ignition key
is turned “ON”.

STARTING AND DRIVING
333
CAUTION
Do not overestimate the antilock brake system:
Although the antilock brake system assists in
providing vehicle control, it is still important to drive
with all due care and maintain a moderate speed and
safe distance from the vehicle in front of you, because
there are limits to the vehicle stability and effectiveness
of steering wheel operation even with the antilock
brake system on.
If tire grip performance exceeds its capability, or if
hydroplaning occurs during high speed driving in the
rain, the antilock brake system does not provide
vehicle control.
Antilock brake system is not designed to shorten the
stopping distance: Always drive at a moderate speed
and maintain a safe distance from the vehicle in front of
you. Compared with vehicles without an antilock
brake system, your vehicle may require a longer
stopping distance in the following cases:
 Driving on rough, gravel or snowcovered roads.
 Driving with tire chains installed.
Driving over the steps such as the joints on the road.
 Driving on roads where the road surface is pitted or
has other differences in surface height.
Install all 4 tires of specified size at appropriate
pressure: The antilock brake system detects vehicle
speeds using the speed sensors for respective wheels’
turning speeds. The use of tires other than specified
may fail to detect the accurate turning speed resulting
in a longer stopping distance.

STARTING AND DRIVING
336
LIMITEDSLIP DIFFERENTIAL
Your Lexus is equipped with a limited−slip center differential
(transfer).
If one wheel − either front or rear − begins to spin, the transfer
(limited −slip center differential) is designed to aid traction by
automatically transmitting driving force to the wheels on the
other drive axle. It transmits driving force to the front wheels
if a rear wheel spins, and to the rear wheels if a front wheel
spins.
CAUTION
Do not start or run the engine while your vehicle is
supported by a jack. The vehicle could be driven off the
jack and could pose a danger or result in serious injury.
NOTICE
Use only a spare tire of the same size, construction and
load capacity as the original tires on your Lexus
because damage to the limitedslip differential could
possibly occur with another tire type.
TYPES OF TIRES
Determine what kind of tires your vehicle is originally equipped
with.
1. Summer tires
Summer tires are high −speed capability tires best suited to
highway driving under dry conditions.
Since summer tires do not have the same traction performance
as snow tires, summer tires are inadequate for driving on
snow−covered or icy roads. For driving on snow −covered or
icy roads, we recommend using snow tires. If installing snow
tires, be sure to replace all four tires.
2. All season tires
All season tires are designed to provide better traction in snow
and to be adequate for driving in most winter conditions, as well
as for use all year round.
All season tires, however, do not have adequate traction
performance compared with snow tires in heavy or loose snow.
Also, all season tires fall short in acceleration and handling
performance compared with summer tires in highway driving.

STARTING AND DRIVING
337
CAUTION
Do not mix summer and all season tires on your
vehicle as this can cause dangerous handling
characteristics, resulting in loss of control.
 Do not use tires other than the manufacturer’s
designated tires, and never mix tires or wheels of the
sizes different from the originals.

DRIVING TIPS
341
TIPS FOR DRIVING IN VARIOUSCONDITIONS
Always slow down in gusty crosswinds. This will allow you
much better control.
 Drive slowly onto curbs and, if possible, at a right angle.
Avoid driving onto high, sharp −edged objects and other
road hazards. Failure to do so can lead to severe tire
damage such as a tire burst.
Drive slowly when passing over bumps or travelling on a
bumpy road. Otherwise, the impact could cause severe
damage to the tires and/or wheels.
 When parking on a hill, turn the front wheels until they touch
the curb so that the vehicle will not roll. Apply the parking
brake, and place the transmission in “P”. If necessary, block
the wheels.
 Washing your vehicle or driving through deep water may get
the brakes wet. To see whether they are wet, check that
there is no traffic near you and then press the pedal lightly.
If you do not feel a normal braking force, the brakes are
probably wet. To dry them, drive the vehicle cautiously while
lightly pressing the brake pedal with the parking brake
applied. If they still do not work safely, pull to the side of the
road and call a Lexus dealer for assistance.
CAUTION
 Before driving off, make sure the parking brake is
fully released and that the parking brake reminder
light is off.
 Do not leave your vehicle unattended while the
engine is running.
 Do not rest your foot on the brake pedal while driving.
It can cause dangerous overheating, needless wear,
and poor fuel economy.
 To drive down a long or steep hill, reduce your speed
and downshift. Remember, if you ride the brakes
excessively, they may overheat and not work
properly. See page 306.
 Be careful when accelerating, upshifting,
downshifting or braking on a slippery surface. The
abrupt change in engine speed, such as sudden
acceleration or engine braking, could cause the
vehicle to spin or skid.
 Do not drive in excess of the speed limit. Even if the
legal speed limit permits it, do not drive over 140 km/h
(85 mph) unless your vehicle has highspeed
capability tires. Driving over 140 km/h (85 mph) may
result in tire failure, loss of control and possible
injury. Be sure to consult a tire dealer to determine
whether the tires on your vehicle are highspeed
capability tires or not before driving at such speeds.

