coolant temperature TOYOTA TUNDRA HYBRID 2023 Owners Manual

922-1. Instrument cluster
Owners Manual_USA_M0C052_en
Engine coolant temperature gauge
Displays the engine coolant temperature
Speedometer
Displays the vehicle speed
Voltmeter
Displays the charge state
Engine oil pressure gauge
Displays the engine oil pressure
Odometer and trip meter ( P.93)
■The meters and display illumi-
nate when
The power swit ch is in ON.
■Tachometer needle feature
The tachometer needle will fade in
or out during the engine starting or
stopping, respectively.
The needle is completely visible
after the engine is turned on or
turned off.
■Clock settings screen
If clock setting item is displayed
when is selected on the multi-
information display, the system may
be malfunctioning. Have the vehicle
inspected by your Toyota dealer.
■Outside temperature display
●In the following si tuations, the cor-
rect outside tempe rature may not
be displayed, or the display may
take longer than normal to
change.
• When stopped, or driving at low
speeds (less than 12 mph [20
km/h])
• When the outside temperature
has changed suddenly (at the
entrance/exit of a garage, tunnel,
etc.)
●When “--” or “E” is displayed, the
system may be malfunctioning.
Take your vehicle to your Toyota
dealer.
●Displays the outsi de temperature
within the range of -40°F (-40°C)
to 122°F (50°C).
●When the outside temperature is
approximately 37°F (3°C) or
lower, the indicator will flash
for approximately 10 seconds,
then stay on.
■Liquid crystal display
 P. 9 6
■Customization
Settings (e. g. mete r display) can be
changed on screen of the multi-
information display. ( P. 9 9 )
WARNING
■The information display at
low temperatures
Allow the interior of the vehicle to
warm up before using the liquid
crystal information display. At
extremely low temperatures, the
information disp lay monitor may
respond slowly, and display
changes may be delayed.

1934-1. Before driving
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4
Driving
brakes too frequently. This
could cause the brakes to
overheat and result in
reduced braking efficiency.
 Due to the added load of the
trailer, your vehicle’s hybrid
system may overheat on hot
days (at temperatures over
85°F [30°C]) when driving up
a long or steep grade. If the
engine coolant temperature
gauge indicates overheating,
immediately turn off the air
conditioning (if in use), pull
your vehicle off the road and
stop in a safe spot. ( P.535)
 Always place wheel blocks
under both the vehicle’s and
the trailer’s wheels when
parking. Apply the parking
brake firmly, and put the
transmission in P. Avoid park-
ing on a slope, but if unavoid-
able, do so only after
performing the following:
1 Apply the brakes and keep
them applied.
2 Have someone place wheel
blocks under both the vehi-
cle’s and trailer’s wheels.
3 When the wheel blocks are in
place, release the brakes
slowly until the blocks absorb
the load.
4 Apply the parking brake
firmly.
5 Shift into P and turn off the
hybrid system. 
When restarting after parking
on a slope:
1 With the transmission in P,
start the hybrid system. Be
sure to keep the brake pedal
pressed.
2 Shift into a forward gear. If
reversing, shift into R.
3 If the parking brake is in man-
ual mode, release the park-
ing brake. ( P.205)
4 Release the brake pedal, and
slowly pull or back away from
the wheel blocks. Stop and
apply the brakes.
5 Have someone retrieve the
blocks.
■Break-in schedule
If your vehicle is new or equipped
with any new power train compo-
nents (such as an engine, transmis-
sion, transfer [4WD models], rear
differential or wheel bearing), Toyota
recommends that y ou do not tow a
trailer until the vehicle has been
driven for over 500 miles (800 km).
After the vehicle has been driven for
over 500 miles (800 km), you can
start towing. However, for the next
500 miles (800 km), drive the vehi-
cle at a speed of less than 50 mph
(80 km/h) when towing a trailer, and
avoid full throttle acceleration.
■Maintenance
●If you tow a trailer, your vehicle
will require more fr equent mainte-
nance due to the additional load.
(See “Owner’s Warranty Informa-
tion Booklet” or “Scheduled Main-
tenance Guide” / “Owner’s Manual
Supplement”.)
●Retighten the fixing bolts of the
towing ball and bracket after

4556-3. Do-it-yourself maintenance
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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.

4616-3. Do-it-yourself maintenance
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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

4997-2. Steps to take in an emergency
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7
When trouble arises
When using a flat-bed truck to
transport the vehicle, use tire
strapping belts. Refer to the
owner’s manual of the flat-bed
truck for the tire strapping
method.
In order to suppress vehicle
movement during transporta-
tion, set the parking brake and
turn the power switch off.
Your vehicle has not towing
hook. If towing is necessary, we
recommend having your vehicle
towed by your Toyota dealer or
commercial towing service. 
Fluid leaks under the vehicle.
(Water dripping from the air
conditioning after use is nor-
mal.)
 Flat-looking tires or uneven
tire wear
 Engine coolant temperature
gauge needle continually
points higher than normal.
 Voltmeter continually points
higher or lower than normal.
 Engine oil pressure gauge
continually points lower than
normal.
 Automatic transmission fluid
temperature warning mes-
sage is displayed
 Changes in exhaust sound
 Excessive tire squeal when
cornering
 Strange noises related to the
suspension system
NOTICE
■Towing with a sling-type truck
Do not tow with a sling-type truck
to prevent body damage.
Using a flatbed truck
Emergency towing
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

5017-2. Steps to take in an emergency
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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
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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
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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.

