Page 497 of 660

4976-3. Do-it-yourself maintenance
6
Maintenance and care
RX450h_U_OM0E013U
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 drive train
If a tire needs frequent inflating, ha ve it checked by your Lexus dealer.
Inspection and adjustment procedure
1
2
1
2
3
4
5
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Page 540 of 660

5407-2. Steps to take in an emergency
RX450h_U_OM0E013U
■When the tire pressure warning light comes on
Inspect the tires to check if a tire is punctured.
If a tire is punctured: P. 549
If none of the tires are punctured:
Turn the power switch off then turn it to ON mode. Check if the tire pressure warning
light comes on or blinks.
If the tire pressure warning light comes on
After the temperature of the tires has lowere d sufficiently, check the inflation pressure
of each tire and adjust th em to the specified level.
If the warning light does not turn off even after several minutes have elapsed, check
that the inflation pressure of each tire is at the specified level and perform initialization.
( P. 489)
If the warning light does not turn off severa l minutes after the initialization has been per-
formed, have the vehicle inspected by your Lexus dealer immediately.
If the tire pressure wa rning light blinks for 1 minute then stays on
There may be a malfunction in the tire pressure warning system. Have the vehicle
inspected by your Lexus dealer immediately.
■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 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 flat
tire has been replaced with the spare tire. Replace the spare tire with the repaired tire
and adjust the tire inflation pressure. The tire pressure warnin g light will go off after a few
minutes.
■Conditions that the tire pressure wa rning system may not function properly
P. 492
■Warning buzzer
In some cases, the buzzer ma y not be heard due to being in a noisy location or audio
sound.
■Customization
Some functions can be customized. ( P. 607)
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2
Page 541 of 660

5417-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
WARNING
■If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediately 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
When the light comes on yellow, the assist to the power steering is restricted. When the
light comes on red, the assist to the power steering is lost and handling operations of
the steering wheel 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.
Page 542 of 660

5427-2. Steps to take in an emergency
RX450h_U_OM0E013U
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.
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.
Page 549 of 660
5497-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
●Stop the vehicle on a hard, flat surface.
●Set the parking brake.
●Shift the shift lever to P.
●Stop the hybrid system.
●Turn on the emergency flashers. (P. 528)
If you have a flat tire
Your vehicle is equipped with a spare tire. The flat tire can be replaced with
the spare tire.
For details about tires: P. 487
WARNING
■If you have a flat tire
Do not continue driving with a flat tire.
Driving even a short distance with a flat ti re can damage the tire and the wheel beyond
repair, which could result in an accident.
Before jacking up the vehicle
Page 550 of 660
5507-2. Steps to take in an emergency
RX450h_U_OM0E013U
*: Documentation relating to the wheel lock key, such as the registration and I.D. card, is
inside the glove box.
Location of the spare tire, jack and tools
Jack handle
Wheel nut wrench
Spare tire Wheel lock key* (if equipped)
Jack1
2
3
4
5
Page 553 of 660
5537-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
Secure the deck board using the hook. (P. 430)
Disengage the hook and take out
the jack.
Remove the wheel nut wrench and then
the jack.
Secure the deck board using the hook. ( P. 430)
Remove the spare tire cover.
Loosen the center fastener that
secures the spare tire.
Taking out the jack
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2
Taking out the spare tire
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2
3
WARNING
■When storing the spare tire
Be careful not to catch fingers or other body parts between the spare tire and the body
of the vehicle.
Page 557 of 660
5577-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
Remove any dirt or foreign matter
from the wheel contact surface.
If foreign matter is on the wheel contact
surface, the wheel nuts may loosen
while the vehicle is in motion, causing
the tire to come off.
Install the spare tire and loosely
tighten each wheel nut by hand by
approximately the same amount.
Tighten the wheel nuts until the tapered
portion comes into loose contact with
the disc wheel seat.
Lower the vehicle.
Firmly tighten each wheel nut two or
three times in the order shown in the
illustration.
For vehicles with wheel lock nuts,
tighten the wheel lock nut last
Tightening torque:
76 ft•lbf (103 N•m, 10.5 kgf•m)
Stow the flat tire, tire jack and all tools.
Installing the spare tire
1
Disc wheel
seat
Tapered portion2
3
4
5