sensor Lexus IS250 2007 Basic Functions / LEXUS 2007 IS350/250 (OM53578U) Owner's Guide

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4-3. Do-it-yourself maintenance
Directional tires
Tire direction marks
The tires listed below are direc-
tional. The tire sidewalls are
marked with arrows indicating the
rolling direction of the tire. If
mounted on the wrong side of the
vehicle, directional tires will per-
form poorly.
Installing tire inflation pressure sensors
When replacing tires or wheels, tire pressure sensors must also be
installed. Tire pressure sensors can be installed in any of the following
three ways:
■The tire pressure warning system
Your Lexus is equipped with a tire pressure warning system that uses
tire pressure sensors to detect low tire pressure before serious
problems arise. (P. 341, 345)
Before removing the tire from the wheel, remove the system’s tire
inflation pressure sensor. Be careful not to damage the sensor when
removing and installing the tires.
Tire size of turning directional tires
Front225/45R17 90W
225/40R18 88Y
Rear245/45R17 95W
255/40R18 95Y

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4-3. Do-it-yourself maintenance
4
Maintenance and care
●Sensors can be removed from the old wheels and installed on the new
wheels.
●When replacing only the tire, the sensor already installed on the wheel
does not need to be replaced.
●Replacing both a wheel and its sensor.
When new tire pressure sensors are installed, new sensor ID codes must be
registered in the ECU and tire inflation pressure sensor must be initialized.
(P. 285, 286)
Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the following
circumstances:
●When the standard tire pressure changes by replacing tires or
wheels
●When tires are rotated.
●When tire pressure sensors are replaced.
●When driving with the tires inflated to a higher than standard tire
pressure.
When the tire pressure warning system is initialized, the current tire
pressure is set as the pressure benchmark.
■How to initialize the tire pressure warning system
To initialize the system, use the satellite switch. (P. 222)
Park the vehicle in safe place and turn off the engine.
Adjust the tire pressure to the specified pressure (P. 389)
Start the engine.
Make sure to adjust the tire pressure to the specified level. The tire infla-
tion pressure warning system will operate based on this pressure level.
STEP1
STEP2
STEP3

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4-3. Do-it-yourself maintenance
The tire pressure initialization
setting display
Continue to press the  or 
switch until the initialization setting
display appears.
It may take several minutes to com-
plete the setting. Wait for several
minutes before turning the engine
switch OFF if necessary.
Recording tire pressure settings
Press the ON/OFF button for
more than 3 seconds. At this time,
the tire inflation pressure warning
indicator flashes 3 times and the
message showing that the initial
setting is complete is displayed on
the multi-information display.
Registering and selecting tire inflation pressure sensor ID codes
The tire inflation pressure sensor is equipped with a unique ID code.
To select tire inflation pressure sensor ID codes, use the satellite switch.
(P. 222)
■Registering ID codes
Two separate sets of ID codes can be registered for each vehicle. This
allows 2 separate sets of settings to be conveniently recorded for all
season and winter tires.
MAIN: The MAIN ID code is used for the factory installed tire pres-
sure sensors.
2nd: The 2nd ID code is used for tire inflation pressure sensors associ-
ated with a secondary set of tires.
Make sure to have all tire inflation pressure warning system ID codes regis-
tered by your Lexus dealer. ID codes must be reset when tires or wheels are
replaced.
STEP4

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4-3. Do-it-yourself maintenance
4
Maintenance and care
CAUTION
■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 fatal or injury accidents.
●Do not mix tires of different makes, models, tread patterns or tread wear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix radial, bias-belted, or bias-ply tires.
●Do not mix summer, all season and winter tires.
NOTICE
■Repairing or replacing tires, wheels and sensors
●When removing the tires from the wheels, be careful not to damage the system’s
tire inflation warning sensors. Contact your Lexus dealer for details regarding the
removal and installation procedures.
●When replacing tires, make sure also to replace the tire inflation pressure sensor
grommets.
■Do not use puncture sealant sprays to repair flats
Puncture sealant sprays may damage tire inflation pressure sensors.

