2023 TOYOTA TUNDRA HYBRID battery

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

4566-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
1Pull the hood lock release
lever.
The hood will pop up slightly.
2Pull up the auxiliary catch
lever and lift the hood.
■12-volt battery
 P. 4 6 3
Hood
Opening the hood
WARNING
■Pre-driving check
Check that the hood is fully closed
and locked.
If the hood is not locked properly,
it may open while the vehicle is in
motion and cause an accident,
which may result in death or seri-
ous injury.

4636-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
6
Maintenance and care
The 12-volt battery is located in
the left-hand side of the rear
seat under.
1 Raising the bottom cushion.
( P.135)
2 Remove the battery cover.
Use the flat-head screwdriver or
mechanical key ( P.110).
■Before recharging
When recharging, the 12-volt bat-
tery produces hydrogen gas which
is flammable and explosive. There-
fore, observe the following precau-
tions before recharging:
●If recharging with the 12-volt bat-
NOTICE
■Do not use any fluid other
than washer fluid
Do not use soapy water or anti-
freeze instead of washer fluid.
Doing so may cause streaking on
the vehicle’s painted surfaces, as
well as damaging the pump lead-
ing to problems of the washer
fluid not spraying.
■Diluting washer fluid
Dilute washer fluid with water as
necessary.
Refer to the freezing tempera-
tures listed on the label of the
washer fluid bottle.
12-volt batter y
Location
Removing the 12-volt bat-
tery cover

4646-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_entery installed on the vehicle, be
sure to disconnect the ground
cable.
●Make sure the power switch on
charger is off when connecting
and disconnecting the charger
cables to the 12-volt battery.
■After recharging/reconnecting
the 12-volt battery
●Unlocking the doors using the
smart key system may not be pos-
sible immediately after reconnect-
ing the 12-volt battery. If this
happens, use the wireless remote
control or the mechanical key to
lock/unlock the doors.
●Start the hybrid system with the
power switch in ACC. The hybrid
system may not start with the
power switch turned off. However,
the hybrid system will operate nor-
mally from the second attempt.
●The power switch mode is
recorded by the vehicle. If the 12-
volt battery is
reconnected, the
vehicle will return the power
switch mode to the status it was in
before the 12-volt battery was dis-
connected. Make sure to turn off
the power switch before discon-
necting the 12-volt battery. Take
extra care when connecting the
12-volt battery if the power switch
mode prior to discharge is
unknown.
●When the 12-volt b attery is recon-
nected, start the hybrid system,
depress the brake pedal, and con-
firm that it is possible to shift into
each shift position.
If the system will not start even after
multiple attempts, contact your Toy-
ota dealer.
WARNING
■Chemicals in the 12-volt bat-
tery
The 12-volt battery contains poi-
sonous and corrosive sulfuric acid
and may produce hydrogen gas
which is flammable and explosive.
To reduce the risk of death or seri-
ous injury, take the following pre-
cautions while working on or near
the 12-volt battery:
●Do not cause sparks by touch-
ing the 12-volt battery terminals
with tools.
●Do not smoke or light a match
near the 12-volt battery.
●Avoid contact with eyes, skin
and clothes.
●Never inhale or swallow electro-
lyte.
●Wear protective safety glasses
when working near the 12-volt
battery.
●Keep children away from the
12-volt battery.
■Where to safely charge the
12-volt battery
Always charge the 12-volt battery
in an open area. Do not charge
the 12-volt battery in a garage or
closed room where there is insuf-
ficient ventilation.
■Emergency measures regard-
ing electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean
water for at least 15 minutes
and get immediate medical
attention. If possible, continue
to apply water with a sponge or
cloth while traveling to the near-
est medical facility.

4656-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
6
Maintenance and care
Make sure that the 12-volt bat-
tery terminals are not corroded
and that there are no loose con-
nections, cracks, or loose
clamps. Terminals
Hold-down clamp
WARNING
●If electrolyte gets on your skin
Wash the affected area thor-
oughly. If you fee
l pain or burn-
ing, get medical attention
immediately.
●If electrolyte gets on your
clothes
It can soak through clothing on
to your skin. Immediately take
off the clothing and follow the
procedure above if necessary.
●If you accidentally swallow elec-
trolyte
Drink a large quantity of water
or milk. Get emergency medical
attention immediately.
■When replacing the 12-volt
battery
Use a 12-volt battery designed for
this vehicle. Failure to do so may
cause gas (hydrogen) to enter the
passenger compartment, causing
a fire or explosion.
For replacement of the 12-volt
battery, contact your Toyota
dealer.
NOTICE
■When recharging the 12-volt
battery
Never recharge the 12-volt bat-
tery while the hybrid system is
operating. Also, be sure all acces-
sories are turned off.
Exterior

