Page 576 of 660
5767-2. Steps to take in an emergency
RX450h_U_OM0E013U
■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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3
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Page 577 of 660

5777-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
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.
6
Page 587 of 660

5878-1. Specifications
8
Vehicle specifications
RX450h_U_OM0E013U
*: The coolant capacity is a reference quantity. If replacement is necessary, contact your Lexus dealer.
Cooling system
Capacity*
Gasoline engine
10.7 qt. (10.1 L, 8.9 Imp. qt.)
Power control unit
2.0 qt. (1.9 L, 1.7 Imp. qt.)
Coolant type
Use either of the following: • “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based
non-silicate, non-amine, non-nitrite, and non-
borate coolant with long-life hybrid organic
acid technology
Do not use plain water alone.
Ignition system (spark plug)
MakeDENSO FK20HBR8
Gap0.03 in. (0.8 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
Electrical system
12-volt battery
Open voltage at 68F (20 C):
12.6 V or higher: Fully charged
12.2 — 12.4 V: Half charged
12.0 V or lower: Discharged
(Voltage is checked 20 minutes after the hybrid
system and all lights are turned off.)
Charging rates5 A max.
Page 601 of 660

6018-1. Specifications
8
Vehicle specifications
RX450h_U_OM0E013U
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pressure
Tire pressure when the vehicle has been parked for
three hours or more, or has not been driven more than 1
mile or 1.5 km un der that condition
Maximum inflation pres-
sureThe maximum cold inflated pr essure to which a tire may
be inflated, shown on the sidewall of the tire
Recommended inflation
pressureCold tire inflation pressure recommended by a manu-
facturer
Accessory weight
The combined weight (in exce ss of those standard items
which may be replaced) of hybrid transmission, power
steering, power brakes, power windows, power seats,
radio and heater, to the extent that these items are avail-
able as factory-installed eq uipment (whether installed
or not)
Curb weight
The weight of a motor vehicle with standard equipment,
including the maximum capacity of fuel, oil and coolant,
and if so equipped, air co nditioning and additional
weight optional engine
Maximum loaded vehicle
weight
The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options weight
Normal occupant weight150 lb. (68 kg) times the numb er of occupants specified
in the second column of Table 1* that follows
Occupant distributionDistribution of occupants in a vehicle as specified in the
third column of Table 1
* below
Page 609 of 660
6098-2. Customization
8
Vehicle specifications
RX450h_U_OM0E013U
■Power back door (P. 142)
*: If equipped
FunctionDefault settingCustomized setting
Power back door switch opera-
tionPress for 1 secondOne short press—O
Automatic closing of the back
door when loweredOnOff—O
Automatic opening of the back
door using the back door opener
switch
OnOff—O
Power back door opening posi-
tion51 to 5OO
Buzzer volumeLevel 3Level 1—OLevel 2
Power back door/touchless sen-
sor*On
Power back door:
On
Touchless sensor:
Off
—O
Off
Power back door open/close
buzzer
When the back
door begins to
operate: On
While the back
door is operating:
Off
Off
—O
When the back
door begins to
operate: Off
While the back
door is operating:
On
On
Sound pattern of the buzzer
when the power back door
begins to operate
Sound pattern A
Sound pattern B
—OSound pattern C
Touchless sensor* sensitivityLevel 1 (standard)Level 1 (standard) to
level 3 (highest)—O
12
Page 611 of 660

6118-2. Customization
8
Vehicle specifications
RX450h_U_OM0E013U
■Wireless remote control (P. 132, 136, 142)
*1: This setting enables opening of the power back door when it is locked or unlocked.
*2: This function is available only when a customized setting that enables opening of the
power back door when it is either locked or unlocked is selected. (See
*1 above.)
FunctionDefault settingCustomized setting
Wireless remote control OnOff — O
Unlocking operation Driver’s door
unlocked in one
step, all doors
unlocked in two
stepAll doors unlocked
in one step
OO
Panic function OnOff — O
Opening/closing of the power
back door using the
switch of the wireless remote
control Open: Press for 1
second
*1
Close: Press for 1
secondOff
—O
Open: Press for 1
second with the
back door
unlocked
Close: Press for 1
second
Open: One short
press with the back
door unlocked
Close: One short
press
Open: Press twice
with the back door
unlocked
Close: Press twice
Open: Press
twice
*1
Close: Press twice
Door unlocked when the power
back door is opened using the switch of the wireless
remote control
*2
All the doors Back door — O
12
Page 612 of 660
6128-2. Customization
RX450h_U_OM0E013U
■Driving position memory ( P. 174)
■Steering wheel ( P. 181)
■Outside rear view mirrors ( P. 185)
FunctionDefault settingCustomized setting
Driver’s seat movement when
exiting the vehicleStandardOffOOPartial
Selecting doors linked to the
memory recall functionDriver’s doorAll doors—O
12
FunctionDefault settingCustomized setting
Auto tilt away functionOnOff—O
12
FunctionDefault settingCustomized setting
Automatic mirror folding and
extending operationLinked to the lock-
ing/unlocking of the
doorsOff
—OLinked to operation of the power switch
12
Page 613 of 660
6138-2. Customization
8
Vehicle specifications
RX450h_U_OM0E013U
■Power windows, and moon roof * or panoramic moon roof*
( P. 189, 193, 197)
*:If equipped
■Moon roof* ( P. 193)
*: If equipped
FunctionDefault settingCustomized setting
Mechanical key linked operationOffOn—O
Wireless remote control linked
operationOffOn (open only)—O
Wireless remote control linked
operation signal (buzzer)OnOff—O
12
FunctionDefault settingCustomized setting
Linked operation of components
when mechanical key is used
(open only)
Slide onlyTilt only—O
Linked operation of components
when wireless remote control is
used
Slide onlyTilt only—O
12