2020 Lexus IS300 inflation pressure

4967-3. Do-it-yourself maintenance
IS350 AWD/IS350/IS300 AWD/IS300_U
Tire valve
Tire pressure gauge
Remove the tire valve cap.
Press the tip of the tire pressure gauge onto the tire valve.
Read the pressure using the gauge gradations.
If the tire inflation pressure is not at the recommended level, adjust the pres-
sure.
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 leakage.
Put the tire valve cap back on.
■Tire inflation pressure check interval
You should check tire inflation pressure ev ery 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 economy
●Reduced driving comfort and poor handling
●Reduced tire life due to wear
●Reduced safety
●Damage to the drivetrain
If a tire needs frequent inflating, ha ve it checked by your Lexus dealer.
Inspection and adjustment procedure
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4977-3. Do-it-yourself maintenance
7
Maintenance and care
IS350 AWD/IS350/IS300 AWD/IS300_U
■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.
It is difficult to judge if a tire is properly 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.
●Never exceed the vehicle capacity weight.
Passengers and luggage weight should be placed so that the vehicle is balanced.
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 resu lting 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.)
NOTICE
■When inspecting and adjust ing tire inflation pressure
Be sure to put the tire valve caps back on.
If a valve cap is not installed, dirt or moisture may get into the valve and cause an air
leak, resulting in decreased tire inflation pressure.

4987-3. Do-it-yourself maintenance
IS350 AWD/IS350/IS300 AWD/IS300_U
When replacing wheels, care should be ta ken 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
●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 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.
■When replacing wheels
The wheels of your vehicle are equipped with tire pressure warning valves and transmit-
ters 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. 486)
Wheels
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

5278-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
(Flashes)
(If equipped)
“AFS OFF” indicator
Indicates a malfunction in the adaptive front-lighting system
 Have the vehicle inspected by your Lexus dealer immediately.
Open door warning light (warning buzzer)*2
Indicates that a door or the trunk is not fully closed
 Check that all the doors and the trunk are closed.
Low fuel level warning light
Indicates that remaining fuel is approximately 2.6 gal. (10 L, 2.2
Imp. gal.) or less
 Refuel the vehicle.
Driver’s and front passenger’s seat belt reminder light (warning
buzzer)
*3
Warns the driver and/or front passenger to fasten their seat belts
 Fasten the seat belt.
If the front passenger’s seat is occupied, the front passenger’s
seat belt also needs to be fastened to make the warning light
(warning buzzer) turn off.
Rear passengers’ seat belt re minder lights (warning buzzer)*3
Warns the rear passengers to fasten their seat belts
 Fasten the seat belt.
Master warning light
A buzzer sounds and the warning light comes on and flashes to
indicate that the master warnin g system has detected a malfunc-
tion.
 P. 532
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such as
• Natural causes ( P. 529)
•Flat tire ( P. 559)
 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 af ter blinking for 1 minute:
Malfunction in the tire pressure warning system
 Have the system checked by your Lexus dealer.
Warning lightWarning light/Details/Actions

5298-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
■Electric power steering system warning light (warning buzzer)
When the battery charge becomes insufficien t or the voltage temporarily drops, the
electric power steering system warning li ght may come on and the warning buzzer may
sound.
■When the tire pressure warning light comes on
Check the tire inflation pressu re 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 ma y 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 caus ed 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 the 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 flat
tire has been replaced with the spare tire.
■Conditions that the tire pressure wa rning system may not function properly
 P. 490
■If the tire pressure warning light freque ntly comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the
engine switch is turned to IGNITION ON mo de, have it checked by your Lexus dealer.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound.
WARNING
■If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediat ely and contact your Lexus dealer. The vehi-
cle will become extremely unstable during braking, and the ABS system may fail, which
could cause an accident resultin g in death or serious injury.
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy.
When steering wheel operations are heavier than usual, grip the steering wheel firmly
and operate it using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precaution s. 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 pressure
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.
●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.

5308-2. Steps to take in an emergency
IS350 AWD/IS350/IS300 AWD/IS300_U
WARNING
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold and
inflated to the inflation pressure recomm ended 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 in formation 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 moni-
toring system (TPMS-tire pressure warning system) that illuminates a low tire pressure
telltale (tire pressure warning light) when on e or more of your tires is significantly
under-inflated. Accordingly, when the low ti re pressure telltale (tire pressure warning
light) illuminates, you should st op and check your tires as soon as possible, and inflate
them to the proper pressure. Driving on a significantly under-inflat ed tire causes the
tire to overheat and 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 wa rning 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 le vel to trigger illumination of the TPMS low
tire pressure telltale (tir e pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system) mal-
function indicator to indicate when the system is not operating properly. The TPMS
(tire pressure warning system) malfunction indi cator is combined with the low tire pres-
sure telltale (tire pressure warning light). When the system detects a malfunction, the
telltale will flash for approximately one mi nute and then remain continuously illumi-
nated. This sequence will cont inue upon subsequent vehicle start-ups as long as the
malfunction exists. When the malfunction indicator is illuminated, the system may not
be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfunctions may occur for a variety of reasons,
including the installation of replacement or alternate tires or wheels on the vehicle that
prevent the TPMS (tire pressure warning system) from functioning properly. Always
check the TPMS (tire pressure warning system) malfunction telltale 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.

5478-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
Indicates a malfunction in:
• The automatic headlight leveling system; or
• The AFS (Adaptive Front-lighting System) (if equipped); or
• The Automatic High Beam system; or
• The LED headlight system
A buzzer also sounds.
 Have the vehicle inspected by your Lexus dealer.
Indicates that the accelerato r and brake pedal are being
depressed simultaneously, and the Brake Override Sys-
tem is operating.
 Release the accelerator pedal and depress the
brake pedal.
Indicates that the tire in flation pressure is low
 Check the tire inflation pressure, and adjust to the
appropriate level.
Warning messageDetails/Actions
(Flashes)

5678-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
■The compact spare tire
●The compact spare tire is identified by the label “TEMPORARY USE ONLY” on the
tire sidewall.
Use the compact spare tire temporarily, and only in an emergency.
●Make sure to check the tire inflation pressure of the compact spare tire.
(  P. 595)
■When using the compact spare tire
As the compact spare tire is not equipped wi th a tire pressure warning valve and trans-
mitter, low inflation pressure of the spare tire will not be indicated by the tire pressure
warning system. Also, if you replace the compact spare tire after the tire pressure warn-
ing light comes on, the light remains on.
■When the compact spare tire is equipped
The vehicle becomes lower when driving with the compact spare tire compared to when
driving with standard tires.
■If you have a flat rear tire on a road covered with snow or ice (vehicles with front and
rear tires of the same size)
Install the compact spare tire on one of the front wheels of the vehicle. Perform the fol-
lowing steps and fit tire chains to the rear tires:
Replace a front tire with the compact spare tire.
Replace the flat rear tire with the tire removed from the front of the vehicle.
Fit tire chains to the rear tires.
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