4936-3. Do-it-yourself maintenance
6
Maintenance and care
RX450h_U_OM0E013U ■
Warning performance of the tire pressure warning system
The warning of the tire pressure warning syst em will change in accordance with the con-
ditions under which it was initialized. For this reason, the system may give a warning even
if the tire pressure does not reach a low enough level, or if the pressure is higher than the
pressure that was adjusted to when the system was initialized. ■
When initialization of the tire pressure warning system has failed
Initialization may take longer to complete if the vehicle is driven on an unpaved road.
When performing initialization, drive on a pa ved road if possible. Depending on the driv-
ing environment and condition of the tires, initialization will be completed in approxi-
mately 10 to 30 minutes. If initialization is not complete af ter driving approximately 10 to
30 minutes, continue driving for a while.
If the inflation pressure of each tire is not displayed after driving for approximately 1 hour,
perform the following procedure. ●
Park the vehicle in a safe place for approxim ately 20 minutes. Then drive straight (with
occasional left and right turns) at approximately 25 mph (40 km/h) or more for
approximately 10 to 30 minutes.
However, in the following situations, the tire inflation pressure will not be recorded and
the system will not operate properly. Perform initialization again. ●
When operating the tire pressure warning reset switch, the tire pressure warning light
does not blink 3 times. ●
After performing initialization, the tire pres sure warning light blinks for 1 minute then
stays on while driving.
If the inflation pressure of each tire is st ill not displayed, have the vehicle inspected by
your Lexus dealer.
4956-3. Do-it-yourself maintenance
6
Maintenance and care
RX450h_U_OM0E013U WA R N I N G ■
When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train as well as dangerous han-
dling characteristics, which may lead to an accident resultin g in death or serious injury.●
Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear. ●
Do not use tire sizes other than those recommended by Lexus. ●
Do not mix differently constructed tires (radial, bias-belted or bias-ply tires). ●
Do not mix summer, all season and snow tires. ●
Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously. ●
Do not tow if your vehicle has a compact spare tire installed. ■
When initializing the tire pressure warning system
Do not initializing tire inflation pressure wi thout first adjusting the tire inflation pressure
to the specified level. Otherwise, the tire pressure warning light may not come on even
if the tire inflation pressure is low, or it may come on when the tire inflation pressure is
actually normal.
NOTICE ■
Repairing or replacing tires, wheels, tire pressure warning valves, transmitters and
tire valve caps ●
When removing or fitting the wheels, tires or the tire pressure warning valves and
transmitters, contact your Lexus dealer as the tire pressure warning valves and trans-
mitters may be damaged if not handled correctly.●
Make sure to install the tire valve caps. If the tire valve caps ar e not installed, water
could enter the tire pressure warning valves 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 pressu re warning valves and transmitters
When a tire is repaired with liquid sealants, the tire pressure warning valve and trans-
mitter may not operate properly. If a liquid se alant is used, contact your Lexus dealer or
other qualified service shop as soon as possible. Make sure to replace the tire pressure
warning valve and transmitter when replacing the tire. ( P. 4 8 8 )■
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 tires
themselves, as well as the vehicle’s wheels and body. ■
If tire inflation pressure of ea ch tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.
496 6-3. Do-it-yourself maintenance
RX450h_U_OM0E013U The recommended cold tire inflation
pressure and tire size are displayed on
the tire and loading information label.
( P. 5 8 9 )
Tire inflation pressure Tire inflation pressure
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
6
498 6-3. Do-it-yourself maintenance
RX450h_U_OM0E013U ■
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 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. ●
Never exceed the vehicle capacity weight.
Passengers and luggage weight should be placed so that the vehicle is balanced.
WA R N I N G ■
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 result ing 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.
4996-3. Do-it-yourself maintenance
6
Maintenance and care
RX450h_U_OM0E013U 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 ●
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. 4 8 8 )Wheels If a wheel is bent, cracked or heavily corroded, it should be replaced. Other-
wise, the tire may separate from the whee l or cause a loss of handling control.
Wheel selection
Aluminum wheel precautions
540 7-2. 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. 5 4 9
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. 4 8 9 )
If the warning light does not turn off several minutes after the initia lization has been per-
formed, have the vehicle inspected by your Lexus dealer immediately.
If the tire pressure warning 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 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 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 warning light will go off after a few
minutes. ■
Conditions that the tire pressure warning system may not function properly
P. 4 9 2 ■
Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound. ■
Customization
Some functions can be customized. ( P. 6 0 7 )1
2
5417-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U WA R N I N G ■
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 resulting 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 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 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.