2003 Lexus GX470 ECU

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.

DRIVING TIPS
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.

IN CASE OF AN EMERGENCY
366To prepare yourself for an emergency, you should familiarize
yourself
with the use of the jack and each tool, and their storage
locations.
When storing the jack, put it into place and secure to prevent
it from flying forward during a collision or sudden braking.
 1 Jack handle extension with bolt

2 Jack handle extension without bolt

3 Jack handle
To remove the spare tire under the luggage compartment:
Put a jack handle and jack handle extensions together as
shown in the illustration.
CAUTION
Make sure they are securely fixed with the screws.
When connecting the jack handle extensions, use a
Phillips −head screwdriver or jack handle to tighten the bolts on
the joints as shown in the illustration. When connecting the
jack handle with extension, tighten the bolt on the joint
securely. Make sure the hollow meets the bolt on every joint
when you tighten the bolts.
NOTICE
Tighten all the joints securely. Otherwise, the extension
may come off and it may damage the paint or vehicle
body.

IN CASE OF AN EMERGENCY
367
40PY041
 1 Lower2 Raise3 Cloth To remove the spare tire:
1. Open the back door and remove the spare tire carrier lid
using a flat−
bladed screwdriver.
2. Insert the end of the jack handle extension into the lowering
screw and put a cloth between the jack handle extension and
rear bumper for protecting the bumper surface.
3. Turn the jack handle counterclockwise with the handle,
making sure the handle remains firmly fitted onto the jack
handle extension.
4. After the tire is lowered completely to the ground, remove
the holding bracket.
When storing the spare tire, put it in place with the outer side
of the wheel facing up. Then secure the tire, taking care that
the tire goes straight up without catching on any other part, to
prevent it from flying forward during a collision or sudden
braking.
NOTICE
Tighten the spare tire clamp bolt to hold the spare wheel
carrier by the hook securely.

IN CASE OF AN EMERGENCY
370
 1 Jack handle end

2 Jack handle extension with bolt

3 Jack handle extension without bolt

4 Jack handle
Put a jack handle, jack handle extensions and jack handle end
together as shown in the illustration.
CAUTION
Make sure they are securely fixed with the screws.
When connecting a jack handle extension with a jack handle
end, use a Phillips −head screwdriver or jack handle to tighten
the bolts on the joints as shown in the illustration. When
connecting the jack handle with extension, tighten the bolt on
the jack handle securely. Make sure the hollow meets the bolt
on any joint when you tighten the bolts.
NOTICE
Tighten all the joints securely. Otherwise, the extension
may come off and it may damage the paint or vehicle
body.

IN CASE OF AN EMERGENCY
373
9. Lower the vehicle completely and tighten the wheel
nuts.
To lower the vehicle, turn the jack handle extension
counterclockwise with the handle, making sure the handle
remains firmly fitted onto the jack handle extension.
Use only the wheel nut wrench to tighten the nuts. Do not use
other tools or any additional leverage other than your hands,
such as a hammer, pipe or your foot. Make sure the wrench
is securely engaged over the nut.
Tighten each nut a little at a time in the order shown. Repeat
the process until all the nuts are tight.
CAUTION
When lowering the vehicle, make sure all portions of
your body and all other persons around will not be
injured as the vehicle is lowered to the ground.
 Have the wheel nuts tightened by torque wrench at
112 N·m (11.5 kgf·m, 83 ft·lbf), as soon as possible
after changing wheels. Otherwise, the nuts may
loosen and the wheels may fall off, which could cause
a serious accident.

IN CASE OF AN EMERGENCY
374
10. Reinstall the wheel ornament.
Put the wheel ornament into position and then tap it firmly with
the side or heel of your hand to snap it into place.
CAUTION
Take due care in handling the ornament to avoid
unexpected personal injury.
11. After changing the wheel, check the air pressure of the
replaced tire. Stow all the tools, jack and flat tire securely.
If the pressure of the replaced tire is low, drive slowly to the
nearest service station and fill to the correct pressure.
Do not forget to reinstall the tire valve cap as dirt and moisture
could get into the valve core and possible cause air leakage.
If the cap is missing, put a new one on as soon as possible.
This is the same procedure for changing or rotating your tires.
CAUTION
Before driving, make sure all the tools, jack and flat tire
are securely in place in their storage location to reduce
the possibility of personal injury during a collision or
sudden braking.

IN CASE OF AN EMERGENCY
380
(d) Emergency towing
If towing is necessary, we recommend you to have it done
by your Lexus dealer or a commercial tow truck service.
If towing service is not available in an emergency, your
vehicle may be temporarily towed by a cable or chain
secured to the emergency towing eyelet. Use extreme
caution when towing the vehicle.
NOTICE
Only use specified towing eyelet; otherwise your
vehicle may be damaged.
A driver must be in the vehicle to steer it and operate the
brakes. Towing in this manner may be done only on hard
−surfaced
roads for a short distance and at low speeds. Also, the wheels,
axles, drive train, steering and brakes must all be in good
condition.
CAUTION
Use extreme caution when towing the vehicle. Avoid
sudden starts or erratic driving maneuvers which would
place excessive stress on the emergency towing eyelet
and towing cable or chain. The eyelet and towing cable
or chain may break and cause serious injury or damage.
NOTICE
Use only a cable or chain specifically intended for use
in towing vehicles. Securely fasten the cable or chain
to the towing eyelet provided.
Before towing, check that the center differential is unlocked.
(The indicator light must be off with the ignition on.) Release
the parking brake and put the transmission in “N”. The ignition
key must be in “ACC” (engine off) or “ON” (engine running).
CAUTION
If the engine is not running, the power assist for the
brakes and steering will not work so steering and
braking will be much harder than usual.