2021 TOYOTA AVALON HYBRID cooling

4036-3. Do-it-yourself maintenance
6
Maintenance and care
Engine compartment
Fuse boxes (P. 442)
Engine oil filler cap (P. 405)
Engine oil level dipstick
(P. 404)
Brake fluid reservoir
(P. 409)
Radiator (P. 408)Electric cooling fan
Condenser (P. 408)
Power control unit
coolant reservoir (P. 407)
Engine coolant reservoir
(P. 407)
Washer fluid tank (P. 410)1
2
3
4
5
6
7
8
9
10

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.

4346-3. Do-it-yourself maintenance
Remove the dust from the air
intake vent with a vacuum
cleaner, etc.
Make sure to only use a vacuum to
suck out dust and clogs. Attempt-
ing to blow out dust and clogs
using an airgun, etc. may push it
into the air intake vent. (P. 4 3 8 )
If dust and clogs cannot be completely removed with the air intake
vent cover installed, remove the cover and clean the filter.
Turn the power switch off.
Using a Phillips screwdriver,
remove the clip.
Cleaning the hybrid batter y (traction bat-
ter y) air intake vent and filter
To prevent the fuel economy from being affected, visually
inspect the hybrid battery (traction battery) air intake vent peri-
odically for dust and clogs. If it is dusty or clogged or if “Mainte-
nance Required for Traction Battery Cooling Parts See Owner’s
Manual” is displayed on the multi-information display, clean the
air intake vent using the following procedures:
Cleaning the air intake vent
If dust and clogs cannot be completely removed
1
2

4376-3. Do-it-yourself maintenance
6
Maintenance and care
■Scheduled maintenance of the air intake vent is necessary when
In some situations such as when the vehicle is used frequently or in heavy
traffic or dusty areas, the air intake vent may need to be cleaned more regu-
larly. For details, refer to “Schedule maintenance guide” or “Owner’s Manual
Supplement”.
■Cleaning the air intake vent
●Dust in the air intake vent may interfere with the cooling of the hybrid battery
(traction battery). If charging/discharging of the hybrid battery (traction bat-
tery) becomes limited, the distance that the vehicle can be driven using the
electric motor (traction motor) may be reduced and the fuel economy may
be reduced.
●Improper handling of the air intake vent cover and filter may result in dam-
age to them. If you have any concerns about cleaning the filter, contact your
Toyota dealer.
■If “Maintenance Required for Traction Battery Cooling Parts See Owner’s
Manual” is displayed on the multi-information display
●If this warning message is displayed on the multi-information display,
remove the air intake vent cover and clean the filter. (P. 434)
●After cleaning the air intake vent, start the hybrid system and check that the
warning message is no longer displayed.
It may take approximately 20 minutes after the hybrid system is started until
the warning message disappears. If the warning message does not disap-
pear, have the vehicle inspected by your Toyota dealer.
WARNING
■When cleaning the air intake vent
●Do not use water or other liquids to clean the air intake vent. If water is
applied to the hybrid battery (traction battery) or other components, a mal-
function or fire may occur.
●Before cleaning the air intake vent, make sure to turn the power switch off
to stop the hybrid system.
■
When removing the air intake vent cover
Do not touch the service plug located near the air intake vent. (P. 82)

4386-3. Do-it-yourself maintenance
NOTICE
■When cleaning the air intake vent
■To prevent damage to the vehicle
●Do not allow water or foreign matter to enter the air intake vent when the
cover is removed.
●Carefully handle the removed filter so that it will not be damaged.
If the filter is damaged, have it replaced with a new filter by your Toyota
dealer.
●Make sure to reinstall the filter and cover to their original positions after
cleaning.
●Do not install anything to the air intake vent other than the exclusive filter
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■If “Maintenance Required for Traction Battery Cooling Parts See
Owner’s Manual” is displayed on the multi-information display
If the vehicle is continuously driven with the warning message (indicating
that charging/discharging of the hybrid battery (traction battery) may
become limited) displayed, the hybrid battery (traction battery) may mal-
function. If a warning message is displayed, clean the air intake vent imme-
diately.
When cleaning the air intake vent, make
sure to only use a vacuum to suck out
dust and clogs. If a compressed air blow
gun, etc. is used to blow out dust and
clogs, the dust or clogs may be pushed
into the air intake vent, which may affect
the performance of the hybrid battery
(traction battery) and cause a malfunc-
tion.

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)

4687-2. Steps to take in an emergency
■If “Hybrid System Overheated Output Power Reduced” is shown
This message may be displayed when driving under severe operating condi-
tions. (For example, when driving up a long steep hill.)
Handling method: P. 494
■If “Maintenance Required for Traction Battery Cooling Parts See Owner’s
Manual” is shown
The filter may be clogged, the air intake vent may be blocked or there may be
a gap in the duct.
●If the air intake vent or filter is dirty, refer to P. 434 for cleaning the air intake
vent and filter.
●If the message is being displayed and the air intake vent and filter are not
dirty, have the vehicle inspected at your Toyota dealer.
■If “Traction Battery Needs to be Protected Refrain From the Use of N
Position” is shown
This message may be displayed when the shift lever is in N.
As the hybrid battery (traction battery) cannot be charged when the shift lever
is in N, shift the shift lever to P when the vehicle is stopped.
■If “Traction Battery Needs to be Protected Shift into P to Restart” is
shown
This message is displayed when the hybrid battery (traction battery) charge
has become extremely low because the shift lever has been left in N for a cer-
tain amount of time.
When operating the vehicle, shift to P and restart the hybrid system.
■If “Shift to P Before Exiting Vehicle” is shown
Message is displayed when the driver’s door is opened without turning the
power switch off with the shift lever in any position other than P.
Shift the shift lever to P.
■If “Shift Is in N Release Accelerator Before Shifting” is shown
Message is displayed when the accelerator pedal has been depressed and
the shift lever is in N. Release the accelerator pedal and shift the shift lever to
D or R.
■If “Press Brake When Vehicle Is Stopped Hybrid System May Overheat”
is shown
Message is displayed when the accelerator pedal is depressed to maintain
the vehicle position when stopped on a upward slope, etc.
If this continues, the hybrid system may overheat.
Release the accelerator pedal and depress the brake pedal.

4937-2. Steps to take in an emergency
7
When trouble arises
WARNING
■When replacing the 12-volt battery
After replacing, securely attach the exhaust hose and exhaust hole plug to
the exhaust hole of the replaced 12-volt battery. If not properly installed,
gases (hydrogen) may leak into the vehicle interior, and there is the possi-
ble danger of the gas igniting and exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entan-
gled in the cooling fan or engine drive belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to be used when charging the 12-volt
battery from another vehicle in an emergency. It cannot be used to jump
start another vehicle.