check engine Lexus GX470 2004 Engine / LEXUS 2004 GX470 THROUGH OCT. 2003 PROD. (OM60A46U) Owner's Guide

DRIVING TIPS
426
Trailer lights
Your vehicle is equipped with a wire harness stored in the rear
end underbody. 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.
Break-in 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
Maintenanceº.
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 LOº (low)
mode. Turn the ignition switch off or push the HEIGHT
CONTROL OFFº 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
OFFº switch to turn on the rear height control air suspension.
Select the Nº (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 LOº (low)
mode. (Make sure the vehicle height is in the LOº (low) mode
by pushing the height select switch on the º side.)
2. Turn the ignition switch off or push the HEIGHT CONTROL
OFFº 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
OFFº 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.

DRIVING TIPS
429 When restarting out after parking on a slope:
1. With the transmission in Pº position, start the engine. Be
sure to keep the brake pedal depressed.
2. Shift into the 3º, 2º, Lº or Rº 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 vehicle-trailer 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 Ð 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 warm-up idling. Once the engine is
running smoothly, begin driving Ð but gently. Remember,
however, that on cold winter days this may take a little
longer.
Always keep the automatic transmission selector lever
in the Dº position when engine braking is not required.
Driving with the overdrive off will reduce the fuel economy.
(For details, see Automatic transmissionº on page 365.)
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 over-revving. Use a gear position suitable
for the road on which you are traveling.

IN CASE OF AN EMERGENCY
438
IF YOUR ENGINE STALLS WHILE
DRIVING
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 ACCº or LOCKº, and try starting the
engine again.
If the engine will not start, see If your vehicle will not startº.
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
engineº on page 363 and that you have sufficient fuel. Since
your vehicle is equipped with the engine immobilizer 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 immobilizer system. Call your Lexus dealer.
See Keysº on page 8.
If the engine is not turning over or is turning over too
slowly Ð
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 startingº 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
Forewordº.)

IN CASE OF AN EMERGENCY
442
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.
IF YOU CANNOT INCREASE THE
ENGINE 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 ACCº or LOCKº position.
CAUTION
Be especially careful to prevent erroneous pedal
operation.

IN CASE OF AN EMERGENCY
443
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 Pº 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.
B: 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.

IN CASE OF AN EMERGENCY
464
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 Nº. The ignition
key must be in ACCº (engine off) or ONº (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.
Emergency towing hook precautions:
Before emergency towing, check that the eyelet is not
broken or damaged and that the installation bolts are not
loose.
Fasten the towing cable or chain securely to the hook.
Do not jerk the eyelet. Apply steady and even force.
To avoid damaging the eyelet, do not pull from the side or at
a vertical angle. Always pull straight ahead.

IN CASE OF AN EMERGENCY
466
IF YOU CANNOT SHIFT AUTOMATIC
TRANSMISSION SELECTOR LEVER
If you cannot shift the selector lever out of Pº position to
other positions even though the brake pedal is depressed,
use the shift lock override button as follows:
1Turn the ignition key to LOCKº. Make sure the parking
brake is applied.
2Pry up the cover with a flat-bladed screwdriver or
equivalent.
3Push down the shift lock override button. You can shift out
of Pº position only while pushing the button.
4Shift into Nº position.
Insert the cover. Start the engine. For your safety, keep
the brake pedal depressed.
Be sure to have the system checked by your Lexus dealer as
soon as possible.

