2010 Lexus HS250h tire pressure

449
4-3. Do-it-yourself maintenance
4
Maintenance and care
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.
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 wh eels are used on your vehicle. 
Tire pressure warning valves and transmitters may not work properly with non-
genuine wheels.

463
4-3. Do-it-yourself maintenance
4
Maintenance and care
3IGN10 A
Electronically controlled brake sys-
tem, multiport fuel injection system/
sequential multiport fuel injection sys-
tem, Lexus link system, 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

496
5-2. Steps to take in an emergency
*1: Open door warning buzzer:
P. 5 0 5
*2: Driver’s and front passenger’s seat belt buzzer:
The driver’s and front passenger’s seat belt buzzer sounds to alert the driver and
front passenger that his or her seat belt is not fastened. The buzzer sounds inter-
mittently for 10 seconds after the vehicle
reaches a speed of 12 mph (20 km/h).
Then, if the seat belt is still unfastened, the buzzer will sound in a different tone
for 20 more seconds.
Tire pressure warning light
When the light comes on: 
Low tire inflation pressureAdjust the tire inflation pres-
sure.
When the light comes on after
blinking for 1 minute: 
Malfunction in the tire pres-
sure warning system
Have the system checked by
your Lexus dealer.
■SRS warning light
This warning light system monitors the airb ag
sensor assembly, front airbag sensors,
side and curtain shield airbag sensors, curtain shield and rear side airbag sensors,
driver’s seat position sensor , driver’s seat belt buckle switch, front passenger occu -
pant classification system, “AIR BAG ON” indicator light, “
AIR BAG OFF” indicator
light, front passenger’s seat belt buckle switch, seat belt pretensioner assemblies,
inflators, interconnecting wiring and power sources. ( P. 1 0 5)
■Front passenger detection sensor, passenger seat belt reminder and warning
buzzer
●If luggage is placed on the front passenger seat, the front passenger detection
sensor may cause the warning light to flash and the warning buzzer to sound
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.
Warning lightWarning light/DetailsCorrection procedure

5
When trouble arises
497
5-2. Steps to take in an emergency
■Electric power steering warning light (warning buzzer)
The electric power steering warning light comes on and the warning buzzer sounds
when the voltage is low or the voltage drops.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank 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 several driving trips. 
If the light does not go off even after several trips, contact your Lexus dealer as soon
as possible.
■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 will not turn off the tire pressure warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural
air leaks and tire inflation pressure chan ges caused by temperature. In this case,
adjusting the tire inflation pressure will turn off the warning light (after a few min-
utes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with a tire pressure warning valve and trans-
mitter. If a tire goes flat, the tire pressure warning light will not turn off even though
the flat tire has been replaced with the spare tire. Replace the spare tire with the
repaired tire and adjust the tire inflatio n pressure. The tire pressure warning light
will go off after a few minutes.
■If the tire pressure warning system is not functioning
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 inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher.

498
5-2. Steps to take in an emergency
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 frequency 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, particularly 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.
■If the tire pressure warning light comes on after flashing frequently for 1 minute
If the tire pressure warning light comes on after flashing frequently for 1 minute
when the “POWER” switch is turned to ON mode, have it checked by your Lexus
dealer.
■Customization that can be configured at Lexus dealer
The vehicle speed linked seat belt reminder buzzer can be disabled. 
(Customizable features P. 5 7 2 )
CAUTION
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy. 
If the steering wheel becomes heavier than usual when operating, hold firmly and
operate it using more force than usual.
■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.
●Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pres-
sure immediately.
●If the tire pressure warning light comes on even after tire inflation pressure adjust-
ment, it is probable that you have a flat tire. Check the tires. If a tire is flat, change
it with the spare tire and have the flat tire repaired by the nearest Lexus dealer.

5
When trouble arises
499
5-2. Steps to take in an emergency
CAUTION
●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.
■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.

500
5-2. Steps to take in an emergency
CAUTION
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 pres sure 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.
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.

504
5-2. Steps to take in an emergency
Have the vehicle inspected by your Lexus dealer immediately.
Failure to investigate the cause of th e following warning may lead to the
system operating abnormally and possibly cause an accident. Have the
vehicle inspected by your Lexus dealer immediately.
Wa r n i n g m e s s a g eDetails
(Flashes and
then remains
on)
Indicates a malfunction in the tire pressure warning
system
The tire pressure warning light comes on after flash-
ing for 1 minute.