2010 Lexus GS350 tire pressure

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When trouble arises
539
5-2. Steps to take in an emergency
GS_G_U (OM30C80U)
June 29, 2011 10:30 am
■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 caused by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with the tire pressure warning valve and
transmitter. If a tire goes flat, the tire pressure warning light will not turn off even
though the flat tire is replaced with the spare tire. Replace the spare tire with the
repaired tire and adjust the proper tire inflation pressure. The tire pressure warning
light will turn off after a few minutes.
■If the tire pressure warning system is inoperative
The tire pressure warning 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 pressure warning select switch is set to a different tire setting.
●If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher.
The tire pressure warning 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 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. (Even if you use Lexus wheels, the tire
pressure warning system may not work properly with some types of tires.)
●If tire chains are used.

540
5-2. Steps to take in an emergency
GS_G_U (OM30C80U)
June 29, 2011 10:30 am
■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 “ENGINE START STOP” switch is turned to IGNITION ON mode, have
it checked by your Lexus dealer.
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 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.
●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.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.

5
When trouble arises
541
5-2. Steps to take in an emergency
GS_G_U (OM30C80U)
June 29, 2011 10:30 am
CAUTION
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold
and inflated to the inflation pressure recommended 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 and 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 the system is not operating properly. The
TPMS (tire pressure warning system) malfunction 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 replacement 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.

542
5-2. Steps to take in an emergency
GS_G_U (OM30C80U)
June 29, 2011 10:30 am
NOTICE
■Precaution when installing a different tire
When a tire of a different specification or maker is installed, the tire pressure warn-
ing system may not operate properly.

5
When trouble arises
557
5-2. Steps to take in an emergency
GS_G_U (OM30C80U)
June 29, 2011 10:30 am
■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 inflation pressure of the compact spare tire. 
(P. 5 9 8 )
■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 indicators appear on the tire, replace the tire. (P. 4 6 3 )
■When using the compact spare tire
As the compact spare tire is not equipped with the tire pressure warning valve and
transmitter, 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.

562
5-2. Steps to take in an emergency
GS_G_U (OM30C80U)
June 29, 2011 10:30 am
Firmly tighten each nut two or
three times in the order shown in
the illustration.
Tightening torque:
76 ft•lbf (103 N•m, 10.5 kgf•m)
Stow the flat tire, tire jack and all tools.
STEP4
■If you have a flat rear tire on a road covered with snow or ice
Install the compact spare tire on the front of the vehicle. Perform the following steps
and fit tire chains to the rear tires.
Replace a front tire with the compact spare tire.
Replace the flat rear tire with the tire removed from the front of the vehi-
cle.
Fit tire chains to the rear tires.
■After completing the tire change
The tire pressure warning system must be reset. (P. 464)
STEP5
STEP1
STEP2
STEP3

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When trouble arises
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5-2. Steps to take in an emergency
GS_G_U (OM30C80U)
June 29, 2011 10:30 am
NOTICE
■Do not drive the vehicle with a flat tire
Do not continue driving with a flat tire.
Driving even a short distance with a flat tire can damage the tire and the wheel
beyond repair.
■Be careful when driving over bumps with the compact spare tire installed on the
vehicle
The vehicle becomes lower when driving with the compact spare tire compared to
when driving with standard tires. Be careful when driving over uneven road sur-
faces.
■Driving with tire chains and the compact spare tire
Do not fit tire chains to the compact spare tire.
Tire chains may damage the vehicle body and adversely affect driving performance.
■When replacing the tires
When removing or fitting the wheels, tires or the tire pressure warning valve and
transmitter, contact your Lexus dealer as the tire pressure warning valve and trans-
mitter may be damaged if not handled correctly.
■To avoid damaging the tire pressure warning valves and transmitters
Do not use liquid sealants on flat tires.

566
5-2. Steps to take in an emergency
GS_G_U (OM30C80U)
June 29, 2011 10:30 am
If you have a flat tire (Vehicles with run-flat tires)
■In some condition (such as at high temperatures)
You can not continue driving for up to 100 miles (160 km).
■Spare tire
A spare tire is not provided on the vehicle with run-flat tires.
■If you cannot distinguish between standard tires and run-flat tires
Consult your Lexus dealer.
■For detailed information on run-flat tires
See the tire warranty book.
Take your vehicle to the nearest Lexus dealer or authorized tire dealer as
soon as possible.
■Run-flat tires (A “RFT” or “DSST” mark is molded on the sidewall)
You can continue driving the
vehicle with run-flat tires even if
any tire goes flat.
The vehicle is able to run for a
maximum of 100 miles (160 km)
at a speed below 55 mph (90
km/h) after the tire pressure
warning light comes on. 
(P. 5 3 7 )