warning Lexus HS250h 2012 Workshop Manual

452
4-3. Do-it-yourself maintenance
HS250h_U_75050U
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 ID codes must be registered in the tire pressure warning computer
and the tire pressure warning system must be initialized. Have tire pres-
sure warning valve and transmitter ID codes registered by your Lexus
dealer. ( →P. 453)
Initializing the tire pressure warning system
■ The tire pressure warning system must be initialized in the following
circumstances:
●Vehicles with P225/45R18 91W tires: When rotating front and rear
tires which have different tire inflation pressures
● When changing the tire size
When the tire pressure warning system is initialized, the current tire
inflation pressure is set as the benchmark pressure.

453
4-3. Do-it-yourself maintenance
4
Maintenance and care
HS250h_U_75050U■
How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the “POWER” switch off.
Initialization cannot be performed while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire inflation
pressure level. ( →P. 567)
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 “POWER” switch to ON mode.
Press and hold the tire pressure warning reset switch until the tire
pressure warning light blinks slowly 3 times and the message
“TIRE PRESSURE RESET PROCEEDING” appears on the
multi-information display.
Wait for a few minutes with the “POWER” switch in ON mode
and then turn the “POWER” switch off.
Registering ID codes
The tire pressure warning valve and transmitter is equipped with a unique
ID code. When replacing a tire pressure warning valve and transmitter, it
is necessary to register the ID code. Have the ID code registered by your
Lexus dealer.

454
4-3. Do-it-yourself maintenance
HS250h_U_75050U
■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, and 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 blinks for 1 minute and stays on to indicate a
system malfunction.
■Tire lif e
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.
■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.
■Low profile tires (vehicles with P225/45R18 91W 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.

455
4-3. Do-it-yourself maintenance
4
Maintenance and care
HS250h_U_75050U
■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
●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.
●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.
●Snow 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 restrictions.
Snow tires should be installed on all wheels. ( →P. 2 5 8 )
■Initializing the tire pressure warning system
Initialize the system with the tire inflation pressure adjusted to the specified level.
■If the tread on snow tires wears down below 0.16 in. (4 mm)
The effectiveness of the tires as snow tires is lost. 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 7 2 )

456
4-3. Do-it-yourself maintenance
HS250h_U_75050U
■If you press the tire pressure warning reset switch accidentally
If initialization is performed, adjust the tire inflation pressure to the specified level
and initialize the tire pressure warning system again.
■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 tire pressure warning reset switch, the tire pressure warn-
ing light does not blink 3 times and the setting message does not appear on the
multi-information display.
●After carrying out the initialization procedure, the tire pressure warning light
blinks for 1 minute then stays on after driving for 20 minutes.
■Tire pressure warning system certification
For vehicles sold in the U.S.A.
FCC ID: PAXPMV107J
FCC ID: HYQ13BCX
NOTE:
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
NOTE:
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.

457
4-3. Do-it-yourself maintenance
4
Maintenance and care
HS250h_U_75050U
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 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 snow 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 operate the tire pressure warning reset 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.

458
4-3. Do-it-yourself maintenance
HS250h_U_75050U
NOTICE
■Repairing or replacing tires, wheels, tire pressure warning valves, transmitters
and tire valve caps
●When removing or fitting the wheels, tires or the tire pressure warning valves and
transmitters, contact your Lexus dealer as the tire pressure warning valves and
transmitters may be damaged if not handled correctly.
●When replacing tire valve caps, do not use tire valve caps other than those speci-
fied. The cap may become stuck.
■To avoid damage to the tire pressu re warning valves and transmitters
When a tire is repaired with liquid sealants, the tire pressure warning valve and
transmitter may not operate properly. If a liquid sealant is used, contact your Lexus
dealer or other qualified service shop as soon as possible. Make sure to replace the
tire pressure warning valve and transmitter when replacing the tire. ( →P. 4 5 2 )
■Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
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 (vehicles with P225/45R18 91W tires)
Low profile tires may cause greater damage than usual to the tire wheel when sus-
taining 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 potholes, uneven pavement, curbs and other road hazards. Failure to do so
may lead to severe tire and wheel damage.
■If tire inflation pressure of each tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.

462
4-3. Do-it-yourself maintenance
HS250h_U_75050U
Wheels
■When replacing wheels
The wheels of your vehicle are equipped with tire pressure warning valves and
transmitters that allow the tire pressure warning system to provide advance warning
in the event of a loss in tire inflation pressure. Whenever wheels are replaced, tire
pressure warning valves and transmitters must be installed. (→P. 4 5 2 )
If a wheel is bent, cracked or heavily corroded, it should be replaced.
Otherwise, the tire may separate fr om the wheel or cause a loss of han-
dling 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 inset*.
Replacement wheels are available at your Lexus dealer.
*: Conventionally referred to as “offset”.
Lexus does not recommend using the following:
●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.

463
4-3. Do-it-yourself maintenance
4
Maintenance and care
HS250h_U_75050U
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 a 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 death or serious injury.
■Use of defective wheels prohibited
Do not use cracked or deformed wheels.
Doing so could cause the tire to leak air during driving, possibly causing an acci-
dent.
NOTICE
■Replacing tire pressure warning valves and transmitters
●Because tire repair or replacement may affect the tire pressure warning valves
and transmitters, make sure to have tires serviced by your Lexus dealer or other
qualified service shop. In addition, make sure to purchase your tire pressure
warning valves and transmitters at your Lexus dealer.
●Ensure that only genuine Lexus wheels are used on your vehicle.
Tire pressure warning valves and transmitters may not work properly with non-
genuine wheels.

477
4-3. Do-it-yourself maintenance
4
Maintenance and care
HS250h_U_75050U
3IGN10 A
Electronically controlled brake sys-
tem, multiport fuel injection system/
sequential multiport fuel injection sys-
tem, smart access system with push-
button start, stop lights
4MET7. 5 AMeters
5WIP30 AWindshield wipers
6WA S H E R15 AWindshield washer
7A/C10 AAir conditioning system
8GAUGE10 AAFS, turn signal lights, emergency
flasher lights
9AFS10 AAdaptive front-lighting system
10ECU-IG NO.210 A
Pre-collision system, LKA, dynamic
radar cruise control, air conditioning
system, outside rear view mirror,
HUD, navigation system, tire inflation
pressure warning system
FuseAmpereCircuit