2003 Lexus GX470 maint

MAINTENANCE
397
Tire rotation
Rotate the
tires according to the maintenance schedule. (For
scheduled maintenance information, please refer to the
“Owner’s Manual Supplement / Scheduled Maintenance”.)
See page 434 for additional information.
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.
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 ef fort
or catching.
Brake pedal
Check the pedal for smooth operation and the proper
clearance and free play. Check the brake booster function.
Brakes
At a safe place, check that the brakes do not pull to one side
when applied.

MAINTENANCE
398Parking 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 “Park” 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 “P” position
and all brakes released.
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 454 for
additional information.
Engine coolant level
Make sure the coolant level is between the “F” and “L” lines on
the see− through reservoir when the engine is cold. See page
422 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 423 for
additional information.
Battery
Check the battery condition by the indicator color. See page
447 for additional information.

MAINTENANCE
399
Brake fluid level
Make sure the brake fluid level is correct. See page 430 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 419 for
additional
information.
Power steering fluid level
Check the level through the reservoir. The level should be in
the “HOT” or “COLD” range depending on the fluid
temperature. See page 431 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 caution” on page 298.)
DOES YOUR VEHICLE NEED REPAIRING?
Be on the alert for changes in performance and sounds, and
visual tip −offs that indicate service is needed. Some important
clues are:
 Engine missing, stumbling, or pinging
 Appreciable loss of power
 Strange engine noises
 A fluid leak under the vehicle (However, water dripping from
the air conditioning after use is normal.)
 Change in exhaust sound (This may indicate a dangerous
carbon monoxide leak. Drive with the windows open and
have the exhaust system checked immediately.)
 Flat−looking tires, excessive tire squeal when cornering,
uneven tire wear
 Vehicle pulls to one side when driving straight on a level
road
 Strange noises related to suspension movement
 Loss of brake effectiveness, spongy feeling brake pedal,
pedal almost touches floors, vehicle pulls to one side when
braking
 Engine coolant temperature continually higher than normal

MAINTENANCE
400If you notice any of these clues, take your vehicle to your Lexus
dealer as soon as possible. It probably needs adjustment or
repair.
CAUTION
Do not continue driving with the vehicle unchecked. It
could result in serious vehicle damage and possibly
personal injury.
EMISSION INSPECTION AND
MAINTENANCE (I/M) PROGRAMS
Some states have vehicle emission inspection programs
which include OBD (On −Board Diagnostics) checks.
The OBD system monitors the operation of the emission
control system. When the OBD system determines that a
problem exists somewhere in the emission control system, the
malfunction indicator lamp comes on. In this case, your vehicle
may not pass the I/M test and need to be repaired. Contact
your Lexus dealer to service the vehicle.
Even if the malfunction indicator lamp does not come on, your
vehicle may not pass the I/M test as readiness codes have not
been set in the OBD system.
Readiness codes are automatically set during ordinary driving.
However, when the battery is disconnected or run down, the
codes are erased. Also, depending on your driving habits, the
codes may not be completely set.
Also, if the malfunction indicator lamp had come on recently
due to temporary malfunction such as a loose fuel tank cap,
your vehicle may not pass the I/M test.
The malfunction indicator lamp will go off after taking several
driving trips, but the error code in the OBD system will not be
cleared unless about 40 trips or more are taken.
If your vehicle does not pass the I/M test and the malfunction
indicator lamp does not come on, contact your Lexus dealer to
prepare the vehicle for re −testing.

