
4286-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
NOTICE
■Repairing or replacing tires, wheels, tire pressure warning valves, transmitters and tire valve caps (vehicles with the tire pressure warning system)
●When removing or fitting the wheels, tires or the tire pressure warning valves and
transmitters, contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer as the tire pressure warning valves and transmitters may be dam- aged if not handled correctly.
●Make sure to install the tire valve caps. If the tire valve caps are not installed, water could enter the tire pressure warning valv es and the tire pressure warning valves could be bound.
●When replacing tire valve caps, do not use tire valve caps other than those specified.The cap may become stuck.
■To avoid damage to the tire pressure warning valves and transmitters (vehicles with
the tire pressure warning system)
When a tire is repaired with liquid sealants, the tire pressure warning valve and trans- mitter may not operate properly. If a liquid sealant is used, contact any authorized
Lexus retailer or Lexus authorized repairer, or any reliable repairer or other qualified service shop as soon as possible. After use of liquid sealant, make sure to replace the tire pressure warning valve and transmitte r when repairing or replacing the tire.
( P. 418)
■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 cushioning ability of the tires. In addition, driving on rough roads may cause damage to the tiresthemselves, as well as the vehicle’s wheels and body.
■Low profile tires (except 225/50R17 tires)
Low profile tires may cause greater damage than usual to the tire wheel when sustain- ing impact from the road surface. Therefore, pay attention to the following:
●Be sure to use proper tire inflation pressu re. If tires are under-inflated, they may be damaged more severely.
●Avoid potholes, uneven pavement, curbs an d 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.

429
6
6-3. Do-it-yourself maintenance
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
Tire inflation pressure
■Effects of incorrect tire inflation pressure
Driving with incorrect tire inflation pressure may result in the following:
●Reduced fuel economy
●Reduced driving comfort and poor handling
●Reduced tire life due to wear
●Reduced safety
●Damage to the drive train
If a tire needs frequent inflating, have it checked by any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer.
■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 than1.5 km or 1 mile, you will get an accurate cold tire inflation pressure reading.
●Always use a tire pressure gauge.It is difficult to judge if a tire is prop erly inflated based only on its appearance.
●It is normal for the tire inflation pressure to be higher after driving as heat is generated
in the tire. Do not reduce tire inflation pressure after driving.
●Passengers and luggage weight should be placed so that the vehicle is balanced.
Make sure to maintain proper tire inflation pressure. Tire inflation pressure
should be checked at least once pe r month. However, Lexus recommends
that tire inflation pressure be checked once every two weeks. (P. 555)
WARNING
■Proper inflation is critical to save tire performance
Keep your tires properly inflated.
If the tires are not properly inflated, the following conditions may occur which could lead to an accident resulting in death or serious injury:
●Excessive wear
●Uneven wear
●Poor handling
●Possibility of blowouts resulting from overheated tires
●Air leaking from between tire and wheel
●Wheel deformation and/or tire damage
●Greater possibility of tire damage while driving (due to road hazards, expansion
joints, sharp edges in the road, etc.)

4306-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
NOTICE
■When inspecting and adjusting tire inflation pressure
Be sure to put the tire valve caps back on. If a valve cap is not installed, dirt or mois ture may get into the valve and cause an air
leak, resulting in decrease d tire inflation pressure.

431
6
6-3. Do-it-yourself maintenance
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
Wheels
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 any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.
*: 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
●Steel wheels (except for vehicles with steel spare wheel)
●Use only Lexus wheel nuts and wrenches designed for use with your alumi-
num wheels.
●When rotating, repairing or changing your tires, check that the wheel nuts are
still tight after driving 1600 km (1000 miles).
●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.
■When replacing wheels (vehicles with the tire pressure warning system)
The wheels of your vehicle are equipped with tire pressure warning valves and transmit- ters that allow the tire pressure warning sy stem 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. 418)
If a wheel is bent, cracked or heavily corroded, it should be replaced. Other-
wise, the tire may separate from the wheel or cause a loss of handling control.
Wheel selection
Aluminum wheel precautions

4637-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
*: 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 intermittently for
30 seconds after the vehicle reaches a speed of 20 km/h (12 mph). Then, if the seat belt is still unfastened , the buzzer will sound in a different tone for 90 more seconds.
■Front passenger detection sensor, 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 passen-
ger is not sitting in the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the warn- ing light may not operate properly.
■If the malfunction indicator lamp comes on while driving
The malfunction indicator lamp will come on if the fuel tank becomes completely empty. If the fuel tank is empty, refuel the vehicle immediately. The malfunction indicator lamp
will go off after several trips.
If the malfunction indicator la mp does not go off, contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer as soon as possible.
■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 warning buzzer
may sound.
(If equipped)
Tire pressure warning light When the light comes on:Low tire inflation pressure such as
• Natural causes ( P. 464) • Flat tire ( P. 498, 509) Adjust the tire inflation pressure 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 thesystem checked by any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer. When the light comes on after blinking for 1 minute:Malfunction in the tire pressure warning system
Have the system checked by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer.
(If equipped)
LKA warning lightThe warning light comes on and a warning message is displayed to
indicate that the LKA (Lane-Keepin g Assist) system is not available temporarily or has detected a malfunction. P. 478
Warning lightWarning light/Details/Actions

4647-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
■When the tire pressure warning light comes on (if equipped)
Carry out the following procedure after the tire temperature has lowered sufficiently.
●Check the tire inflation pressure and adjust to the appropriate level.
●If the warning light does not go out even afte r several minutes, check that the tire infla- tion pressure is at the specifie d level and carry out initialization.
The warning light may come on again if the above operations are conducted without first
allowing the tire temperature to lower sufficiently.
■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 changes caused by temperature. In this case, adjusting the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with a tire pressure warning valve and transmit- ter. If a tire goes flat, the tire pressure warning light will not turn off even though the flattire has been replaced with the spare tire.
■Conditions that the tire pressure warning system may not function properly
P. 420
■If the tire pressure warning light frequently comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the power switch is turned to ON mode, have it checked by any authorized Lexus retailer orLexus authorized repairer, or any reliable repairer.
■Warning buzzer
In some cases, the buzzer may not be heard because of noisy place or an audio sound.

4657-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediately and contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer. The vehicle will become
extremely unstable during braking, and the ABS system may fail, which could cause an accident resulting in death or serious injury.
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy. If the steering wheel becomes heavier than us ual when operating, hold firmly and oper- ate 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 a 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 pressureimmediately.
●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 any authorized Lexusretailer or Lexus authorized repa irer, or any reliable repairer.
●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 syst em may not activate immediately.
NOTICE
■To ensure the tire pressure warning system operates properly
Do not install tires with different specifications or makers, as the tire pressure warning system may not operate properly.

4857-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
Indicates that the accelerator and brake pedals are being depressed simultaneously, and the brake override
system is operating. Release the accelerator or brake pedal. (P. 201)
(If equipped)
Indicates that the tire inflation pressure is low
Check the tire inflation pressure, and adjust to the appropriate level.
Warning messageDetails/Actions
(Flashes)