flat tire Lexus GS450h 2007 Using the hands-free system (for cellular phone) / LEXUS 2007 GS450H FROM JULY 2006 PROD. (OM30A05U) Owner's Guide

395
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.

397
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.

When trouble arises5
427
5-1. Essential information............ 428If your vehicle needs to be 
towed .......................................... 428
If you think something is 
wrong .......................................... 435
Event data recorder ................. 436
5-2. Steps to take in an 
emergency............................ 438
If a warning light turns on or a 
warning buzzer sounds............ 438
If a warning message is 
displayed.................................... 444
If you have a flat tire (Vehicles 
with run-flat tires) ................... 460
If you have a flat tire (Vehicles 
with standard tires) .................. 461
If the hybrid system will not 
start ................................................ 471
If the shift lever cannot be 
shifted from P............................ 472
If you lose your keys .................. 473
When the electronic key 
battery is discharged ............. 474
If the 12 volt battery is 
discharged ................................. 476
If your vehicle overheats ....... 480
If the vehicle becomes  stuck ............................................ 483

5
When trouble arises
435
5-1. Essential information
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■ Visible symptoms
●Fluid leaks under the vehicle 
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temper ature gauge needle continually points
higher than normal
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the hybrid system
■ Operational symptoms
●Engine missing, stumbling or running rough
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, sp ongy feeling, pedal almost touches
the floor

440
5-2. Steps to take in an emergency
Have the malfunction repaired immediately.After taking the specified steps to correct the suspected problem, check
that the warning light turns off.
Warning lightWarning light/DetailsCorrection procedure
Open door warning light 
(warning buzzer)
*2
A door or the trunk is not
fully closed.
Check that all doors and the
trunk are closed.
Low fuel level warning light Remaining fuel 
(Approximately 2.6 gal. [10
L, 2.2 Imp.gal.] or less)
Refuel the vehicle.
Driver’s seat belt reminder
light (warning buzzer)
*3
Warns the driver to fasten
his/her seat belt.Fasten the seat belt.
Front passenger’s seat belt
reminder light
(warning buzzer)
*3
Warns the front passenger to
fasten his/her seat belt.
Fasten the seat belt.
Tire pressure warning light
When the light comes on:
Low tire inflation pressure.Adjust the tire inflation pres-
sure.
When the light comes on after
blinking for 1 minute:
Malfunction in the tire pres-
sure warning system.
Have the system checked by
your Lexus dealer.

442
5-2. Steps to take in an emergency
■SRS warning light
This warning light system monitors the following:
●The airbag sensor assembly
●Front airbag sensors
●The curtain shield airbag sensors
●The side and curtain shield airbag sensors
●The occupant detection sensor
●The front passenger occupant classification ECU
●“AIRBAG ON” and “AIRBAG OFF” indicator lights
●The pressure sensor
●The belt tension sensor
●The seat belt buckle switches
●The driver's seat position sensor
●The inflators
●The warning light
●The interconnecting wiring and power sources
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure warning reset switch does not turn off the tire pressure warning light.
■The tire pressure warning light may turn on due to natural causes
The tire pressure warning light may turn on due to natural causes such as natural air
leaks or tire inflation pressure changes caus ed by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the warning light.

5
When trouble arises
443
5-2. Steps to take in an emergency
CAUTION
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause loss of
vehicle control and result in death or serious injury.
●Vehicles with run-flat tires:
• Decelerate to the lowest appropriate speed as soon as possible. Do not drive
over 55 mph (90 km/h).
• Check and adjust the tire inflation pressure immediately.
• If the tire pressure warning light comes on even after tire inflation pressure
adjustment, it is probable that you have a flat tire. Have the tire replaced by
the nearest Lexus dealer.
• Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you
could lose control of the steering wheel or the brakes.
●Vehicles with standard tires:
• Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pressure immediately.
• If the tire pressure warning light comes on even after tire inflation pressure adjustment, it is probable that you have a flat tire. Check the tires. If the tire is
flat, change to the spare tire and have the flat tire repaired by the nearest
Lexus dealer.
• Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you
could lose control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.

5
When trouble arises
447
5-2. Steps to take in an emergency
■If the tire pressure warning system is inoperative
The system will be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●If tires not equipped with tire pressure warning valves and transmitters are used.
●If the ID code on the tire pressure warning valves and transmitters is not regis-
tered in the tire pressure warning computer.
●If the tire inflation pressure is more than 73 psi (500 kPa, 5.1 kgf/cm2 or bar).
The system may be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●If electronic devices or facilities using similar radio wave frequencies are nearby.
●If a radio set at similar frequencies is in use in the vehicle.
●If a window tint that affects the radio wave signals is installed.
●If the tire pressure warning select switch is set to a different tire setting.
●If there is a lot of snow or ice on the vehicle, in particular around the wheels or
wheel housings.
●If non-genuine Lexus wheels are used.
●If tire chains are used.
■If the tire pressure warning light comes on after blinking for 1 minute frequently
If the tire pressure warning light comes on after blinking for 1 minute frequently
when the power switch is turned to “IG-ON” mode, have it checked by your Lexus
dealer.
NOTICE
■Precaution when insta lling a different tire
When a tire of a different specification or maker is installed, the tire pressure warn-
ing system may not operate properly.

452
5-2. Steps to take in an emergency
Wa r n i n g m e s s a g eDetailsCorrection procedure

Low tire inflation pres-
sure.Check the tire inflation
pressure, and adjust to the
appropriate level.
(Flashing)
(If equipped)The PCS is not currently
functional.
Clean the grille and the
sensor. This message appears
when the pre-collision
system is hot. In this case,
wait until the system
cools down.
(If equipped)
Intuitive parking assist is
dirty or covered with ice.
(The illustration shows
something on the left
front sensor.)
Clean the sensor.
(Flashing) 
(If equipped)
The radar cruise control
sensor is dirty or covered
with ice.
Clean the sensor.