2019 LEXUS RX450H warning

6197-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL_U
WARNING
■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 resulting 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 be en 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 inflatio n pressure without 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 are 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 sealant 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. 612)
■Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
These conditions may cause lo sses 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.

6227-3. Do-it-yourself maintenance
RX450h_RX450hL_U
■Instructions for checking tire inflation pressure
When checking tire in flation 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 inflat ion 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 on 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.

6237-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL_U
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 referre d 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. 612)
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

6247-3. Do-it-yourself maintenance
RX450h_RX450hL_U
WARNING
■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 a 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.
■Use of defective wheels prohibited
Do not use cracked or deformed wheels.
Doing so could cause the tire to leak air du ring driving, possibly causing an accident.
NOTICE
■Replacing tire pressure warning valves and transmitters
●Because tire repair or replacement may affe ct the tire pressure warning valves and
transmitters, make sure to have tires serviced by your Lexus dealer or other qualified
service shop. In addition, ma ke 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 transmitte rs may not work properly with non-genu-
ine wheels.
■Selectable Color Trim (if equipped)
●If rattles, noise, or ot her problems occur while
Selectable Color Trim are installed, contact
your Lexus dealer.
●Do not remove or install Selectable Color
Trim yourself, as it may be damaged. Have the
Selectable Color Trim removed and installed
by your Lexus dealer.

6317-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL_U
■Use a CR2032 lithium battery
●Batteries can be purchased at your Lexus dealer, loca l electrical appliance shops or
camera stores.
●Replace only with the same or equivalent type recommended by the manufacturer.
●Dispose of used batteries according to the local laws.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart access system with push-button start and wireless remote control will not
function properly.
●The operational rang e will be reduced.
WARNING
■Removed battery and other parts
These parts are small and if swallowed by a child, they can cause choking. Keep away
from children. Failure to do so coul d result in death or serious injury.
NOTICE
■For normal operation after replacing the battery
Observe the following precautions to prevent accidents:
●Always work with dry hands.
Moisture may cause the battery to rust.
●Do not touch or move any other co mponent inside the remote control.
●Do not bend either of the battery terminals.

6347-3. Do-it-yourself maintenance
RX450h_RX450hL_U
Check if the fuse is blown. Normal fuse
Blown fuse
Replace the blown fuse with a new
fuse of an appropriate amperage rat-
ing. The amperage rating can be
found on the fuse box lid.
Many types of fuse are used on this
vehicle. This illustration shows a com-
mon type of fuse used on this vehicle.
■After a fuse is replaced
●If the lights do not turn on even after the fuse has been replaced, a bulb may need
replacement. ( P. 637)
●If the replaced fuse blows again, have th e vehicle inspected by your Lexus dealer.
■If there is an overload in a circuit
The fuses are designed to blow, protecting the wiring harness from damage.
■When replacing light bulbs
Lexus recommends that you use genuine Lexus products designed for this vehicle.
Because certain bulbs are conne cted to circuits designed to prevent overload, nongenu-
ine parts or parts not designed for this vehicle may be unusable.
4
1
2
WARNING
■To prevent system breakdowns and vehicle fire
Observe the following precautions.
Failure to do so may cause damage to th e vehicle, and possibly a fire or injury.
●Never use a fuse of a higher amperage rating than that indicated, or use any other
object in place of a fuse.
●Always use a genuine Lexus fuse or equivalent.
Never replace a fuse with a wire, even as a temporary fix.
●Do not modify the fuses or fuse boxes.
■Fuse box near the power control unit
Never check or replace the fuses as there are high volt age parts and wiring near the
fuse box.
Doing so may cause electric shock, re sulting in death or serious injury.
NOTICE
■Before replacing fuses
Have the cause of electrical overload determined and repaired by your Lexus dealer as
soon as possible.

6497-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL_U
■LED lights
The headlight low beams, headlight high beams, front turn signal lights (vehicles with tri-
ple-beam headlights), parking lights and da ytime running lights, fog lights, cornering
lights (if equipped), front side marker lights (vehicles with triple-beam headlights), side
turn signal lights, stop/tail lights, rear turn signal light (vehicles with triple-beam head-
lights), rear side marker lights, high mounted stoplight, license plate lights, and outer foot
lights consist of a number of LEDs. If any of the LEDs has burned out, take your vehicle to
your Lexus dealer to have the light replaced.
■Condensation build-up on the inside of a lens
Temporary condensation build-up on the inside of the headlight lens does not indicate a
malfunction. Contact your Lexus dealer for mo re information in the following situations:
●Large drops of water have built up on the inside of a lens.
●Water has built up inside a headlight.
■When replacing light bulbs
P. 634
WARNING
■To prevent injury
Before performing any light bulb replacement procedure, be sure to turn the power
switch off. Failure to do so may result in burns from hot components or a part of your
body may get caught on an operating co mponent, possibly causing serious injury.
■Replacing light bulbs
●Turn off the lights. Do not attempt to replac e the bulb immediately after turning off the
lights.
The bulbs become very hot and may cause burns.
●Do not touch the glass portion of the light bu lb with bare hands. When it is unavoid-
able to hold the glass portion, use and hold with a clean dry cloth to avoid getting
moisture and oils on the bulb.
Also, if the bulb is sc ratched or dropped, it may blow out or crack.
●Fully install light bulbs and any parts used to secure them. Failure to do so may result
in heat damage, fire, or water entering th e headlight unit. This may damage the head-
lights or cause condensation to build up on the lens.
●Do not attempt to repair or disassemble th e light bulbs, connectors, electric circuits
or component parts.
Doing so may result in death or se rious injury due to electric shock.
■To prevent damage or fire
●Make sure bulbs are fully seated and locked.
●Check the wattage of the bulb before installing to prevent heat damage.

651
8When trouble arises
RX450h_RX450hL_U
8-1. Essential informationEmergency flashers .................. 652
If your vehicle has to be stopped in
an emergency .......................... 653
8-2. Steps to take in an emergency
If your vehicle needs to be towed................................ 654
If you think something is wrong ........................................... 659
If a warning light turns on or a warning buzzer
sounds..........................................660
If a warning message is displayed..................................... 667
If you have a flat tire .................. 673
If the hybrid system will
not start .......................................690
If the electronic key does not operate properly ............. 692
If the 12-volt battery is discharged ................................. 695
If your vehicle overheats ......... 702
If the vehicle becomes stuck ............................................. 706