inflation pressure Lexus GS450h 2007 Using the audio system / LEXUS 2007 GS450H FROM JULY 2006 PROD. (OM30A05U) Owner's Guide

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.

5
When trouble arises
455
5-2. Steps to take in an emergency
CAUTION
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold
and inflated to the inflation pressure re commended by the vehicle manufacturer on
the vehicle placard or tire inflation pressure label (tire and load information label).
(If your vehicle has tires of a different size than the size indicated on the vehicle
placard or tire inflation pressure label [tire and load information label], you should
determine the proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle has been equipped with a tire pressure
monitoring system (TPMS-tire pressure warning system) that illuminates a low tire
pressure telltale (tire pressure warning light) when one or more of your tires is sig-
nificantly under-inflated. Accordingly, when the low tire pressure telltale (tire pres-
sure warning light) illuminates, you should stop and check your tires as soon as
possible, and inflate them to the proper pressure. Driving on a significantly under-
inflated tire causes the tire to overheat an d can lead to tire failure. Under-inflation
also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling
and stopping ability.
Please note that the TPMS (tire pressure warning system) is not a substitute for
proper tire maintenance, and it is the driver's responsibility to maintain correct tire
pressure, even if under-inflation has not reached the level to trigger illumination of
the TPMS low tire pressure telltale (tire pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system)
malfunction indicator to indicate when th e system is not operating properly. The
TPMS (tire pressure warning system) malf unction indicator is combined with the
low tire pressure telltale (tire pressure warning light). When the system detects a
malfunction, the telltale will flash for approximately one minute and then remain
continuously illuminated. This sequence will continue upon subsequent vehicle
start-ups as long as the malfunction exists . When the malfunction indicator is illumi-
nated, the system may not be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfunctions may occur for a variety of rea-
sons, including the installation of replacem ent or alternate tires or wheels on the
vehicle that prevent the TPMS (tire pressure warning system) from functioning
properly. Always check the TPMS (tire pressure warning system) malfunction tell-
tale after replacing one or more tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow the TPMS (tire pressure warning
system) to continue to function properly.

462
5-2. Steps to take in an emergency
■The compact spare tire
●The compact spare tire is identified by the label “TEMPORARY USE ONLY”
on the tire sidewall.
Use the compact spare tire temporarily only in an emergency.
●Make sure to check the tire inflatio n pressure of the compact spare tire. 
(  P. 4 9 3 )
■Tr e a d l i f e
The compact spare tire can be used many times, if necessary. It has tread life of up
to 3000 miles (4800 km) depending on road conditions and your driving habits.
When treadwear indicato rs appear on the tire, replace the tire. ( P. 383)
■When using the compact spare tire
As the spare tire is not equipped with the tire pressure warning valve and transmit-
ter, low inflation pressure of the spare tire will not be warned. Also, if you replace the
compact spare tire after the tire pressure warning light comes on, the light remains
on.
■ Compact spare tire
The compact tire saves space in your luggage compartment, and its
lighter weight helps to enhance fuel economy and permits easier
installation in case of a flat tire.
The compact spare tire is
designed for temporary emer-
gency use only.

493
6-1. Specifications
6
Vehicle specifications
Tires and wheels
Ti r e s i z e245/40R18 93Y, P245/40R18 93V, 
245/40ZR18, T155/70D17 110M (spare)
Front and rear tire inflation 
pressure
(Recommended cold tire inflation
pressure)
Driving under normal conditions
35 psi (240 kPa, 2.4 kgf/cm2 or bar)
Driving at high speeds above 100 mph (160
km/h) (in countries where such speeds are per-
mitted by law) Add 9 psi (60 kPa, 0.6 kgf/cm
2 or bar) to the
front tires and rear tires. Never exceed the
maximum cold tire inflation pressure indicated
on the tire sidewall.
Spare tire inflation pressure 
(Recommended cold tire inflation
pressure)
60 psi (420 kPa, 4.2 kgf/cm2 or bar)
Wheel size18  8 J, 17  4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

