2021 TOYOTA TUNDRA key battery

2184-2. Driving procedures
■When the steering lock cannot be released
■ Key reminder function
A buzzer sounds if the driver’s door is opened while the engine switch is in
ACC or OFF to remind you to remove the key. When starting the engine, the engine
switch may seem stuck in the OFF. To
free it, turn the key while turning the steer-
ing wheel slightly left and right.
WARNING
■ When starting the engine
Always start the engine while sitting in the driver’s seat. Do not depress the
accelerator pedal while starting the engine under any circumsta nces.
Doing so may cause an accident resulting in death or serious in jury.
■ Caution while driving
Do not turn the engine switch to OFF while driving. If, in an e mergency, you
must turn the engine off while the vehicle is moving, turn the engine switch
only to ACC to stop the engine. An accident may result if the e ngine is
stopped while driving. ( P. 475)
NOTICE
■To prevent battery discharge
Do not leave the engine switch in ACC or ON for long periods of time with-
out the engine running.
■ When starting the engine
● Do not crank the engine for more than 30 seconds at a time. This may
overheat the starter and wiring system.
● Do not race a cold engine.
● If the engine becomes difficult to start or stalls frequently, have your vehi-
cle checked by your Toyota dealer immediately.

2214-2. Driving procedures
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Driving
If the engine is stopped with the shift lever in a position other than P,
the engine switch will not be turn ed off but instead be turned to ACC.
Perform the following procedure to turn the switch off:
Check that the park ing brake is set.
Shift the shift lever to P.
Check that “Turn Power OFF” is displayed on the multi-informati on
display and then press the engine switch once.
Check that “Turn Power OFF” on the multi-information display is off.
■Auto power off function
If the vehicle is left in ACC for more than 20 minutes or ON (the engine is not
running) for more than an hour with the shift lever in P, the engine switch will
automatically turn off. However, this function cannot entirely prevent battery
discharge. Do not leave the vehicle with the engine switch in ACC or ON for
long periods of time when the engine is not running.
■ Automatic engine shut off feature (except for New Caledonia)
●The vehicle is equipped with a feature that automatically shuts off the
engine when the shift lever is in P with the engine running for an extended
period.
● The engine will automatically shut off after approximately 1 ho ur if it has
been left running while the shift lever is in P.
● The timer for the automatic engine shut off feature will reset if the brake
pedal is depressed or if the shift lever is in a position other than P.
● After the vehicle is parked, if the door is locked with the door lock switch
(P. 130) from the inside or the mechanical key ( P. 523) from the outside,
the automatic engine shut off feature will be disabled. The tim er for the auto-
matic engine shut off feature will be re-enabled if the driver’ s door is
opened.
When stopping the engine with the shift lever in a position other
than P
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2224-2. Driving procedures
■Electronic key battery depletion
P. 124
■ Conditions affecting operation
P. 142
■ Note for the entry function
P. 142
■ If the engine does not start
●The engine immobilizer system may not have been deactivated. ( P. 85)
Contact your Toyota dealer.
● Check that the shift lever is securely set in P. The engine may not start if the
shift lever is displaced out of P. “Shift to P Position” will b e displayed on the
multi-information display.
■ Steering lock
After turning the engine switch off and opening and closing the doors, the
steering wheel will be locked due to the steering lock function . Operating the
engine switch again automatically cancels the steering lock.
■ When the steering lock cannot be released
■ Steering lock motor overheating prevention
To prevent the steering lock motor from overheating, operation of the motor
may be suspended if the engine is turned on and off repeatedly in a short
period of time. In this case, refrain from running the engine. After about
10 seconds, the steering lock motor will resume functioning.
■ When “Smart Entry & Start System Check” is displayed on the multi-
information display
The system may be malfunctioning. Have the vehicle inspected by your
Toyota dealer immediately.
■ If the electronic key battery is depleted
P. 451 A message will be displayed on the multi-
information display.
Check that the shift lever is in P. Press the
engine switch while turning the steering
wheel left and right.

2384-3. Operating the lights and wipers
■Automatic light off system
●When the headlights come on: The headlights and tail lights tur n off 30 sec-
onds after a door is opened and closed if the engine switch is turned to ACC
or OFF. (The lights turn off immediately if the button on the key is
pressed after all the doors are locked.)
● When only the tail lights come on: The tail lights turn off aut omatically if the
engine switch is tuned to ACC or OFF and the driver’s door is o pened.
Vehicles with automatic headlight system: If any of the doors i s kept open, the
lights automatically turn off after 20 minutes.
To turn the lights on again, turn the engine switch to ON, or turn the light
switch off once and then back to or .
■ Light reminder buzzer
A buzzer sounds when the key is removed from the engine switch and the
driver’s door is opened while the lights are turned on.
■ Customization that can be configured at Toyota dealer
Settings (automatic light off system) can be changed.
(Customizable features: P. 564)
NOTICE
■To prevent battery discharge
Do not leave the lights on longer than necessary when the engin e is not
running.

3595-2. Using the interior lights
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Interior features
“OFF”
The cargo lamp can be individually
turned on or off.
“DOOR”
The cargo lamp comes on when a
door is opened. They turn off when
the doors are closed.
“ON”
The cargo lamp cannot be individually turned off.
■Illuminated entry system
Vehicles without a smart key system
The lights automatically turn on/off according to the engine sw itch position,
whether the doors are locked/unlocked, and whether the doors are opened/
closed.
Vehicles with a smart key system
The lights automatically turn on/off according to engine switch mode, the
presence of the electronic key, whether the doors are locked/un locked, and
whether the doors are opened/closed.
■ To prevent battery discharge
If the following lights remain on when the door is not fully closed and the main
switch is in the “DOOR” position, the lights will go off automatically after 20
minutes:
●Personal lights
● Interior lights
● Cargo lamp
■ Customization that can be configured at Toyota dealer
Settings (e.g. the time elapsed before lights turn off) can be changed.
(Customizable features: P. 564)
Cargo lamp main switch
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399
6Maintenance and care
6-1. Maintenance and careCleaning and protecting the vehicle exterior .......... 400
Cleaning and protecting the vehicle interior ........... 403
6-2. Maintenance Maintenance requirements ................... 406
General maintenance ........ 408
Emission inspection and maintenance (I/M)
programs ......................... 411 6-3. Do-it-yourself maintenance
Do-it-yourself service precautions ..................... 412
Hood ................................. 414
Engine compartment ......... 415
Tires .................................. 426
Tire inflation pressure ....... 442
Wheels .............................. 445
Air conditioning filter.......... 448
Wireless remote control/ electronic key battery ...... 451
Checking and replacing fuses ............................... 454
Light bulbs......................... 457

4236-3. Do-it-yourself maintenance
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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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4516-3. Do-it-yourself maintenance
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Maintenance and care
Wireless remote control/electronic key bat-
ter y

●Flathead screwdriver
● Small flathead screwdriver
● Lithium battery CR2016 (vehicles without a smart key system), o r
CR2032 (vehicles with a smart key system)
Vehicles without a smart key system
Remove the cover.
To prevent damage to the key,
cover the tip of the screwdriver with
a rag.
To prevent the buttons from being
disassembled, face the button sur-
face downward.
Remove the module.
: If equipped
Replace the battery with a n ew one if it is depleted.
You will need the following items:
Replacing the battery
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