2021 TOYOTA 4RUNNER key battery

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4RUNNER (U)6-1. Maintenance and care
Cleaning and protecting the vehicle exterior .......... 392
Cleaning and protecting the vehicle interior ........... 395
6-2. Maintenance Maintenance requirements ................... 398
General maintenance ........ 400
Emission inspection and maintenance (I/M)
programs ......................... 403
6-3. Do-it-yourself maintenance
Do-it-yourself service precautions ..................... 404
Hood.................................. 407
Engine compartment ......... 408
Tires .................................. 422
Tire inflation pressure........ 436
Wheels .............................. 439
Air conditioning filter .......... 441
Wireless remote control/ electronic key
battery ............................. 443
Checking and replacing fuses ............................... 446
Light bulbs ......................... 449 7-1. Essential information
Emergency flashers ........... 462
If your vehicle has to be stopped in an
emergency....................... 463
If the vehicle is trapped in rising water ...................... 465
7-2. Steps to take in an emergency
If your vehicle needs to be towed .......................... 466
If you think something is wrong............................... 472
Fuel pump shut off system ............................. 473
If a warning light turns on or a warning buzzer
sounds ............................. 474
If a warning message is displayed ......................... 484
If you have a flat tire .......... 489
If the engine will not start ................................. 504
If you cannot operate back door opener ............ 506
If the electronic key does not operate properly
(vehicles with a smart
key system) ..................... 507
If the vehicle battery is discharged ....................... 510
If your vehicle overheats......................... 514
If the vehicle becomes stuck ................................ 517
6Maintenance and care7When trouble arises

791-3. Theft deterrent system
1
For safety and security
4RUNNER (U)
The alarm uses light and sound to give an alert when an intrusion is
detected.
The alarm is triggered in the following situations when the ala rm is
set:
● A locked door is unlocked or opened in any way other than using
the entry function, wireless remote control or mechanical key. (The
doors will lock aga in automatically.)
● The hood is opened.
● The battery is reconnected.
Close the doors and hood, and
lock all the doors. The system will
be set automatically after 30 sec-
onds.
The indicator light changes from
being on to flashing when the sys-
tem is set.
Do one of the following to deac tivate or stopping the alarms:
● Unlock the doors.
● Vehicles without a smart key sy stem: Turn the engine switch to
“ACC” or “ON” position, or start the engine. (The alarm will be deac-
tivated or stopped after a few seconds.)
● Vehicles with a smart key syst em: Turn the engine switch is in
ACCESSORY or IGNITION ON mode, or start the engine. (The
alarm will be deactivated or s topped after a few seconds.)
Alar m
: If equipped
The alarm
Setting the alarm system
Deactivating or stopping the alarm

801-3. Theft deterrent system
4RUNNER (U)
■System maintenance
The vehicle has a maintenance-free type alarm system.
■ Items to check before locking the vehicle
To prevent unexpected triggering of the alarm and vehicle theft , make sure of
the following:
● Nobody is in the vehicle.
● The windows and moon roof are closed before the alarm is set.
● No valuables or other personal items are left in the vehicle.
■ Triggering of the alarm
The alarm may be triggered in the following situations:
(Stopping the alarm deactivates the alarm system.)
■ Alarm-operated door lock
●When the alarm is operating, the doors are locked automatically to prevent
intruders.
● Do not leave the key inside the vehicle when the alarm is operating, and
make sure the key is not inside the vehicle when recharging or replacing the
battery.
●
A person inside the vehicle opens a door
or the hood.
● The battery is recharged or replaced
when the vehicle is locked.
NOTICE
■To ensure the system operates correctly
Do not modify or remove the system. If modified or removed, the proper
operation of the system cannot be guaranteed.

1053-1. Key information
3
Operation of each component
4RUNNER (U)■
If you lose your keys
New genuine keys can be made by your Toyota dealer using the ot her key
(vehicles without a smart key system) or mechanical key (vehicles with a
smart key system) and the key number stamped on your key number plate.
Keep the plate in a safe place such as your wallet, not in the vehicle.
■ When riding in an aircraft
When bringing a key with wireless remote control function onto an aircraft,
make sure you do not press any buttons on the key while inside the aircraft
cabin. If you are carrying the key in your bag etc., ensure tha t the buttons are
not likely to be pressed accidentally. Pressing a button may cause the key to
emit radio waves that could interfere with the operation of the aircraft.
■ Conditions affecting operation
Vehicles without a smart key system
The wireless remote control function may not operate normally i n the follow-
ing situations:
● When the wireless key battery is depleted
● Near a TV tower, electric power plant, gas station, radio stati on, large dis-
play, airport or other facility that generates strong radio wav es or electrical
noise
● When carrying a portable radio, cellular phone or other wireles s communi-
cation device
● When the wireless key is in contact with, or is covered by a me tallic object
● When other wireless keys (that emits radio waves) are being use d nearby
● If window tint with a metallic content or metallic objects are attached to the
rear window
Vehicles with a smart key system
P. 122

