maintenance Lexus GS450h 2007 Using the hands-free system (for cellular phone) / LEXUS 2007 GS450H FROM JULY 2006 PROD. (OM30A05U) Workshop Manual

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4-3. Do-it-yourself maintenance
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■Tire inflation pressure check interval
You should check tire inflation pressure every 2 weeks, or at least once a month.
If equipped, do not forget to check the spare.
■ Inspection and adjustment procedure
Ti r e v a l v e
Tire pressure gauge
Remove the tire valve cap.
Press the tip of the tire pressure gauge onto the tire valve.
Read the pressure using the graduations of the gauge.
If the tire inflation pressure is not within the recommended lev-
els, adjust tire pressure. 
If you add too much air, press the center of the valve to lower.
After completing the tire inflation pressure measurement and
adjustment, apply soapy water to the valve and check for leak-
age.
Reinstall the tire valve cap.
STEP1
STEP2
STEP3
STEP4
STEP5
STEP6

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4-3. Do-it-yourself maintenance
4
Maintenance and care
■Effects of incorrect tire inflation pressure
Driving with incorrect tire inflation pressure may result in the following:
●Reduced fuel efficiency
●Reduced driving comfort and tire life
●Reduced safety
●Damage to the drive train
If a tire needs frequent refilling, have it checked by your Lexus dealer.
■Instructions for checking tire inflation pressure
When checking tire inflation pressure, observe the following:
●Check only when the tires are cold. 
If your vehicle has been parked for at least 3 hours and has not been driven for
more than 1 mile or 1.5 km, you will get an accurate cold tire inflation pressure
reading.
●Always use a tire pressure gauge. 
The appearance of the tire can be misleadi ng. In addition, tire inflation pressures
that are even just a few pounds off can degrade ride and handling.
●Do not bleed or reduce tire inflation pressure after driving. It is normal for the
tire inflation pressure to be higher after driving.
●Never exceed the vehicle capacity weight. 
Passengers and luggage weight should be placed so that the vehicle is bal-
anced.

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4-3. Do-it-yourself maintenance
CAUTION
■Proper inflation is critical to save tire performance
Keep your tires properly inflated. Otherwise, the following conditions may occur
and result in an accident causing death or serious injury.
●Excessive wear
●Uneven wear
●Poor handling
●Possibility of blowouts resulting from overheated tires
●Poor sealing of the tire bead
●Wheel deformation and/or tire separation
●A greater possibility of tire damage from road hazards
NOTICE
■When inspecting and adjusting tire inflation pressure
Be sure to reinstall the tire valve caps.
Without the valve caps, dirt or moisture co uld get into the valve and cause air leak-
age, which could result in an accident. If the caps have been lost, replace them as
soon as possible.

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4-3. Do-it-yourself maintenance
4
Maintenance and care
Wheels
■When replacing wheels
The wheels of your Lexus are equipped with tire pressure warning valves and trans-
mitters that allow the tire pressure warning system to provide advanced warning in
the event of a loss in tire inflation pressure. Whenever wheels are replaced, the tire
pressure warning valves and transmitters must be switched over from the old
wheels. ( P. 3 8 4 )
If a wheel is bent, cracked or heavily corroded, it should be replaced. 
Otherwise, the tire may separate from the wheel or cause loss of handling
control.
■ Wheel selection
When replacing wheels, care should be taken to ensure that they
are equivalent to those removed in load capacity, diameter, rim
width, and offset. 
Replacement wheels are available at your Lexus dealer.
Lexus does not recommend using:
• Wheels of different sizes or types
• Used wheels
• Bent wheels that have been straightened
• Lexus wheels with after market chrome plating
■ Aluminum wheel precautions
●Use only Lexus wheel nuts and wr enches designed for use with
your aluminum wheels.
● When rotating, repairing or changi ng your tires, check that the
wheel nuts are still tight after driving 1000 miles (1600 km).
● Be careful not to damage the aluminum wheels when using tire
chains.
● Use only Lexus genuine balance weights or equivalent and a
plastic or rubber hammer when balancing your wheels.