MAINTENANCE
401

INTRODUCTION
406
DOITYOURSELF SERVICEPRECAUTIONS
If you perform maintenance yourself, be sure to follow the
correct procedure given in this section.
You should be aware that improper or incomplete servicing
may result in operating problems.
Performing do −it−yourself maintenance during the warranty
period may affect your warranty coverage. Read the separate
Lexus Warranty statement for details and suggestions.
This Section gives instructions only for those items that are
relatively easy for an owner to perform. As explained in
Section 5, there are still a number of items that must be
performed by a qualified technician with special tools.
For information on tools and parts for do−it−yourself
maintenance, see “Parts and tools” on page 407.
Utmost care should be taken when working on your vehicle to
prevent accidental injury. Here are a few precautions that you
should be especially careful to observe:
CAUTION
 When the engine is running, keep hands, clothing,
and tools away from the moving fan and engine drive
belt. (Removing rings, watches, and ties is
advisable.)
 Right after driving, the engine compartment the
engine, radiator, exhaust manifold and power
steering fluid reservoir, etc. will be hot. So be
careful not to touch them. Oil, other fluids and spark
plugs may also be hot.
 If the engine is hot, do not remove the radiator cap or
loosen the drain plugs to prevent burning yourself.
 Do not smoke, cause sparks or allow open flames
around fuel or the battery. Their fumes are
flammable.
 Do not get under your vehicle with just the body jack
supporting it. Always use automotive jack stands or
other solid supports.
 Use eye protection whenever you work on or under
your vehicle where you may be exposed to flying or
falling material, fluid spray, etc.
 Be extremely cautious when working on the battery.
It contains poisonous and corrosive sulfuric acid.
 Warning: Battery posts, terminals and related
accessories contain lead and lead compounds,
chemicals known to the State of California to cause
cancer and reproductive harm. Wash hands after
handling.

INTRODUCTION
407
NOTICE
Remember that battery and ignition cables carry high
currents or voltages. Be careful of accidentally
causing a short circuit.
 Before closing the engine hood, check to see that you
have not forgotten any tools, rags, etc.
 Do not drive with the air cleaner removed, or
excessive engine wear could result. Also backfiring
could cause a fire in the engine compartment.
 Do not overfill automatic transmission fluid and
power steering fluid, or the transmission and power
steering could be damaged.
 Be careful not to scratch the glass surface with the
wiper frame.
PARTS AND TOOLS
Here is a list of parts and tools you will need to perform
do−it−yourself maintenance. Remember all Lexus parts are
designed in metric sizes, so your tools must be metric.
Checking the engine oil level
Parts (if level is low):
“Toyota Genuine Motor Oil” or equivalent
See page 420 for details about engine oil selection.
Tools:
 Rag or paper towel
 Funnel (only for adding oil)
Checking the engine coolant level
Parts (if level is low):
“Toyota Genuine Long Life Coolant” or equivalent
See “Checking the engine coolant level” on page 422 for
instructions.
 Demineralized or distilled water
Tools:
 Funnel (only for adding coolant)

ENGINE
414
FUEL
Fuel type
Your vehicle must use only unleaded gasoline.
To help prevent gas station mixups, your Lexus has a smaller
fuel tank opening. The special nozzle on pumps with unleaded
fuel will fit it, but the larger standard nozzle on pumps with
leaded gas will not.
At a minimum, the gasoline you use should meet the
specifications of ASTM D4814 in the U.S.A. and CGSB
3.5−M93 in Canada.
NOTICE
Do not use leaded gasoline. Use of leaded gasoline will
cause the threeway catalytic converter to lose its
effectiveness and the emission control system to
function improperly. Also, this can increase
maintenance costs.
Octane rating
Select Octane Rating 87 (Research Octane Number 91) or
higher. For improved vehicle performance, the use of
premium unleaded gasoline with an Octane Rating of 91
(Research Octane Number 96) or higher is recommended. Use of unleaded fuel with an octane number or rating lower
than stated above will cause persistent heavy knocking. If
severe, this will lead to engine damage.
If your engine knocks ...
If you detect heavy knocking even when using the
recommended fuel, or if you hear steady knocking while
holding a steady speed on level roads, consult your Lexus
dealer.
However, occasionally, you may notice light knocking for a
short
time while accelerating or driving up hills. This is normal
and there is no need for concern.
Gasoline containing detergent additives
Lexus recommends the use of gasoline that contains
detergent additives to avoid buildup of engine deposits.
However, all gasoline sold in the U.S. contains detergent
additives to keep clean and/or clean intake systems.
Quality gasoline
Automotive manufacturers in the U.S., Europe and Japan
have developed a specification for quality fuel named
WorldWide Fuel Charter (WWFC) that is expected to be
applied world wide. The WWFC consists of three
categories t hat depend on required emission levels. In the
U.S., category 3 has been adopted. The WWFC improves
air quality by providing for better emissions in vehicle
fleets, and customer satisfaction through better vehicle
performance.