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5417-2. Steps to take in an emergency
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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 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 562 of 660

5627-2. Steps to take in an emergency
RX450h_U_OM0E013U
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. (P. 568)
●One or both of the 12-volt battery terminals may be disconnected. ( P. 483)
Contact your Lexus dealer if the problem cannot be repaired, or if repair procedures
are unknown.
When the hybrid system does not start, the following steps can be used as an
interim measure to start the hybrid system if the power switch is functioning nor-
mally.
Do not use this starting procedur e except in cases of emergency.
Turn the power switch to ON mode an d check that the parking brake is set.
( P. 233, 245)
Shift the shift lever to P.
Turn the power switch to ACCESSORY mode.
Press and hold the power switch for ab out 15 seconds while depressing the
brake pedal firmly.
Even if the hybrid system can be starte d using the above steps, the system may
be malfunctioning. Have the vehicle inspected by your Lexus dealer.
The interior lights and headlights do not turn on, or the horn does not
sound.
Emergency start function
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Page 568 of 660
5687-2. Steps to take in an emergency
RX450h_U_OM0E013U
If you have a set of jumper (or booster) cables and a second vehicle with a 12-volt
battery, you can jump start your vehicle by following the steps below.
Confirm that the electronic key is
being carried.
When connecting the jumper (or
booster) cables, depe nding on the situa-
tion, the alarm may activate and doors
locked. (
P. 88)
Open the hood ( P. 473) and fuse
box cover.
Open the exclusive jump starting
terminal cover.
If the 12-volt battery is discharged
The following procedures may be used to start the hybrid system if the vehi-
cle’s 12-volt battery is discharged.
You can also call your Lexus deal er or a qualified repair shop.
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Page 574 of 660

5747-2. Steps to take in an emergency
RX450h_U_OM0E013U
■“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information displayStop the vehicle in a safe place and turn off the air conditioning system, and
then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has
cooled down sufficiently, inspect
the hoses and radiator core (radi-
ator) for any leaks.Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The coolant level is satisfactory if
it is between the “FULL” and
“LOW” lines on the reservoir.Reservoir
“FULL” line
“LOW” line
Radiator cap
If your vehicle overheats
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( P. 97) enters the
red zone, or a loss of hybrid system power is experienced. (For example, the
vehicle speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” or
“Hybrid System Overheated Reduced Output Power” is shown on the
multi-information display.
●Steam comes out from under the hood.
Correction procedures
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Page 575 of 660

5757-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
Add coolant if necessary.
Water can be used in an emergency
if coolant is unavailable.
Start the hybrid system and turn the air conditioning system on to check
that the radiator cooling fans operate and to check for coolant leaks from
the radiator or hoses.
The fans operate when the air conditioning system is turned on immediately after a
cold start. Confirm that the fans are operating by checking the fan sound and air
flow. If it is difficult to check these, tu rn the air conditioning system on and off
repeatedly. (The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the hybrid system immediately and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
Check if “Engine Coolant Temp High Stop in a Safe Place See Owner’s
Manual” 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.
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Page 591 of 660

5918-1. Specifications
8
Vehicle specifications
RX450h_U_OM0E013U
■Gasoline quality
In very few cases, driveability problems may be caused by th e brand of gasoline you are
using. If driveability problems persist, try ch anging the brand of gasoline. If this does not
correct the problem, consult your Lexus dealer.
■Gasoline quality standards
●Automotive manufacturers in the U.S.A., Europe and Japan have developed a specifi-
cation for fuel quality calle d the World-Wide Fuel Charte r (WWFC), which is expected
to be applied worldwide.
●The WWFC consists of four categories that are based on required emission levels. In
the U.S., category 4 has been adopted.
●The WWFC improves air quality by lowering emissions in vehicle fleets, and improves
customer satisfaction th rough better performance.
■Recommendation of the use of gasoline containing detergent additives
●Lexus recommends the use of gasoline that contains detergent additives to avoid the
build-up of engine deposits.
●All gasoline sold in the U.S.A. contains minimum detergent additives to clean and/or
keep clean intake systems, per EPA’s lowest additives concentration program.
●Lexus strongly recommends the use of Top Tier Detergent Gasoline. For more informa-
tion on Top Tier Detergent Gasoline and a lis t of marketers, please go to the official
website www.toptiergas.com.
Fuel information
You must only use unleaded gasoline.
Select premium unleaded gasoline with an octane rating of 91 (Research
Octane Number 96) or higher required for optimum engine performance.
If 91 octane cannot be obtained, yo u may use unleaded gasoline with an
octane rating as low as 87 (Researc h Octane Number 91). Use of unleaded
gasoline with an octane rating lower than 91 may result in engine knocking
and significantly reduced performance. Persistent knocking can lead to
engine damage and should be correct ed by refueling with higher octane
unleaded gasoline.
At minimum, the gasoline you use should meet the specifications of ASTM
D4814 in the U.S.A.
Page 595 of 660

5958-1. Specifications
8
Vehicle specifications
RX450h_U_OM0E013U
Tire size( P. 597)
DOT and Tire Identification Number (TIN) ( P. 596)
Location of treadwear indicators (P. 487)
Tire ply composition and materials
Plies are layers of rubber-c oated parallel cords. Cords are the strands which form the
plies in a tire.
Radial tires or bias-ply tires
A radial tire has “RADIAL” on the sidewall. A tire not marked “RADIAL” is a bias-ply
tire.
TUBELESS or TUBE TYPE
A tubeless tire does not have a tube and air is directly put into the tire. A tube type tire
has a tube inside the tire and the tube maintains the air pressure.
Load limit at maximum cold tire inflation pressure ( P. 490)
Maximum cold tire inflation pressure ( P. 589)
This means the pressure to which a tire may be inflated.
Uniform tire quality grading
For details, see “Uniform Tire Quality Grading” that follows.
Summer tires or all season tires ( P. 491)
An all season tire has “M+S” on the side wall. A tire not marked “M+S” is a summer
tire.
“TEMPORARY USE ONLY”
A compact spare tire is identified by the phrase “TEMPORARY USE ONLY” molded
on its sidewall. This tire is designed for temporary emergency use only.
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