radiator LEXUS RC300 2020 Owners Manual

2426-2. Maintenance
Radiator, con-
denser and inter-
cooler radiator
The radiator, con-
denser and inter-
cooler radiator should
be free from foreign
objects. (P.254)
Washer fluid
Is there sufficient
washer fluid?
( P.256)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator
pedal should move
smoothly (without
uneven pedal effort
or catching).
Automatic trans-
mission “Park”
mechanism
•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?
Parking brake
• Does the parking brake pedal move
smoothly?
• 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

2466-3. Do-it-yourself maintenance
Light bulbs
( P.272)
• Bulb with same num-
ber and wattage rat-
ing as original
• Phillips-head screw- driver
• Flathead screw- driver
• Wrench
Radiator, con-
denser and inter-
cooler radiator
(  P.254)

Tire inflation pres-
sure ( P.263)• Tire pressure gauge
• Compressed air
source
Washer fluid
( P.256)
• 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
●Keep hands, clothi ng and tools away
from the moving fans and engine drive
belt.
●Be careful not to touch the engine,
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 or the battery.
Fuel and battery fumes are flammable.
●Be extremely cautious when working
on the battery. It contains poisonous
and corrosive sulfuric acid.
■When working near the electric cool-
ing fans or radiator grille
Be sure the engine switch is off.
With the engine switch in IGNITION
ON mode, the electric cooling fans may
automatically start to run if the air condi-
tioning is on and/or the coolant tempera-
ture is high. ( P.254)
■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.

2496-3. Do-it-yourself maintenance
6
Maintenance and care
RC350/RC300 AWDFuse boxes ( P.269)
Battery ( P.255)
Engine oil level dipstick ( P.250)
Engine coolant reservoir ( P.252)
Engine oil filler cap ( P.250)
Brake fluid reservoir ( P.254)
Washer fluid tank ( P.256)
Electric cooling fans
Condenser ( P.254)
Radiator ( P.254)
Engine compartment
Components
A
B
C
D
E
F
G
H
I
J

2506-3. Do-it-yourself maintenance
RC300Fuse boxes ( P.269)
Battery ( P.255)
Engine oil level dipstick ( P.250)
Engine oil filler cap ( P.250)
Engine coolant reservoir ( P.252)
Brake fluid reservoir ( P.254)
Washer fluid tank ( P.256)
Electric cooling fans
Condenser ( P.254)
Intercooler radiator ( P.254)
Radiator ( P.254)
Intercooler coolant reservoir ( P.252)
With the engine at operating tempera-
ture and turned off, check the oil level
on the dipstick.
■Checking the engine oil
1 Park the vehicle on level ground.
After warming up the engine and
turning it off, wait more than 5 min-
utes for the oil to drain back into the
bottom of the engine.
A
B
C
D
E
F
G
H
I
J
K
L
Checking and adding the engine
oil

2546-3. Do-it-yourself maintenance
Check the radiator, condenser and
intercooler radiator and clear away
any foreign objects.
If any of the above parts are extremely
dirty or you are not sure of their condi-
tion, have your vehicle inspected by
your Lexus dealer.
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
RC350/RC300 AWD
RC300
■Adding fluid
Make sure to check the fluid type and
prepare the necessary item.
 Fluid type
SAE J1703 or FMVSS No.116 DOT 3
brake fluid
SAE J1704 or FMVSS No.116 DOT 4
brake fluid
Item
Clean funnel
WARNING
■When the engine is hot
Do not remove the engine coolant reser-
voir cap, intercooler coolant reservoir
cap and coolant inlet cap. ( P.314)
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 neither 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 damagi ng parts or paint.
Checking the radiator, con-
denser and intercooler radiator
(if equipped)
WARNING
■When the engine is hot
Do not touch the radiator, condenser or
intercooler radiator as they may be hot
and cause serious injuries, such as burns.
Checking and adding the brake
fluid

3117-2. Steps to take in an emergency
7
When trouble arises
1Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the engine.
2
If you see steam:
Carefully lift the hood after the
steam subsides.
If you do not see steam:
Carefully lift the hood.
3
After the engine has cooled down
sufficiently, inspect the hoses and
radiator core (radiator) for any
leaks.
WARNING
●When working with the battery, always
wear safety glasses and take care not
to allow any battery fluids (acid) to
come into contact with skin, clothing
or the vehicle body.
●Do not lean over the 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 battery support, terminals, and
other battery-related parts.
●Do not allow children near the battery.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or engine drive
belt.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The engine coolant temperature
gauge ( P.64) is in the red zone
or a loss of engine power is expe-
rienced. (For example, the vehicle
speed does not increase.)
 “Engine Coolant Temp High Stop
in a Safe Place See Owner’s
Manual” is shown on the
multi-information display.
 Steam comes out from under the
hood.
Correction procedures

