coolant temperature LEXUS RX450h 2021 Owners Manual

792-1. Instrument cluster
2
Vehicle status information and indicators
Warning lights inform the driver of mal-
functions in the indicated vehicle’s sys-
tems.
Warning lights
(U.S.A.)
Brake system warning light*1
(  P.418)
(red)
(Canada)
Brake system warning light*1
(  P.418)
(yellow)
Brake system warning light*1
(  P.418)
High coolant temperature
warning light
*2 (  P.418)
Hybrid system overheat warn-
ing light
*2 (  P.419)
Charging system warning
light
*3 (  P.419)
Low engine oil pressure warn-
ing light
*2 (  P.419)
(U.S.A.)
Malfunction indicator lamp*1
(  P.419)
(Canada)
Malfunction indicator lamp*1
(  P.419)
SRS warning light
*1 (  P.420)
(U.S.A.)
ABS warning light*1 ( P.420)
(Canada)
ABS warning light*1 ( P.420)
Brake Override System warn-
ing light/Drive-Start Control
warning light
*2 (  P.420)
(red)
Electric power steering system
warning light
*1 ( P.421)
(yellow)
Electric power steering system
warning light
*1 ( P.421)
Low fuel level warning light
(  P.421)
Driver’s and front passenger’s
seat belt reminder light
(  P.421)
(RX450h)
Rear passengers’ seat
belt reminder light
*4
(  P.422)
(RX450hL)
Rear passengers’ seat
belt reminder
light
*4( P.422)
Tire pressure warning light
*1
(  P.422)
(orange)
LTA indicator ( P.422)
(flashes)
Intuitive parking assist OFF indi-
cator
*1 (if equipped) ( P.423)
(flashes)
RCTA OFF indicator*1 (if
equipped) ( P.423)
(flashes)
PKSB OFF indicator*1 (if
equipped) ( P.423)
(flashes or
illuminates)PCS warning light*1 (  P.424)
Slip indicator
*1 (  P.424)
(flashes)
(U.S.A.)
Parking brake indicator
(  P.424)

832-1. Instrument cluster
2
Vehicle status information and indicators
■Locations of gauges and meters
Except F SPORT models
The units used on the meters may differ depending on the target region.
Engine coolant temperature gauge
Displays the engine coolant temperature
Hybrid System Indicator
Displays hybrid system output or regeneration level (P.85)
This display changes to a tachometer depending on the drive mode, and can be set to show
the tachometer in any drive mode on the settings display. ( P.92, 281)
Outside temperature
Displays the outside temperature within the range of -40°F (-40°C) to 122°F (50°C). Low
outside temperature indicator comes on when the ambient temperature is 37°F (3°C) or
lower.
Multi-information display
Presents the driver with a variety of vehicle data ( P.88)
Displays warning messages in case of a malfunction (P.428)
Clock
Time displayed is linked to the analog clock on the instrument panel. (P.343)
Speedometer
Fuel gauge
Displays the quantity of fuel remaining in the tank
Gauges and meters
Meter display
A
B
C
D
E
F
G

842-1. Instrument cluster
Shift position display (P.191)
Odometer and trip meter display ( P.87)
F SPORT models
The units used on the meters may differ depending on the target region.
Outside temperature
Displays the outside temperature within the range of -40°F (-40°C) to 122°F (50°C). Low
outside temperature indicator comes on when the ambient temperature is 37°F (3°C) or
lower.
Multi-information display
Presents the driver with a variety of vehicle data ( P.88)
Displays warning messages in case of a malfunction (P.428)
Hybrid System Indicator
Displays hybrid system outp ut or regeneration level (P.85)
This display changes to a tachometer depending on the drive mode, and can be set to show
the tachometer in any drive mode on the settings display. ( P.92, 281)
Speedometer
Engine coolant temperature gauge
Displays the engine coolant temperature
Fuel gauge
Displays the quantity of fuel remaining in the tank
Shift position display ( P.191)
Odometer and trip meter display ( P.87)
Clock
Time displayed is linked to the analog clock on the instrument panel. (P.343)
H
I
A
B
C
D
E
F
G
H
I

872-1. Instrument cluster
2
Vehicle status information and indicators
■Display items
 Odometer
Displays the total distance the vehicle has
been driven.
Trip meter A/trip meter B
Displays the distance the vehicle has been
driven since the meter was last reset. Trip
meters A and B can be used to record and
display different distances independently.
 Distance until next engine oil
change
Displays the distance the vehicle can be
driven until an oil change is necessary.
■Changing the display
Each time the “ODO TRIP” switch is
pressed, the displayed item will be changed. When the trip meter is dis-
played, pressing and holding the switch
will reset the trip meter.
■Pop-up display
Distance until next engine oil change
Displays the distance until the next engine
oil change. This display will be displayed in
the following situations:
 When the power switch is turned to
ON mode.
 When a warning message indicating
that oil maintenance should be per-
formed soon or is required is dis-
played.
The brightness of the instrument panel
lights can be adjusted.
If the brightness is adjusted when the sur-
roundings are bright and the tail lights are
on (day mode bright ness adjustment), the
brightness level of night mode will be
adjusted at the same time.
WARNING
For example, there is a lag between the
driver’s shifting and the new gear number
appearing on the display. This lag could
cause the driver to downshift again,
causing rapid and excessive engine brak-
ing and possibly an accident resulting in
death or injury.
NOTICE
■To prevent damage to the engine and
its components
●Do not let the indicator needle of the
tachometer enter the red zone, which
indicates the maximum engine speed.
●The engine may be overheating if the
engine coolant temperature gauge is
in the red zone (H). In this case, imme-
diately stop the vehicle in a safe place,
and check the engine after it has
cooled completely. ( P.454)
Odometer and trip meter dis-
play
Changing the instrument panel
light brightness

