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3174-5. Using the driving support systems
4
Driving
■When the front-wheel drive cont rol switch is shifted to “4L”
VSC is automatically turned off.
■ If the “4HI” indicator flashes
The transfer mode may not successfully change. Drive straight a head while
accelerating or decelerating, or drive in reverse.
■ If the “4LO” indicator continues to flash
The transfer mode may not successfully change. Operate the fron t-wheel
drive control switch again.
■ If the “4LO” indicator continues to flash and a buzzer sounds
The shift lever is not in N and/or the vehicle is moving. Stop the vehicle com-
pletely, shift the shift lever to N and make sure that the indi cator stops flash-
ing.
■ If the “4HI” or “4LO” indicator flashes rapidly
There may be a malfunction in the four-wheel drive system. Have the vehicle
inspected by your Toyota dealer immediately.
■ Four-wheel drive usage frequency
You should drive in four-wheel drive for at least 10 miles (16 km) each month.
This will assure that the front drive components are lubricated .
WARNING
■Shifting the front-wheel drive control switch from “2WD” to “4H ” while
driving
Never operate the front-wheel drive control switch if the wheels are slipping.
Stop the slipping or spinning before shifting.
■ When the vehicle is parked
If the shift lever is moved before the “4LO” indicator turns on/off, the transfer
mode may not be shifted completely. The transfer mode disengage s both
the front and rear driveshafts from the powertrain and allows t he vehicle to
move regardless of the shift position. (At this time, the indic ator blinks and
the buzzer sounds.)
Therefore, the vehicle is free to roll even if the automatic tr ansmission is in
P. You or someone else could be seriously injured. You must com plete the
shifting of the transfer mode before placing transmission in P.
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3184-5. Using the driving support systems
AUTO LSD system
The system can be used on 2WD models and in 2WD mode on 4WD
models. The system is activated when driving at a speed under
62 mph (100 km/h). The AUTO LSD system will be activated with th e
following two procedures.
Press the briefly to turn on
the system.
The “AUTO LSD” indicator will
come on.
To turn off the system, press
again.
Stop the vehicle completely, and
press for more than 3 sec-
onds.
The “AUTO LSD” and VSC off
indicators will come on.
To turn off the system, press
again.
The AUTO LSD system aids trac tion by using the traction con-
trol system to control engine performance and braking when
one of the drive wheels begins to spin.
The system should be used only when one of the drive wheels
spinning occurs in a ditch or rough surface.
System operation
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3194-5. Using the driving support systems
4
Driving
■If the brake system overheats
The system will cease operation and a buzzer will alert the driver. At this time,
the “TRAC OFF” indicator will come on. Stop the vehicle in a safe place.
(There is no problem with continuing normal driving.) The syste m will be auto-
matically restored after a short time.
WARNING
■ To avoid an accident
Failure to do so, a much greater steering effort and more careful cornering
control will be required.
● Do not use the AUTO LSD system in conditions other than when on e of
the drive wheels spinning occurs in a ditch or rough surface.
● Do not drive with the AUTO LSD system continuously turned on.
NOTICE
■Activating while driving
Do not activate the AUTO LSD system if the wheel is slipping. Stop the slip-
ping or spinning before activating.
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3204-5. Using the driving support systems
Driving assist systems
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenl y,
or if the brakes are applied while driving on a slippery road surface
◆Brake assist
Generates an increased level of braking force after the brake p edal
is depressed when the system de tects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or
turning on slippery road surfaces
◆Trailer Sway Control
Helps the driver to control trailer sway by selectively applying brake
pressure for individual wheels and reducing driving torque when
trailer sway is detected
◆TRAC (Traction Control) for 2WD models and 2WD mode on
4WD models
Helps to maintain drive power and prevent the drive wheels from
spinning when starting the vehicl e or accelerating on slippery roads
◆Hill-start assist control
Helps to reduce the backward movement of the vehicle when start -
ing on an uphill
To keep driving safety and perf ormance, the following systems
operate automatically in respon se to various driving situations.
Be aware, however, that these systems are supplementary and
should not be relied upon too heav ily when operating the vehi-
cle.
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3214-5. Using the driving support systems
4
Driving
The slip indicator light will flash
while the TRAC/VSC/Trailer Sway
Control systems are operating.
If the vehicle gets stuck in mud, dirt or snow, the TRAC system may
reduce power from the engine to the wheels. Pressing to turn
the system off may make it easier for you to rock the vehicle i n order
to free it.
■Turning off TRAC system
2WD models and 2WD mode on 4WD models
To turn the TRAC system off,
press .