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4-3. Do-it-yourself maintenance
CAUTION
■When replacing wheels
●Do not use wheels that are a different size from those recommended in the
Owner’s Manual, as this may result in loss of handling control.
●Never use an inner tube in a leaking wheel which is designed for a tubeless tire.
Doing so may result in an accident, causing death or serious injury.
NOTICE
■Replacing tire pressure warning valves and transmitters
●Because tire repair or replacement may affect the tire pressure warning valves
and transmitters, make sure to have tires serviced by your Lexus dealer or other
qualified service shop. In addition, make sure to purchase your tire pressure
warning valves and transmitters at your Lexus dealer.
●Ensure that only genuine Lexus wheels are used on your vehicle. 
Tire pressure warning valves and transmitters may not work properly with non-
genuine wheels.

399
4-3. Do-it-yourself maintenance
4
Maintenance and care
Air conditioning filter
The air conditioning filter must be cleaned or changed regularly to main-
tain air conditioning efficiency.
■ Removal method
Set the air conditio ning system to recirculated mode.
The air conditioning filter case cannot be removed with the system in
the outside air mode.
Turn the power switch to “OFF” mode.
Open the glove box and
remove the partition.
Remove the filter cover.
Push the tabs and remove the
filter case.
STEP1
STEP2
STEP3
STEP4
STEP5

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4-3. Do-it-yourself maintenance
■Checking interval
Inspect and replace the air conditioning filter according to the maintenance sched-
ule. In dusty areas or areas with heavy traffic flow, early replacement may be
required. (For scheduled maintenance information, refer to the “Warranty and Ser-
vices Guide/Owner's Manual Supplement/Scheduled Maintenance”.)
■If air flow from the vents decreases dramatically
The filter may be clogged. Check the filter and replace if necessary.
NOTICE
■To prevent damage to the system
●When using the air conditioning system, make sure that a filter is always installed.
●When cleaning the filter, do not clean the filter with water.
■Cleaning method
If the filter is dirty, clean by blow-
ing compressed air through the
filter from the downward side.
Hold the air gun 2 in. (5 cm)
from the filter and blow for
approximately 2 minutes at 72
psi (500 kPa, 5.0 kgf/cm
2 or
bar). 
If it is not available, have the filter
cleaned by your Lexus dealer.
■ Replacement method
Remove the air conditioning fil-
ter from the filter case and
replace it with a new one.
The “UP” marks shown on the
filter and the filter case should
be pointing up.

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4-3. Do-it-yourself maintenance
4
Maintenance and care
Electronic key battery
Replace the battery with a new one if it is discharged.
■You will need the following items:
●Flathead screwdriver
● Small Phillips-head sc rewdriver
● Lithium battery (CR1632)
■ Replacing the battery
Take out the mechanical key.
Remove the cover.
Remove the depleted battery.
Insert a new battery with the “+”
terminal facing up.
STEP1
STEP2
STEP3

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4-3. Do-it-yourself maintenance
■If the electronic key battery is discharged
The following symptoms may occur.
●The smart access system with push-button start and wireless remote control will
not function properly.
●The operational range is reduced.
■Use a CR1632 lithium battery
●Batteries can be purchased at your Lexus dealer, jewelers, or camera stores.
●Replace only with the same or equivalent type recommended by a Lexus dealer.
●Dispose of used batteries according to the local laws.
CAUTION
■Removed battery and other parts
Keep away from children. 
These parts are small and if swallowed by a child they can cause choking.
NOTICE
■For normal operation after replacing the battery
Observe the following precautions to prevent accidents.
●Always work with dry hands. 
Moisture may cause the battery to rust.
●Do not touch or move any other comp onents inside the electronic key.
●Do not bend the battery terminals.

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4-3. Do-it-yourself maintenance
4
Maintenance and care
Checking and replacing fuses
If any of the electrical components do not operate, a fuse may have blown.
If this happens, check and replace the fuses as necessary.
Turn the power switch to “OFF” mode.
Remove the engine compartment cover if necessary.
P. 3 7 0
Open the fuse box cover.
Engine compartment
Remove the clips.
Front controller in the engine compartment fuse box Lift the lid off while pushing the
tabs on either side.STEP1
STEP2
STEP3