2021 TOYOTA 4RUNNER engine

4186-3. Do-it-yourself maintenance
4RUNNER (U)■
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 ACCESSORY mode. The engine
may not start when the engine switch turned from off. However, the engine
will 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.
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 the
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.
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4196-3. Do-it-yourself maintenance
6
Maintenance and care
4RUNNER (U)
WARNING
■Where to safely charge the battery
Always charge the battery in an open area. Do not charge the ba ttery 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 explo de 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 ge t 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.

4216-3. Do-it-yourself maintenance
6
Maintenance and care
4RUNNER (U)
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 et c.
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.

4256-3. Do-it-yourself maintenance
6
Maintenance and care
4RUNNER (U)
◆Installing tire pressure warning valve and transmitters
When replacing the tires or wheels, the tire pressure warning v alve
and transmitters must be install ed to the wheels which will be
installed to the vehicle.
When new tire pressure warning valve and transmitters are
installed, new ID codes must be registered in the tire pressure
warning computer and the tire pressure warning system must be
initialized. ( P. 426)
◆Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the fol-
lowing circumstances:
● When the tire inflation pressure is changed such as when chang-
ing traveling speed or load weight.
● When the tire inflation pressure is changed such as when the ti re
size is changed.
● When rotating the tires.
● After performing the transmitter ID code registration procedure .
(  P. 426)
When the tire pressure warning sy stem is initialized, the current tire
inflation pressure is set as the benchmark pressure.
■How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the engine switch off .
The initialization procedure cannot be started while the vehicle is
moving.
Adjust the tire inflation pressure to the specified cold tire i nflation
pressure level. ( P. 528)
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.
Start the engine. ( P. 209, 212)
Select on the multi-information display using the meter con-
trol switches on the steering wheel. ( P. 9 6 )
Select “Vehicle Settings” and then press and hold .
Select “TPWS” and then press .
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4316-3. Do-it-yourself maintenance
6
Maintenance and care
4RUNNER (U)■
The initialization operation
●Make sure to carry out initializ
ation 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 to the “LOCK” position
(vehicles without a smart key system) or off (vehicles with a s mart key
system) during initialization, it is not necessary to press the reset switch
again as initialization will rest art automatically when the engine switch
has been turned to the “ON” posi tion (vehicles without a smart key sys-
tem) or IGNITION ON mode (vehicl es with a smart key system) 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.
■When initialization of the tire pressure warning system has fai led
●Do not move the vehicle backward during initialization. Initialization is
started again from the beginning and it may take longer than usual.
●Initialization may take longer to complete if the vehicle is driven on an
unpaved road.
When performing initialization, drive on a paved road if possib le.
Depending on the driving environment and condition of the tires , initial-
ization will be complet ed in approximately 10 to 30 minutes.
• If initialization is not complet e after driving approximately 30 minutes,
continue driving for a while.
• If initialization is not complet e after driving approximately 1 hour, park
the vehicle in a safe place for approximately 20 minutes. Then drive
straight (with occasional left a nd right turns) at approximatel y 25 mph
(40 km/h) or more
* for approximately 10 to 30 minutes.
• If initialization is still not co mplete, have the vehicle inspected by your
Toyota dealer.
*: Except when making a left/right turn
●In the following situations, the tire inflation pressure will n ot be recorded
and the system will not operate p roperly. Perform initialization again.
• When operating the tire pressure warning reset switch, the tir e pres-
sure warning light does not blink 3 times.
• After performing initialization, the tire pressure warning light blinks for
1 minute then stays on after driving for about 20 minutes.

4326-3. Do-it-yourself maintenance
4RUNNER (U)■
When ID code registration has failed
●Registration may take long time or the ID codes may not be regi
stered in
the following situations.
• When the vehicle is moved backward during registration.
Registration is started again from the beginning and it may tak e lon-
ger than usual.
• When another vehicle is running the side of the vehicle such a s in
heavy traffic.
It may take longer to detect the vehicle’ tire pressure warning valves
and transmitters.
• If tire pressure warning valves and transmitters are in the vehicle.
The ID codes may n ot be registered.
●When performing registration, drive on a paved road if possible .
Depending on the driving environment and condition of the tires, regis-
tration will be complet ed in approximately 10 to 30 minutes.
• If registration is not complete after driving approximately 30 minutes,
continue driving for a while.
• If registration is not complete after driving approximately 1 hour, park
the vehicle in a safe place for approximately 20 minutes. Then drive
straight (with occasional left and right turns) at approximatel y 40 km/h
(25 mph) or more
* for approximately 10 to 30 minutes.
If registration is still not comp lete, have the vehicle inspected by your
Toyota dealer.
*: Except when making a left/right turn
●When the tire pressure warning light does not blink slowly 3 ti mes, the
ID code will not be registered and the system will not operate properly.
Perform registration again.
■When registering ID codes
●Initialize the tire pressure war ning system after ID code regis tration. Ini-
tialization is disable d if the system was initialized before re gistration.
●After ID code registration, the tires are hot by driving. Initi alize the tire
pressure warning system af ter the tires become cold.
■Canceling the change wheel set mode
●If turning the engine switch to the “LOCK” position (vehicles w ithout a
smart key system) or off (vehicles with a smart key system) whe n in the
change wheel set mode before driving, the change wheel set mode is
canceled.
●After driving when in the change wheel set mode, the change whe el set
mode cannot be canceled. To cancel the mode, perform the proced ure
for ID code registration again and turn the engine switch to th e “LOCK”
position (vehicles without a smart key system) or off (vehicles with a
smart key system ) before driving.
●If the change wheel set mode is canceled, the ID codes that hav e
already been registered are commu nicated. When communication is fin-
ished, the tir e pressure warning light will turn off.

4416-3. Do-it-yourself maintenance
6
Maintenance and care
4RUNNER (U)
Turn the engine switch off.
Open the glove box and
remove the cover.
Remove the filter cover.
Remove the air conditioning fil-
ter and replace it with a new
one.
The “UP” marks shown on the fil-
ter should be pointing up.
Air conditioning filter
The air conditioning filter must b e changed regularly to maintain
air conditioning efficiency.
Removal method
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4466-3. Do-it-yourself maintenance
4RUNNER (U)
Turn the engine switch off.
Open the Fuse box cover.
Engine compartment
Push the tab in and lift the lid off.
Driver’s side instrument panel
Remove the lid.
Remove the fuse with the pull-
out tool.
Only type A fuse can be removed
using the pullout tool.
Checking and replacing fuses
If any of the electrical components do not operate, a fuse may
have blown. If this happens, che ck and replace the fuses as nec-
essary.
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