maintenance Lexus IS250 2010 Using The Air Conditioning System And Defogger / LEXUS 2010 IS350 IS250 (OM53A23U) Service Manual

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4-3. Do-it-yourself maintenance
Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and trans-
mitters must also be installed.
When new tire pressure warning valves and transmitters are installed,
new tire pressure warning valve and transmitter ID codes must be regis-
tered in the tire pressure warning computer and tire pressure warning
system must be initialized. Have tire pressure warning valve and transmit-
ter ID codes registered by your Lexus dealer. (P. 4 1 8 )
Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the following
circumstances:
●When rotating the tires on vehicles differing with front and rear tire
inflation pressures.
●When changing the tire inflation pressure by changing traveling
speed.
●When changing the tire size.
When the tire pressure warning system is initialized, the current tire
inflation pressure is set as the pressure benchmark.

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Maintenance and care
■How to initialize the tire pressure warning system
To initialize the system, use the satellite switch. (P. 3 4 2 )
Park the vehicle in safe place and turn the “ENGINE START
STOP” switch OFF.
While the vehicle is moving, initialization is not performed.
Adjust the tire inflation pressure to the specified cold tire inflation
pressure level. (P. 5 2 9 )
Make sure to adjust the tire pressure to the specified cold tire inflation
pressure level. The tire pressure warning system will operate based on
this pressure level.
Turn the “ENGINE START STOP” switch to IGNITION ON
mode.
The tire inflation pressure initial-
ization setting display
Continue to press “” or “” until
the initialization setting display
appears.
Recording tire inflation pressure
settings
Push and hold the “ON/OFF” but-
ton until the tire pressure warning
light blinks slowly three times.
Wait for a few minutes with the IGNITION ON mode, and then
turn the “ENGINE START STOP” switch OFF.
STEP1
STEP2
STEP3
STEP4
STEP5

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4-3. Do-it-yourself maintenance
Registering and selecting ID codes
To select tire pressure warning valve and transmitter ID codes, use the
satellite switch. (P. 3 4 2 )
■Registering ID codes
2 sets of tire pressure warning valve and transmitter ID codes can be
registered. Once a second set of tires is registered at “2ND”, you can
switch between tire set settings simply by pressing the tire pressure
warning select switch.
There are 2 settings:
“MAIN” position: The ID code of the tire pressure warning valve and
transmitter on the tires originally installed on the vehicle is registered.
“2ND” position:The ID code is not registered. When you replace a
new set of tires, purchase tire pressure warning valves and transmitters
from your Lexus dealer and have the new ID code registered by your
Lexus dealer.

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4-3. Do-it-yourself maintenance
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Maintenance and care
■Selecting ID codes
When replacing tires, make sure to select the ID code set that matches
the new tire set. If the tire pressure select switch is set to the wrong tire
setting, the tire pressure warning system will not operate properly.
After driving for about 20 minutes, the tire pressure warning light
comes on after blinking for 1 minute to indicate a system malfunction.
Tire pressure warning valve and
transmitter ID code settings dis-
play
Press “” or “” repeatedly until
the setting display appears.
Switching ID codes
Press the “ON/OFF” button to
switch between “MAIN” and
“2ND” ID codes.

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4-3. Do-it-yourself maintenance
■When to replace your vehicle’s tires
Tires should be replaced if:
●You have tire damage such as cuts, splits, cracks deep enough to expose the
fabric or bulges indicating internal damage
●A tire goes flat repeatedly or cannot be properly repaired due to the size or
location of a cut or other damage
If you are not sure, consult with your Lexus dealer.
■Replacing tires and wheels
If the ID code of the tire pressure warning valve and transmitter is not registered,
the tire pressure warning system will not work properly. After driving for about 20
minutes, the tire pressure warning light comes on after blinking for 1 minute to indi-
cate a system malfunction.
■Tire life
Any tire over 6 years old must be checked by a qualified technician even if it has sel-
dom or never been used or damage is not obvious.
■If the tread wears down below 0.16 in. (4 mm) on snow tires
The effectiveness of snow tires is lost.
■Low profile tires (models not equipped with 16-inch tires)
Generally, low profile tires will wear more rapidly and tire grip performance will be
reduced on snowy and/or icy roads when compared to standard tires. Be sure to
use snow tires or tire chains
* on snowy and/or icy roads and drive carefully at a
speed appropriate for road and weather conditions.
*: Tire chains cannot be mounted on 18-inch tires.

