2023 TOYOTA SIENNA HYBRID coolant level

3444-6. Driving tips
Use fluids that are appropriate
to the prevailing outside tem-
peratures.
• Engine oil
• Engine coolant
• Power control unit coolant
• Washer fluid
Have a service technician
inspect the condition of the
12-volt battery.
 Have the vehicle fitted with
four snow tires or purchase a
set of tire chains for the front
tires.
*
Ensure that all tires are the same
size and brand, and that chains
match the size of the tires.
*: Tire chains cannot be mounted
on vehicles with 20-inch tires.
Winter driving tips
Carry out the necessary
preparations and inspec-
tions before driving the
vehicle in winter. Always
drive the vehicle in a man-
ner appropriate to the pre-
vailing weather conditions.
Pre-winter preparations
WARNING
■Driving with snow tires
Observe the following precautions
to reduce the risk of accidents.
Failure to do so may result in a
loss of vehicle control and cause
death or serious injury.
●Use tires of the specified size.
●Maintain the recommended
level of air pressure.
●Do not drive in excess of 75
mph (120 km/h), regardless of
the type of snow tires being
used.
●Use snow tires on all, not just
some wheels.
■Driving with tire chains (vehi-
cles with 17-inch or 18-inch
tires)
Observe the following precautions
to reduce the risk of accidents.
Failure to do so may result in the
vehicle being unable to be driven
safely, and may cause death or
serious injury.
●Do not drive in excess of the
speed limit specifi ed for the tire
chains being used, or 30 mph
(50 km/h), whichever is lower.
●Avoid driving on bumpy road
surfaces or over potholes.
●Avoid sudden acceleration,
abrupt steering, sudden brak-
ing and shifting operations that
cause sudden engine braking.
●Slow down sufficiently before
entering a curve to ensure that
vehicle control is maintained.
●Do not use LTA (Lane Tracing
Assist) system.

4046-2. Maintenance
General maintenance
Listed below are the general
maintenance items that
should be performed at the
intervals specified in the
“Owner’s Warranty Informa-
tion Booklet” or “Owner’s
Manual Supplement/Sched-
uled Maintenance Guide”. It
is recommended that any
problem you notice should
be brought to the attention
of your Toyota dealer or
qualified service shop for
advice.
WARNING
■If the hybrid system is run-
ning
Turn the hybrid system off and
ensure that there is adequate
ventilation before performing
maintenance checks.
Engine compartment
ItemsCheck points
Brake fluid
Is the brake fluid at
the correct level?
(  P.417)
Engine/power
control unit
coolant
Is the
engine/power con-
trol unit coolant at
the correct level?
( P.416)
Engine oil
Is the engine oil at
the correct level?
( P.413)
Exhaust sys-
temThere should not
be any fumes or
strange sounds.
Radiator/con-
denser
The radiator and
condenser should
be free from for-
eign objects.
( P.417)
Washer fluid
Is there sufficient
washer fluid?
( P.418)
Luggage compartment
ItemsCheck points
12-volt batteryCheck the connec-
tions. ( P.419)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator
pedal should
move smoothly
(without uneven
pedal effort or
catching).
Hybrid trans-
mission “Park”
mechanism
• When parked on a slope and the
shift lever is in P,
is the vehicle
securely
stopped?
ItemsCheck points

4086-3. Do-it-yourself maintenance
6-3.Do-it-yourself maintenance
Do-it-yourself service
precautions
If you perform maintenance
by yourself, be sure to fol-
low the correct procedure
as given in these sections.
Maintenance
ItemsParts and tools
12-volt bat-
tery condi-
tion
( P.419)•Grease
• Conventional
wrench (for termi-
nal clamp bolts)
Brake fluid
level
( P.417)
• FMVSS No.116
DOT 3 or SAE
J1703 brake fluid
• FMVSS No.116 DOT 4 or SAE
J1704 brake fluid
• Rag or paper towel
• Funnel (used only for adding brake
fluid)
Engine/power
control unit
coolant level
( P.416)
• “Toyota Super
Long Life Cool-
ant” or a similar
high quality eth-
ylene glycol-based
non-silicate, non-
amine, non-nitrite
and non-borate
coolant with long-
life hybrid organic
acid technology
For the U.S.A.:
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 50% coolant
and 50% deion-
ized water.
For Canada:
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 55% coolant
and 45% deion-
ized water.
• Funnel (used only for adding coolant)
Engine oil
level
( P.413)
• “Toyota Genuine
Motor Oil” or
equivalent
• Rag or paper towel
• Funnel (used only for adding engine
oil)
Fuses
( P.446)• Fuse with same
amperage rating
as original
ItemsParts and tools

4136-3. Do-it-yourself maintenance
6
Maintenance and care
Fuse box (P.446)
Engine oil filler cap ( P.414)
Engine oil level dipstick ( P.413)
Brake fluid reservoir ( P.417)
Radiator ( P.417)
Electric cooling fan
Condenser ( P.417)
Power control unit coolant reservoir ( P.416)
Washer fluid tank ( P.418)
Engine coolant reservoir ( P.416)
■12-volt battery
 P.419
With the engine at operating
temperature and turned off,
Engine compartment
Components
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B
C
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E
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4166-3. Do-it-yourself maintenance
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. ( P.509)
■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. ( P.510)
■Coolant selection
Only use “Toyota Super Long Life
Coolant” or a similar high quality
ethylene glycol ba sed 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% c oolant 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 radiators, 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
NOTICE
●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
A
B
C
A
B
C

4176-3. Do-it-yourself maintenance
6
Maintenance and care
check for leaks in the cooling sys-
tem.
Check the radiator and con-
denser, and clear away any for-
eign 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.
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
lines on the tank.
■Adding fluid
Make sure to check the fluid
type and prepare the necessary
item.
 Fluid type
FMVSS No.116 DOT 3 or SAE
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 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
B e s ur e t o wa sh it o ff w ith w at er to
prevent it from d amaging parts or
paint.
Checking the radiator and
condenser
WARNING
■When the hybrid system is
hot
Do not touch the radiator or con-
denser as they may be hot and
cause serious injuries, such as
burns.
■When the electric cooling fan
is operating
Do not touch the engine compart-
ment.
With the power switch in ON, the
electric cooling fa n may automati-
cally start to run if the air condi-
tioning is on and/or the coolant
temperature is high. Be sure the
power switch is OFF when work-
ing near the electric cooling fan or
radiator grille.
Checking and adding the
brake fluid

4637-2. Steps to take in an emergency
7
When trouble arises
Fluid leaks under the vehicle
(Water dripping from the air
conditioning after use or drip-
ping from the muffler 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
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 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

5097-2. Steps to take in an emergency
7
When trouble arises
■If the engine coolant tem-
perature gauge enters the
red zone or “Engine Cool-
ant Temp High Stop in a
Safe Place See Owner’s
Manual” is shown on the
multi-information 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
If your vehicle over-
heats
The following may indicate
that your vehicle is over-
heating.
The needle of the engine
coolant temperature gauge
( P.97, 101) 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 dis-
play.
Steam comes out from
under the hood.
Correction procedures
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B
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B