2003 Lexus GX470 engine

IN CASE OF AN EMERGENCY
359
IF YOUR ENGINE STALLS WHILEDRIVING
If your engine stalls while driving ...
1. Reduce your speed gradually, keeping a straight line. Move
cautiously off the road to a safe place.
2. Turn on your emergency flashers.
3. Turn the ignition key to “ACC” or “LOCK”, and try starting
the engine again.
If the engine will not start, see “If your vehicle will not start”\
.
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.
IF YOUR VEHICLE WILL NOT START
(a) Simple checks
Before making these checks, make sure you have followed the
correct starting procedure instructions in “How to start the
engine” on page 302 and that you have sufficient fuel. Since
your vehicle is equipped with the engine immobiliser system,
also check whether the other keys will start the engine. If they
work, your key may be broken. Have the key checked at your
Lexus dealer. If none of your keys work, there may be a
malfunction in the immobiliser system. Call your Lexus dealer.
See “Keys” on page 8.
If the engine is not turning over or is turning over too
slowly
1. Check that the battery terminals are tight and clean.
2. If the battery terminals are O.K., switch on the interior light.
3. If the light is out, dim or goes out when the starter is cranked,
the battery is discharged. You may try jump starting. See “(c)
Jump starting” for further instruction.
If the light is O.K., but the engine still will not start, it needs
adjustment or repair. Call a Lexus dealer, Roadside
Assistance or Customer Service Assistance. (See
“Foreword”.)

IN CASE OF AN EMERGENCY
360
NOTICE
Do not pull or pushstart the vehicle. It may damage
the vehicle or cause a collision when the engine starts.
Also the threeway catalytic converter may overheat
and become a fire hazard.
If the engine turns over at its normal speed but will not
start
1. Turn the ignition key to “ACC” or “LOCK” and try starting the
engine again.
2. The engine may be flooded because of repeated cranking.
See “(b) Starting a flooded engine” for further instructions.
3. If the engine still will not start, it needs adjustment or repair.
Call a Lexus dealer, Roadside Assistance or Customer Service
Assistance. (See “Foreword”.)
(b) Starting a flooded engine
If the engine will not start, your engine may be flooded
because of repeated cranking.
If this happens, turn the ignition key to “START” with the
accelerator pedal fully depressed, and hold the key at this
position for about 30 seconds. Then the cranking hold function
stops cranking automatically, and you can try starting the
engine with your foot off the accelerator pedal.
If the engine does not start, wait a few minutes and try again.
If the engine still will not start, it needs adjustment or repair.
Call a Lexus dealer, Roadside Assistance or Customer Service
Assistance. (See “Foreword”.)
(c) Jump starting
To avoid serious personal injury and damage to your
vehicle which might result from battery explosion, acid
burns, electrical burns, or damaged electronic
components, these instructions must be followed
precisely.
If you are unsure about how to follow this procedure, we
strongly recommend that you seek help from your Lexus
dealer, Roadside Assistance or Customer Service Assistance.
(See “Foreword”.)

IN CASE OF AN EMERGENCY
362JUMP STARTING PROCEDURE
1. If the booster battery is installed in another vehicle, make
sure the vehicles are not touching. Turn off all unnecessary
lights and accessories.
2. If required, remove all the vent plugs from the booster
battery. Lay a cloth over the open vents on the booster battery.
(This
helps reduce the explosion hazard, personal injuries and
burns.)
If the booster battery is an extended maintenance interval
battery, it is not necessary to remove the vent plugs.
3. If the engine in the vehicle with the booster battery is not
running, start it and let it run for about 5 minutes. During jump
starting, run the engine at about 2000 rpm with the accelerator
pedal lightly depressed.
4. Locate positive (+) and negative ( −) terminals of each
battery. Connect the jumper cables in the exact order (
1
2
3
4
) shown in the illustration.
1Connect a positive (red) jumper cable clamp to the
positive (+) terminal of the discharged battery.
2Connect the clamp at the other end of the positive (red)
cable to the positive (+) terminal of the booster battery.
3Connect a negative (black) cable clamp to the negative
(−) terminal of the booster battery.
4Connect the clamp at the other end of the negative (black)
cable to a solid, stationary, unpainted metallic point (e.g.
engine hanger) away from the battery. Do not connect it
to or near any part that moves when the engine is
cranked.
CAUTION
When making the connections, to avoid serious injury,
do not lean over the battery or accidentally let the
jumper cables or clamps touch anything except the
correct battery terminals or the ground.
5. Start your engine in the normal way. After starting, run it at
about 2000 rpm for several minutes with the accelerator pedal
lightly depressed.
6. Carefully disconnect the cables in the exact reverse order:
the negative cable and then the positive cable.
7. Carefully dispose of the battery cover cloths which may
now contain sulfuric acid.
8. If removed, replace all the battery vent plugs.
If the cause of your battery discharging is not apparent (for
example, lights left on), you should have it checked at your
Lexus dealer.