The “AUTO LSD” indicator light
will come on.
Press again to turn the
system back on.
When the TRAC/VSC/Trailer Sway Control systems are operating
Disabling the TRAC systems
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3264-5. Using the driving support systems
WARNING
■When the TRAC/VSC/Trailer Sway Control systems are turned off
Be especially careful and drive at a speed appropriate to the r oad condi-
tions. As these are the systems to help ensure vehicle stabilit y and driving
force, do not turn the TRAC/VSC/Trailer Sway Control systems of f unless
necessary.
Trailer Sway Control is part of the VSC system and will not operate if VSC is
turned off or experiences a malfunction.
■ Replacing tires
Make sure that all tires are of the specified size, brand, trea d pattern and
total load capacity. In addition, make sure that the tires are inflated to the
recommended tire inflation pressure level.
The ABS, TRAC, VSC and Trailer Sway Control systems will not function
correctly if different tires are installed on the vehicle.
Contact your Toyota dealer for further information when replaci ng tires or
wheels.
■ Handling of tires and the suspension
Using tires with any kind of problem or modifying the suspensio n will affect
the driving assist systems, and may cause a system to malfuncti on.
■ Trailer Sway Control precaution
The Trailer Sway Control system is not able to reduce trailer sway in all situ-
ations. Depending on many factors such as the conditions of the vehicle,
trailer, road surface, and driving environment, the Trailer Swa y Control sys-
tem may not be effective. Refer to your trailer owner’s manual for informa-
tion on how to tow your trailer properly.
■ If trailer sway occurs
Observe the following precautions.
Failure to do so may cause death or serious injury.
● Firmly grip the steering wheel. Steer straight ahead.
Do not try to control trailer swaying by turning the steering w heel.
● Begin releasing the accelerator pedal immediately but very grad ually to
reduce speed.
Do not increase speed. Do not apply vehicle brakes.
If you make no extreme correction with the steering or brakes, your vehicle
and trailer should stabilize. ( P. 213)
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![TOYOTA TUNDRA 2021 Owners Manual (in English) 3294-5. Using the driving support systems
4
Driving
Using the GAIN (+/-) selection
buttons, set a starting gain of
5.0.
While driving 20 - 25 mph [35 - 40 km/h], fully apply the
TOYOTA TUNDRA 2021 Owners Manual (in English) 3294-5. Using the driving support systems
4
Driving
Using the GAIN (+/-) selection
buttons, set a starting gain of
5.0.
While driving 20 - 25 mph [35 - 40 km/h], fully apply the](/manual-img/14/43052/w960_43052-328.png)
3294-5. Using the driving support systems
4
Driving
Using the GAIN (+/-) selection
buttons, set a starting gain of
5.0.
While driving 20 - 25 mph [35 - 40 km/h], fully apply the
manual
TRAILER BRAKE OUTPUT
slider.
Adjust the gain setting, using t he GAIN (+/-) selection buttons , to
either increase or decrease to j ust below the point of trailer wheel
lock-up.
For confirmation, repeat steps and until desired gain setting
is reached (just below point of trailer wheel lock-up).
■ When using the trailer brake control system
Please turn off the intuitive parking assist while towing a tra iler. If left on,
sonar sensors will detect the trailer being towed.
■ When setting the gain
Wheel lock-up occurs when the trailer wheel squeals or tire smo ke occurs.
Trailer wheels may not lock-up while driving heavily loaded trailer. During this
case, adjust the Trailer gain to the highest allowable setting for the towing
condition.
■ When disconnecting and reco nnecting battery terminals
The gain setting data will be reset.
5
6
7
867
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3304-5. Using the driving support systems
WARNING
■Trailer brake type setting
It is the responsibility of the driver to make sure the trailer brakes are func-
tioning normally and adjusted appropriately. Failure to check a nd maintain
trailer brakes may result in loss of vehicle control, crash, or serious injury.
Trailer brake control system will work with most electric and e lectric-over-
hydraulic trailer braking systems up to 3 axles (24A output to trailer brakes).
Please be sure to test compatibility with the system at low spe eds and in a
safe area. If a warning message appears in the multi-information display
( P. 500), have the vehicle inspected by your Toyota dealer immed iately.
Some electric-over-hydraulic trailer brakes will take some mini mum output
to activate. Trailer brake control system will not work with tr ailer hydraulic
surge brakes.
■ When driving on slippery road surfaces
When stopping with ABS activated, output to the trailer might b e reduced in
order to reduce the likelihood of trailer wheels to lock. The trailer is not
equipped with ABS. Drive safely on slippery road surfaces.