2015 LEXUS RX450h tire pressure

6814-3. Do-it-yourself maintenance
4
Maintenance and care ■
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 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 mislea ding. In addition, tire inflation pressure
that is even just a few pounds off can degrade ride and handling.●
Do not reduce tire inflation pressure after driving. It is normal for tire inflation
pressure to be higher after driving.●
Never exceed the vehicle capacity weight.
Passengers and luggage weight should be placed so that the vehicle is bal-
anced.

6824-3. Do-it-yourself maintenance
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 co uld 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.

6834-3. Do-it-yourself maintenance
4
Maintenance and care 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 advanced warn-
ing in the event of a loss in tire inflation pressure. Whenever wheels are replaced,
tire pressure warning valves and transmitters must be installed. (  P. 6 7 1 )If a wheel is bent, cracked or heavily corroded, it should be replaced.
Otherwise, the tire may separate from 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 capaci ty, diameter, rim
width, and inset*.
Replacement wheels are available at your Lexus dealer. *: Conventionally referred to as “offset”.
Lexus does not recommen d 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 changi ng 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.

6844-3. Do-it-yourself maintenance
CAUTION■
When replacing wheels ●
Do not use wheels that are a different size from those recommended in the
Owner’s Manual, as this may result in loss of handling control.●
Never use an inner tube in a leaking wheel which is designed for a tubeless tire.
Doing so may result in an accident , causing death or serious injury.
NOTICE■
Replacing tire pressure warning valves and transmitters ●
Because tire repair or replacement may affect the tire pressure warning valves
and transmitters, make sure to have tires serviced by your Lexus dealer or other
qualified service shop. In addition, make sure to purchase your tire pressure
warning valves and transmitters at your Lexus dealer.●
Ensure that only genuine Lexus wheels are used on your vehicle.
Tire pressure warning valves and transmitters may not work properly with non-
genuine wheels.

7014-3. Do-it-yourself maintenance
4
Maintenance and care 7
ECU-IG1 NO. 1 10 A Multiplex communication system,
steering sensor, shift lock control sys-
tem, tilt and telescopic steering,
power back door, pre-collision sys-
tem, vehicle dynamics integrated
management, tire pressure warning
system8
S/ROOF 30 A Moon roof9
FUEL OPN 7. 5 A Fuel filler door opener10
PSB 30 A Pre-collision seat belt11
TI & TE 30 A Tilt and telescopic steering system12
DR LOCK 10 A13
FR FOG 7. 5 A Front fog lights14
P-S E AT L H 30 A Po w e r s e a t ( l e f t - s i d e )15
4WD 7. 5 A AW D s y s t e m16
INVERTER 20 A Po w e r o u t l e t17
RR FOG 7. 5 A18
D/L ALT B 25 A Multiplex communication system,
power door lock system, power back
door19
EPS 10 A Electric power steering system20
ECU-IG1 NO. 2 10 A Intuitive parking assist, pre-collision
seat belt, capacitor
21
PA N E L 10 A Switch illumination, navigation system,
hybrid transmission system, audio sys-
tem, multi-information display, air con-
ditioning system, multiplex
communication systemFuse Ampere Circuit

5
When trouble arises
7375-2. Steps to take in an emergency
* 1
: Open door warning buzzer:
The open door warning buzzer sounds to alert one or more of the doors is not
fully closed (with the vehicle having reached a speed of 3 mph [5 km/h]).
(  P. 74 8 )
* 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. 7 3 9 )
• Flat tire (  P. 76 4 ) Adjust the tire inflation pres-
sure (including the full-size
spare tire) 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. 74 0 ) Have the system checked by
your Lexus dealer.Warning light Warning light/Details Correction procedure

7385-2. Steps to take in an emergency
■
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 lamp 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.■
SRS warning light
This warning light system monitors the airb ag sensor assembly, front airbag sensors,
side and curtain shield airbag sensors, curtain shield and rear side airbag sensors,
door sensors, driver's seat position sensor, driver's seat belt buckle switch, front
passenger occupant classification system (ECU and sensors), “AIR BAG ON” indi-
cator light, “AIR BAG OFF” in dicator light, front pass enger's seat belt buckle
switch, seat belt pretensioner assemblies, inflators, interconnecting wiring and
power sources. (  P. 1 3 2 )■
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.
■
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.

5
When trouble arises
7395-2. Steps to take in an emergency
■
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 chan ges caused by temperature. In this case,
adjusting the tire inflation pressure will turn off the warning light (after a few min-
utes).■
When a tire is replaced with a spare tire
Vehicles with a compact spare tire
The compact spare tire is not equipped with a tire pressure warning valve and trans-
mitter. 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 inflatio n pressure. The tire pressure warning light
will go off after a few minutes.
Vehicles with a full-size spare tire
The spare tire is also equipped with the tire pressure warning valve and transmitter.
The tire pressure warning light will turn on if the tire inflation pressure of the spare
tire is low. If a tire goes flat, even though the flat tire is replaced with the spare tire,
the tire pressure warning light does not turn off. Replace the spare tire with the
repaired tire and adjust to the proper tire inflation pressure. The tire pressure warn-
ing light will turn off after a few minutes.■
If the tire pressure warning system is not functioning
The tire pressure warning system will be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.) ●
If tires not equipped with tire pressure warning valves and transmitters are used●
If the ID code on the tire pressure warning valves and transmitters is not regis-
tered in the tire pressure warning computer●
If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm 2
or bar) or higher
The tire pressure warning system may be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●
If electronic devices or facilities using similar radio wave frequencies are nearby
●
If a radio set at similar frequencies is in use in the vehicle
●
If a window tint that affects the radio wave signals is installed
●
If there is a lot of snow or ice on the vehicle, in particular around the wheels or
wheel housings