499
6-1. Specifications
6
Vehicle specifications
Typical DOT and tire identification number (TIN)DOT symbol
*
Tire Identification Number (TIN)
Tire manufacturer’s identifica-
tion mark
Tire size code
Manufacturer’s optional tire
type code (3 or 4 letters)
Manufacturing week
Manufacturing year
*: The DOT symbol certifies that the tire conforms to applicable
Federal Motor Vehicle Safety
Standards.
Radial tires or bias-ply tires
A radial tire has RADIAL on the sidewall. A tire not marked RADIAL is a
bias-ply tire.
TUBELESS or TUBE TYPE
A tubeless tire does not have a tube and air is directly filled in the tire. A tube
type tire has a tube inside the tire and the tube maintains the air pressure.
Load limit at maximum cold tire inflation pressure ( P. 503)
Maximum cold tire inflation pressure ( P. 503)
This means the pressure to which a tire may be inflated.
Uniform tire quality grading
For details, see “Uniform Tire Quality Grading” that follows.
Summer tire or all season tire (P. 388)
An all season tire has “M+S” on the si dewall. A tire not marked “M+S” is a
summer tire.
“TEMPORARY USE ONLY” ( P. 4 6 2 )
A compact spare tire is identified by the phrase “TEMPORARY USE
ONLY” molded into its sidewall. This tire is designed for temporary emer-
gency use only.

503
6-1. Specifications
6
Vehicle specifications
Warning: The temperature grades for this tire are established for a tire that
is properly inflated and not overloaded.
Excessive speed, underinflation, or excess ive loading, either separately or in
combination, can cause heat build up and possible tire failure.
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pres-
sureTire pressure when the vehicle has been parked for
three hours or more, or has not been driven more
than 1 mile or 1.5 km under that condition
Maximum inflation pres-
sureThe maximum cold inflated pressure to which a tire
may be inflated, shown on the sidewall of the tire
Recommended inflation
pressureCold tire inflation pressure recommended by a man-
ufacturer
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of transmission, power
steering, power brakes, power windows, power seats,
radio and heater, to the extent that these items are
available as factory-installed equipment (whether
installed or not)
Curb weight
The weight of a motor vehicle with standard equip-
ment, including the maximum capacity of fuel, oil and
coolant, and if so equipped, air conditioning and
additional weight optional engine
Maximum loaded vehicle
weight
The sum of: 
(a) Curb weight 
(b) Accessory weight 
(c) Vehicle capacity weight 
(d) Production options weight
Normal occupant weight150 lb. (68 kg) times the number of occupants speci-
fied in the second column of Table 1
* that follows

505
6-1. Specifications
6
Vehicle specifications
Tire related termMeaning
We a t h e r s i d eThe surface area of the rim not covered by the
inflated tire
Bead
The part of the tire that is made of steel wires,
wrapped or reinforced by ply cords and that is
shaped to fit the rim
Bead separationA breakdown of the bond between components in
the bead
Bias ply tire
A pneumatic tire in which the ply cords that extend to
the beads are laid at alternate angles substantially
less than 90 degrees to the centerline of the tread
CarcassThe tire structure, except tread and sidewall rubber
which, when inflated, bears the load
ChunkingThe breaking away of pieces of the tread or sidewall
CordThe strands forming the plies in the tire
Cord separationThe parting of cords from adjacent rubber com-
pounds
CrackingAny parting within the tread, sidewall, or innerliner of
the tire extending to cord material
CT
A pneumatic tire with an inverted flange tire and rim
system in which the rim is designed with rim flanges
pointed radially inward and the tire is designed to fit
on the underside of the rim in a manner that encloses
the rim flanges inside the air cavity of the tire
Extra load tire
A tire designed to operate at higher loads and at
higher inflation pressures than the corresponding
standard tire
GrooveThe space between two adjacent tread ribs

506
6-1. Specifications
Tire related termMeaning
InnerlinerThe layer(s) forming the inside surface of a tubeless
tire that contains the inflating medium within the tire
Innerliner separationThe parting of the innerliner from cord material in the
carcass
Intended outboard side-
wall
(a) The sidewall that contains a whitewall, bears white lettering, or bear s manufacturer, brand,
and/or model name molding that is higher or
deeper than the same molding on the other side-
wall of the tire, or
(b) The outward facing sidewall of asymmetrical tire
that has a particular side that must always face
outward when mounted on a vehicle
Light truck (LT) tire
A tire designated by its manufacturer as primarily
intended for use on lightweight trucks or multipur-
pose passenger vehicles
Load ratingThe maximum load that a tire is rated to carry for a
given inflation pressure
Maximum load ratingThe load rating for a tire at the maximum permissible
inflation pressure for that tire
Maximum permissible
inflation pressureThe maximum cold inflation pressure to which a tire
may be inflated
Measuring rimThe rim on which a tire is fitted for physical dimension
requirements
Open spliceAny parting at any junction of tread, sidewall, or
innerliner that extends to cord material
Outer diameterThe overall diameter of an inflated new tire
Overall width
The linear distance between the exteriors of the side-
walls of an inflated tire, including elevations due to
labeling, decorations, or protective bands or ribs