radiator LEXUS RX450h 2021 Owners Manual

3646-2. Maintenance
Radiator/con-
denser
The radiator and con-
denser should be free
from foreign objects.
( P.374)
Washer fluid
Is there sufficient
washer fluid?
( P.375)
Luggage compartment
ItemsCheck points
12-volt batteryCheck the connec-
tions. ( P.376)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator
pedal should move
smoothly (without
uneven pedal effort
or catching).
Hybrid transmis-
sion “Park” mech-
anism
•When parked on a slope and the shift
lever is in P, is the
vehicle securely
stopped?
Brake pedal
• Does the brake pedal move
smoothly?
• Does the brake pedal have appro-
priate clearance
from the floor?
• Does the brake pedal have the cor-
rect amount of free
play?
ItemsCheck points
Brakes
• The vehicle should not pull to one side
when the brakes are
applied.
•The brakes should work effectively.
• The brake pedal should not feel
spongy.
• The brake pedal should not get too
close to the floor
when the brakes are
applied.
Head restraints
•Do the head restraints move
smoothly and lock
securely?
Indicators/buzz-
ers•Do the indicators and buzzers function
properly?
Lights
• Do all the lights come on?
• Are the headlights aimed correctly?
( P.397)
Parking brake
• Does the parking
brake switch oper-
ate normally?
• When parked on a slope and the park-
ing brake is on, is the
vehicle securely
stopped?
Seat belts
• Do the seat belts operate smoothly?
• The seat belts should not be damaged.
ItemsCheck points

3686-3. Do-it-yourself maintenance
Light bulbs
( P.399)
•Bulb with same num-
ber and wattage rat-
ing as original
•Flathead screw- driver
•Wrench
Radiator and con-
denser ( P.374)
Tire inflation pres-
sure ( P.387)• Tire pressure gauge
•Compressed air
source
Washer fluid
( P.375)
• Water or washer
fluid containing anti-
freeze (for winter
use)
• Funnel (used only for adding water or
washer fluid)
WARNING
The engine compartment contains many
mechanisms and fluids that may move
suddenly, become hot, or become elec-
trically energized. To avoid death or seri-
ous injury, observe the following
precautions.
■When working on the engine com-
partment
●Make sure that the “ACCESSORY” or
“IGNITION ON” on the multi-infor-
mation display and the “READY” indi-
cator are both off.
●Keep hands, clothi ng and tools away
from the moving fan and engine drive
belt.
●Be careful not to touch the engine,
power control unit, radiator, exhaust
manifold, etc. right after driving as they
may be hot. Oil and other fluids may
also be hot.
ItemsParts and tools●Do not leave anything that may burn
easily, such as paper and rags, in the
engine compartment.
●Do not smoke, cause sparks or expose
an open flame to fuel. Fuel fumes are
flammable.
■When working near the electric cool-
ing fan or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the
electric cooling fans may automatically
start to run if the air conditioning is on
and/or the coolant temperature is high.
(  P.374)
■Safety glasses
Wear safety glasses to prevent flying or
falling material, fluid spray, etc. from get-
ting in your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter
removed may cause excessive engine
wear due to dirt in the air.

3716-3. Do-it-yourself maintenance
6
Maintenance and care
Washer fluid tank (P.375)
Brake fluid reservoir ( P.375)
Engine oil level dipstick ( P.372)
Engine coolant reservoir ( P.373)
Power control unit coolant reservoir ( P.373)
Fuse boxes ( P.395)
Radiator ( P.374)
Power control unit coolant radiator ( P.374)
Condenser ( P.374)
Electric cooling fans
Engine oil filler cap ( P.372)
■12-volt battery
 P.376
With the engine at operating tempera-
ture and turned off, check the oil level
Engine compartment
Components
A
B
C
D
E
F
G
H
I
J
K
Checking and adding the engine
oil

3746-3. Do-it-yourself maintenance
■Power control unit coolant reser-
voir
The coolant level is satisfactory if it is
between the “FULL” and “LOW” lines
on the reservoir when the hybrid sys-
tem is cold.
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” line,
add coolant up to the “FULL” line.
( P.454)
■Coolant selection
Only use “Toyota Super Long Life Coolant”
or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite,
and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mix-
ture of 50% coolant and 50% deionized
water. (Minimum temperature: -31°F
[-35°C])
Canada:
“Toyota Super Long Life Coolant” is a mix-
ture of 55% coolant and 45% deionized
water. (Minimum temperature: -44°F
[-42°C])
For more details about coolant, contact
your Lexus dealer.
■If the coolant level drops within a short
time of replenishing
Visually check the radiator, hoses,
engine/power control unit coolant reservoir
caps, drain cock and water pump.
If you cannot find a leak, have your Lexus
dealer test the cap and check for leaks in
the cooling system.
Check the radiator and condenser and
clear away any foreign objects.
If either of the above parts is extremely
dirty or you are not sure of their condi-
tion, have your vehicle inspected by
your Lexus dealer.
A
B
C
WARNING
■When the hybrid system is hot
Do not remove the en gine/power control
unit coolant reservoir caps and radiator
cap.
The cooling system may be under pres-
sure and may spray hot coolant if the cap
is removed, causing serious injuries, such
as burns.
NOTICE
■When adding coolant
Coolant is neithe r plain water nor
straight antifreeze. The correct mixture
of water and antifreeze must be used to
provide proper lubrication, corrosion
protection and cooling. Be sure to read
the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to pre-
vent it from damaging parts or paint.
Checking the radiator and con-
denser

