2023 TOYOTA HIGHLANDER HYBRID radiator

3886-2. Maintenance
General maintenance
Listed below are the general
maintenance items that
should be performed at the
intervals specified in the
“Owner’s Warranty Informa-
tion Booklet” or “Owner’s
Manual Supplement/Sched-
uled Maintenance Guide”. It
is recommended that any
problem you notice should
be brought to the attention
of your Toyota dealer or
qualified service shop for
advice.
WARNING
■If the hybrid system is operat-
ing
Turn the hybrid system off and
ensure that there is adequate
ventilation before performing
maintenance checks.
Engine compartment
ItemsCheck points
Brake fluid
Is the brake fluid at
the correct level?
(  P.400)
Engine/power
control unit
coolant
Is the
engine/power con-
trol unit coolant at
the correct level?
( P.399)
Engine oil
Is the engine oil at
the correct level?
( P.396)
Exhaust sys-
temThere should not
be any fumes or
strange sounds.
Radiator/con-
denser
The radiator and
condenser should
be free from for-
eign objects.
( P.400)
Washer fluid
Is there sufficient
washer fluid?
( P.401)
Luggage compartment
ItemsCheck points
12-volt batteryCheck the connec-
tions. ( P.402)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator
pedal should
move smoothly
(without uneven
pedal effort or
catching).
Hybrid trans-
mission “Park”
mechanism
• When parked on a slope and the
shift lever is in P,
is the vehicle
securely
stopped?
ItemsCheck points

3936-3. Do-it-yourself maintenance
6
Maintenance and care
Hybrid battery
(traction bat-
tery) air intake
vent (P.420)• Vacuum cleaner,
etc.
• Phillips screw- driver
Headlight aim
( P.427)• Phillips-head
screwdriver
Light bulbs
( P.428)
• Bulb with same
number and
wattage rating as
original
• Phillips-head screwdriver
• Flathead screw- driver
• Wrench
Radiator and
condenser
(  P.400)

Tire inflation
pressure
( P.415)• Tire pressure
gauge
• Compressed air source
Washer fluid
( P.401)
• Water or washer
fluid containing
antifreeze (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 electrically energized.
To avoid death or serious injury,
observe the following precautions.
ItemsParts and tools■When working on the engine
compartment
●Make sure that the “ACCES-
SORY” or “IGNITION ON” on
the multi-information display
and the “READY” indicator are
both off.
●Be careful not to touch the
engine, power control unit, radi-
ator, exhaust manifold, etc. right
after driving as they may be hot.
Oil and other fluids may also be
hot.
●Do not leave anything that may
burn easily, such as paper and
rags, in the engine compart-
ment.
●Do not smoke, cause sparks or
expose an open flame to fuel.
Fuel fumes are flammable.
■When working near the elec-
tric cooling fan or radiator
grille
Be sure the power switch is off.
With the power switch in ON, the
electric cooling fa n may automati-
cally start to run if the air condi-
tioning is on and/or the coolant
temperature is high. ( P.400)
■Safety glasses
Wear safety glasses to prevent
flying or falling material, fluid
spray, etc. from getting 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.

3966-3. Do-it-yourself maintenance
Engine coolant reservoir ( P.399)
Fuse boxes ( P.425)
Engine oil filler cap ( P.397)
Engine oil level dipstick ( P.397)
Brake fluid reservoir ( P.400)
Washer fluid tank ( P.401)
Electric cooling fan
Condenser ( P.400)
Radiator ( P.400)
Power control unit coolant reservoir ( P.399)
■12-volt battery
 P. 4 0 2
With the engine at operating
temperature and turned off,
check the oil level on the dip-
Engine compar tment
Components
Checking and adding the
engine oil

4006-3. Do-it-yourself maintenance
For more details about coolant, con-
tact your Toyota 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
Toyota dealer test the cap and
check for leaks in the cooling sys-
tem.
Check the radiator and con-
denser and clear away any for-
eign 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 Toyota 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
SAE J1704 or FMVSS No.116 DOT
4 brake fluid
Item
Clean funnel
WARNING
■When the hybrid system is
hot
Do not remove the engine/power
control unit coolant reservoir caps
and radiator cap.
The cooling system may be under
pressure and may spray hot cool-
ant 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
prevent it from d amaging parts or
paint.
Checking the radiator and
condenser
WARNING
■When the hybrid system is
hot
Do not touch the radiator or con-
denser as they may be hot and
cause serious injuries, such as
burns.
Checking and adding the
brake fluid

