2021 TOYOTA AVALON HYBRID engine coolant

4076-3. Do-it-yourself maintenance
6
Maintenance and care
Engine coolant reservoir
The coolant level is satisfactory if it is between the “F” and “L” lines on
the reservoir when the hybrid system is cold.
Reservoir cap
“F” line
“L” line
If the level is on or below the “L”
line, add coolant up to the “F” line.
(P. 494)
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. 494)
■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.
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deion-
ized water. (Minimum temperature: -31F [-35C])
Coolant
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4086-3. Do-it-yourself maintenance
■If the coolant level drops within a short time of replenishing
Visually check the radiators, hoses, engine/power control unit coolant reser-
voir 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.
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 condition, have your vehicle inspected by your Toyota dealer.
WARNING
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or the
radiator cap.
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.

4547-2. Steps to take in an emergency
●Fluid leaks under the vehicle.
(Water dripping from the air conditioning 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, spongy feeling, pedal almost touches
the floor
If you think something is wrong
If you notice any of the following symptoms, your vehicle proba-
bly needs adjustment or repair. Contact your Toyota dealer as
soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

4557-2. Steps to take in an emergency
7
When trouble arises
If a warning light turns 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.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
(Red)
Brake system warning light (warning buzzer)
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.
(Yellow)
Brake system warning light (warning buzzer)
Indicates a malfunction in:
• The regenerative braking system;
• The electronically controlled brake system; or
• The electric parking brake
Have the vehicle inspected by your Toyota dealer
immediately.
High coolant temperature warning light (warning
buzzer)
*1
Indicates that the engine coolant temperature is too high
Immediately stop the vehicle in a safe place.
Handling method (P. 494)
Charging system warning light*1
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Immediately stop the vehicle in a safe place and con-
tact your Toyota dealer.
Low engine oil pressure warning light (warning
buzzer)
*1
Indicates that the engine oil pressure is too low
Immediately stop the vehicle in a safe place and con-
tact your Toyota dealer.

4677-2. Steps to take in an emergency
7
When trouble arises
■Warning messages
The warning messages explained below may differ from the actual messages
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■System warning lights
The master warning light does not come on or flash in the following cases.
Instead, a separate system warning light will come on along with a message
shown on the multi-information display.
●Malfunction in the ABS
The ABS warning light comes on. (P. 456)
●Malfunction in the brake system
The brake system warning light (yellow) comes on. (P. 455)
●Malfunction in the tire pressure warning system
The tire pressure warning light comes on. (P. 458)
●Remaining fuel level is low
The low fuel level warning light comes on. (P. 458)
■If a message instructing to refer to the Owner’s Manual is displayed
●If the following messages are shown, there may be a malfunction.
Immediately stop the vehicle in a safe place and contact your Toyota dealer.
Continuing to drive the vehicle may be dangerous.
• “Low Braking Power 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 Man-
ual”
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Immediately have the vehicle inspected by your Toyota dealer.
• “Hybrid System Malfunction”
• “Check Engine”
• “Hybrid Battery System Malfunction”
• “Accelerator System Malfunction”
• “Smart Key System Malfunction”
●If “Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
displayed, follow the instructions accordingly. (P. 494)
●If “Maintenance Required for Traction Battery Cooling Parts See Owner’s
Manual” is displayed, follow the instructions accordingly. (P. 434)

4947-2. Steps to take in an emergency
■If the needle of the engine coolant temperature gauge enters
the red zone or “Engine Coolant Temp High Stop in a Safe
Place See Owner’s Manual” is shown on the multi-information
display
Stop the vehicle in a safe place and turn off the air conditioning sys-
tem, 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 radiator
core (radiator) for any leaks.
Radiator
Cooling fan
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.
●The needle of the engine coolant temperature gauge (P. 98)
enters the red zone or a loss of hybrid system power is experi-
enced. (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 display
●Steam comes out from under the hood.
Correction procedures
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4977-2. Steps to take in an emergency
7
When trouble arises
After stopping the hybrid system and waiting for 5 minutes or
more, start the hybrid system again and check for 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:
The hybrid system temperature has dropped and the vehicle
may be driven normally.
However, if the message appears again frequently, contact your To y o t a
dealer.
WARNING
■To prevent an accident or injury when inspecting under the hood of
your vehicle
Observe the following precautions.
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●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 is off. When the hybrid system is operating, the gasoline engine may
automatically 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 muf-
fler) getting caught, resulting in serious injury.
●Do not loosen the radiator cap and the coolant reservoir cap while the
hybrid system and radiator are hot.
High temperature steam or coolant could spray out.
NOTICE
■When adding engine/power control unit coolant
Wait until the hybrid system has cooled down before adding engine/power
control unit coolant.
When adding coolant, do so slowly. Adding cool coolant to a hot hybrid sys-
tem 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 additives.
6

5068-1. Specifications
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
(Reference)
Gasoline engine
6.4 qt. (6.1 L, 5.4 Imp. qt.)
Power control unit
1.9 qt. (1.8 L, 1.6 Imp. qt.)
Coolant typeUse either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based
non-silicate, non-amine, non-nitrite, and
non-borate coolant with long-life hybrid
organic acid technology
Do not use plain water alone.
Ignition system
Spark plug
MakeDENSO FC16HR-Q8
Gap0.031 in. (0.8 mm)
NOTICE
■Iridium-tipped spark plugs
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