2021 TOYOTA HIGHLANDER HYBRID coolant temperature

5047-2. Steps to take in an emergency
HIGHLANDER HV_U
If the engine coolant tempera-
ture gauge enters the red
zone or “Engine Coolant
Temp High Stop in a Safe
Place See Owner’s Manual”
is shown on the multi-informa-
tion display
1 Stop the vehicle in a safe
place and turn off the air con-
ditioning system, and then
stop the hybrid system.
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 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 contact your Toyota
dealer.
4The coolant level is satisfac-
tory if it is between the
“FULL” and “LOW” lines on
the reservoir.
Reservoir
“FULL” line
“LOW” line
If your vehicle over-
heats
The following may indicate
that your vehicle is over-
heating.
The needle of the engine
coolant temperature gauge
( P.89) enters the red zone
or a loss of hybrid system
power is experienced. (For
example, the vehicle speed
does not increase.)
 “Engine Coolant Temp High
Stop in a Safe Place See
Owner’s Manual” or “Hybrid
System Overheated Output
Power Reduced” is shown
on the multi-information dis-
play.
 Steam comes out from
under the hood.
Correction procedures

5057-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER HV_U
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 op erating by check-
ing the fan sound and air flow. If it is
difficult to check th ese, turn the air
conditioning system on and off
repeatedly. (The fan may not oper-
ate in freezing temperatures.)
7 If 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 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 contact your Toyota
dealer.
4The coolant level is satisfac-
tory if it is between the

5067-2. Steps to take in an emergency
HIGHLANDER HV_U
“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. However, if the m
essage 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.

5138-1. Specifications
8
Vehicle specifications
HIGHLANDER HV_U
Outside temperature
SAE 0W-16 is the best choice
for good fuel economy and good
starting in cold weather.
If SAE 0W-16 is not available,
SAE 0W-20 oil may be used.
However, it must be replaced
with SAE 0W-16 at the next oil
change.
Oil viscosity (0W-16 is explained
here as an example):
• The 0W in 0W-16 indicates the characteristic of the oil
which allows cold startability.
Oils with a lower value before the W allow for easier starting
of the engine in cold weather.
• The 16 in 0W-16 indicates the viscosity characteristic of the
oil when the oil is at high tem-
perature. An oil with a higher
viscosity (one with a higher
value) may be better suited if
the vehicle is operated at high
speeds, or under extreme
load conditions.
How to read oil container label:
API registered mark is added to
some oil containers to help you
select the oil you should use.
Cooling system
Capacity
Gasoline
engine10.5 qt. (9.9 L , 8.7 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 et hylene glycol-based
non-silicate, non -amine, non-nitrite, and
non-borate coolant with long-life hybrid organic
acid technology
Do not use pla in water alone.

5248-1. Specifications
HIGHLANDER HV_UGrade C corresponds to a level of
performance which all passenger
car tires must meet under the Fed-
eral Motor Vehicle Safety Standard
No. 109.
Grades B and A represent higher
levels of performance on the labo-
ratory test wheel
than the minimum
required by law. Warning: The temperature grades
of a tire assume tha
t it is properly
inflated and not overloaded.
Excessive speed, underinflation, or
excessive loading, either sepa-
rately or in combination, can cause
heat buildup and possible tire fail-
ure.
Glossary of tire terminology
Tire related termMeaning
Cold tire infl ation 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 pressure
The maximum cold inf lated pressure to
which a tire may be inflated, shown on the
sidewall of the tire
Recommended inflation pres-
sureCold tire inflation pressure recommended
by a manufacturer
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
hybrid transmission, power steering,
power brakes, power windows, power
seats, radio and heater, to the extent that
these items are available as fac-
tory-installed equipment (whether installed
or not)
Curb weight
The weight of a motor vehicle with stan-
dard equipment, including the maximum
capacity of fuel, oil and coolant, and if so
equipped, air conditioning and additional
weight optional engine

