warning LEXUS RX450h 2018 Owners Manual

6878-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85U■
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 tempor arily, and only in an emergency.●
Make sure to check the tire inflation pressure of the compact spare tire. ( → P. 717)■
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 compac t spare tire after the tire pressure warn-
ing light comes on, the light remains on. ■
When the compact spare tire is equipped
When driving with the compact spare tire inst alled, the vehicle height will be different
than when driving with standard tires. ■
If you have a flat front tire on a road covered with snow or ice
Install the compact spare tire on one of the re ar wheels of the vehicle. Perform the follow-
ing steps and fit tire chains to the front tires:
Replace a rear tire with the compact spare tire.
Replace the flat front tire with the tire removed from the rear of the vehicle.
Fit tire chains to the front tires. 1
2
3

688 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85UWARNING ■
When using the compact spare tire ●
Remember that the compact spare tire provid ed is specifically designed for use with
your vehicle. Do not use your comp act spare tire on another vehicle.●
Do not use more than one comp act spare tire simultaneously.●
Replace the compact spare tire with a standard tire as soon as possible.●
Avoid sudden acceleration, abrupt steering, sudden braking and shifting operations
that cause sudden engine braking. ■
When the compact spare tire is attached
The vehicle speed may not be correctly detected, and the following systems may not
operate correctly:
Also, not only can the following system not be utilized fully, but it may even negatively
affect the drive-train components:
•E-Four ■
Speed limit when using the compact spare tire
Do not drive at speeds in excess of 50 mph (80 km/h) when a compact spare tire is
installed on the vehicle.
The compact spare tire is not designed for driving at high speeds. Failure to observe
this precaution may lead to an accid ent causing death or serious injury.■
After using the tools and jack
Before driving, make sure all the tools and jack are securely in place in their storage
location to reduce the possibilit y of personal injury during a collision or sudden brak-
ing.• ABS & Brake assist
•VSC
•TRAC
•EPS
• Trailer Sway Control
•VDIM
• Adaptive Variable Suspension System
(if equipped)
• Dynamic radar cruise control with full-
speed range
• PCS (Pre-Collision System)
• LKA (Lane-Keeping Assist) • Automatic High Beam
• AFS (Adaptive Front-lighting System)
(if equipped)
• Tire pressure warning system
• Intuitive parking assist (if equipped)
• Intelligent Clearance Sonar (ICS) (if
equipped)
• Lexus parking assist monitor (if
equipped)
• Panoramic view monitor (if equipped)
• BSM (Blind Spot Monitor) (if
equipped)
• Navigation system (if equipped)

6898-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UNOTICE ■
Be careful when driving over bumps with th e compact spare tire installed on the vehi-
cle
When driving with the compact spare tire installed, the vehi cle height will be different
than when driving with standard tires. Be careful when driving over uneven road sur-
faces, etc. ■
Driving with tire chains and the compact spare tire
Do not fit tire chains to the compact spare tire.
Tire chains may damage the vehicle body and adversely affect driving performance.■
When replacing the tires
When removing or fitting the wheels, tires or the tire pressure warning valve and trans-
mitter, contact your Lexus dealer as the tire pressure warning valve and transmitter
may be damaged if not handled correctly. ■
When stowing the flat tire (RX450hL) ●
Ensure that there is no object caught between the tire and the vehicle underbody. ●
Securely tighten the spare tire clamp bolt to hold the spare wheel carrier by the hook. ●
Stow the flat tire in the spare tire location. Failure to do so may cause damage to the
spare tire carrier. Pr oper storage reduces the possibilit y of injury in a collision or
during sudden braking. ●
Have the flat tire repaired and the spare tire replaced with it as soon as possible. ■
Proper storage of the spare tire (RX450hL)
●
If the spare tire clamp bolt is turned withou t a tire on the hoist assembly, the wire cable
may not be able to be lowered. If the wire cable cannot be lowered, contact your
Lexus dealer. ●
If the hoist assembly is slanted when stowing a
tire, the hoist assembly may become stuck in
the wheel opening and the tire may not be
raised properly, causing damage to the wheel
or the wire cable.