4857-2. Steps to take in an emergency
7
When trouble arises
the steam subsides.
If you do not see steam:
Carefully lift the hood.
3 After the hybrid system has
cooled down sufficiently,
inspect the hoses and radia-
tor core (radiator) for any
leaks.
Radiator
Cooling fan
If a large amount of coolant leaks,
immediately cont act your Toyota
dealer.
4 The coolant level is satisfac-
tory 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 emer-
gency if coolant is unavailable.
6Start the hybrid system and
turn the air conditioning sys-
tem on to check that the radi-
ator cooling fan operates and
to check for coolant leaks
from the radiator or hoses.
The fan operates when the air con-
ditioning system is turned on imme-
diately after a cold start. Confirm
that the fan is operating by check-
ing the fan sound and air flow. If it is
difficult to check these, turn the air
conditioning system on and off
repeatedly. (The fan may not oper-
ate in freezing temperatures.)
7If the fan is not operating:
Stop the hybrid system
immediately and contact your
Toyota dealer.
If the fan is operating:
Have the vehicle inspected at
the nearest Toyota dealer.
8 Check if “Engine Coolant
Temp High Stop in a Safe
Place See Owner's Manual”
is shown on the multi-infor-
mation display.
If the message does not disappear:
Stop the hybrid system and contact

4867-2. Steps to take in an emergency
your Toyota dealer.
If the message is not displayed:
Have the vehicle inspected at the
nearest Toyota dealer.
If “Hybrid System Over-
heated Output Power
Reduced” is shown on the
multi-information display
1 Stop the vehicle in a safe
place.
2 Stop the hybrid system and
carefully lift the hood.
3 After the hybrid system has
cooled down, inspect the
hoses and radiator core (radi-
ator) for any leaks.
Radiator
Cooling fan
If a large amount of coolant leaks,
immediately cont act your Toyota
dealer.
4 The coolant level is satisfac-
tory 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 emer-
gency if coolant is unavailable.
6After stopping the hybrid sys-
tem and waiting for 5 minutes
or more, start the hybrid sys-
tem again and check if
“Hybrid System Overheated
Output Power Reduced” is
shown on the for the
multi-information display.
If the message does not disappear:
Stop the hybrid system and contact
your Toyota dealer.
If the message is not displayed:
The hybrid system temperature has
dropped and the vehicle may be
driven normally.

4877-2. Steps to take in an emergency
7
When trouble arises
However, if the message appears
again frequently, contact your Toy-
ota dealer.
WARNING
■When inspecting under the
hood of your vehicle
Observe the following precau-
tions.
Failure to do so may result in seri-
ous injury such as burns.
●If steam is seen coming from
under the hood, do not open the
hood until the steam has sub-
sided. The engine compart-
ment may be very hot.
●After the hybrid system has
been turned off, check that the
“READY” indicator is off.
When the hybrid system is oper-
ating, the gasoline engine may
automatically start, or the cool-
ing fan may suddenly operate
even if the gasoline engine
stops. Do not touch or approach
rotating parts such as the fan,
which may lead to fingers or
clothing (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 system 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 system
Observe the following precau-
tions:
●Avoid contaminating the coolant
with foreign matter (such as
sand or dust, etc.).
●Do not use any coolant additive.

549Alphabetical Index
Parking lightsLight switch .......................... 223
Replacing light bulbs ............ 428
Parking Support Brake function (for rear-crossing vehicles) . 307Function ............................... 307
Parking Support Brake function (static objects) ...................... 304Function ............................... 304
PCS (Pre-Collision System) Function ............................... 242
PCS OFF switch................... 245
Warning light ........................ 451
Personal lights ....................... 343
PKSB (Parking Support Brake) ............................................... 297Warning message ................ 303
Power control unit .................... 73
Power control unit coolant Capacity ............................... 493
Checking .............................. 399
Preparing and c hecking before
winter.................................. 320
Power outlets .................. 363, 364
Power steering (Electric power steering system)................... 312Warning light ........................ 448
Power switch .......................... 207 Auto power off function ........ 210
Changing the power switch modes ................................ 209
Power switch ( engine switch)
If your vehicle has to be stopped in an emergency................. 438
Power windows Door lock linked window opera-tion ..................................... 174
Jam protection function ........ 173
Operation ............................. 173
Window lock switch .............. 175
Pre-Collision System (PCS) Function ............................... 242 PCS OFF switch ...................245
Warning light.........................451
Predictive deceleration support .................................................72
Predictive SOC control ............72
R
Radar cruise control (dynamic radar cruise control with
full-speed range)...................263
Radiator ...................................400
RCTA Function................................291
Warning message.................292
RCTA function .........................292
Rear automatic air conditioning system ...................................337
Rear Cross Traffic Alert (RCTA) ...............................................291
Rear door sunshades .............369
Rear seats ...............................148 Head restraints .....................156
Seat heaters ....... ..................341
Rear side marker lights Light switch...........................223
Replacing light bulbs ............428
Rear turn signal lights Replacing light bulbs ............428
Turn signal lever ...................216
Rear view mirror Digital Rearview Mirror .........161
Inside rear view mirror ..........160
Outside rear view mirrors .....171
Rear window defogger ...........330
Refueling Capacity ...............................491
Fuel types .............................491
If the fuel filler door cannot be opened ...............................476
Opening the fuel tank cap ....234
Regenerative braking ...............70