IN CASE OF AN EMERGENCY
363
IF YOU CANNOT INCREASE THEENGINE SPEED
If the engine speed does not increase with the accelerator
pedal depressed down, there may be a problem somewhere
in your electronic throttle control system.
At this time, vibration may occur. However, if you depress the
accelerator pedal more firmly and slowly, you can drive your
vehicle at low speeds. Have your vehicle checked by your
Lexus dealer as soon as possible.
Even if the abnormality of the electronic throttle control system
is corrected during low speed driving, the system may not be
recovered until the engine is stopped and the ignition key is
turned to “ACC” or “LOCK” position.
CAUTION
Be especially careful to prevent erroneous pedal
operation.
IF YOUR VEHICLE OVERHEATS
If your engine coolant temperature gauge indicates
overheating, if you experience a loss of power, or if you
hear a loud knocking or pinging noise, the engine has
probably overheated.
When the engine overheats
Pull safely off the road, stop the vehicle and turn on your
emergency flashers. Put the transmission in “P” and apply the
parking brake.
A: If steam is coming from your engine:
Turn off the engine. Leave the hood closed until there is no sign
of steam or coolant. Your engine could have been seriously
damaged already. Call your Lexus dealer for assistance.
CAUTION
To help avoid personal injury, keep the hood closed until
there is no steam. Escaping steam or coolant is sign of
very high pressure.

IN CASE OF AN EMERGENCY
364B: If no steam is coming from your engine:
Leave the engine running and turn off the air conditioning.
Check the following.

Is the cooling fan operating?
 Is the coolant in the acceptable range?
 Is the engine drive belt O.K.?
CAUTION
When the engine is running, keep hands and clothing
away from the moving fan and engine drive belt.
 Do not attempt to remove the radiator cap when the
engine and radiator are hot. Serious injury could
result from scalding hot fluid and steam blown out
under pressure.
If the cooling fan is not operating or the coolant is not in the
acceptable range, turn off the engine and call your Lexus
dealer.
If both conditions are O.K., after the engine coolant
temperature has cooled to normal, continue driving your
vehicle.
If the engine coolant temperature does not cool down, or your
vehicle overheats again, have it checked as soon as possible
by your Lexus dealer.
IF YOU HAVE A FLAT TIRE
1. Reduce your speed gradually, keeping a straight line. Move
cautiously off the road to a safe place − well away from the
traffic. A void stopping on the center divider of a highway. Park
on a level spot with firm ground.
2. Stop the engine and turn on your emergency flashers.
3. Firmly set the parking brake and put the transmission in “P”.
4. Have everyone get out of the vehicle on the side away from
traffic.
5. Read the following instructions thoroughly.
CAUTION
When jacking, be sure to observe the following to
reduce the possibility of personal injury:
 Turn off the active height control suspension by
pushing the active height control switch.
 Follow jacking instructions.
 Do not put any part of your body under a vehicle
supported by a jack. Personal injury may occur.
 Do not start or run the engine while your vehicle is
supported by the jack.
 Stop the vehicle on a level firm ground, firmly set the
parking brake and put the transmission in “P”. Block
the wheel diagonally opposite to the one being
changed if necessary.

IN CASE OF AN EMERGENCY
365
Make sure to set the jack properly in the jack point.
Raising the vehicle with jack improperly positioned
will damage the vehicle or may allow the vehicle to fall
off the jack and cause personal injury.
 Never get under the vehicle when the vehicle is
supported by the jack alone.
 Use the jack only for lifting your vehicle during wheel
changing.
 Do not raise the vehicle with someone in the vehicle.
 When raising the vehicle, do not place any objects on
top of or underneath the jack.
 Raise the vehicle only high enough to remove and
change the tire.
NOTICE
Do not continue driving with a deflated tire. Driving
even a short distance can damage a tire and wheel
beyond repair.
 When jacking up or installing tire chains, be sure to
turn off the rear height control air suspension with
the “HEIGHT CONTROL OFF” switch and stop the
engine. Otherwise, the vehicle height may change
because of the automatic leveling function resulting
in accident.
40PY040
 1 Jack

2 Spare tire

3 Tool tray
1. Get the tool, jack and spare tire.
To remove the tool tray, turn the knob counterclockwise and
open the cover, then pull the tray out.

IN CASE OF AN EMERGENCY
375
IF YOUR VEHICLE BECOMESSTUCK
If your vehicle becomes stuck in snow, mud, sand, etc.,
then you may attempt to rock the vehicle free by moving
it forward and backward.
In this situation, lock the center differential and turn off the
vehicle skid control system. (For details, see “Fourwheel
drive system” on page 309.)
CAUTION
Do not attempt to rock the vehicle free by moving it
forward and backward if people or objects are anywhere
near the vehicle. During the rocking operation the
vehicle may suddenly move forward or backward as it
becomes unstuck, causing injury or damage to nearby
people or objects.
NOTICE
If you rock your vehicle, observe the following
precautions to prevent damage to the transmission and
other parts.
 Do not depress the accelerator pedal while shifting
the selector lever or before the transmission is
completely shifted to forward or reverse gear.
 Do not race the engine and avoid spinning the
wheels.
 If your vehicle remains stuck after rocking the vehicle
several times, consider other ways such as towing.

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.