2023 TOYOTA TUNDRA HYBRID radiator

4506-2. Maintenance
Owners Manual_USA_M0C052_en
Exhaust sys-
temThere should not
be any fumes or
strange sounds.
Radiator/con-
denser/inter-
cooler
The radiator, con-
denser and inter-
cooler should be
free from foreign
objects. (P.461)
Washer fluid
Is there sufficient
washer fluid?
( P.462)
Vehicle interior
ItemsCheck points
12-volt batteryCheck the connec-
tions. ( P.463)
Accelerator
pedal
• The accelerator
pedal should
move smoothly
(without uneven
pedal effort or
catching).
Automatic
transmission
“Park” mecha-
nism
• When parked on a slope and the
shift lever is in P,
is the vehicle
securely
stopped?
ItemsCheck points
Brake pedal
• Does the brake pedal move
smoothly?
• Does the brake pedal have
appropriate
clearance from
the floor?
• Does the brake pedal have the
correct amount
of free play?
Brakes
• The vehicle should not pull to
one side when
the brakes are
applied.
• The brakes should work
effectively.
• The brake pedal should not feel
spongy.
• The brake pedal should not get
too close to the
floor when the
brakes are
applied.
Head
restraints
• Do the head restraints move
smoothly and
lock securely?
Indica-
tors/buzzers
• Do the indica-tors and buzzers
function prop-
erly?
ItemsCheck points

4556-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
6
Maintenance and care
Light bulbs
(  P.490)
• Bulb with same
number and
wattage rating as
original
• Phillips-head screwdriver
• Wrench
Radiator and
condenser
(  P.461)

Tire inflation
pressure
( P.476)• Tire pressure
gauge
• Compressed air source
Washer fluid
( P.462)
• Water or washer
fluid containing
antifreeze (for
winter use)
• Funnel (used only for adding
water or washer
fluid)
WARNING
The engine compartment contains
many mechanisms and fluids that
may move suddenly, become hot,
or become electrically energized.
To avoid death or serious injury,
observe the following precautions.
■When working on the engine
compartment
●Make sure that the “ACCES-
SORY” or “IGNITION ON” on
the multi-inform ation display
and the “READY” indicator are
both off.
●Keep hands, clothing and tools
away from the moving fan and
engine.
ItemsParts and tools●Be careful not to touch the
engine, inverter, radiator,
exhaust manifold, etc., right
after driving as they may be hot.
Oil and other fluids may also be
hot.
●Do not leave anything that may
burn easily, such as paper and
rags, in the engine compart-
ment.
●Do not smoke, cause sparks or
expose an open flame to fuel.
■When working near the elec-
tric cooling fan or radiator
grille
Be sure the power switch is off.
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. ( P.461)
■Safety glasses
Wear safety glasses to prevent
flying or falling material, fluid
spray, etc., from getting in your
eyes.
NOTICE
■If you remove the air cleaner
filter
Driving with the air cleaner filter
removed may cause excessive
engine wear due to dirt in the air.

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

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

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

5377-2. Steps to take in an emergency
Owners Manual_USA_M0C052_en
7
When trouble arises
6 Start the hybrid system to
check that the radiator cool-
ing fan operates and to check
for coolant leaks from the
radiator or hoses.
7 If the fan is not operating:
Stop the hybrid system
immediately and contact your
Toyota dealer.
If the fan is operating:
Have the vehicle inspected at
the nearest Toyota dealer.
8 Check if “Engine Coolant
Temp High Stop in a Safe
Place See Owner’s Manual”
is shown on 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:
Have the vehicle i nspected at the
nearest Toyota dealer.
WARNING
■When inspecting under the
hood of your vehicle
Observe the following precau-
tions.
Failure to do so may result in seri-
ous injury such as burns.
●If steam is seen coming from
under the hood, do not open the
hood until the steam has sub-
sided. The engine compart-
ment may be very hot.
●After the hybrid system has
been turned off , check that the
“READY” indicator is off. When
the hybrid system is operating,
the gasoline engine may auto-
matically 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
muffler) getting caught, resulting
in serious injury.
●Do not loosen the coolant reser-
voir caps, while the hybrid sys-
tem and radiator are hot.
High temperature steam or
coolant could spray out.
NOTICE
■When adding coolant
Add coolant slowly after the
hybrid system has cooled down
sufficiently. Adding cool coolant to
a hot hybrid system too quickly
can cause damage to the hybrid
system.
■To prevent damage to the
cooling system
Observe the following precau-
tions:
●Avoid contaminating the coolant
with foreign matter (such as
sand or dust, etc.,).
●Do not use any coolant additive.

602Alphabetical Index
Owners Manual_USA_M0C052_en
........................................... 289
Parking Support Brake function (rear-crossing vehicles) ...... 295
Parking Support Brake function (static objects) .................... 292
Warning lights....................... 504
Warning message ................ 291
Power back window ............... 163
Power bed step ....................... 126
Power control unit .................... 76
Power control unit coolant .... 460 Capacity ............................... 544
Checking .............................. 460
Power easy access system ... 137
Power outlet ............................ 426
Power running boards ........... 117
Power steering (Electric power steering system)Warning light ........................ 503
Power switch .......................... 195 Auto power off function ........ 198
Changing the power switch modes ................................ 198
If your vehicle has to be stopped in an emergency................. 494
Starting the hybrid system.... 195
Power switch light .................. 410
Power windows Door lock linked window opera-tion ..................................... 161
Jam protection function ........ 160
Operation ............................. 160
Window lock switch .............. 162
Pre-Collision System (PCS)... 230 Enabling/disabling the system........................................... 234
Function ............................... 230
Warning light ........................ 503
R
Radar cruise control (dynamic radar cruise control with full- speed range) .........................256
Radiator ...................................461
RCTA (Rear Cross Traffic Alert) ...............................................281Enabling/disabling the system ...........................................282
Warning lights .......................505
Warning message.................282
Rear Cross Traffic Alert (RCTA) ...............................................281Enabling/disabling the system ...........................................282
Warning lights .......................505
Warning message.................282
Rear differential lock system.364
Rear door sunshades .............432
Rear seats ...............................134 Cleaning ...............................445
Head restraints .....................140
Seat heaters ....... ..................407
Seat ventilators.....................407
Rear turn signal lights............204 Replacing light bulbs ............490
Turn signal lever ...................204
Rear view mirror Digital Rear-view Mirror ........146
Inside rear view mirror ..........145
Outside rear view mirrors .....155
Rear window defogger ...........401
Refueling ............ .....................222
Capacity ...............................542
Fuel types .............................542
Opening the fuel tank cap ....222
When the fuel door cannot be opened ...............................526
Regenerative braking ...............74 Warning lights .......................501
Replacing Electronic key battery ...........484
Fuses....................................486
Light bulbs ............................489
Road accident cautions ...........77