4816-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
6
Maintenance and care
■Scheduled maintenance of the
air intake vents is necessary
when
In some situations such as when the
vehicle is used frequently or in
heavy traffic or dusty areas, the air
intake vents may need to be
cleaned more regularly.
For details, refer to the “Owner’s
Warranty Information Booklet” or
“Owner’s Manual Supplement”.
■Cleaning the air intake vent
Improper handling of the air intake
vent cover and filter may result in
damage to them. If you have any
concerns about cleaning the filter,
contact your Toyota dealer.
1 Turn the power switch off.
2 Remove the air intake vent
cover.
1 Pull the cover as shown in
the illustration to disengage
the 2 claws.
2 Pull the cover toward the side
of the vehicle to remove it.
3 Remove the filter from the air
intake vent cover.
If dust has accumula ted on the air
intake vent cover, remove the dust
Cleaning the hybrid
batter y (traction bat-
ter y) air intake vents
To prevent the fuel economy
from being affected, visually
inspect the hybrid battery
(traction battery) air intake
vents periodically for clogs.
If it is dusty or clogged or if
“Maintenance 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:
NOTICE
■If “Maintenance Required for
Traction Battery Cooling
Parts See Owner’s Manual” is
displayed on the multi-infor-
mation display
Clean the air intake vent immedi-
ately.
If the vehicle is continuously
driven with the warning message
displayed, it may cause a mal-
function or output restriction of the
hybrid battery (traction battery).
Cleaning procedure

4836-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
6
Maintenance and care
ing it.
7 Install the air intake vent
cover.
1 Insert the tab of the cover as
shown in the illustration.
2 Push the cover to engage the
2 claws.
If “Maintenance Required for
Traction Battery Cooling Parts
See Owner’s Manual” was
displayed on the multi-infor-
mation display
8 Start the hybrid system and
check that the warning mes-
sage is no longer displayed.
It may take approximately 20 min-
utes after the hybrid system is
started until the warning message
disappears.
If the warning message does not
disappear after some time, have
the vehicle inspected by your Toy-
ota dealer.
■If the dust or sand on the filter
cannot be removed
It is recommended to use a vacuum
cleaner with plastic brushes.
WARNING
■When cleaning the air intake
vent
●Do not use water or other liq-
uids to clean the air intake vent.
If water is applied to the hybrid
battery (traction battery) or
other components, a malfunc-
tion or fire may occur.
●Before cleaning the air intake
vent, make sure to turn the
power switch off to stop the
hybrid system.
●Do not put a han d or leg in the
air intake vent. If it is caught in a
cooling fan, or if it touches a
high voltage part that results in
an electric shock, death or seri-
ous injuries may result.
●Do not touch the service plug
located near the air intake vent.
(  P. 7 7 )
NOTICE
■When cleaning the air intake
vent
Do not use an ai r blow gun, etc.
Dust may be blown out, possibly
causing a malfunction or output
restriction of the hybrid battery
(traction battery).

4846-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
■If the electronic key battery is
depleted
The following symptoms may occur:
●The smart key system and wire-
less remote control will not func-
tion properly.
●The operational range will be
reduced.
 Flathead screwdriver
 Small flathead screwdriver
 Lithium battery CR2450
■Use a CR2450 lithium battery
●Batteries can be purchased at
your Toyota dealer, local electrical
appliance shops or camera stores.
●Replace only with the same or
equivalent type recommended by
the manufacturer.
●Dispose of used batteries accord-
ing to local laws.
NOTICE
■To prevent damage to the
vehicle
Observe the following precau-
tions:
●Do not allow water or foreign
matter to enter t he air intake
vent.
●Make sure to reinstall the filter
and cover to their original posi-
tions after cleaning.
●Do not install anything to the air
intake vent other than the exclu-
sive filter for this vehicle or use
the vehicle without the filter
installed.
■To prevent damage to the fil-
ter
Observe the following precau-
tions.
If the filter is damaged, have it
replaced with a new filter by your
Toyota dealer.
●Do not use an air blow gun, etc.
●Do not press hard a vacuum
cleaner, etc. against the filter.
●Do not use a hard brush, such
as a metal brush.
●Do not break the fold of the fil-
t er.
Electronic key batter y
Replace the battery with a
new one if it is depleted.
As the key may be damaged
if the following procedure is
not performed properly, it is
recommended that key bat-
tery replacement be per-
formed by your Toyota
dealer.
Items to prepare