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4-3. Do-it-yourself maintenance
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Maintenance and care
■Maximum load of tire
Check that the maximum load of the replacement tire is greater than 1 /2 of the
Gross Axle Weight Ratings (GAWR) of either the front axle or the rear axle, which-
ever is greater.
■Tire types
1 Summer tires
Summer tires are high-speed performance tires best suited to highway driving
under dry conditions. Since summer tires do not have the same traction perfor-
mance as snow tires, summer tires are inadequate for driving on snow-covered
or icy roads. For driving on snow-covered roads or icy roads, the use of snow tires
is recommended. When installing snow tires, be sure to replace all four tires.
2 All season tires
All season tires are designed to provide better traction in snow and to be ade-
quate for driving in most winter conditions, as well as for use year round. All sea-
son tires, however, do not have adequate traction performance compared with
snow tires in heavy or loose snow. Also, all season tires fall short in acceleration
and handling performance compared with summer tires in highway driving.
3Snow tires
For driving on snow-covered roads or icy roads, we recommend using snow tires.
If you need snow tires, select tires of the same size, construction and load capac-
ity as the originally installed tires. Since your vehicle has radial tires as original
equipment, make sure your snow tires also have radial construction. Do not install
studded tires without first checking local regulations for possible restriction.
Snow tires should be installed on all wheels. (P. 2 1 0 )
■Initializing the tire pressure warning system
Initialize the tires with the tire inflation pressure adjusted to the specified level.
For the GAWR, see the Certification Label.
For the maximum load of the tire, see the load
limit at maximum cold tire inflation pressure
mentioned on the sidewall of the tire.
(
P. 5 3 8 ) .

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4-3. Do-it-yourself maintenance
■When the initialization of the tire pressure warning system has failed
Initialization can be completed in a few minutes. However, in the following cases,
the settings have not been recorded and the system will not operate properly. If
repeated attempts to record tire inflation pressure settings are unsuccessful, have
the vehicle inspected by your Lexus dealer.
●When operating the satellite switch, the tire pressure warning light does not
flash 3 times.
●After carrying out the initialization procedure, the tire pressure warning light
blinks for 1 minute then stays on after driving for about 20 minutes.
■Routine tire inflation pressure checks
The tire pressure warning system does not replace routine tire inflation pressure
checks. Make sure to check tire inflation pressure as part of your routine of daily
vehicle checks.
■Tire pressure warning system certification
MODEL/FCC IDs:
Transmitter: PAXPMV107J
Receiver: HYQ13BCE
IC (Canada) IDs:
Transmitter: 3729A-PMV107J
Receiver: 1551A-13BCE
For vehicles sold in the U.S.A.
This device complies with Part 15 of the FCC Rules. Operation is subject to the fol-
lowing two conditions: (1) this device may not cause harmful interference, and (2)
this device must accept any interference received, including interference that may
cause undesired operation.
FCC WARNING:
Changes or modifications not expressly approved by the party responsible for
compliance could void the user's authority to operate the equipment.
For vehicles sold in Canada
Operation is subject to the following two conditions: (1) this device may not cause
interference, and (2) this device must accept any interference, including interfer-
ence that may cause undesired operation of the device.

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Maintenance and care
CAUTION
■Tire pressure warning system operation
The tire pressure warning system may not provide warning immediately if a tire
bursts or if sudden air leakage occurs.
■When inspecting or replacing tires
Observe the following precautions to prevent accidents. Failure to do so may cause
damage to parts of the drive train, as well as dangerous handling characteristics,
which may lead to an accident resulting in death or serious injury.
●Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix differently constructed tires (radial, bias-belted or bias-ply tires).
●Do not mix summer, all season and winter tires.
●Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously.
■When initializing the tire pressure warning system
Do not press the satellite switch without first adjusting the tire inflation pressure to
the specified level. Otherwise, the tire pressure warning light may not come on
even if the tire inflation pressure is low, or it may come on when the tire inflation
pressure is actually normal.
NOTICE
■Repairing or replacing tires, wheels and tire pressure warning valves and trans-
mitters
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.

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4-3. Do-it-yourself maintenance
NOTICE
■Driving on rough roads
Take particular care when driving on roads with loose surfaces or pot holes.
These conditions may cause losses in tire inflation pressure, reducing the cushion-
ing ability of the tires. In addition driving on rough roads may cause damage to the
tires themselves, as well as the vehicle’s wheels and body.
■Low profile tires and wheels
Wheels with profile tires like 17- and 18-inch tires may cause greater damage than
usual to the tire wheel when receiving impact from the road surface. Therefore pay
attention to the following:
●Be sure to use proper tire inflation pressure. If tires are under-inflated, they may
be damaged more severely.
●Avoid pot holes, uneven pavement, curbs and other road hazards.
Failure to do so can lead to severe tire and wheel damage.
■If tire inflation pressure become low while driving
Do not continue driving, or your tires and/or wheels may be ruined.

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4-3. Do-it-yourself maintenance
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Maintenance and care
Tire inflation pressure
■Tire inflation pressure
The recommended cold tire inflation pressure and tire size is dis-
played on the tire and loading information label. (P. 5 2 9 )