2003 Lexus GX470 engine

DRIVING TIPS
343
CAUTION
Always observe the following precautions to minimize
the risk of serious personal injury or damage to your
vehicle:
Drive carefully when off the road. Do not take
unnecessary risks by driving in dangerous places.
 Do not grip the steering wheel spokes when driving
offroad. A bad bump could jerk the wheel and injure
your hands. Keep both hands and especially your
thumbs on the outside of the rim.
 Always check your brakes for effectiveness
immediately after driving in sand, mud, water or
snow.
 After driving through tall grass, mud, rock, sand,
rivers, etc., check that there is no grass, bush, paper,
rags, stone, sand, etc. adhering or trapped on the
underbody. Clear off any such matter from the
underbody. If the vehicle is used with these materials
trapped or adhering to the underbody, a breakdown
or fire could occur.
 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.
 When driving offroad or in rugged terrain, do not
drive at excessive speeds, jump, make sharp turns,
strike objects, etc. This may cause loss of control or
vehicle rollover causing death or serious injury. You
are also risking expensive damage to your vehicle’s
suspension and chassis.
NOTICE
 If driving through water, such as when crossing
shallow streams, first check the depth of the water
and the bottom of the river bed for firmness. Drive
slowly and avoid deep water.
 Take all necessary safety measures to ensure that
water damage to the engine or other components
does not occur.
Water entering the engine air intake will cause severe
engine damage.
Water can wash the grease from wheel bearings,
causing rusting and premature failure, and may also
enter the differentials, transmission and transfer
case, reducing the gear oil’s lubricating qualities.
 Sand and mud that has accumulated in brake drums
and around brake discs may affect braking ef ficiency
and may damage brake system components.

DRIVING TIPS
344
Always perform a maintenance inspection after each
day of offroad driving that has taken you through
rough terrain, sand, mud, or water. For scheduled
maintenance information, refer to the “Owner’s
Manual Supplement / Scheduled Maintenance”.
WINTER DRIVING TIPS
Make sure your coolant is properly protected against
freezing.
Your coolant must contain ethylene −glycol type coolant for a
proper corrosion protection of aluminum components. Use
“Toyota Genuine Long Life Coolant” or equivalent. See
“Checking the engine coolant level” on page 422 for
instructions.
NOTICE
Do not use alcohol type antifreeze or plain water alone.
When it is extremely cold, we recommend to use 60% solution
for your Lexus, to provide protection down to about −50C
(−58 F). Do not use more than 70% solution for better coolant
performance.
Check the condition of the battery and cables.
Cold temperatures reduce the capacity of any battery, so it
must be in top shape to provide enough power for winter
starting. Page 447 tells you how to visually inspect the battery.
Your Lexus dealer and most service stations will be pleased to
check the battery charge level.
Make sure the engine oil viscosity is suitable for the cold
weather.
See page 420 for recommended viscosity. Leaving a heavy
summer oil in your vehicle during winter months may cause
harder starting. If you are not sure about which oil to use, call
your Lexus dealer − they will be pleased to help.

DRIVING TIPS
345
Check the electronic ignition system for loose
connections or obvious damage.
Keep the door locks from freezing.
Squirt
lock de− icer or glycerine into the locks to keep them from
freezing.
Use a washer fluid containing an antifreeze solution.
This product is available at your Lexus dealer and most auto
parts stores. Follow the manufacturer’s directions for how
much to mix with water.
NOTICE
Do not use engine antifreeze or any other substitute
because it may damage your vehicle’s paint.
Do not use your parking brake when there is a possibility
it could freeze.
When parking, put the transmission into “P” and block the front
wheels. Do not use the parking brake, or snow or water
accumulated in and around the parking brake mechanism may
freeze the parking brake, making it hard to release.
Keep ice and snow from accumulating under the fenders.
Ice and snow built up under your fenders can make steering
difficult. During bad winter driving, stop and check under the
fenders occasionally. Depending on where you are driving, we recommend you
carry some emergency equipment.
Some of the things you might put in the vehicle are tire chains,
window scraper, bag of sand or salt, flares, small shovel,
jumper cables, etc.