3756-3. Do-it-yourself maintenance
6
Maintenance and care
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
■Adding fluid
Make sure to check the fluid type and
prepare the necessary item.
 Fluid type
FMVSS No.116 DOT 3 or SAE J1703
brake fluid
Item
Clean funnel
■Brake fluid can absorb moisture from
the air
Excess moisture in the brake fluid can cause
a dangerous loss of braking efficiency. Use
only newly opened brake fluid.
If any washer does not work or the
warning message appears on the
multi-information display, the washer
tank may be empty. Add washer fluid.
WARNING
■When the hybrid system is hot
Do not touch the radiator or condenser
as they may be hot and cause serious
injuries, such as burns.
Checking and adding the brake
fluid
WARNING
■When filling the reservoir
Take care as brake fluid can harm your
hands and eyes and damage painted sur-
faces.
If fluid gets on your hands or in your eyes,
flush the affected area with clean water
immediately.
If you still experience discomfort, see a
doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go
down slightly as the brake pads wear out
or when the fluid leve l in the accumulator
is high.
If the reservoir needs frequent refilling,
there may be a serious problem.
Washer fluid
WARNING
■When adding washer fluid
Do not add washer fluid when the hybrid
system is hot or operating as washer fluid
contains alcohol and may catch fire if
spilled on the engine, etc.

4557-2. Steps to take in an emergency
7
When trouble arises
and radiator core (radiator) for any
leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
Radiator cap
5 Add coolant if necessary.
Water can be used in an emergency if coolant is unavailable.
6
Start the hybrid system and turn the
air conditioning system on to check
that the radiator cooling fans oper-
ate 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 oper-
ating by checking the fan sound and air
flow. If it is difficult to check these, turn the
air conditioning system on and off repeat-
edly.
(The fans may not oper ate in freezing tem-
peratures.)
7 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.
8 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
A
B
A
B
C
D

4567-2. Steps to take in an emergency
Lexus dealer.
If “Hybrid System Overheated Out-
put power reduced” is shown on the
multi-information display
1 Stop the vehicle in a safe place.
2 Stop the hybrid system and care-
fully lift the hood.
3 After the hybrid system has cooled
down, inspect the hoses and radia-
tor core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line 5
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
6Start the hybrid system and check if
“Hybrid System Overheated Out-
put power reduced” 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.
A
B
A
B
C
WARNING
■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
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.

4577-2. Steps to take in an emergency
7
When trouble arises
1Stop the hybrid system. Shift the
shift lever to P and set the parking
brake.
2 Remove the mud, snow or sand
from around the front wheels.
3 Place wood, stones or some other
material under the front wheels to
help provide traction.
4 Restart the hybrid system.
5 Shift the shift lever to D or R and
release the parking brake. Then,
while exercising caution, depress
the accelerator pedal.
■When it is difficult to free the vehicle
Press to turn off TRAC.
WARNING
●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 rotat-
ing parts such as the fans, which may
lead to fingers or cl othing (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 while 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 sys-
tem 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 sys-
tem
Observe the following precautions:
●Avoid contaminating the coolant with
foreign matter (such as sand or dust,
etc.).
●Do not use any coolant additive.
If the vehicle becomes stuck
Carry out the following proce-
dures if the tires spin or the vehicle
becomes stuck in mud, dirt or snow:
Recovering procedure

521Alphabetical Index
Power control unit coolantCapacity ......................................................... 464
Checking ....................................................... 373
Preparing and checking before winter........................................................................... 291
Power easy access system ........................ 142
Power outlets ................................................ 343
Power steering (Elect ric power steering
system).......................................................... 284 Warning light ................................................. 421
Power switch .................................................. 184 Auto power off function ...........................187
Changing the power switch modes ..187
Power switch (engine switch) If your vehicle has to be stopped in an
emergency ................................................. 410
Power windows Door lock linked window operation..154
Jam protection function............................153
Operation........................................................153
Window lock switch ................................. 155
Pre-Collision System (PCS) Function .......................................................... 220
PCS OFF switch .........................................222
Warning light ............................................... 424
R
Radar cruise control (dynamic radar cruise control with full-speed range)............. 238
Radiator ........................................................... 374
RCTA Function ............................................................ 261
Warning message..................................... 262
RCTA (Rear Cross Traffic Alert) ......... 253
RCTA function ............................................. 262
Rear automatic air conditioning system ............................................................................315
Rear Cross Traffic Alert (RCTA) ........... 261
Rear door sunshades ................................. 345
Rear fog lights Switch ..............................................................206 Rear seats .........................................................132
Adjustment ..................................................... 133
Folding down the rear seatbacks ....... 133
Head restraints............................................. 145
Seat heaters ................................................... 318
Rear side marker lights Light switch .................................................. 200
Replacing light bulbs ............................... 400
Rear turn signal lights Replacing light bulbs ...................400, 404
Turn signal lever .......................................... 194
Wattage ......................................................... 468
Rear view mirror Inside rear view mirror ............................. 149
Outside rear view mirrors...................... 150
Rear window defogger ............................. 306
Rear window wiper.......................................210
Refueling Capacity ......................................................... 462
Fuel types ....................................................... 462
If the fuel filler do or cannot be opened
..........................................................................446
Opening the fuel tank cap ....................... 211
Regenerative braking ....................................67
Remote Touch .............................................. 298
Replacing Electronic key battery ..............................393
Fuses................................................................ 395
Light bulbs .................................................... 399
Tires .................................................................. 432
Resetting the message indicating mainte- nance is required ...................................... 362
Rev indicator .................................................... 85
Rev peak............................................................. 85
Road Sign Assist .......................................... 236
RSA (Road Sign Assist) ............................ 236
S
Seat belt reminder light....................421, 422
Seat belts............................................................ 26 Automatic Locking Retractor................. 28
Child restraint system installation ......... 46