DRIVING TIPS
350
NOTICE
Do not install weight distributing hitch to weight
carrying hitch receiver because it will damage your
vehicle.
 Do not use axlemounted hitches as they can cause
damage to the axle housing, wheel bearings, wheels
or tires. Also, never install a hitch which may
interfere with the normal function of an Energy
Absorbing Bumper.
Trailer ball
Follow these easy steps to properly determine the correct
trailer ball for your application:
1. Determine the correct trailer ball size for the trailer coupler.
Most couplers are stamped with the required trailer ball size.
The sizes you’ll most likely find stamped on the coupler are:
Trailer Class
Typical Trailer Ball Size
III 2 5/16 in.
II 2 in.
I 1 7/8 in.
2. Select the appropriate trailer ball to match or exceed the
gross trailer weight rating of the trailer. The trailer ball load
rating should be printed on the top of the ball.
 1 Trailer ball load rating 2 Ball diameter

3 Shank length 4 Shank diameter
3. When mounted in the ball mount, the threaded ball shank
must protrude beyond the bottom of the lock washer and nut
at least 2 threads. The trailer ball shank must be matched to
the ball mount hole diameter size.
NOTICE
Only use a ball mount attachment specified for the
Lexus GX470.

DRIVING TIPS
352
Service connector for towing brake controller
Your vehicle is equipped with a service connector for the
towing brake controller as shown. Link the connector to the
towing brake controller via the sub wire harness stored in the
glove box. The detailed explanation of the sub wire harness
circuit is packed together with the sub wire harness. Be sure
to position the towing brake controller where it does not prevent
the driver from operating the pedal. Lexus recommends that
the sub wire harness be stored in the glove box when it is not
in use.
Tires
 Ensure that your vehicle’s tires are properly inflated. Adjust
the tire pressure to the recommended cold tire pressure
indicated below.
Tire pressure: 220 kPa (2.2 kgf/cm
2 or bar, 32 psi)
 The trailer tires should be inflated to the pressure
recommended by the trailer manufacturer in respect to the
total trailer weight.

DRIVING TIPS
356When restarting out after parking on a slope:
1. With the transmission in “P” position, start the engine. Be
sure to keep the brake pedal depressed.
2. Shift into the “3”, “2”, “L” or “R” position.
3. Release the parking brake and brake pedal and slowly pull
or back away from the wheel blocks. Stop and apply your
brakes.
4. Have someone retrieve the blocks.
CAUTION

Do not exceed 72 km/h (45 mph) or the posted towing
speed limit, whichever is lower. Because instability
(swaying) of a towing vehicletrailer combination
usually increases as the speed increases, exceeding
72 km/h (45 mph) may cause loss of control.
 Slow down and downshift before descending steep
or long downhill grades. Do not make sudden
downshifts.
 Avoid holding the brake pedal down too long or too
frequently. This could cause the brakes to overheat
and result in reduced braking efficiency.
HOW TO SAVE FUEL AND MAKE
YOUR VEHICLE LAST LONGER
Improving fuel economy is easy − just take it easy. It will help
make your vehicle last longer, too. Here are some specific tips
on how to save money on both fuel and repairs:
 Keep your tires inflated at the correct pressure. Check
the pressure every two weeks, or at least once a month.
Underinflation causes tire wear and wastes fuel.
 Do not carry unneeded weight in your vehicle. Excess
weight puts a heavier load on the engine, causing greater
fuel consumption.
 Avoid lengthy warmup idling. Once the engine is
running smoothly, begin driving − but gently. Remember,
however, that on cold winter days this may take a little
longer.
 Always keep the automatic transmission selector lever
in the “D” position when engine braking is not required.
Driving with the overdrive off will reduce the fuel economy.
(For details, see “Automatic transmission” on page 303.)
 Accelerate slowly and smoothly. Avoid jackrabbit starts.
 Avoid long engine idling. If you have a long wait and you
are not in traffic, it is better to turn off the engine and start
again later.
 Avoid engine overrevving. Use a gear position suitable
for the road on which you are traveling.