2021 TOYOTA TUNDRA engine

4236-3. Do-it-yourself maintenance
6
Maintenance and care
■Before recharging
When recharging, the battery produces hydrogen gas which is flammable and
explosive. Therefore, observe the following before recharging:
●If recharging with the battery installed on the vehicle, be sur e to disconnect
the ground cable.
● Make sure the power switch on the charger is off when connectin g and dis-
connecting the charger cables to the battery.
■ After recharging/reconnecting the battery (vehicles with a smar t key sys-
tem)
The engine may not start. Follow the procedure below to initial ize the system.
Shift the shift lever to P.
Open and close any of the doors.
Restart the engine.
● Unlocking the doors using the smart key system may not be possi ble imme-
diately after reconnecting the battery. If this happens, use the wireless
remote control or the mechanical key to lock/unlock the doors.
● Start the engine with the engine switch in ACC. The engine may not start
when the engine switch turned from off. However, the engine wil l operate
normally from the second attempt.
● The engine switch mode is recorded by the vehicle. If the batte ry is recon-
nected, the vehicle will return the engine switch mode to the s tatus it was in
before the battery was disconnected. Make sure to turn off the engine
before disconnect the battery. Take extra care when connecting the battery
if the engine switch mode prior to discharge is unknown.
If the system will not start even after multiple attempts, contact your Toyota
dealer.
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4246-3. Do-it-yourself maintenance
WARNING
■Chemicals in the battery
Batteries contain poisonous and corrosive sulfuric acid and may produce
hydrogen gas which is flammable and explosive. To reduce the ri sk of death
or serious injury, take the following precautions while working on or near
battery:
● Do not cause sparks by touching the battery terminals with tool s.
● Do not smoke or light a match near the battery.
● Avoid contact with eyes, skin and clothes.
● Never inhale or swallow electrolyte.
● Wear protective safety glasses when working near the battery.
● Keep children away from the battery.
■ Where to safely charge the battery
Always charge the battery in an open area. Do not charge the battery in a
garage or closed room where there is insufficient ventilation.
■ How to recharge the battery
Only perform a slow charge (5 A or less). The battery may explod e if
charged at a quicker rate.
■ Emergency measures regarding electrolyte
● If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immedi-
ate medical attention. If possible, continue to apply water wit h a sponge or
cloth while traveling to the nearest medical facility.
● If electrolyte gets on your skin
Wash the affected area thoroughly. If you feel pain or burning, get medical
attention immediately.
● If electrolyte gets on your clothes
It can soak through clothing on to your skin. Immediately take off the cloth-
ing and follow the procedure above if necessary.
● If you accidentally swallow electrolyte
Drink a large quantity of water or milk. Get emergency medical attention
immediately.
NOTICE
■ When recharging the battery
Never recharge the battery while the engine is running. Also, b e sure all
accessories are turned off.

4256-3. Do-it-yourself maintenance
6
Maintenance and care
Add washer fluid in the following
situations:
●A washer does not work.
● The warning message appears
on the display.
Washer fluid
WARNING
■When adding washer fluid
Do not add washer fluid when the engine is hot or running as wa sher fluid
contains alcohol and may catch fire if spilled on the engine, e tc.
NOTICE
■Do not use any fluid ot her than washer fluid
Do not use soapy water or engine antifreeze instead of washer f luid.
Doing so may cause streaking on the vehicle’s painted surfaces, as well as
damaging the pump leading to problems of the washer fluid not s praying.
■ Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures listed on the label of the washer fluid bot-
tle.

4286-3. Do-it-yourself maintenance
■How to initialize the tire pressure warning systemPark the vehicle in a safe place and turn the engine switch off .
Initialization cannot be performed while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire i nflation
pressure level. ( P. 548)
Make sure to adjust the tire pre ssure to the specified cold tire infla-
tion pressure level. The tire pressure warning system will oper ate
based on this pr essure level.
Turn the engine switch to ON.
Press and hold the tire pres-
sure warning reset switch
until the tire pressure warn-
ing light blinks 3 times.
A message is displayed on the
multi-information display. Also,
“--” is displayed for inflation
pressure of each tire on the
multi-information display while
the tire pressure warning sys-
tem determines the position.
Drive straight (with occasional left and right turns) at approxi-
mately 25 mph (40 km/h) or more for approximately 10 to 30 min-
utes.
Initialization is complete when the position of each tire is determined
and the inflation pressure of ea ch tire is displayed on the multi-infor-
mation display.
Initialization may take longer than approximately 30 minutes in cer-
tain situations, such as when the vehicle is stopped for a long time at
traffic lights, etc. ( P. 434)
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4336-3. Do-it-yourself maintenance
6
Maintenance and care
■The initialization operation
●Make sure to carry out initialization after adjusting the tire inflation pres-
sure.
Also, make sure the tires are co ld before carrying out initialization or tire
inflation pressure adjustment.
●If you have accidentally turned the engine switch off during in itialization,
it is not necessary to press the reset swit ch again as initialization will
restart automatically when the engine switch has been turned to ON for
the next time.
●If you accidentally press the reset switch when initialization is not neces-
sary, adjust the tire inflation pressure to the specified level when the
tires are cold, and cond uct initialization again.
●While the position of each tire is being determined and the inf lation pres-
sures are not being displayed on the multi-information display, if the
inflation pressure of a tire drops, the tire pressure warning l ight will come
on.
■Warning performance of the tire pressure warning system
The warning of the tire pressu re warning system will change in accor-
dance with the conditions under which it was initialized. For t his reason,
the system may give a warning even if the tire pressure does no t reach a
low enough level, or if the pressure is higher than the pressur e that was
adjusted to when the sys tem was initialized.

4486-3. Do-it-yourself maintenance
Air conditioning filter
Turn the engine switch off.
Open the glove box.
Remove the tray.
Remove the cover by sliding up
while pulling toward you.
The air conditioning filter must be changed regularly to maintain
air conditioning efficiency.
Removal method
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4546-3. Do-it-yourself maintenance
Checking and replacing fuses
Turn the engine switch off.
Open the fuse box cover.
Engine compartment
Push the tab in and lift the
cover off.
Under the instrument panel
Remove the cover.
Remove the fuse with the pull-
out tool.
Only type A fuse can be removed
using the pullout tool.
If any of the electrical components do not operate, a fuse may
have blown. If this happens, check and replace the fuses as nec-
essary.
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473
7When trouble arises
7-1. Essential informationEmergency flashers .......... 474
If your vehicle has to be stopped in
an emergency ................. 475
If the vehicle is trapped in rising water .................. 477 7-2. Steps to take in an emergency
If your vehicle needs to be towed ......................... 478
If you think something is wrong .............................. 483
Fuel pump shut off system ............................ 484
If a warning light turns on or a warning buzzer
sounds ............................ 485
If a warning message is displayed......................... 493
If you have a flat tire.......... 506
If the engine will not start ................................. 521
If the electronic key does not operate
properly (vehicles with
a smart key system) ........ 523
If the vehicle battery is discharged ...................... 525
If your vehicle overheats ... 529
If the vehicle becomes stuck ............................... 532