DRIVING TIPS
353
Trailer lights
 Socket for trailer lights
Your vehicle is equipped with a wire harness stored in the rear
end underbody. Models with weight carrying hitch receiver are
fitted with a socket for trailer lights under the rear bumper. Use
either of them to connect and operate the trailer lights.
However, the 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.
Breakin 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 “Owner’s Manual Supplement /
Scheduled Maintenance”.
 Retighten all fixing bolts of the towing ball and bracket after
approximately 1000 km (600 miles) of trailer driving.
Connecting a trailer
Stop your vehicle and a trailer in line and perform the following:
1. Put the rear height control air suspension in the “LO” (low)
mode. Turn the ignition switch off or push the “HEIGHT
CONTROL OFF” switch to turn off the rear height control air
suspension.
2. Connect a trailer.
3. Turn the ignition switch on or push the “HEIGHT CONTROL
OFF” switch to turn on the rear height control air suspension.
Select the “N” (normal) mode with the height select switch.
Disconnecting a trailer
Stop your vehicle and a trailer in line and perform the following:
1. Put the rear height control air suspension in the “LO” (low)
mode. (Make sure the vehicle height is in the “LO” (low) mode
by pushing the height select switch on the “
” side.)
2. Turn the ignition switch off or push the “HEIGHT CONTROL
OFF” switch to turn off the rear height control air suspension.

DRIVING TIPS
355

Remember that when making a turn, the trailer wheels will
be closer than the vehicle wheels to the inside of the turn.
Therefore, compensate for this by making a larger than
normal turning radius with your vehicle.
 Crosswinds and rough roads will adversely affect handling
of your vehicle and trailer, causing sway. Pay attention to
the rear from time to time to prepare yourself for being
passed by large trucks or buses, which may cause your
vehicle and trailer to sway. If swaying happens, firmly grip
the steering wheel and reduce speed immediately but
gradually. Never increase speed. If it is necessary to
reduce speed, brake slowly. Steer straight ahead. If you
make no extreme correction with the steering or brakes,
your vehicle and trailer will stabilize.
 Be careful when passing other vehicles. Passing requires
considerable distance. After passing a vehicle, do not forget
the length of your trailer and be sure you have plenty of room
before changing lanes.
 In order to maintain efficient engine braking and electrical
charging performance, do not use overdrive. Transmission
must be “4” position.
 Because of the added load of the trailer, your vehicle’s
engine may overheat on hot days (at temperatures over
30C [85 F]) when going up a long or steep grade with a
trailer. If the engine coolant temperature gauge indicates
overheating, immediately turn off the air conditioning (if in
use), pull your vehicle off the road and stop in a safe spot.
See “If your vehicle overheats” on page 363. 
Always pl ace wheel blocks under both the vehicle and trailer
wheels when parking. Apply the parking brake firmly. Put
the transmission in “P”. Avoid parking on a slope with a
trailer, but if it cannot be avoided, do so only after performing
the following:
1. Apply the brakes and keep them applied.
2. Have someone place wheel blocks under both the vehicle
and trailer wheels.
3. When the wheel blocks are in place, release your brakes
slowly until the blocks absorb the load.
4. Apply the parking brake firmly.
5. Shift into “P” and turn off the engine.

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.

DRIVING TIPS
357

Avoid continuous speeding up and slowing down.
Stop−and−go driving wastes fuel.
 Avoid unnecessary stopping and braking. Maintain a
steady pace. Try to time the traf fic signals so you only need
to stop as little as possible or take advantage of through
streets to avoid traffic lights. Keep a proper distance from
other vehicles to avoid sudden braking. This will also
reduce wear on your brakes.
 Avoid heavy traffic or traffic jams whenever possible.
 Do not rest your foot on the brake pedal. This causes
premature wear, overheating and poor fuel economy.
 Maintain a moderate speed on highways. The faster you
drive, the greater the fuel consumption. By reducing your
speed, you will cut down on fuel consumption.
 Keep the front wheels in proper alignment. Avoid hitting
the curb and slow down on rough roads. Improper
alignment not only causes faster tire wear but also puts an
extra load on the engine, which, in turn, wastes fuel.
 Keep the bottom of your vehicle free from mud, etc. This
not only lessens weight but also helps prevent corrosion. 
Keep your vehicle tunedup and in top shape. A dirty air
cleaner, improper valve clearance, dirty plugs, dirty oil and
grease, brakes not adjusted, etc. all lower engine
performance and contribute to poor fuel economy. For
longer life of all parts and lower operating costs, keep all
maintenance work on schedule, and if you often drive under
severe conditions, see that your vehicle receives more
frequent maintenance. (For scheduled maintenance
information, please refer to the “Owner’s Manual
Supplement / Scheduled Maintenance”.)
CAUTION
Never turn off the engine to coast down hills. Your
power steering and brake booster will not function
without the engine running. Also, the emission control
system operates properly only when the engine is
running.

SECTION 4
358
IN CASE OF AN EMERGENCY
In case of an emergency
If your engine stalls while driving359
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If your vehicle will not start 359
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If you cannot increase the engine speed 363
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If your vehicle overheats 363
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If you have a flat tire 364
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.
If your vehicle becomes stuck 375
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If your vehicle needs to be towed 376
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If you cannot shift automatic transmission
selector lever 382
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Lexus link system 383
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. . .
If you lose your keys or lock yourself out 392
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