2003 Lexus GX470 Basic Functions / LEXUS 2003 GX470 OWNER'S MANUAL (OM60979U)

STARTING AND DRIVING
332You may hear a small sound in the engine compartment after
the engine is started or the brake pedal is depressed
repeatedly. This is a pump pulsating sound of the brake
system, and it is not a malfunction.
CAUTION

Do not pump the brake pedal if the engine stalls.
Each push on the pedal uses up your brake fluid
pressure reserve.
 Even if the power assist is completely lost, the brakes
will still work. But you will have to push the pedal
hard, much harder than normal. And your braking
distance will be longer.
Antilock brake system
The antilock brake system is designed to automatically
help prevent lockup of the wheels during a sudden brake
or braking on slippery road surfaces. This assists in
providing directional stability and steering performance
of the vehicle under these circumstances.
Effective way to press the ABS brake pedal: When the
anti−lock brake system function is in action, you may feel the
brake pedal pulsating and hear a noise. In this situation, to
let the anti−lock brake system work for you, just hold the
brake pedal down more firmly. Do not pump the brake in a
panic stop. This will result in reduced braking performance.
The anti−lock brake system becomes operative after the
vehicle has accelerated to a speed in excess of approximately
10 km/h (6 mph). It stops operating when the vehicle
decelerates to a speed below approximately 5 km/h (3 mph).
Depressing the brake pedal on slippery road surfaces such as
on the manhole cover, the steel plate under the construction,
joints in the bridge, etc. on a rainy day tends to activate the
anti−lock brake system.
You may hear a click or motor sound in the engine
compartment for a few seconds when the engine is started or
just after the vehicle begins to move. This means that the
anti−lock brake system is in the self −check mode, and does not
indicate a malfunction.
When the antilock brake system is activated, the
following conditions may occur. They do not indicate a
malfunction of the system:
 You may hear the anti −lock brake system operating and feel
the brake pedal pulsating and the vibrations of the vehicle
body and steering wheel. You may also hear the motor
sound in the engine compartment even after the vehicle is
stopped.
 At the end of the anti−lock brake system activation, the
brake pedal may move a little to the forward.

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 tires 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 the 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
334“ABS” warning light
The light comes on when the ignition key is turned to the “ON”
position. If the anti−lock brake system and the brake assist
system work properly, the light turns off after a few seconds.
Thereafter, if either of the systems malfunctions, the light
comes on again.
When the “ABS” warning light is on (and the brake system
warning light is off), the anti
−lock brake system, the brake
assist system, the active traction control system and the
vehicle skid control system do/does not operate, but the brake
system still operates conventionally.
When the “ABS” warning light is on (and the brake system
warning light is off), the anti −lock brake system does not
operate so that the wheels could lock up during a sudden
braking or braking on slippery road surfaces. If either of the following conditions occurs, this indicates
a malfunction somewhere in the parts monitored by the
warning
light system. Contact your Lexus dealer as soon
as possible to service the vehicle.
 The light does not come on when the ignition key is turned
to the “ON” position, or remains on.
 The light comes on while you are driving.
A warning light turning on briefly during operation does not
indicate a problem.
CAUTION
If the “ABS” warning light remains on together with the
brake system warning light, immediately stop your
vehicle at a safe place and contact your Lexus dealer.
In this case, not only the antilock brake system will fail
but also the vehicle will become extremely unstable
during braking.
Either of the following conditions may occur, but do not
indicate the malfunction:
 The light may stay on for about 60 seconds after the ignition
key is turned to the “ON” position. It is normal if it turns off
after a while.
 Depressing the brake pedal repeatedly may turn on the
light. It is normal if it turns off after a few seconds.

STARTING AND DRIVING
335
Brake assist system
When you slam the brakes on, the brake assist system
judges as an emergency stop and provides more powerful
braking for a driver who cannot hold down the brake pedal
firmly.
When you slam the brakes on, more powerful braking will be
applied. At this time, you may hear a sound in the engine
compartment and feel the vibrations of the brake pedal. This
does not indicate a malfunction.
The brake assist system becomes operative after the vehicle
has accelerated to a speed in excess of approximately 10 km/h
(6 mph). It stops operating when the vehicle decelerates to a
speed below approximately 5 km/h (3 mph).
The brake assist system may not work for about 60 seconds
after the engine is started.
For an explanation of this system’s warning light, see “ABS
warning light” on page 48.
Drumindisc type parking brake system
Your vehicle has a drum−in−disc type parking brake system.
This type of brake system needs bedding −down of the brake
shoes periodically or whenever the parking brake shoes and/or
drums are replaced.
Have your Lexus dealer perform the bedding −down.
BRAKE PAD WEAR LIMIT
INDICATORS
The brake pad wear limit indicators on your disc brakes
give a warning noise when the brake pads are worn to the
extent that replacement is required.
If you hear a squealing or scraping noise while driving, have the
brake pads checked and replaced by your Lexus dealer as
soon as possible. Expensive rotor damage can result if the
pads are not replaced when needed.

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.

SECTION 3 – 2
338
STARTING AND DRIVING
Driving tips
Off−road vehicle precautions 339
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Break−in period 340
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Operation in foreign countries 341
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Tips for driving in various conditions 341
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Off −road driving precautions 343
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Winter driving tips 345
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Dinghy towing 346
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Trailer towing 347
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How to save fuel and make your vehicle
last longer 356
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DRIVING TIPS
339
OFFROAD VEHICLEPRECAUTIONS
This vehicle belongs to the utility vehicle class, which has
higher ground clearance and narrower tread in relation to
the height of its center of gravity to make it capable of
performing in a wide variety of offroad applications.
Specific design characteristics give it a higher center of
gravity than ordinary passenger cars. This vehicle design
feature causes this type of vehicle to be more likely to
rollover. And, utility vehicles have a significantly higher
rollover rate than other types of vehicles. An advantage
of the higher ground clearance is a better view of the road
allowing you to anticipate problems. It is not designed for
cornering at the same speeds as ordinary passenger cars
any more than lowslung sports cars designed to perform
satisfactorily under offroad conditions. Therefore, sharp
turns at excessive speeds may cause rollover.
CAUTION
Always observe the following precautions to minimize
the risk of serious personal injury or damage to your
vehicle:
 In a rollover crash, an unbelted person is
significantly more likely to die than a person wearing
a seat belt. Therefore, the driver and all passengers
should fasten their seat belts whenever the vehicle is
moving.
 Avoid sharp turns or abrupt maneuvers, if at all
possible. Failure to operate this vehicle correctly
may result in loss of control or vehicle rollover
causing death or serious injury.
 Loading cargo on the roof luggage carrier will make
the center of the vehicle gravity higher. Avoid high
speeds, sudden starts, sharp turns, sudden braking
or abrupt maneuvers, otherwise it may result in loss
of control or vehicle rollover due to failure to operate
this vehicle correctly.
 Always slow down in gusty crosswinds. Because of
its profile and higher center of gravity, your vehicle is
more sensitive to side winds than an ordinary
passenger car . Slowing down will allow you to have
better control.