2003 Lexus GX470 maintenance

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.

ENGINE
418
Importance of engine oil level check
One of the most important points in proper vehicle
maintenance is to keep the engine oil at the optimum level so
that oil function will not be impaired. Therefore, it is essential
that the oil level be checked regularly. Lexus recommends that
the oil level be checked every time you refuel the vehicle.
NOTICE
Failure to check the oil level regularly could lead to
serious engine trouble due to insufficient oil.
For detailed information on oil level check, see “Checking the
engine oil level” described below.
USED ENGINE OIL
CAUTION
 Used engine oil contains potentially harmful
contaminants which may cause skin disorders such
as inflammation or skin cancer, so care should be
taken to avoid prolonged and repeated contact with
it. To remove used engine oil from your skin, wash
thoroughly with soap and water.
 Dispose of used oil and used oil filters only in a safe
and acceptable manner. Do not dispose of used oil
and used oil filters in household trash, in sewers or
onto the ground. Call your Lexus dealer or a service
station for information concerning recycling or
disposal.
 Do not leave used oil within the reach of children.

CHASSIS
428 AUTOMATIC TRANSMISSION
Fluid capacity Drain and refill
Up to 3.0 L (3.2 qt., 2.6 lmp.qt.)
Fluid typeToyota Genuine ATF Type TIV*
*Change automatic transmission fluid only as necessary.
Generally, it is necessary to change automatic transmission
fluid only if your vehicle is driven under one of the Special
Operating Conditions listed in your “Owner’s Manual
Supplement / Scheduled Maintenance”. When changing the
automatic transmission fluid, use only “Toyota Genuine ATF
Type T−IV” (ATF JWS3309 or NWS6500) to aid in assuring
optimum transmission performance.NOTICE
Using automatic transmission fluid other than “Toyota
Genuine ATF Type TIV” may cause deterioration in
shift quality, locking up of your transmission
accompanied by vibration, and ultimately damage the
automatic transmission of your vehicle.
Please contact your Lexus dealer for further details.
BRAKES
Pedal clearance
55 mm (2.2 in.) Min. *1
Pedal free play1 − 6 mm (0.04 − 0.24 in.)
Brake pad wear limit1.0 mm (0.04 in.)
Parking brake lining wear limit1.0 mm (0.04 in.)
Parking brake adjustment5 − 7 clicks *2
Fluid typeSAE J1703 or FMVSS No. 116 DOT 3
*1: Minimum pedal clearance when depressed with the force of 490 N (50 kgf,\
110 lbf) with the engine running
*
2: Parking brake adjustment when pulled with the force of 196 N (20 kgf, 4\
4 lbf)

CHASSIS
434
ROTATING TIRES
To equalize tire wear and help extend tire life, Lexus
recommends that you rotate your tires according to the
maintenance schedule. (For scheduled maintenance
information, please refer to the “Owner’s Manual
Supplement / Scheduled Maintenance”.) However, the
most appropriate timing for tire rotation may vary
according to your driving habits and road surface
conditions.
The wheel assemblies must be rotated as illustrated above.
When rotating tires, check for uneven wear and damage.
Abnormal wear is usually caused by incorrect tire pressure,
improper wheel alignment, out−of− balance wheels, or severe
braking.
Before storing radial, snow or studded tires, mark the direction
of rotation and be sure to install them in the same direction
when using them again. Tires should be stored in a cool dry
place.
CHECKING AND REPLACING TIRES
When to replace your tires
 1 New tread 2 Tread wear indicator

3 Worn tread
Replace the tires when the tread wear indicators show.
The location of the tread wear indicators is shown by the
marks molded on the sidewall of each tire.
The tires on your Lexus have built− in tread wear indicators to
help you know when the tires need replacement. When the
tread depth wears to 1.6 mm (0.06 in.) or less, the indicators
will appear. If you can see the indicators in two or more
adjacent grooves, the tire should be replaced.
The effectiveness of snow tires is lost if the tread wears
down below 4 mm (0.16 in.).