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

Tongue load
Total trailer weight x 100= 9 to 11%
DRIVING TIPS
348

Trailer hitch assemblies have different weight
capacities established by the hitch manufacturer.
Even though the vehicle may be physically capable of
towing a higher weight, the operator must determine
the maximum weight rating of the particular hitch
assembly and never exceed the maximum weight
rating specified for the trailer hitch. Exceeding the
maximum weight rating set by the trailer hitch
manufacturer can cause an accident resulting in
serious personal injuries.
 The gross vehicle weight must not exceed the Gross
Vehicle Weight Rating (GVWR) indicated on the
Certification Label. The gross vehicle weight is the
sum weight of the unloaded vehicle, driver,
passengers, luggage, hitch and trailer tongue load.
It also includes the weight of any special equipment
installed on your vehicle.
 The load on either the front or rear axle resulting from
distribution of the gross vehicle weight on both axles
must not exceed the front and rear Gross Axle W eight
Ratings (GAWR) listed on the Certification Label.
 Total trailer weight  Tongue load
 The trailer cargo load should be distributed so that
the tongue load is 9 to 11% of the total trailer weight,
not exceeding the maximum of 226 kg (500 lb.).
 Never load the trailer with more weight in the back
than in the front. About 60 % of the trailer load should
be in the front half of the trailer and the remaining 40%
in the rear.

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349
Tow hitch receiver (on some models)
The tow hitch receiver is installed under the rear bumper.
CAUTION
A tow hitch receiver is rated for weight carrying towing
only up to 2268 kg (5000 lbs.) Only use this tow hitch
receiver on your vehicle. Do not use this tow hitch
receiver on any other vehicle.
Hitches
Use only weight carrying hitch hardware designed for the
total trailer weight with the factory installed hitch.
 If you wish to install an aftermarket hitch, the hitch must be
bolted securely to the vehicle frame and installed according
to the hitch manufactures’ instructions.
 The hitch ball and king pin should have a light coat of grease.
 Lexus recommends the ball mount assembly be removed
when not towing to prevent injury and to prevent damage in
the event of a rear end collision. After removing the ball
mount assembly, install the grommet to the hitch to prevent
entry of dirt and mud.
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.
I1 −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.

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350
 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.
Matching trailer ball height to trailer coupler
height
No matter which class of tow hitch applies, for a safe trailer
hookup, the trailer ball setup on must be the proper height for
the coupler on the trailer.
32PY007
 1 Coupler2 Trailer ball

DRIVING TIPS
351
Brakes and safety chains
Lexus recommends trailers with brakes that conform to
any applicable federal and state/provincial regulations.
 A safety chain must always be used between the towing
vehicle and the trailer. Leave sufficient slack in the
chain for turns. The chain should cross under the
trailer tongue to prevent the tongue from dropping to
the ground in case it becomes damaged or separated.
For correct safety chain procedures, consult your
Lexus dealer.
CAUTION
If the total trailer weight exceeds 453 kg (1000 lb.),
trailer brakes are required.
 Never tap into your vehicle’s hydraulic system as it
will lower its braking effectiveness.
 Never tow a trailer without using a safety chain
securely attached to both the trailer and the vehicle.
If damage occurs to the coupling unit or hitch ball,
there is possible danger of the trailer wandering over
into another lane.
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.

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352
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.
Trailer lights
 Socket for trailer lights
Your vehicle is equipped with a wire harness stored in the rear
end underbody. Models with tow 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.

DRIVING TIPS
353
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.
3. Set the supporting leg of a trailer on the ground and raise
the hitch by 100 mm (4 in.).
4. Turn the ignition switch on or push the “HEIGHT CONTROL
OFF” switch to turn on the rear height control air suspension.
5. Wait for about 20 seconds until the rear vehicle height is
lowered by the automatic leveling function.
6. Make sure the hitch is disconnected. If not, raise the hitch
higher and repeat steps 2 through 5.
7. Move the vehicle forward in the “LO” (low) mode where the
hitch does not touch anything in the “N” (normal) mode.
8. Put the rear height control air suspension in the “N” (normal)
mode.

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354
Pretowing 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 regulations. If they do not, install
required rear view mirrors appropriate for towing purposes.
Trailer towing tips
When towing a trailer, your vehicle will handle differently
than when not towing. The three main causes of
vehicletrailer accidents are driver error, excessive speed
and improper trailer loading. Keep these in mind when
towing:
 Before starting out, check the operation of the lights and all
vehicle −trailer connections. After driving a short distance,
stop and recheck the lights and connections. Practice
turning, stopping and backing with a trailer in an area away
from traffic until you learn the feel. 
Backing with a trailer is difficult and requires practice. Grip
the bottom of the steering whe el and move your hand to the
left to move the trailer to the left. Move your hand to the right
to move the trailer to the right. (This procedure is generally
opposite to that when backing without a trailer.) Also, just
turn the steering wheel a little at a time, avoiding sharp or
prolonged turning. Have someone guide you when backing
to reduce the risk of an accident.
 Because stopping distance may be increased,
vehicle −to−vehicle distance should be increased when
towing a trailer. For each 16 km/h (10 mph) of speed, allow
at least one vehicle and trailer length between you and the
vehicle ahead. Avoid sudden braking as you may skid,
resulting in jackknifing and loss of control. This is especially
true on wet or slippery surfaces.
 Avoid jerky starts or sudden acceleration.
 Avoid jerky steering and sharp turns. The trailer could hit
your vehicle in a tight turn. Slow down before making a turn
to avoid the need of sudden braking.
 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.

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355

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.

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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.