Page 704 of 792
7048-2. Steps to take in an emergency
RX450h_RX450hL_U
■If “Hybrid System Overheated Reduced Output Power” is shown on the
multi-information displayStop the vehicle in a safe place.
Stop the hybrid system an d carefully lift the hood.
After the hybrid system has
cooled down, inspect the hoses
and radiator core (radiator) 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
Add coolant if necessary.
Water can be used in an emergency
if coolant is unavailable.
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Page 705 of 792

7058-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL_U
Start 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.
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Page 706 of 792
7068-2. Steps to take in an emergency
RX450h_RX450hL_U
Stop the hybrid system. Shift the shift lever to P and set the parking brake.
Remove the mud, snow or sand from around the front wheels.
Place wood, stones or some other materi al under the front wheels to help pro-
vide traction.
Restart the hybrid system.
Shift the shift lever to D or R and rele ase the parking brake. Then, while exer-
cising caution, depress the accelerator pedal.
■When it is difficult to free the vehicle
If the vehicle becomes stuck
Carry out the following procedures if the tires spin or the vehicle becomes
stuck in mud, dirt or snow:
Press to turn off TRAC.
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Page 728 of 792

7289-1. Specifications
RX450h_RX450hL_U
This 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 grades 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 lowest, 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
Page 767 of 792

767What to do if... (Troubleshooting)
RX450h_RX450hL_U
●Did you press the power switch while firmly depressing the brake pedal? \
(P. 239)
●Is the shift lever in P? ( P. 241)
●Is the electronic key anywhere detectable inside the vehicle? ( P. 158)
●Is the steering wheel unlocked? ( P. 242)
●Is the electronic key battery weak or depleted?
In this case, the hybrid system can be started in a temporary way. ( P. 693)
●Is the 12-volt battery discharged? ( P. 695)
●Is the power switch in ON mode?
If you cannot release the shift lever by depressing the brake pedal with the
power switch in ON mode ( P. 250)
●It is locked automatically to prevent theft of the vehicle. ( P. 242)
●Is the window lock switch pressed?
The power window except for the one at the driver’s seat cannot be operated
if the window lock switch is pressed. ( P. 196)
●The auto power off function will be operated if the vehicle is left in
ACCESSORY or ON mode (the hybrid sy stem is not operating) for a period
of time. ( P. 241)
If you think something is wrong
The hybrid system does not start
The shift lever cannot be shifted from P even if you depress the brake
pedal
The steering wheel cannot be turned after the hybrid system is stopped
The windows do not open or close by operating the power window
switches
The power switch is turned off automatically
Page 768 of 792

768What to do if... (Troubleshooting)
RX450h_RX450hL_U
●The seat belt reminder light is flashing
Are the driver and the passengers wearing the seat belts?
( P. 662, 662)
●The parking brake indicator is on
Is the parking brake released? ( P. 253)
Depending on the situation, other types of warning buzzer may also sound.
( P. 660, 667)
●Did anyone inside the vehicle open a door during setting the alarm?
The sensor detects it and the alarm sounds. ( P. 86)
Do one of the following to stop the alarms:
• Unlock the doors.
• Turn the power switch to ACCESSORY or ON mode, or start the hybrid system.
●Is the message displayed on the multi-information display?
Check the message on the multi-information display. ( P. 667)
●When a warning light turns on or a warning message is displayed, refer to
P. 660, 667.A warning buzzer sounds during driving
An alarm is activated and the horn sounds
A warning buzzer sounds when leaving the vehicle
A warning light turns on or a warning message is displayed
Page 769 of 792
769What to do if... (Troubleshooting)
RX450h_RX450hL_U
●Stop the vehicle in a safe place and replace the flat tire with the spare tire.
( P. 673)
●Try the procedure for when the vehicle becomes stuck in mud, dirt, or snow.
( P. 706)
When a problem has occurred
If you have a flat tire
The vehicle becomes stuck
Page 776 of 792

776Alphabetical index
RX450h_RX450hL_U
Emergency, in case ofIf a warning buzzer sounds.......... 660
If a warning light turns on.............. 660
If a warning message is displayed.............................................667
If the 12-volt battery is discharged ........................................ 695
If the electronic key does not operate properly.............................692
If the hybrid system will not start ............................................... 690
If you have a flat tire ..........................673
If you lose your keys ................ 133, 135
If you think something is wrong .................................................. 659
If your vehicle becomes stuck ..................................................... 706
If your vehicle has to be stopped in an
emergency........................................ 653
If your vehicle needs to be towed................................................... 654
If your vehicle overheats ................702
Energy monitor ....................................... 124 Engine
ACCESSORY mode ..................... 240
Compartment ..................................... 597
Engine switch ...................................... 239
Hood........................................................595
How to start the hybrid system .................................................. 239
Identification number......................... 712
If your vehicle has to be stopped in an emergency..........653
Ignition switch (power switch) .... 239
Overheating......................................... 702
Power switch ....................................... 239
Engine coolant Capacity................................................... 715
Checking ................................................ 601
Preparing and checking before winter ....................................390
Engine coolant temperature gauge .........................................................96
Engine oil Capacity................................................... 713
Checking .............................................. 598
Preparing and checking before winter ....................................390
Engine oil maintenance data ........... 600
Engine switch ......................................... 239
Enhanced VSC ..................................... 382
EPS (Electronic Power Steering) ........ 383 Warning light .........................................661
EV drive mode .......................................244
EV indicator ............................................... 76
Event data recorder (EDR).....................11