2021 LEXUS RX450h engine coolant

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

4648-1. Specifications
*: The coolant capacity is a reference quantity.If replacement is necessary, contact your Lexus dealer.
Cooling system
Capacity*
Gasoline
engine
RX450h (Vehicles with out towing package)
10.3 qt. (9.8 L, 8.6 Imp. qt.)
RX450h (Vehicles with towing package)
10.7 qt. (10.1 L, 8.9 Imp. qt.)
RX450hL
13.2 qt. (12.5 L, 11 Imp. qt.)
Power con-
trol unit2.0 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 orga nic 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.

4758-1. Specifications
8
Vehicle specifications
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 under that condition
Maximum inflation pressureThe maximum cold inflated pressure to which a tire
may be inflated, shown on the sidewall of the tire
Recommended inflation pressureCold tire inflation pressure recommended by a
manufacturer
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of hybrid transmis-
sion, power steering, power brakes, power win-
dows, power seats, radio and heater, to the extent
that these items are available as factory-installed
equipment (whether installed or not)
Curb weight
The weight of a motor vehicle with standard equip-
ment, including the maximum capacity of fuel, oil
and coolant, and if so equipped, air conditioning
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 weight
150 lb. (68 kg) times the number of occupants
specified in the second column of Table 1
* that fol-
lows
Occupant distributionDistribution of occupants in a vehicle as specified in
the third column of Table 1
* below
Production options weight
The combined weight of installed regular produc-
tion options weighing over 5 lb. (2.3 kg) in excess of
the standard items which they replace, not previ-
ously considered in curb weight or accessory
weight, including heavy duty brakes, ride levelers,
roof rack, heavy duty 12-volt battery, and special
trim

516Alphabetical Index
If the electronic key does not operate properly....................................................... 447
If the fuel filler door cannot be opened ......................................................................... 446
If the hybrid system will not start ........ 444
If the vehicle is trapped in rising water411
If you have a flat tire .................................. 432
If you lose your keys................................. 446
If you think something is wrong ........... 417
If your vehicle becomes stuck............. 457
If your vehicle has to be stopped in an
emergency ................................................. 410
If your vehicle needs to be towed ....... 413
If your vehicle overheats ........................ 454
Energy monitor ..................................... 99, 100
Engine ACCESSORY mode ...............................187
Compartment ............................................... 371
Engine switch................................................ 184
Hood................................................................369
How to start the hybrid system ........... 184
Identification number .................................461
If the hybrid system will not start ........ 444
If your vehicle has to be stopped in an
emergency ................................................. 410
Ignition switch (power switch) ............. 184
Overheating................................................. 454
Power switch ................................................ 184
Tachometer ..................................................... 83
Engine coolant Capacity ......................................................... 464
Checking ....................................................... 373
Preparing and checking before winter........................................................................... 291
Engine coolant temperature gauge ....... 83
Engine oil Capacity ......................................................... 463
Checking ......................................................... 371
Preparing and checking before winter........................................................................... 291
Warning light .................................................419
Engine oil maintenance data .................. 373 Engine switch (power switch) ................. 184
If your vehicle has to be stopped in an emergency .................................................. 410
EPS (Electric Power Steering) .............. 284 Warning light .................................................421
EV drive mode............................................... 189
EV indicator .......................................................67
Event data recorder (E DR) ........................... 8
F
Flat tire
Tire pressure warning system .............382
Vehicles with a spare tire....................... 432
Floor mats .......................................................... 24
Fluid Brake ............................................................... 465
Hybrid transmission................................. 465
Washer ...........................................................375
Fog lights Switch.............................................................. 206
Footwell light ...................................................321
Front automatic air conditioning system .......................................................................... 304
Front fog lights Replacing light bulbs ............................... 400
Front passenger footwell hooks ............ 345
Front passenger occupant classification system .............................................................. 39
Front seats Adjustment ....................................................... 131
Cleaning ........................................................ 359
Correct driving posture ............................ 25
Driving position memory .........................142
Head restraints............................................. 145
Memory recall function.............................143
Power easy access system .....................142
Seat heaters ................................................... 318
Seat position memory ...............................142
Seat ventilators ............................................. 318
Front side marker light Light switch .................................................. 200
Replacing light bulbs ............................... 400

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

525Alphabetical Index
Intuitive parking assist.................. 260, 423
Low engine oil pressure...........................419
LTA (Lane Tracing Assist)227, 230, 422
Open door........................................................112
Open window ...............................................154
PKSA (Parking Support Alert) ........... 253
PKSB (Parking Support Brake) ......... 423
Pre-collision braking.................................. 221
RCTA (Rear Cross Traffic Alert) ...... 423
Seat belt ................................................ 421, 422
Warning label .................................................. 69
Warning lights................................................ 418 ABS .................................................................. 420
Brake hold operated indicator ........... 425
Brake Override System ......................... 420
Brake system ................................................ 418
Charging system .........................................419
Drive-Start Control .................................. 420
Electric power steering ............................ 421
High coolant temperature ..................... 418
Hybrid system overheat warning light...........................................................................419
Intuitive parking assist OFF indicator423
Low engine oil pressure...........................419
Low fuel level ................................................. 421
LTA indicator ............................................... 422
Malfunction indicator lamp.....................419
Master warning light ................................ 425
Parking brake indicator .......................... 424
PKSB OFF indicator ................................ 423
Pre-collision system ................................. 424
RCTA OFF indicator............................... 423
Seat belt reminder light ................ 421, 422
Slip indicator ................................................ 424
SRS.................................................................... 420
Tire pressure ................................................ 422
Warning messages ..................................... 428
Washer Adding ............................................................ 375
Preparing and checking before winter........................................................................... 291
Switch ..............................................................206 Washing and waxing.................................. 356
Weight
Cargo capacity .................................. 169, 172
Load limits ....................................................... 172
Weight............................................................ 460
Wheels ............................................................. 389 Size ....................................................................466
Window lock switch .................................... 155
Windows Power windows ........................................... 153
Rear window defogger.......................... 306
Washer .......................................................... 206
Windshield wiper de-icer ........................... 311
Windshield wiper inserts .......................... 392
Windshield wipers Position........................................................... 208
Rain-sensing windshield wipers ........ 206
Replacing a windshield wiper insert.392
Winter driving tips.........................................291
Wireless charger ......................................... 335
Wireless remote control Battery-Saving Function...........................126
Locking/Unlocking ................................... 107
Replacing the battery ...............................393
For information regarding the equipment listed below, refer to
the “NAVIGATION AND MULTI-
MEDIA SYSTEM OWNER’S
MANUAL”.
· Navigation system
· Audio/visual system
· Panoramic view monitor
· Lexus parking assist monitor