562Alphabetical Index
HIGHLANDER HV_UEDR (Event data recorder)......... 7
E-Four ...................................... 326
Elapsed time ..................... 96, 106
Electric motor (traction motor)71
Electric Power Steering (EPS)
............................................... 326Warning light ........................ 469
Electronic key ......................... 128 Battery-saving function......... 147
If the electronic key does not operate properly ................. 496
Replacing the battery ........... 444
Electronic roof sunshade Jam protection function ........ 186
Operation ............................. 185
Electronically Controlled Brake System (ECB) ....................... 325
Emergency flashers ............... 458
Emergency, in case of If a warning buzzer sounds .. 466
If a warning light turns on ..... 466
If a warning message is dis-played................................. 476
If the 12-volt battery is dis- charged .............................. 498
If the electronic key does not operate properly ................. 496
If the fuel filler door cannot be opened ............................... 495
If the hybrid sy stem will not start
........................................... 493
If the vehicle is trapped in rising water .................................. 459
If you have a flat tire ............. 481
If you lose your keys ............ 495
If you think something is wrong ........................................... 464
If your vehicle becomes stuck ........................................... 507
If your vehicle has to be stopped in an emergency................. 458 If your vehicle needs to be towed
...........................................461
If your vehicle ove rheats ......504
Energy monitor ....................... 117
Engine ACCESSORY mode . ............216
Compartment........................416
Engine switch .......................213
Hood .....................................414
How to start the hybrid system ...........................................213
Identification number ............ 511
If the hybrid sys tem will not start
...........................................493
If your vehicle has to be stopped in an emergency .................458
Ignition switch (power switch) ...........................................213
Overheating ..........................504
Power switch ........................213
Tachometer.............................89
Engine coolant Capacity ...............................513
Checking ..............................418
Preparing and checking before winter ..................................333
Engine coolant temperature gauge .......................................89
Engine oil Capacity ...............................512
Checking ..............................416
Preparing and checking before winter ..................................333
Warning light.........................467
Engine switch (power switch)213 If your vehicle has to be stopped in an emergency .................458
EPS (Electric Po wer Steering)
...............................................326 Warning light.........................469
EV drive mode.........................218
EV indicator...............................72

571Alphabetical Index
HIGHLANDER HV_UTraction Control (TRAC) ........ 325
Traction motor (electric motor)71
Trail Mode ............................... 323
Trailer Sway Control .............. 325
Trailer towing .......................... 201
Transmission
Driving mode select switch... 322
Hybrid transmission.............. 220
If the shift lever cannot be shifted from P................................. 221
S mode ................................. 222
Trip meters ................................ 91
Turn signal lights Replacing light bulbs ............ 449
Turn signal lever ................... 223
U
USB charging ports................ 374
V
Vanity lights ............................ 388
Vanity mirrors ......................... 388
VDIM (Vehicle Dynamics Inte-grated Management) ............ 326
Vehicle data recording ............... 6
Vehicle Dynamics Integrated Management (VDIM) ............. 326
Vehicle identifi cation number510
Vehicle information display ... 96, 106
Vehicle Stability Control (VSC) ............................................... 325
Ventilators (seat ventilators) . 358
VSC (Vehicle Stability Control) ............................................... 325
W
Warning buzzers ABS ...................................... 468
Airbags ................................. 468 Approach warning ................278
Brake hold ............................473
Brake Override System ........468
Brake system ........................466
Charging system ..................467
Downshifting .........................222
Drive-Start Control
................468
Electric power steering .........469
Engine ..................................467
Hands off steering wheel warn- ing (LTA) .............................269
High coolant temperature .....466
Hybrid system .......................467
Hybrid system overheat ........467
Intuitive parking assist .296, 299, 471
Low engine oil pressure .......467
LTA (Lane Tracing Assist) ...260, 264, 470
Open door ....................132, 134
PKSB (Parking Support Brake) ...........................................471
Pre-collision braking .............251
RCTA (Rear Cross Traffic Alert) ...........................................471
RCTA function.......................301
Seat belt .......................469, 470
Warning label ............................75
Warning lights .........................466 ABS ......................................468
Brake hold operated indicator...........................................473
Brake Override System ........468
Brake system ........................466
Charging system ..................467
Drive-Start Control ................468
Electric power steering .........469
High coolant temperature .....466
Hybrid system overheat warning light .....................................467
Intuitive parking assist OFF indi- cator ...................................471