Page 403 of 604

4036-3. Do-it-yourself maintenance
HIGHLANDER_HV_U (OM48F02U)
6
Maintenance and care
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the hybrid system is cold.
Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line.
Power control unit coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line.
■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% deion-
ized water. (Minimum temperature: -31 F [-35 C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deion-
ized water. (Minimum temperature: -44 F [-42 C])
For more details about coolant, contact 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 system.
Coolant
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Page 404 of 604

4046-3. Do-it-yourself maintenance
HIGHLANDER_HV_U (OM48F02U)
Check the radiator and condenser and clear away any foreign objects.
If any of the above parts is extremel y dirty or you are not sure of their
condition, have your vehicle insp ected by your Toyota dealer.
WARNING
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps.
The cooling system may be under pressure and may spray hot coolant 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.
Radiator and condenser
WARNING
■When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause seri\
-
ous injuries, such as burns.
Page 456 of 604
4567-2. Steps to take in an emergency
HIGHLANDER_HV_U (OM48F02U)
●Fluid leaks under the vehicle.
(Water dripping from the air co nditioning 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 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 side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, spon gy feeling, pedal almost touches
the floor
If you think something is wrong
If you notice any of the follow ing symptoms, your vehicle proba-
bly needs adjustment or repair. Contact your Toyota dealer as
soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms
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4737-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER_HV_U (OM48F02U)
Color display only
Indicates that the engine coolant temperature is
too highA buzzer also sounds.
P. 521
Color display onlyIndicates a malfunction in the vehicle’s charging
system
Immediately stop the vehicle in a safe place
and contact your Toyota dealer. Continuing
to drive the vehicle may be dangerous.
Color display only
(If equipped)
Indicates that the radar sensor is dirty or covered
with ice A buzzer also sounds.
Clean the sensor.
Color display only
(If equipped)
Indicates that the dynamic radar cruise control
system is unable to judge vehicle-to-vehicle dis-
tance
A buzzer also sounds.
Turn off snow mode.
If the windshield wipers are on, turn them
off or set them to a mode other than high
speed wiper operation.
(If equipped)
Indicates that the LDA (Lane Departure Alert)
system is suspended (The camera sensor tem-
perature is higher than the operation temperature
range)
A buzzer also sounds.
Restart the LDA after driving for a while.
(If equipped)
Indicates that a Blind Spot Monitor sensor or the
surrounding area on the bumper is dirty or cov-
ered with ice
A buzzer also sounds.
Clean the sensor and its surrounding area
on the bumper.
Warning messageDetails/Actions
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5217-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER_HV_U (OM48F02U)
●The needle of the engine coolant temperature gauge ( P. 103)
enters the red zone or a loss of hybrid system power is experi-
enced. (For example, the vehicle speed does not increase.)
● “Hybrid System Overh eat” is shown on the multi-information dis-
play.
● Steam comes out from under the hood.
■If the needle of the engine coolant temperature gauge enters
the red zone
Stop the vehicle in a safe place and turn off the air conditioning
system, and then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has
cooled down sufficiently,
inspect the hoses and radia-
tor core (radiator) for any
leaks.Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact
your Toyota dealer.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
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Page 522 of 604
5227-2. Steps to take in an emergency
HIGHLANDER_HV_U (OM48F02U)
The coolant level is satisfac-
tory if it is between the
“FULL” and “LOW” lines on
the reservoir.Reservoir
“FULL”
“LOW”
Radiator cap
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fans operate and to check for
coolant leaks from th e radiator or hoses.
The fans operate when the air conditioning system is turned on immedi-
ately after a cold start. Confirm that the fans are operating by checking
the fan sound and air flow. If it is difficult to check these, turn the air con-
ditioning system on and off repeatedly.
(The fan may not operate in freezing temperatures.)
If the fans are not operating:
Stop the hybrid system immediately and contact your Toyota
dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Toyota dealer.
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Page 523 of 604
5237-2. Steps to take in an emergency
7
When trouble arises
HIGHLANDER_HV_U (OM48F02U)■
If “Hybrid System Overheat” is shown on the multi-information
display
Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has
cooled down, inspect the
hoses and radiator core
(radiator) for any leaks.Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact
your Toyota dealer.
The coolant level is satisfac-
tory if it is between the
“FULL” and “LOW” lines on
the reservoir.Reservoir
“FULL”
“LOW”
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and check 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:
Have the vehicle in spected at the nearest Toyota dealer.
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Page 524 of 604

5247-2. Steps to take in an emergency
HIGHLANDER_HV_U (OM48F02U)
■Messages displays
The message illustrations used are intended as examples, and may differ
from the image that is actually displayed on the multi-information display.
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 compartment may be very hot.
● After the hybrid system has been turned off, check that the “READY” indi-
cator are off.
When the hybrid system is operating, the gasoline engine may automati-
cally start, or the cooling 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 precautions:
● Avoid contaminating the coolant with foreign matter (such as sand or dust
etc.).
● Do not use any coolant additive.