2012 Lexus HS250h flat tire

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4-3. Do-it-yourself maintenance
HS250h_U_75050U
■Tire inflation pressure check interval
You should check tire inflation pressure every two weeks, or at least once a month.
Do not forget to check the spare.
■Effects of incorrect tire inflation pressure
Driving with incorrect tire inflation pressure may result in the following:
●Reduced fuel efficiency
●Reduced driving comfort and tire life
●Reduced safety
●Damage to the drive train
If a tire needs frequent inflating, have it checked by your Lexus dealer.
■Instructions for checking tire inflation pressure
When checking tire inflation pressure, observe the following:
●Check only when the tires are cold.
If your vehicle has been parked for at least 3 hours or has not been driven for
more than 1 mile or 1.5 km, you will get an accurate cold tire inflation pressure
reading.
●Always use a tire pressure gauge.
The appearance of the tire can be misleading. In addition, tire inflation pressure
that is even just a few pounds off can affect ride quality and handling.
●Do not reduce tire inflation pressure after driving. It is normal for tire inflation
pressure to be higher after driving.
If the tire inflation pressure is not at the recommended level,
adjust the pressure.
If you add too much air, press the center of the valve to deflate.
After completing the tire inflation pressure measurement and
adjustment, apply soapy water to the valve and check for leak-
age.
Put the tire valve cap back on.

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4-3. Do-it-yourself maintenance
4
Maintenance and care
HS250h_U_75050U
●Never exceed the vehicle capacity weight.
Passengers and luggage weight should be placed so that the vehicle is bal-
anced.
CAUTION
■Proper inflation is critical to save tire performance
Keep your tires properly inflated. Otherwise, the following conditions may occur
and result in an accident causing death or serious injury:
●Excessive wear
●Uneven wear
●Poor handling
●Possibility of blowouts resulting from overheated tires
●Poor sealing of the tire bead
●Wheel deformation and/or tire separation
●A greater possibility of tire damage from road hazards
NOTICE
■When inspecting and adjusting tire inflation pressure
Be sure to put the tire valve caps back on.
Without the valve caps, dirt or moisture could get into the valve and cause air leak-
age, which could result in an accident. If the caps are lost, replace them as soon as
possible.

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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.

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4-3. Do-it-yourself maintenance
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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

When trouble arises5
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HS250h_U_75050U
5-1. Essential informationEmergency flashers .............. 494
If your vehicle needs to be towed ................................ 495
If you think something is wrong ....................................... 501
5-2. Steps to take in an emergency
If a warning light turns on or a warning buzzer
sounds... ................................. 502
If a warning message is displayed................................. 512
If you have a flat tire............... 532
If the hybrid system will not start .......................................... 541
If you lose your keys .............. 543
If the electronic key does not operate properly.......... 544
If the vehicle 12-volt battery is discharged ......... 547
If your vehicle overheats ..... 552
If the vehicle becomes stuck........................................ 556
If your vehicle has to be stopped in
an emergency ...................... 558

5
When trouble arises
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5-1. Essential information
HS250h_U_75050U
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■Visible symptoms
● Fluid leaks under the vehicle
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● High engine coolant temperature warning light flashes or comes
on
■ Audible symptoms
● Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the hybrid system
■ Operational symptoms
● Engine missing, stumbling or running rough
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road.
● Loss of brake effectiveness, spongy feeling, pedal almost touches
the floor

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5-2. Steps to take in an emergency
HS250h_U_75050U*
1: Open door warning buzzer:
→ P. 5 1 6
*
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 pressure
such as
• Natural causes (→ P. 5 0 8 )
• Flat tire ( →P. 5 3 2 )
Adjust the tire inflation pres-
sure to the specified level.
The light will turn off after a
few minutes. In case the light
does not turn off even if the
tire inflation pressure is
adjusted, have the system
checked by your Lexus
dealer.
When the light comes on after
blinking for 1 minute:
Malfunction in the tire pres-
sure warning system
(→ P. 509)
Have the system checked by
your Lexus dealer.
Warning lightWarning light/DetailsCorrection procedure

5
When trouble arises
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5-2. Steps to take in an emergency
HS250h_U_75050U
■SRS warning light
This warning light system monitors the airbag 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 (ECU and sensors), “AIR BAG ON” indicator light, “AIR
BAG OFF” indicator light, front passenger’s seat belt buckle switch, seat belt pre-
tensioner assemblies, inflators, interconnecting wiring and power sources. (→P.
109)
■Front passenger detection sensor, passen ger 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.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage temporarily
drops, the electric power steering system warning light may come on and the warn-
ing buzzer may sound.
■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.