2021 LEXUS IS300 radiator cap

2956-3. Do-it-yourself maintenance
6
Maintenance and care
IS350 AWD/IS350/IS300 AWDFuse boxes ( P.318)
Battery ( P.301)
Engine oil level dipstick ( P.296)
Engine coolant reservoir ( P.298)
Engine oil filler cap ( P.297)
Brake fluid reservoir ( P.300)
Washer fluid tank ( P.302)
Electric cooling fans
Condenser ( P.300)
Radiator ( P.300)
Engine compartment
Components
A
B
C
D
E
F
G
H
I
J

2966-3. Do-it-yourself maintenance
IS300Fuse boxes ( P.318)
Battery ( P.301)
Intercooler
Engine oil level dipstick ( P.296)
Engine oil filler cap ( P.297)
Engine coolant reservoir ( P.298)
Brake fluid reservoir ( P.300)
Washer fluid tank ( P.302)
Electric cooling fans
Condenser ( P.300)
Intercooler radiator ( P.300)
Radiator ( P.300)
Intercooler coolant reservoir ( P.298)
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
A
B
C
D
E
F
G
H
I
J
K
L
M
Checking and adding the engine
oil

3006-3. Do-it-yourself maintenance
Check the radiator, condenser and
intercooler radiator (if equipped) 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.
■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
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.
WARNING
■When the engine is hot
Do not remove the engine coolant reser-
voir cap, intercooler coolant reservoir
cap (IS300), or coolant inlet cap.
(  P.367)
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 (if equipped) 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.

3657-2. 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.
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” or “F” and
“LOW” or “L” lines on the reservoir.
Engine (IS350
AWD/IS350/IS300 AWD)
Reservoir cap
“FULL” line
“LOW” line
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The needle of the engine coolant
temperature gauge ( P.71)
enters the red zone or a loss of
engine power is experienced.
(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
A
B
A
B
C

3667-2. Steps to take in an emergency
Engine (IS300)Reservoir cap
“FULL” line
“LOW” line
Intercooler (IS300)
Reservoir cap
“F” line
“L” line
5 Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
Engine (IS350
AWD/IS350/IS300 AWD)
Engine (IS300)
Intercooler (IS300)
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-
A
B
C
A
B
C

3677-2. Steps to take in an emergency
7
When trouble arises
edly. (The fans may not operate in freezing
temperatures.)
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.
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 engine and contact your
Lexus dealer.
If the message is not displayed:
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.
●IS350 AWD/IS350/IS300 AWD:
Do not loosen the coolant inlet cap or
coolant reservoir cap while the engine
and radiator are hot. (The coolant inlet
cap is located under the engine cover.)
High temperature steam or coolant
could spray out.
●IS300: Do not loosen the coolant inlet
cap, coolant reservoir cap, or inter-
cooler reservoir cap while the engine
and radiator are hot. High tempera-
ture 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.

428Alphabetical Index
Parking Support Brake function (for rear-crossing vehicles) .......................... 232Function .......................................................... 232
Parking Support Brake function (static objects) ......................................................... 226Function .......................................................... 226
PCS (Pre-Collision System) Function ............................................................170
PCS OFF switch .......................................... 173
Warning light ............................................... 342
Personal lights............................................... 263
PKSA (Parking Support Alert) ..............208
PKSB (Parking Support Brake)............... 221 Warning message..................................... 225
Power easy access system ....................... 108
Power outlets .................................................. 271
Power steering (Elect ric power steering
system).......................................................... 238 Warning light ...............................................340
Power window switch lights .................... 263
Power windows Door lock linked window operation... 119
Jam protection function............................. 118
Operation......................................................... 118
Window lock switch ................................... 119
Pre-Collision System (PCS) Function ............................................................170
PCS OFF switch .......................................... 173
Warning light ............................................... 342
R
Radar cruise control (dynamic radar cruise control with full-speed range)...............192
Radiator ...........................................................300
RCTA Function ............................................................ 216
Warning message....................................... 217
RCTA (Rear Cross Traffic Alert) .........208
RCTA function ............................................... 217
Rear Cross Traffic Alert (RCTA) ........... 216
Rear seats .........................................................107 Head restraints ................................................ 111 Rear side marker lights
Light switch .................................................... 149
Rear sunshades .............................................272
Rear turn signal lights Replacing light bulbs .................... 322, 323
Turn signal lever ...........................................142
Wattage ........................................................... 381
Rear view mirror Inside rear view mirror ............................... 114
Outside rear view mirrors........................ 116
Rear window defogger ............................. 255
Refueling Capacity ......................................................... 374
Fuel types ....................................................... 374
If the fuel filler do or cannot be opened
......................................................................... 359
Opening the fuel tank cap ....................... 161
Remote Touch .............................................. 248
Replacing Electronic key battery ............................... 316
Fuses.................................................................. 318
Light bulbs .......................................................321
Tires ..................................................................349
Resetting the message indicating mainte- nance is required ...................................... 286
Rev indicator .....................................................73
Rev peak..............................................................74
Road Sign Assist ........................................... 189
RSA (Road Sign Assist) ............................. 189
S
Seat belt reminder light............................. 340
Seat belts............................................................ 24 Automatic Locking Retractor................. 26
Child restraint system installation ......... 42
Cleaning and maintaining the seat belt..........................................................................283
Emergency Locking Retractor .............. 26
How to wear your seat belt ..................... 25
How your child should wear the seat belt ............................................................................. 25