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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 sensors that allow the tire pressure
warning system sensors to provide advanced warning in the event of a loss in tire
pressure. Whenever wheels are replaced, the tire inflation pressure sensors must
be switched over from the old wheels. (P. 2 8 5 )
If a wheel is bent, cracked or heavily corroded, it should be replaced. Oth-
erwise, the tire may separate from the wheel or cause loss of handling con-
trol.
■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
■Aluminum wheel precautions
●Use only Lexus wheel nuts and wrenches designed for use with
your aluminum wheels.
●When rotating, repairing or changing 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 serious injury or death.
NOTICE
■Replacing tire inflation pressure sensors
●Because tire repair or replacement may affect the tire pressure sensors, make
sure to have tires serviced by your Lexus dealer or other qualified service shop. In
addition, make sure to purchase your tire pressure sensors at your Lexus dealer.
●Ensure that only Genuine Lexus wheels are used on your vehicle.
Tire pressure sensors may not work properly with non-genuine wheels.

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4-3. Do-it-yourself maintenance
4
Maintenance and care
■Driver’s side instrument panel
FuseAmpereCircuit
1FR P/SEAT LH30APo w e r s e a t
2A/C7. 5 AAir conditioning system
3MIR HTR15AOutside rear view mirror defoggers
4TV NO.110ADisplay
5FUEL OPEN10AFuel filler door opener
6TV NO.27. 5 A
7PSB30APre-collision seat belt
8S/ROOF25AElectric moon roof
9TA I L10ATail lights, license plate lights, parking
lights
10PA N E L7. 5 ASwitch illumination, air conditioning
system, display
11RR FOG7. 5 A
12ECU-IG LH10A
Cruise control, air conditioning sys-
tem, power steering, rain sensor, anti-
glare inside rear view mirror, shift lock
system, moon roof, tire inflation pres-
sure warning system
13FR S/HTR LH15ASeat heaters and ventilators

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4-3. Do-it-yourself maintenance
FuseAmpereCircuit
14RR DOOR LH20APo w e r w i n d o w s
15FR DOOR LH20APo w e r w i n d o w s
16SECURITY7. 5 ASmart access system with push-button
start
17H-LP LVL7. 5 AAFS
18LH-IG10A
Charging system, headlight cleaner,
rear window defogger, electric cool-
ing fans, emergency flashers, turn sig-
nal lights, back-up lights, stop lights,
mirror heaters, sun shade, seat belts,
Lexus parking assist-sensor, cruise
control, air conditioning system, PTC
heater
19FR WIP30AWindshield wipers

5
When trouble arises
337
5-1. Essential information
Event data recorder
In a crash or a near car crash event
The SRS airbag sensor assembly contains the EDR. In a crash or a near
car crash event, this device may record some or all of the following infor-
mation:
●Engine speed
●Whether the brake pedal was applied or not
●Ve h i c l e s p e e d
●To what extent the accelerator pedal was depressed
●Position of the transmission shift lever
●Whether the driver and front passenger wore seat belts or not
●Driver's seat position
●SRS airbag deployment data
●SRS airbag system diagnostic data
If your vehicles is equipped with a vehicle stability control (VSC) system
The VSC Electronic Control Unit (ECU) may contain another EDR. In
case the VSC or Brake Assist system is activated, or the lateral accelera-
tion is beyond a certain valve, this device may record some or all of the
following information:
●Behavior of the vehicle
●Steering wheel angle
Your vehicle has computers that monitor and control certain aspects of
your vehicle. These computers assist in driving and maintaining optimal
vehicle performance.
Besides storing data useful for troubleshooting, there is an event data
recorder (EDR) that records data in a crash or a near car crash event.

5
When trouble arises
343
5-2. Steps to take in an emergency
■If the electronic engine control system warning light comes on while driving
First check the following:
●Is the fuel empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after taking several driving trips.
If the light does not go off even after several trips, contact your Lexus dealer as soon
as possible.
■Front passenger detection sensor and passenger seat belt reminder
●If luggage is placed on the front passenger seat, the front passenger detection
sensor may cause the warning light to flash, even if a passenger is not sitting in
the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the
warning light may not operate properly.