check engine Lexus GS430 2006 Scheduled Maintenance Guide / LEXUS 2006 GS430/GS300 FROM JAN. 2005 PROD. (OM30649U) Repair Manual

ENGINE
521
The amount of engine oil consumed depends on the
viscosity of the oil, the quality of the oil and the way the
vehicle is driven.
More oil is consumed under driving conditions such as high
speeds and frequent acceleration and deceleration.
A new engine consumes more oil, since its pistons, piston rings
and cylinder walls have not become conditioned.
Oil consumption: Max. 1.0 L per 1000 km (1.1 qt./600 miles,
0.9 lmp·qt./600 miles).
When judging the amount of oil consumption, keep in
mind that the oil may have become diluted, making it
difficult to judge the true level accurately.
For example, if a vehicle is used for repeated short trips and
consumes a normal amount of oil, the dipstick may not show
any drop in the oil level at all, even after 1000 km (600 miles)
or more. This is because
the oil is gradually becoming diluted
with fuel or moisture, making it appear that the oil level has not
changed.
The diluting ingredients evaporate out when the vehicle is then
driven at high speeds, as on an expressway, making it appear
that oil is excessively consumed after driving at high speeds.
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” on page 522.

ENGINE
522
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.
 Do not leave used oil within the reach of children.
 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.
CHECKING THE ENGINE OIL LEVEL
G62001
 GS430
G62002
GS300
With the engine at operating temperature and turned off,
check the oil level on the dipstick.

ENGINE
524
G62006
GS300 (fourwheel drive models)
1
Add oil 2O.K. 3Too full
4. Pull the dipstick out and look at the oil level while holding a
rag under the end. If it is between the full level mark (
5 ) and
the low level mark ( 4 ), it is O.K.
NOTICE
Be careful not to drop engine oil on the vehicle
components.
G62003
GS430 GS300
If the oil level is below or only slightly above the low level
mark, add engine oil of the same type as already in the
engine.
Remove the oil filler cap and add engine oil a little at a time,
checking the dipstick. We recommend that you use a funnel
when adding oil. The approximate quantity of oil needed to
raise the level between low and full on the dipstick is indicated
as follows:
1.5 L (1.6 qt., 1.3 lmp. qt.)
For the engine oil capacity, see “Specifications” on pages 512
and 515.
When the level reaches within the correct range, return the
filler cap and turn the cap clockwise until you hear a click.

ENGINE
525
NOTICE
Be careful not to spill engine oil on the vehicle
components.
 Avoid overfilling, or the engine could be damaged.
 Check the oil level on the dipstick once again after
adding the oil.
Engine oil selection
“Toyota Genuine Motor Oil” is used in your Lexus vehicle. Use
Lexus approved “Toyota Genuine Motor Oil” or equivalent to
satisfy the following grade and viscosity.
Oil grade: API grade SL “Energy −Conserving” or ILSAC
multigrade engine oil.
Recommended viscosity: 5W−30
62L042
Outside temperature
SAE 5W30 is the best choice for good fuel economy, and
good starting in cold weather.
If SAE 5W30 is not available, SAE10W30 may be used.
However, it should be replaced with 5W30 at the next oil
change.

ENGINE
527
CHECKING THE ENGINE COOLANTLEVEL
G62007
GS430
1
Reservoir cap 2“FULL” line 3“LOW” line
G62008
GS300
1
Reservoir cap 2“FULL” line 3“LOW” line Look at the seethrough coolant reservoir when the
engine is cold. The coolant level is satisfactory if it is
between the”FULL” and ”LOW” lines on the reservoir. If
the level is low, add the coolant. (For the coolant type, see
“Coolant type selection” described below.)
The coolant level in the reservoir will vary with engine
temperature. However, if the level is on or below the ”LOW”
line, add coolant. Bring the level up to the ”FULL” line.
If the coolant level drops within a short time after replenishing,
there
may be a leak in the system. V isually check the radiator,
hoses, engine coolant filler cap, radiator cap and drain cock
and water pump.
If you can find no leak, have your Lexus dealer test the cap
pressure and check for leaks in the cooling system.
CAUTION
To prevent burning yourself, do not remove the radiator
cap when the engine is hot.

