2021 TOYOTA 4RUNNER ECU

4016-2. Maintenance
6
Maintenance and care
4RUNNER (U)
Vehicle interior
ItemsCheck points
Accelerator pedal• The accelerator pedal should move smoothly(without uneven pedal effort or catching).
Automatic transmis-
sion “Park” mecha-
nism• When parked on a slope and the shift lever is in P,is the vehicle securely stopped?
Brake pedal
• Does the brake pedal move smoothly?
• Does the brake pedal have appropriate clearancefrom the floor? ( P. 527)
• Does the brake pedal have the correct amount of
free play? ( P. 527)
Brakes
• The vehicle should not pull to one side when the
brakes are applied.
• The brakes should work effectively.
• The brake pedal should not feel spongy.
• The brake pedal should not get too close to the floor when the brakes are applied.
Head restraints• Do the head restraints move smoothly and locksecurely?
Indicators/buzzers• Do the indicators and buzzers function properly?
Lights • Do all the lights come on?
Parking brake
• Does the parking brake pedal move smoothly?
• When parked on a slope and the parking brake is
on, is the vehicle securely stopped?
Seat belts• Do the seat belts operate smoothly?
• The seat belts should not be damaged.
Seats• Do the seat controls operate properly?
Steering wheel
• Does the steering wheel rotate smoothly?
• Does the steering wheel have the correct amountof free play?
• There should not be any strange sounds coming
from the steering wheel.

4096-3. Do-it-yourself maintenance
6
Maintenance and care
4RUNNER (U)■
Removing the engine
compartment cover
■Installing the clips
Push up center portion
Insert
Press
Engine compa rtment cover
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NOTICE
■After installing an engine compartment cover
Make sure that the cover is securely installed in its original position.

4516-3. Do-it-yourself maintenance
6
Maintenance and care
4RUNNER (U)■
Headlight high beam (if equi
pped)/daytime running lights
Turn the bulb base counter-
clockwise.
Pull the bulb out while press-
ing the lock release of the
connector.
Replace the light bulb, and
install the bulb base.
Align the 3 tabs on the light bulb
with the mounting and insert.
Turn and secure the bulb
base.
Shake the bulb base gently to
check that it is not loose, turn
the headlights on once and visu-
ally confirm that no light is leak-
ing through the mounting.
Replacing light bulbs
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3
4

4596-3. Do-it-yourself maintenance
6
Maintenance and care
4RUNNER (U)■
Replacing the following bulbs
If any of the lights listed below has burnt out, have it replac
ed by
your Toyota dealer.
● Headlight low beams (if equipped)
● Headlight low/high beams (if equipped)
● Fog lights
● Side turn signal lights
● Stop/tail lights
● Rear side marker lights
● High mounted stoplight
● Outer foot lights (if equipped)
■LED light bulbs
The headlight low beams (if equipped), headlight low/high beams (if
equipped), fog lights, side turn signal lights, stop/tail light s, rear side marker
lights, high mounted stoplight and outer foot lights consist of a number of
LEDs. If any LEDs burn out, take your vehicle to your Toyota de aler to have
the light replaced.
■ Condensation build-up on the inside of the lens
Temporary condensation build-up on the inside of the lens does not indicate a
malfunction. Contact your Toyota dealer for more information in the following
situations:
● Large drops of water have built up on the inside of the lens.
● Water has built up inside the lens.
WARNING
■Replacing light bulbs
● Turn off the lights. Do not attempt to replace the bulb immedia tely after
turning off the lights.
The bulbs become very hot and may cause burns.
● Do not touch the glass portion of the light bulb with bare hands. When it is
unavoidable to hold the glass portion, use and hold with a clea n dry cloth
to avoid getting moisture and oils on the bulb.
Also, if the bulb is scratched or dropped, it may blow out or crack.
● Fully install light bulbs and any parts used to secure them. Fa ilure to do so
may result in heat damage, fire, or water entering the headligh t unit. This
may damage the headlights or cause condensation to build up on the lens.
■ To prevent damage or fire
● Make sure bulbs are fully seated and locked.
● Check the wattage of the bulb before installing to prevent heat damage.