694 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
Stopping the hybrid system
Shift the shift lever to P, set the parking brake, and press the power switch as you normally
do when stopping the hybrid system. ■
Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the electronic
key battery be replaced immediately when the battery is depleted. ( → P. 630)■
Changing power switch modes
Release the brake pedal and press the power switch in step above.
The hybrid system does not start and modes will be changed each time the switch is
pressed. ( → P. 240)■
When the electronic key does not work properly ●
Make sure that the smart access system wi th push-button start has not been deacti-
vated in the customization setting. If it is off, turn the function on.
(Customizable features → P. 740)●
Check if battery-saving mode is set. If it is set, cancel the function. ( → P. 160)
WARNING ■
When using the mechanical key and operating the power windows or the moon roof
or panoramic moon roof
Operate the power window or the moon roof or panoramic moon roof after checking
to make sure that there is no possibility of any passenger having an y of their body parts
caught in the window or the moon roof or panoramic moon roof.
Also, do not allow children to op erate the mechanical key. It is possible for children and
other passengers to get caught in the powe r window or the moon roof or panoramic
moon roof. 3

6998-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85U●
Use a 12-volt battery with a handle. If a 12-volt battery without a handle is used, removal
is more difficult. ●
After replacing, firmly attach the following items to the exhaust hole of the 12-volt bat-
tery.
• Use the exhaust hose that was attached to
the 12-volt battery before replacing and
confirm that it is firmly connected to the
hole section of the vehicle.
• Use the exhaust hole plug included with the
12-volt battery replaced or the one installed
on the 12-volt battery prior to the replace-
ment. (Depending on the 12-volt battery to
be replaced, the exhaust hole may be
plugged.)
Exhaust hole plug
Exhaust hole
Exhaust hose
Hole section of the vehicle 
RX450h
For details, consult your Lexus dealer. 
RX450hL
WARNING ■
When removing the battery terminals
Always remove the negative (-) terminal first. If the positive (+) terminal contacts any
metal in the surrounding area when the posi tive (+) terminal is removed, a spark may
occur, leading to a fire in addition to el ectrical shocks and de ath or serious injury.1
2
3
4

700 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85UWARNING ■
Avoiding 12-volt battery fires or explosions
Observe the following precautions to preven t accidentally igniting the flammable gas
that may be emitted from the 12-volt battery: ●
Make sure each jumper cable is connected to the correct terminal and that it is not
unintentionally in contact with any other than the intended terminal.●
Do not allow the other end of the jumper cab le connected to the “+” terminal to come
into contact with any other parts or metal surfaces in the area, such as brackets or
unpainted metal. ●
Do not allow the + and - clamps of the jump er cables to come in to contact with each
other. ●
Do not smoke, use matches, cigarette light ers or allow open flame near the 12-volt
battery. ■
12-volt battery precautions
The 12-volt battery contains poisonous and co rrosive acidic electr olyte, while related
parts contain lead and lead compounds. Ob serve the following precautions when han-
dling the 12-volt battery: ●
When working with the 12-volt battery, always wear safety glasses and take care not
to allow any battery fluids (acid) to come in to contact with skin, clothing or the vehicle
body. ●
Do not lean over the 12-volt battery. ●
In the event that battery fluid comes into contact with the skin or eyes, immediately
wash the affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medical attention can be
received. ●
Always wash your hands after handling the 12-volt battery support, terminals, and
other battery-related parts. ●
Do not allow children near the 12-volt battery. ■
After recharging the 12-volt battery
Have the 12-volt battery inspected at yo ur Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, continued use may cause the 12-volt battery to
emit a malodorous gas, which may be de trimental to the health of passengers.■
When replacing the 12-volt battery ●
When the vent plug and indicator are close to the hold down clamp, the battery fluid
(sulfuric acid) may leak. ●
For information regarding 12-volt battery replacement, contact your Lexus dealer.●
Make sure to replace the 12-volt battery with one designed for this vehicle. Other-
wise, hydrogen gas may enter the vehicle, possibly causing a fire or explosion. ●
After replacing, securely attach the exhaust hose and exhaust hole plug to the
exhaust hole of the replaced 12-volt battery. If not properly installed, gases (hydro-
gen) may leak into the vehicle interior, an d there is the possible danger of the gas
igniting and exploding.