ENGINE
529
CHECKING THE RADIATOR ANDCONDENSER
If either of the above parts are extremely dirty or you are not
sure of their condition, take your vehicle to your Lexus dealer.
CAUTION
To prevent burning yourself , be careful not to touch the
radiator or condenser when the engine is hot.
NOTICE
To prevent damage to the radiator and condenser, do
not perform the work by yourself.
SPARK PLUGS
62R031c
GS430
Your engine is fitted with iridiumtipped spark plugs.
NOTICE
Use only iridiumtipped spark plugs and do not adjust
gaps for your engine performance and smooth
drivability.

ELECTRICAL COMPONENTS
573
NOTICE
Make sure the engine and all accessories are turned
off before performing maintenance.
 When checking the battery, remove the ground cable
first and reinstall it last.
 Be careful not to cause a short circuit with tools.
 Take care no solution gets into the battery when
washing it.
If the battery is disconnected or run down
The following functions may not operate correctly when you
reconnect or replace the battery. In these cases, you should
normalize each system referring to the following pages.
Power windows (See page 59.)
 Moon roof (See page 134.)
 Variable gear ratio steering system (See page 424.)
 Intuitive parking assist (See page 380.)
Checking battery condition
Checking by indicator
G64009
Check the battery condition by the indicator color.
1
BLUE − Good condition.
2
WHITE − Charging necessary. Have the battery checked
by your Lexus dealer.
3 RED − Have the battery checked by your Lexus dealer.
NOTICE
Do not refill the battery with water.

ELECTRICAL COMPONENTS
574
BATTERY RECHARGINGPRECAUTIONS
During recharging, the battery is producing hydrogen
gas.
Therefore, before recharging:
1. If recharging with the battery installed on the vehicle, be
sure to disconnect the ground cable.
2. Make sure the power switch on the recharger is off when
connecting the charger cables to the battery and when
disconnecting them.
CAUTION
Always charge the battery in an unconfined area. Do
not charge the battery in a garage or closed room
where there is not sufficient ventilation.
 Only do a slow charge (5 A or less). Charging at a
quicker rate is dangerous. The battery may explode
causing personal injuries.
NOTICE
Never recharge the battery while the engine is running.
Also, be sure all accessories are turned off.
CHECKING AND REPLACING THE
BLADE TYPE FUSES
G64010
Left side kick panel
G64011
Right side kick panel

ELECTRICAL COMPONENTS
577
It is a good idea to purchase a
set of spare fuses and keep them
in your vehicle for emergencies.
If the new fuse immediately blows out, there is a problem with
the electrical system. Have your Lexus dealer correct it as
soon as possible.
CAUTION
Never use a fuse with a higher amperage rating, or any
other object, in place of a fuse. This may cause
extensive damage and possibly a fire.
CHECKING THE CARTRIDGE TYPE FUSES
G64015
Engine compartment

ELECTRICAL COMPONENTS
579
ADDING WASHER FLUID
If the washer tank becomes nearly empty, add washer
fluid.
You may use plain water as washer fluid. However, in cold
areas where temperatures range below the freezing point, use
washer fluid containing antifreeze. This product is available at
your Lexus dealer and most auto parts stores. Follow the
manufacturer’s directions for how much to mix with water.
NOTICE
Do not use engine antifreeze or any other substitute
because it may damage your vehicle’s paint.
CHECKING THE HEADLIGHT AIM
G64020
 1 Beam angle gauge
(horizontal movement for high beam)
2 Beam angle gauge
(vertical movement for high beam)
3 Beam angle gauge
(vertical movement for low beam)
4 Beam angle gauge
(horizontal movement for low beam)
Before checking the headlight aim:
1. Be sure that the body around the headlight is not deformed.
2. Park the vehicle on a level spot.
3. The driver gets into the driver’s seat and puts the vehicle in
a state readying for a driving (with a full tank).
4. Bounce the vehicle several times.