Owners Manual_USA_M0C052_en
Alphabetical Index597
........................................... 499
If your vehicle becomes stuck ........................................... 538
If your vehicle has to be stopped in an emergency................. 494
If your vehicle needs to be towed ........................................... 497
If your vehicle overheats ...... 535
Engine ..................................... 542 ACC...................................... 198
Compartment ....................... 457
How to start the hybrid system........................................... 195
If the hybrid sy stem will not start
........................................... 524
If your vehicle has to be stopped in an emergency................. 494
Overheating.......................... 535
Power switch ........................ 195
Engine coolant ....................... 460 Capacity ............................... 544
Checking .............................. 460
Preparing and c hecking before
winter.................................. 395
Engine coolant temperature gauge....................................... 91
Engine oil Capacity ............................... 543
Checking .............................. 458
Warning light ........................ 502
Engine oil pressure gauge ...... 91
Engine switch (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
Enhanced Vehicle Stability Con- trol (Enhanced VSC) ............ 375
Enhanced VSC (Enhanced Vehi- cle Stability Control) ............ 375 EPS (Electric Po
wer Steering)
...............................................375 Warning light.........................503
Event data recorder (EDR) .........8
F
Flat tire.....................................515 Tire pressure w arning system
...........................................468
Floor mats .................................26
Fluid Automatic transm ission ........545
Brake ....................................546
Washer .................................462
Fog light Replacing light bulbs ............490
Switch ...................................214
Footwell lights ........................410
Four-wheel drive system .......361
Front fog light Replacing light bulbs ............490
Front passenger occupant clas- sification system ....................46
Front seats ..............................133 Adjustment ...........................133
Cleaning ...............................445
Correct driving posture ...........27
Driving position memory .......137
Head restraints .....................140
Memory recall function .........139
Power easy access system ..137
Seat heaters ....... ..................407
Seat position memory...........137
Seat ventilators.....................407
Front tray light ........................410
Front turn signal lights ..........204 Turn signal lever ...................204
Front turn signal/parking lights Replacing light bulbs ............490
Wattage ................................548
Fuel Capacity ...............................542

Owners Manual_USA_M0C052_en
Alphabetical Index607
W
Warning buzzersApproach warning ................ 263
Brake hold ............................ 506
Brake Override System ........ 505
Brake system ....................... 501
Charging system .................. 502
Downshifting......................... 203
Drive-Start Control ............... 505
Electric power steering ......... 503
Engine .................................. 502
Hands off steering wheel warn-ing (LTA) ............................. 251
Hybrid system ...................... 502
Intuitive parking assist .. 280, 504
Low engine oil pressure ....... 502
LTA (Lane Tracing Assist) ... 242, 246, 504
Open door .................... 114, 116
Open window ....................... 161
PCS (Pre-Collision System) . 503
PKSB (Parking Support Brake) ........................................... 504
Pre-collision braking ............. 230
Pre-collision warning ............ 230
RCTA (Rear Cross Traffic Alert) ................................... 282, 505
Seat belt ............................... 507
SRS airbag ........................... 502
Vehicle sway warning function (LTA) ................................... 252
Warning label ............................ 76
Warning lights .................. 87, 501 ABS ...................................... 503
Air suspension malfunction indi-cator ................................... 508
Brake hold operated indicator ........................................... 506
Brake Override System ........ 505
Brake system ....................... 501
Charging system .................. 502 Drive-Start Control
................505
Electric power steering .........503
High coolant temperature .....501
Hybrid system .......................502
Intuitive parking assist OFF indi- cator ...................................504
Low engine oil pressure .......502
Low fuel level........................507
LTA indicator .........................504
Malfunction indica tor lamp ....502
Parking brake indicator.........506
PKSB OFF indicator .............504
Pre-collision syst em .............503
RCTA OFF indicator .............505
Rear differential lock indicator ...........................................506
Seat belt reminder light ........507
Slip indicator .........................505
SRS airbag ...........................502
Tire pressure ...... ..................506
Trailer brake warn ing light ....508
Warning messages ................. 511
Washer .....................................218 Adding ..................................462
Preparing and checking before winter ..................................395
Switch ...................................218
Washing and waxing ..............442
Weight Cargo capacity .....................180
Load limits ............................180
Wheel lock nut ........................516
Wheels .....................................478 Replacing .............................478
Size ......................................547
Wheel lock nut ......................516
Window lock switch ...............162
Windows Power back window..............163
Power windows ....................160
Rear window defogger .........401
Washer .................................218