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

DRIVING TIPS
348
CAUTION
The maximum gross trailer weight (trailer weight plus
cargo weight) must never exceed the following for
vehicle with equipped.
For weight carrying hitch 2268 kg (5000 lb.)
Also for weight distributing hitch 2948 kg (6500 lb.)
If towing a trailer and cargo weighting over 2268 kg
(5000 lb.), it is necessary to use a weight distributing
hitch.
If towing a trailer and cargo weighing over 907 kg
(2000 lb.), Lexus recommends to use a sway control
device with sufficient capacity. The combination of
the gross trailer weight added to the total weight of
the vehicle, occupants and vehicle cargo must never
exceed a total of the following.
According to the hitch receiver type, the maximum
gross trailer weight and hitch that can be used
differs. Refer to the illustrations to confirm the hitch
receiver type for your vehicle.
For weight carrying hitch 4764 kg (10500 lb.)
Also for weight distributing hitch 5443 kg (12000 lb.)
Exceeding the maximum weight of the trailer, the
vehicle, or the vehicle and trailer combination, can
cause an accident resulting in serious personal
injuries.
 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.

Tongue load
Total trailer weight x 100 = 10%
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349

Total trailer weight  Tongue load
 The trailer cargo load should be distributed so that
the tongue load is 10% of the total trailer weight, not
exceeding the maximum of the following.
For weight carrying hitch 227 kg (500 lb.)
Also for weight distributing hitch 294 kg (650 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.
Hitches
If you wish to install a trailer hitch, you should consult with
your Lexus dealer.
 Use only a hitch recommended by the hitch manufacture
and the one which conforms to the total trailer weight
requirement.
 According to the hitch receiver type, the maximum gross
trailer weight and hitch that can be used differs. Refer to the
illustrations to confirm the hitch receiver type for your
vehicle.
 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.

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
351
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
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.

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
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
3543. 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.
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.

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.