2023 TOYOTA TUNDRA HYBRID coolant level

3944-6. Driving tips
Owners Manual_USA_M0C052_en
Use fluids that are appropriate
to the prevailing outside tem-
peratures.
• Engine oil
• Engine/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 rear
tires
*.
*: Tire chains cannot be mounted
on 285/65R18 tires.
Ensure that all tires are the same
size and brand, and that chains
match the size of the 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.
Preparation for winter
WARNING
■Driving with snow tires
Observe the following precautions
to reduce the risk of accidents.
Failure to do so m ay 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.
●4WD models: Do not mix tires of
different makes, models, tread
patterns or treadwear.
■Driving with tire chains (vehi-
cles without 285/65R18 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) (if equipped) system.

4496-2. Maintenance
Owners Manual_USA_M0C052_en
6
Maintenance and care
■Resetting the message indicat-
ing maintenance is required
After the required maintenance is
performed according to the mainte-
nance schedule, please reset the
message.
To reset the messa ge, follow the
procedure described below:
1 Press or of meter control
switches and select on the
multi-information display.
2 Press or of meter control
switches and select “Vehicle Set-
tings”, and then press and hold
.
3 Press or of meter control
switches and select “Scheduled
Maintenance”, and then press
.
4 Select the “Yes” and press .
You can perform some mainte-
nance procedures by yourself.
Please be aware that do-it-your-
self maintenance may affect
warranty coverage.
The use of Toyota repair manuals is
recommended.
For details about warranty cover-
age, refer to the separate “Owner’s
Warranty Information Booklet” or
“Owner’s Manual Supplement”.
Do-it-yourself mainte-
nance
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 operat-
ing
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.461)
Engine/inter-
cooler/power
control unit
coolantIs the engine/inter-
cooler/power con-
trol unit coolant at
the correct level?
( P.460)
Engine oil
Is the engine oil at
the correct level?
( P.458)

4546-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
6-3.Do-it-yourself maintenance
Do-it-yourself ser vice
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 battery
condition
( P.463)
•Grease
•Warm water
• Baking soda
• Distilled water
• Flat-head screw-
driver or
mechanical key
( P. 1 1 0 )
• Conventional wrench (for ter-
minal clamp
bolts)
Brake fluid
level ( P.461)
• 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/inter-
cooler/power
control unit
coolant level
( P.460)
• “Toyota Super
Long Life Cool-
ant” or a similar
high quality eth-
ylene glycol-
based non-sili-
cate, nonamine,
non-nitrite and
non-borate cool-
ant with longlife
hybrid organic
acid technology
For the U.S.A.:
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 50% cool-
ant and 50%
deionized water.
For Canada:
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 55% cool-
ant and 45%
deionized water.
• Funnel (used only for adding
coolant)
Engine oil level
( P.458)
• “Toyota Genuine
Motor Oil” or
equivalent
• Rag or paper towel
• Funnel (used only for adding
engine oil)
Fuses
( P.486)• Fuse with same
amperage rating
as original
ItemsParts and tools

4576-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
6
Maintenance and care
Fuse boxes ( P.486)
Power control unit coolant reservoir ( P.460)
Intercooler coolant reservoir ( P.460)
Engine coolant reservoir ( P.460)
Engine oil filler cap ( P.458)
Engine oil level dipstick ( P.458)
Brake fluid reservoir ( P.461)
Engine radiator ( P.461)
Condenser ( P.461)
Electric cooling fans
Radiator cooling fan ( P.460)
Washer fluid tank ( P.462)
Intercooler radiators ( P.460)
Engine compar tment
Components

4606-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
The coolant level is satisfactory
if it is between the “F” and “L”
lines on the reservoir when the
hybrid system is cold.
Engine coolant Engine coolant reservoir cap
“F” line
“L” line
If the level is on or below the “L”
line, add coolant up
to the “F” line.
(  P.535)
Intercooler coolant
Intercooler coolant reservoir
cap
“F” line
“L” line
If the level is on or below the “L”
line, add coolant up to the “F” line.
(  P.535)
Power control unit coolant
Power control unit coolant
reservoir cap
“FULL” line
NOTICE
■To prevent serious engine
damage
Check the oil level on a regular
basis.
■When replacing the engine oil
●Be careful not to spill engine oil
on the vehicle components.
●Avoid overfilling, or the engine
could be damaged.
●Check the oil le vel on the dip-
stick every time you refill the
vehicle.
●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

4616-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
6
Maintenance and care
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. ( P.535)
■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% deionized water.
(Minimum temperature: -31°F [-
35°C])
Canada: “Toyota Super Long Life
Coolant” is a mixture of 55% coolant
and 45% deionized water.
(Minimum temperature: -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 radiator, hoses,
engine coolant reser voir cap, inter-
coolant reservoir cap, 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 sys-
tem.
Check the radiator, condenser
and intercooler radiators 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.
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
WARNING
■When the hybrid system is
hot
Do not remove the coolant reser-
voir cap.
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
Be sure to wash it off with water to
prevent it from damaging parts or
paint.
Checking the radiator,
condenser and inter-
cooler radiators
WARNING
■When the hybrid system is
hot
Do not touch the radiator, con-
denser or intercooler radiators or
condenser as they may be hot
and cause serious injuries, such
as burns.
Checking and adding the
brake fluid

5017-2. Steps to take in an emergency
Owners Manual_USA_M0C052_en
7
When trouble arises
■Brake system warning light (warning buzzer)
■Brake system warning light (warning buzzer)
■High coolant temperature warning light*
*: This light illuminates on the mu lti-information display with a message.
If a war ning light tur ns 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 malfunc-
tion in the system. However, if this continues to occur, have
the vehicle inspected by your Toyota dealer.
Actions to the warning lights or warning buzzers
Warning lightDetails/Actions
(U.S.A.)
or
(Red)
(Canada)
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. C ontinuing to drive the vehi-
cle may be dangerous.
Warning lightDetails/Actions
(Yellow)
Indicates a malfunction in:
 The parking brake system;
 The regenerative braking system; or
 The electronically controlled brake system
 Have the vehicle inspecte d by your Toyota dealer
immediately.
Warning lightDetails/Actions
Indicates that the engine is overheating
 Immediately stop the v ehicle in a safe place.
Handling method ( P.535)

5357-2. Steps to take in an emergency
Owners Manual_USA_M0C052_en
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, engine
radiator core (radiator) and
intercooler radiator core
(radiator) for any leaks.
If a large amount of coolant leaks,
immediately cont act your Toyota dealer.
Cooling fan
Radiator
Intercooler radiators
4 The coolant level is satisfac-
tory if it is between the “F” or
“FULL” and “L” or “LOW”
lines on the reservoir.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
The needle of the engine coolant temperature gauge ( P.91)
enters the red zone or a loss of engine (hybrid system) power i s
experienced. (For example, the vehicle speed does not
increase.)
 “Engine Coolant Temp High Stop in a Safe Place See Owner’s
Manual” is shown on the multi-information display.
Steam comes out from under the hood.
Correction procedures