3127-2. Steps to take in an emergency
RC350/RC300 AWD
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
 RC300
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4 The coolant level is satisfactory if it
is between the full (“FULL” or “F”)
and low (“LOW” or “L”) lines on the
reservoir.
 Engine (RC350/RC300 AWD) Reservoir cap
“FULL” or “F”
“LOW” or “L”
 Engine (RC300)
Reservoir cap
“FULL” or “F”
“LOW” or “L”
 Intercooler (RC300)
Reservoir cap
“FULL” or “F”
“LOW” or “L”
A
B
A
B
A
B
C
A
B
C
A
B
C

3137-2. Steps to take in an emergency
7
When trouble arises
5Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
Engine (RC350/RC300 AWD)
 Engine (RC300)
 Intercooler (RC300)
6
Start the engine 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.)
7If the fans are not operating:
Stop the engine immediately and
contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the
nearest Lexus dealer.
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.
●Keep hands and clothing (especially a
tie, a scarf or a muffler) away from the
fans and belts. Failure to do so may
cause the hands or clothing to be
caught, resulting in serious injury.

3147-2. Steps to take in an emergency
WARNING
●RC350/RC300 AWD: While the
engine and radiator are hot, do not
loosen or remove the coolant reser-
voir cap or coolant inlet cap. (The
coolant inlet cap is located under the
engine cover.)
High temperature steam or coolant
could spray out.
●RC300: While the engine and radia-
tors are hot, do not loosen or remove
the coolant reservoir cap, coolant inlet
cap, or intercooler coolant reservoir
cap.
High temperature steam or coolant
could spray out.
NOTICE
■When adding engine coolant
Add coolant slowly after the engine has
cooled down sufficiently. Adding cool
coolant to a hot engine too quickly can
cause damage to the engine.
■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.

382Alphabetical Index
Power control unit coolantPreparing and checking before winter.......................................................................... 198
Power easy access system ....................... 100
Power outlet .................................................. 222
Power steering (Elect ric power steering
system)............................................................194 Warning light ...............................................286
Power windows Door lock linked window operation..... 111
Jam protection function............................. 110
Operation......................................................... 110
Window lock switch ..................................... 111
Pre-Collision System (PCS) Function ........................................................... 156
PCS OFF switch ......................................... 158
Warning light ............................................... 287
Warning message..................................... 292
R
Radar cruise control (dynamic radar cruise control) ...........................................................170
Radiator ........................................................... 254
RCTA Function ........................................................... 184
Rear Cross Traffic Alert (RCTA) .......... 184
Rear seats .......................................................... 99 Head restraints ............................................ 103
Seat heaters .................................................... 214
Seat ventilators.............................................. 214
Rear side marker lights Light switch ..................................................... 137
Rear turn signal lights Turn signal lever ...........................................134
Wattage.......................................................... 328
Rear view mirror Inside rear view mirror..............................107
Outside rear view mirrors ..................... 108
Rear window defogger ................................ 211
Refueling Capacity ......................................................... 320
Fuel types....................................................... 320 If the fuel filler do
or cannot be opened
......................................................................... 305
Opening the fuel tank cap ..................... 149
Remote Touch .............................................. 202
Replacing Electronic key battery .............................. 267
Fuses.................................................................269
Light bulbs ..................................................... 272
Tires ..................................................................296
Resetting the message indicating mainte- nance is required ...................................... 240
Rev indicator .....................................................67
Rev peak..............................................................67
S
Seat belt reminder light.............................288
Seat belts............................................................ 24 Automatic Locking Retractor................. 26
Child restraint system installation ..40, 41
Cleaning and maintaining the seat belt.......................................................................... 237
Emergency Locking Retractor .............. 26
How to wear your seat belt ..................... 25
How your child should wear the seat belt ............................................................................. 25
Pregnant women, proper seat belt use ............................................................................. 24
Reminder light and buzzer .................. 288
Seat belt extender......................................... 25
Seat belt pretensioners .............................. 27
SRS warning light...................................... 285
Seat heaters ..................................................... 214
Seat position memory................................. 100
Seat ventilators ............................................... 214
Seating capacity.............................................123
Seats Adjustment ....................................................... 97
Cleaning ......................................................... 237
Driving position memory ........................ 100
Head restraints............................................. 103
Power easy access system .................... 100
Properly sitting in the seat ........................ 23