2021 TOYOTA AVALON HYBRID engine

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.

4106-3. Do-it-yourself maintenance
Add washer fluid in the following
situations:
●A washer does not work.
●“Windshield Washer Fluid Low”
is displayed on the multi-infor-
mation display.
Washer fluid
WARNING
■When adding washer fluid
Do not add washer fluid when the hybrid system is hot or operating as
washer fluid contains alcohol and may catch fire if spilled on the engine, etc.
NOTICE
■Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid.
Doing so may cause streaking on the vehicle's painted surfaces, as well as
damaging the pump leading to problems of the washer fluid not spraying.
■Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures listed on the label of the washer fluid bot-
tle.

4426-3. Do-it-yourself maintenance
Turn the power switch off.
Open the fuse box cover.
Checking and replacing fuses
If any of the electrical components do not operate, a fuse may
have blown. If this happens, check and replace the fuses as nec-
essary.
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Engine compartment (type A)Engine compartment (type B)
Push the tabs in and lift the lid off. Push the tabs in and lift the lid
off.
Under the driver’s side instru-
ment panel
Remove the lid.
Make sure to push the claw when
removing/installing the lid.

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.

4567-2. Steps to take in an emergency
Malfunction indicator lamp (warning buzzer)
Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system; or
• The electronic throttle control system; or
• The electronic hybrid transmission control system
Have the vehicle inspected by your Toyota dealer
immediately.
SRS warning light (warning buzzer)
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
Have the vehicle inspected by your Toyota dealer
immediately.
ABS warning light (warning buzzer)
Indicates a malfunction in:
• The ABS; or
• The brake assist system
Have the vehicle inspected by your Toyota dealer
immediately.
Brake Override System/Drive-Start Control/Intelligent
Clearance Sonar warning light (warning buzzer)
*1
When a buzzer sounds:
• Brake Override System is malfunctioning;
• Drive-Start Control is operating;
• Drive-Start Control is malfunctioning; or
• The Intelligent Clearance Sonar (if equipped) is operat-
ing (P. 300)
Follow the instructions displayed on the multi-infor-
mation display.
When a buzzer does not sound:
Brake Override System is operating
Release the accelerator pedal and depress the brake
pedal.
Parking brake indicator (warning buzzer)*2
It is possible that the parking brake is not fully engaged or
released
Operate the parking brake once again.
This light comes on when the parking brake is not
released. If the light turns off after the parking brake is fully
released, the system is operating normally.
Warning lightWarning light/Details/Actions

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)