MAINTENANCE
489 Your copy of the repair order is proof that all required
maintenance has been performed for warranty coverage. If
any problems should arise with your vehicle while under
warranty, your Lexus dealer will promptly take care of it. Again,
be sure to keep a copy of the repair order for any service
performed on your Lexus.
What about do-it-yourself maintenance?
Many of the maintenance items are easy to do yourself, if you
have a little mechanical ability and a few basic automotive
tools. Simple instructions for how to perform them are
presented in Section 6.
If you are a skilled do-it-yourself mechanic, the Lexus service
manuals are recommended. Please be aware that
do-it-yourself maintenance can affect your warranty
coverage. See your Owner's Guideº, Owner's Manual
Supplementº or Warranty Bookletº for the details.
GENERAL MAINTENANCE
Listed below are the general maintenance items that should be
performed at the intervals specified. It is recommended that
any problem you notice be brought to the attention of your
Lexus dealer or qualified service shop for their advice.
CAUTION
Make these checks only with adequate ventilation if you
run the engine.
Engine compartment
Items listed below should be checked from time to time,
e.g. each time when refueling.
Washer fluid
Make sure there is sufficient fluid in the tank. See page 572 for
additional information.
Engine coolant level
Make sure the coolant level is between the Fº and Lº lines on
the see-through reservoir when the engine is cold. See page
519 for additional information.
Radiator, condenser and hoses
Check that the front of the radiator and condenser are clean
and not blocked with leaves, dirt, or insects. See page 521 for
additional information.

MAINTENANCE
490Battery
Check the battery condition by the indicator color. See page
562 for additional information.
Brake fluid level
Make sure the brake fluid level is correct. See page 529 for
additional information.
Engine oil level
Check the level on the dipstick with the engine turned off and
the vehicle parked on a level spot. See page 515 for additional
information.
Power steering fluid level
Check the level through the reservoir. The level should be in
the HOTº or COLDº range depending on the fluid
temperature. See page 530 for additional information.
Exhaust system
If you notice any change in the sound of the exhaust or smell
exhaust fumes, have the cause located and corrected
immediately. (See Engine exhaust cautionº on page 359.)
Vehicle interior
Items listed below should be checked regularly, e.g. while
performing periodic services, cleaning the vehicle, etc.
Lights
Make sure the headlights, stop lights, tail lights, turn signal
lights, and other lights are working. Check headlight aim.Service reminder indicators and warning buzzers
Check that all service reminder indicators and warning buzzers
function properly.
Steering wheel
Check that it has the specified free play. Be alert for changes
in steering condition, such as hard steering, excessive free
play or strange noise.
Seats
Check that all front seat controls such as seat adjusters,
seatback recliner, etc. operate smoothly. Check that the head
restraints move up and down smoothly and that the locks hold
securely in any latched position. For folding-up second and
third seats, and detachable third seat, check that the latches
lock securely.
Seat belts
Check that the seat belt system such as buckles, retractors
and anchors operate properly and smoothly. Make sure the
belt webbing is not cut, frayed, worn or damaged.
Accelerator pedal
Check the pedal for smooth operation and uneven pedal effort
or catching.
Brake pedal
Check the pedal for smooth operation and the proper
clearance and free play. Check the brake booster function.

MAINTENANCE
491 Brakes
At a safe place, check that the brakes do not pull to one side
when applied.
Parking brake
Check that the lever has the proper travel and that, on a safe
incline, your vehicle is held securely with only the parking brake
applied.
Automatic transmission Parkº mechanism
Check the lock release button of the selector lever for proper
and smooth operation. On a safe incline, check that your
vehicle is held securely with the selector lever in Pº position
and all brakes released.
Vehicle exterior
Items listed below should be performed from time to time,
unless otherwise specified.
Fluid leaks
Check underneath for leaking fuel, oil, water or other fluid after
the vehicle has been parked for a while. If you smell fuel fumes
or notice any leak, have the cause found and corrected
immediately.
Doors and engine hood
Check that all side doors and back door, operate smoothly and
all latches lock securely. Make sure the engine hood
secondary latch secures the hood when the primary latch is
released.
Tire inflation pressure
Check the pressure with a gauge every two weeks,
or at least once a month and adjust as shown on the
tire pressure label. See page 532 for additional
information.
Tire surface
Check the tires carefully for cuts, damage or
excessive wear. See page 545 for additional
information.
Wheel nuts
When checking the tires, make sure to check the nuts
for looseness. Tighten them if necessary.
Tire rotation
Rotate the tires according to the maintenance
schedule. (For scheduled maintenance information,
please refer to the Owner's Manual
Supplement/Scheduled Maintenanceº.) See page 544
for additional information.