4637-1. Essential information
7
When trouble arises
4RUNNER (U)
Steadily step on the brake pedal with both feet and firmly depress it.
Do not pump the brake pedal repeatedly as this will increase th e effort
required to slow the vehicle.
Shift the shift lever to N.
If the shift lever is shifted to N
After slowing down, stop the vehi cle in a safe place by the road.
Stop the engine.
If the shift lever cann ot be shifted to N
Keep depressing the brake pedal with both feet to reduce vehicl e
speed as much as possible.
Vehicles without a smart key
system: Stop the engine by
turning the engine switch to the
“ACC” position.
Vehicles with a smart key sys-
tem: To stop the engine, press
and hold the engine switch for 2
consecutive seconds or more,
or press it briefly 3 times or
more in succession.
Stop the vehicle in a s afe place by the road.
If your vehicle has to be stopped in an
emergency
Only in an emergency, such as if it becomes impossible to stop
the vehicle in the normal way, st op the vehicle using the follow-
ing procedure:
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2
3
4
3
4
Press and hold for 2 seconds or more
or press briefly 3 times or more
Q
R

4677-2. Steps to take in an emergency
7
When trouble arises
4RUNNER (U)
WARNING
■While towing
● When towing using cables or chains, avoid sudden starts, etc. w hich place
excessive stress on the towing eyelets, cables or chains. The towing eye-
lets, cables or chains may become damaged, broken debris may hit peo-
ple, and cause serious damage.
● Vehicles with a smart key system: Do not turn the engine switch off.
There is a possibility that the steering wheel is locked and ca nnot be oper-
ated.
● Vehicles without a smart key system: Do not turn the engine switch to the
“LOCK” position.
There is a possibility that the steering wheel is locked and ca nnot be oper-
ated.
NOTICE
■ To prevent damage to the vehicle when towing using a wheel-lift type
truck
● Vehicles with a smart key system: Do not tow the vehicle from the rear
when the engine switch is off. The steering lock mechanism is n ot strong
enough to hold the front wheels straight.
● Vehicles without a smart key system: Do not tow the vehicle fro m the rear
when the engine switch is in the “LOCK” position or the key is removed.
The steering lock mechanism is not strong enough to hold the front wheels
straight.
● When raising the vehicle, ensure adequate ground clearance for towing at
the opposite end of the raised vehicle. Without adequate clearance, the
vehicle could be damaged while being towed.
■ To prevent damage to the vehicle when towing with a sling-type truck
Do not tow with a sling-type truck, either from the front or re ar.
■ To prevent damage to the vehic le during emergency towing
Do not secure cables or chains to the suspension components.
■ Recreational towing (behind mo tor home, etc.) (4WD models)
Never dinghy tow your vehicle to prevent
causing serious damage to the transmis-
sion. (P. 208)

4697-2. Steps to take in an emergency
7
When trouble arises
4RUNNER (U)
When using a flat-bed truck to transport the vehicle, use tire strapping
belts. Refer to the owner's manual of the flat-bed truck for th e tire
strapping method.
Vehicles with a smart key system: In order to suppress vehicle move-
ment during transportation, set the parking brake and turn the engine
switch off.
Vehicles without a smart key system: In order to suppress vehic le
movement during transportation, set the parking brake and turn the
engine switch to the “LOCK” position.
If a tow truck is not available in an emergency, your vehicle m ay be
temporarily towed using cables or chains secured to the emergen cy
towing hooks. This should only be attempted on hard surfaced roads
for at most 80 km (50 miles) at under 30 km/h (18 mph).
A driver must be in the vehicle to steer and operate the brakes . The
vehicle’s wheels, drive train, a xles, steering and brakes must be in
good condition.
NOTICE
■ Towing with a sling-type truck
Using a flatbed truck
Emergency towing
Do not tow with a sling-type truck to pre-
vent body damage.

4707-2. Steps to take in an emergency
4RUNNER (U)
Vehicles with front covers only:
Before using the front emer-
gency towing eyelet(s), remove
the cover(s).Removing the clips
Installing the clips
Securely attach cables or
chains to the towing hook.
Take care not to damage the vehi-
cle body.
Enter the vehicle being towed and start the engine.
Vehicles with a smart key system: If the engine does not start, turn the
engine switch to ON.
Vehicles without a smart key system: If the engine does not sta rt, turn the
engine switch to the “ON” position.
Emergency towing procedure
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