1063-1. Key information
4RUNNER (U)■
Key battery depletion
Vehicles with a smart key system
● The standard battery life is 1 to 2 years.
● If the battery becomes low, an alarm will sound in the cabin wh en the engine
stops.
● As the electronic key always receives radio waves, the battery will become
depleted even if the electronic key is not used. The following symptoms indi-
cate that the electronic key battery may be depleted. Replace the battery
when necessary. ( P. 443)
• The smart key system or the wireless remote control does not o perate.
• The detection area becomes smaller.
• The LED indicator on the key surface does not turn on.
● To avoid serious deterioration, do not leave the electronic key within 3 ft. (1
m) of the following electrical appliances that produce a magnet ic field:
•TVs
• Personal computers
• Cellular phones, cordless phones and battery chargers
• Recharging cellular phones or cordless phones
• Table lamps
• Induction cookers
Vehicles without a smart key system
If the wireless remote control function does not operate, the b attery may be
depleted. Replace the battery when necessary. ( P. 443)
■ Precautions when disconnecting the battery (vehicles with a sma rt key
system)
● In some cases, it may not be possible to unlock the doors using the smart
key system immediately after the battery has been disconnected. Use the
wireless remote control or the mechanical key to lock or unlock the doors.
● The engine may not start on the first attempt after reconnectin g the battery
but will start normally after the second attempt. This is not a malfunction.
● The engine switch mode is memorized by the vehicle. When the ba ttery is
reconnected, the system will return to the mode it was in befor e the battery
was disconnected. Before disconnecting the battery, turn the en gine switch
off.
If you are unsure what mode the engine switch was in when the b attery was
disconnected, be especially careful when reconnecting the batte ry.

1073-1. Key information
3
Operation of each component
4RUNNER (U)■
Replacing the battery
P. 443
■ Confirmation of the registered key number
The number of keys already registered to the vehicle can be confirmed. Ask
your Toyota dealer for details.
■ If a wrong key is used (vehicles with a smart key system)
The key cylinder rotates freely to isolate inside mechanism.
■ Certification for wireless remote control
For vehicles sold in the U.S.A.

1123-1. Key information
4RUNNER (U)
■Operation signals
Vehicles without a smart key system
The emergency flashers flash to indicate that the doors have been locked/
unlocked. (Locked: once; Unlocked: twice)
Vehicles with a smart key system
A buzzer sounds and the emergency flashers flash to indicate th at the doors
have been locked/unlocked. (Locked: once; Unlocked: twice)
■ Security feature
Vehicles without a smart key system
If a door is not opened within approximately 60 seconds after t he vehicle is
unlocked, the security feature automatically locks the vehicle again.
Vehicles with a smart key system
If a door is not opened within approximately 60 seconds after t he vehicle is
unlocked, the security feature automatically locks the vehicle again. (How-
ever, depending on the location of the electronic key, the key may be
detected as being in the vehicle. In this case, vehicle may be unlocked.)
■ When the door cannot be locked by the lock sensor on the upper part of
the door handle (vehicles with a smart key system)
■ Door lock buzzer
If an attempt to lock the doors is made when a door is not full y closed, a
buzzer sounds continuously. Fully close the door to stop the bu zzer, and lock
the vehicle once more.
■ Alarm (if equipped)
Locking the doors will set the alarm system. ( P. 79)
■ If the smart key system or the wireless remote control does not operate
properly
Vehicles with a smart key system: Use the mechanical key to loc k and unlock
the doors. ( P. 507)
Replace the battery with a new one if it is depleted. ( P. 443)
If the door will not lock even when the top-
side sensor area is touched, try touching
both the topside and underside sensor
areas at the same time.

1213-2. Opening, closing and locking the doors
3
Operation of each component
4RUNNER (U)■
Battery-saving function
The battery-saving function will be activated in order to preve nt the electronic
key battery and the vehicle battery from being discharged while the vehicle is
not in operation for a long time.
● In the following situations, the smart key system may take some time to
unlock the doors.
• The electronic key has been left in an area of approximately 6 ft. (2 m) of
the outside of the vehicle for 10 minutes or longer.
• The smart key system has not been used for 5 days or longer.
● If the smart key system has not been used for 14 days or longer , the doors
cannot be unlocked at any doors except the driver’s door. In th is case, take
hold of the driver’s door handle, or use the wireless remote co ntrol or the
mechanical key, to unlock the doors.
■ Electronic key battery-saving function
When battery-saving mode is set, battery depletion is minimized by stopping
the electronic key from receiving radio waves.
Interior alarm sounds
once.
The engine switch was
pressed after the doors
were unlocked with the
mechanical key.
Touch the electronic
key to the engine
switch while depressing
the brake pedal.
The engine switch was
pressed two consecu-
tive times without the
electronic key being
present.
AlarmSituationCorrection procedure
Press twice while pressing and
holding . Confirm that the electronic
key indicator flashes 4 times.
While the battery-saving mode is set, the
smart key system cannot be used. To
cancel the function, press any of the
electronic key buttons.