1824-1. Before driving
frequently. This could cause the
brakes to overheat and result in
reduced braking efficiency.
 Due to the added load of the trailer,
your vehicle’s engine may overheat
on hot days (at temperatures over
85°F [30°C]) when driving up a
long or steep grade. If the engine
coolant temperature gauge indi-
cates overheating, immediately turn
off the air conditioning (if in use),
pull your vehicle off the road and
stop in a safe spot. ( P.454)
 Always place wheel blocks under
both the vehicle’s and the trailer’s
wheels when parking. Put the trans-
mission in P and apply the parking
brake. Avoid parking on a slope, but
if unavoidable, do so only after per-
forming the following:
1 Apply the brakes and keep them
applied.
2 Have someone place wheel blocks
under both the vehicle’s and trailer’s
wheels.
3 When the wheel blocks are in
place, release the brakes slowly
until the blocks absorb the load.
4 Shift into P and apply the parking
brake.
5 Turn off the hybrid system.
 When restarting after parking on a
slope:
1 With the transmission in P, start the
hybrid system. Be sure to keep the
brake pedal depressed. 2
Shift into a forward gear. If revers-
ing, shift into R.
3 If the parking brake is in manual
mode, release the parking brake.
(P.195)
4 Release the brake pedal, and slowly
pull or back away from the wheel
blocks. Stop and apply the brakes.
5 Have someone retrieve the blocks.

2914-6. Driving tips
4
Driving
Use fluids that are appropriate to
the prevailing outside temperatures.
•Engine oil
• Engine/power control unit coolant
•Washer fluid
Have a service technician inspect
the condition of the 12-volt battery.
 Have the vehicle fitted with four
snow tires or purchase a set of tire
chains for the front tires.
Ensure that all tires ar e of the specified size
and the same brand, and that chains match
the size of the tires.
Perform the following according to the
driving conditions:
 Do not try to forcibly open a window
or move a wiper that is frozen. Pour
warm water over the frozen area to
melt the ice. Wipe away the water
Winter driving tips
Carry out the necessary prepara-
tions and inspections before driving
the vehicle in winter. Always drive
the vehicle in a manner appropriate
to the prevailing weather condi-
tions.
Pre-winter preparations
WARNING
■Driving with snow tires
Observe the following precautions to
reduce the risk of accidents.
Failure to do so may result in a loss of
vehicle control and cause death or seri-
ous injury.
●Use tires of the specified size.
●Maintain the recommended level of air
pressure.
●Do not drive in excess of 75 mph (120
km/h), regardless of the type of snow
tires being used.
●Use snow tires on all, not just some
wheels.
■Driving with tire chains
Observe the following precautions to
reduce the risk of accidents.
Failure to do so may result in the vehicle
being unable to be driven safely, and may
cause death or serious injury.
●Do not drive in excess of the speed
limit specified for the tire chains being
used, or 30 mph (50 km/h), which-
ever is lower.
●Avoid driving on bumpy road surfaces
or over potholes.
●Avoid sudden acceleration, abrupt
steering, sudden br aking and shifting
operations that cause sudden engine
braking.
●Slow down sufficiently before entering
a curve to ensure that vehicle control is
maintained.
●Do not use the LTA (Lane Tracing
Assist) system.
NOTICE
■Repairing or replacing snow tires
Request repairs or replacement of snow
tires from your Lexus dealer or legitimate
tire retailers.
This is because the removal and attach-
ment of snow tires affects the operation
of the tire pressure warning valves and
transmitters.
Before driving the vehicle

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.

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

4177-2. Steps to take in an emergency
7
When trouble arises
Fluid leaks under the vehicle
(Water dripping from the air condi-
tioning after use is normal.)
 Flat-looking tires or uneven tire
wear
 Engine coolant temperature gauge
needle continually points higher
than normal
 Changes in exhaust sound
 Excessive tire squeal when corner-
ing
 Strange noises related to the sus-
pension system
 Pinging or other noises related to
the hybrid system
 Engine missing, stumbling or run-
ning roughly
 Appreciable loss of power
 Vehicle pulls heavily to one side
when braking 
Vehicle pulls heavily to one side
when driving on a level road
 Loss of brake effectiveness, spongy
feeling, pedal almost touches the
floor
If you think something is
wrong
If you notice any of the following
symptoms, your vehicle probably
needs adjustment or repair. Con-
tact your Lexus dealer as soon as
possible.
Visible symptoms
Audible symptoms
Operational symptoms

4187-2. Steps to take in an emergency
■Brake system warning light
■Brake system warning light
■High coolant temperature warning light* (warning buzzer)
*: This light illuminates on the multi-information display.
If a warning light turns on or a warning buzzer sounds
Calmly perform the following actions if any of the warning lights comes on or
flashes. If a light comes on or flashes, bu t then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspected by your Lexus dealer.
Actions to the warning lights or warning buzzers
Warning lightDetails/Actions
(U.S.A.)
or
(red)
(Canada)
Indicates that:
 The brake fluid level is low; or
 The brake system is malfunctioning
 Immediately stop the vehicle in a safe place and contact your Lexus
dealer. Continuing to drive the vehicle may be dangerous.
Warning lightDetails/Actions
(yellow)
Indicates a malfunction in:
 The regenerative braking system;
 The electronically controlled brake system; or
 The electric parking brake
 Have the vehicle inspected by your Lexus dealer immediately.
Warning lightDetails/Actions
Indicates that the engine coolant temperature is too high
Immediately stop the vehicle in a safe place.
Handling method ( P.454)