7058-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UStart the hybrid system and check if “Hybrid System Overheated Reduced
Output Power” is shown on the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer. WARNING ■
To prevent an accident or injury when inspecting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.●
If steam is seen coming from under the h ood, do not open the hood until the steam
has subsided. The engine compartment may be very hot. ●
After the hybrid system has been turned off, check that the “READY” indicator is off.
When the hybrid system is operating, the gasoline engine may automatically start, or
the cooling fans may suddenly operate even if the gasoline engine stops. Do not
touch or approach rotating parts such as th e fans, which may lead to fingers or cloth-
ing (especially a tie, a scarf or a muffler) getting caught, resulting in serious injury.●
Do not loosen the radiator cap and the coolant reservoir caps wh ile the hybrid system
and radiator are hot.
High temperature steam or coolant could spray out.
NOTICE ■
When adding engine/power control unit coolant
Add coolant slowly after the hybrid system has cooled down sufficiently. Adding cool
coolant to a hot hybrid system too quickly can cause damage to the hybrid system.■
To prevent damage to the cooling system
Observe the following precautions: ●
Avoid contaminating the coolant with foreig n matter (such as sand or dust etc.).●
Do not use any coolant additive. 6

7078-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UWARNING ■
When attempting to free a stuck vehicle
If you choose to push the vehicle back and forth to free it, make sure the surrounding
area is clear to avoid striking other vehicl es, objects or people. The vehicle may also
lunge forward or lunge back suddenly as it becomes free. Use extreme caution. ■
When shifting the shift lever
Be careful not to shift the shift lever with the accelerator pedal depressed.
This may lead to unexpected rapid acceleration of the vehicle that may cause an acci-
dent resulting in deat h or serious injury.
NOTICE ■
To avoid damage to the hybrid transmission and other components●
Avoid spinning the front wheels and depre ssing the accelerator pedal more than nec-
essary. ●
If the vehicle remains stuck even after th ese procedures are performed, the vehicle
may require towing to be freed.

728 9-1. Specifications
RX450h_RX450hL _U_OM48F85UThis information has been prepared in acco rdance with regulations issued by the
National Highway Traffic Safety Administra tion of the U.S. Department of Trans-
portation.
It provides the purchasers and/or prospe ctive purchasers of Lexus vehicles with
information on uniform tire quality grading.Your Lexus dealer will help answer any ques tions you may have as you read this infor-
mation.■
DOT quality grades
All passenger vehicle tires must conform to Federal Safety Requirements in
addition to these grades. Quality grad es can be found where applicable on
the tire sidewall between tread shoulder and maximum section width. For example: Treadwear 200 Traction AA Temperature A■
Treadwear
The treadwear grade is a comparative rati ng based on the wear rate of the tire
when tested under controlled conditio ns on a specified government test
course. For example, a tire graded 150 would wear one and a half (1 - 1/2) times as well on
the government course as a tire graded 100.
The relative performance of tires depends upon the actua l conditions of their use.
Performance may differ significantly from the norm due to variations in driving
habits, service practices and difference s in road characteristics and climate.■
Traction AA, A, B, C
The traction grades, from highest to lo west, are AA, A, B and C, and they rep-
resent the tire’s ability to stop on wet pavement as measured under controlled
conditions on specified government test surfaces of asphalt and concrete. A tire marked C may have poor traction performance.
Warning: The traction grade assigned to this tire is based on braking (straight
ahead) traction tests and does not include cornering (turning) traction.Uniform Tire Quality Grading

7299-1. Specifications
9
Vehicle specifications
RX450h_RX450hL _U_OM48F85U■
Temperature A, B, C
The temperature grades are A (the highes t), B, and C, representing the tire’s
resistance to the generation of heat and its ability to dissipate heat when
tested under controlled conditions on a specified indoor laboratory test
wheel. Sustained high temperature can cause the ma terial of the tire to degenerate and
reduce tire life, and excessive temperature can lead to sudden tire failure.
Grade C corresponds to a level of perfor mance which all passenger car tires must
meet under the Federa l Motor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels of performance on the laboratory test
wheel than the minimum required by law.
Warning: The temperature grades of a tire assume that it is properly inflated and
not overloaded.
Excessive speed, underi nflation, or excessive loading, either separately or in com-
bination, can cause heat buildup and possible tire failure.