2021 TOYOTA HIGHLANDER HYBRID engine coolant

4166-3. Do-it-yourself maintenance
HIGHLANDER HV_U
Engine coolant reservoir ( P.418)
Fuse boxes ( P.446)
Engine oil filler cap ( P.417)
Engine oil level dipstick ( P.417)
Brake fluid reservoir ( P.420)
Washer fluid tank ( P.420)
Electric cooling fan
Condenser ( P.419)
Radiator ( P.419)
Power control unit coolant reservoir ( P.419)
■12-volt battery
 P. 4 2 1
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

4186-3. Do-it-yourself maintenance
HIGHLANDER HV_Ube consumed while driving. In the
following situatio
ns, oil consump-
tion may increase, and engine oil
may need to be ref illed in between
oil maintenance intervals.
●When the engine is new, for
example directly after purchasing
the vehicle or after replacing the
engine
●If low quality oil or oil of an inap-
propriate viscosity is used
●When driving at high engine
speeds or with a heavy load,
when towing, or when driving
while accelerating o r decelerating
frequently
●When leaving the engine idling for
a long time, or wh en driving fre-
quently through heavy traffic
■Engine coolant reservoir
The coolant level is satisfactory
if it is between the “FULL” and
“LOW” lines on the reservoir
when the engine is cold.
WARNING
■Used engine oil
●Used engine oil contains poten-
tially harmful contaminants
which may cause skin disorders
such as inflammation and skin
cancer, so care should be taken
to avoid prolonged and
repeated contact. To remove
used engine oil from your skin,
wash thoroughly with soap and
water.
●Dispose of used oil and filters
only in a safe an d acceptable
manner. Do not dispose of used
oil and filters in household trash,
in sewers or onto the ground.
Call your Toyota dealer, service
station or auto parts store for
information concerning recy-
cling or disposal.
●Do not leave used engine oil
within the rea ch of children.
NOTICE
■To prevent serious engine
damage
Check the oil le vel on a regular
basis.
■When replacing the engine oil
●Be careful not to spill engine oil
on the vehicle components.
●Avoid overfilling, or the engine
could be damaged.
●Check the oil level on the dip-
stick every time you refill the
vehicle.
●Be sure the engine oil filler cap
is properly tightened.
■If oil is spilled on the engine
cover
To prevent the engine cover from
being damaged, remove any
engine oil from the engine cover
as soon as possible using a neu-
tral detergent. Do not use an
organic solvent such as brake
cleaner.
Checking the coolant

4196-3. Do-it-yourself maintenance
6
Maintenance and care
HIGHLANDER HV_U
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. (P.504)
■Power control unit coolant
reservoir
The coolant level is satisfactory
if it is between the “FULL” and
“LOW” lines on the reservoir
when the hybrid system 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.504)
■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 mixture of 50% coolant and 50%
deionized water. (Minimum tem-
perature: -31°F [-35°C])
Canada: “Toyota Super Long Life Coolant” is
a mixture of 55% c
oolant and 45%
deionized water. (Minimum tem-
perature: -44°F [-42°C])
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-
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 damaging parts or
paint.
Checking the radiator and
condenser

4647-2. Steps to take in an emergency
HIGHLANDER HV_U
be in good condition.
Fluid leaks under the vehicle
(Water dripping from the air
conditioning after use is nor-
mal.)
 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
cornering
 Strange noises related to the
suspension system
 Pinging or other noises
related to the hybrid system
 Engine missing, stumbling or
running roughly
 Appreciable loss of power
 Vehicle pulls heavily to one If you think something
is wrong
If you notice any of the fol-
lowing symptoms, your
vehicle probably needs
adjustment or repair. Con-
tact your Toyota dealer as
soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

4667-2. Steps to take in an emergency
HIGHLANDER HV_U
■Brake system warning light
■Brake system warning light
■High coolant temperature warning light* (warning buzzer)
*: This light illuminat es on the multi-information display.
If a war ning light tur ns on or a war ning buzzer
sounds
Calmly perform the following actions if any of the warning
lights comes on or flashes. If a light comes on or flashes, but
then goes off, this does not necessarily indicate a malfunction
in the system. However, if this continues to occur, have the
vehicle inspected by your Toyota 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 con-
tact your Toyota dealer. Continuing to drive the vehi-
cle may be dangerous.
Warning lightDetails/Actions
(yellow)
Indicates a malfunction in:
The regenerative braking system;
 The electronically contr olled brake system; or
 The electric parking brake
 Have the vehicle inspected by your Toyota 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.504)

4807-2. Steps to take in an emergency
HIGHLANDER HV_Uare shown on the multi-informa-
tion display, it may indicate a mal-
function. Immediat
ely stop the
vehicle and contact your Toyota
dealer.
• “Braking Power Low Stop in a
Safe Place See Owner's Manual”
• “Oil Pressure Low Stop in a Safe Place See Owner's Manual”
• “Charging System Malfunction Stop in a Safe Place See Owner's
Manual”
• “Stop in a Safe Place See Owner's Manual”
• “Shift to P See Owner's Manual”
●If any of the following messages
are shown on the multi-informa-
tion display, the vehicle may have
run out of fuel. Stop the vehicle in
a safe place and, if the fuel level is
low, refuel the vehicle.
• “Hybrid System Stopped”
• “Engine Stopped”
●If any of the following messages
are shown on the multi-informa-
tion display, it may indicate a mal-
function. Have the vehicle
inspected by you r Toyota dealer
immediately.
• “Hybrid System Malfunction”
• “Check Engine”
• “Hybrid Battery System Malfunc- tion”
• “Accelerator System Malfunction”
• “Smart Key System Malfunction
See Owner's Manual”
●If any of the following messages
are shown on the multi-informa-
tion display, follow the instruc-
tions.
• “Engine Coolant Temp High Stop in a Safe Place See Owner's Man-
ual” ( P.504)
• “Maintenance Required for Trac- tion Battery Cooling Parts See
Owner's Manual” ( P.441)
NOTICE
■If “High Power Consumption
Partial Limit on AC/Heater
Operation” is displayed fre-
quently
There is a possible malfunction
relating to the charging system or
the 12-volt battery may be deteri-
orating. Have the vehicle
inspected by you r Toyota dealer.

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