2021 TOYOTA TUNDRA trailer

3244-5. Using the driving support systems
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC,
Trailer Sway Control and hill-start assist control systems
● A sound may be heard from the engine compartment when the brake pedal
is depressed repeatedly, when the engine is started or just aft er the vehicle
begins to move. This sound does not indicate that a malfunction has
occurred in any of these systems.
● Any of the following conditions may occur when the above system s are
operating. None of these indicates that a malfunction has occur red.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard also after the vehicle comes to a s top.
• The brake pedal may pulsate slightly after the ABS is activate d.
• The brake pedal may move down slightly after the ABS is activa ted.
■ Automatic reactivation of TRAC, Trailer Sway Control and VSC sy stems
After turning the TRAC, Trailer Sway Control and VSC systems of f, the sys-
tems will be automatically re-enabled in the following situations:
● When the engine switch is turned off
● If only the TRAC system is turned off, the TRAC will turn on wh en vehicle
speed increases
If both the TRAC and VSC systems are turned off, automatic re-enabling will
not occur when vehicle speed increases.
■ If the brake system overheats
TRAC will cease operation, and the slip indicator will change f rom flashing to
being on continuously to alert the driver. Stop the vehicle in a safe place.
(There is no problem with continuing normal driving.)
■ Shifting to “4L”
VSC and Trailer Sway Control are automatically turned off.

3254-5. Using the driving support systems
4
Driving
WARNING
■The ABS does not operate effectively when
● The limits of tire gripping performance have been exceeded (suc h as
excessively worn tires on a snow covered road).
● The vehicle hydroplanes while driving at high speed on wet or s lick roads.
■ Stopping distance when the ABS is operating may exceed that of nor-
mal conditions
The ABS is not designed to shorten the vehicle’s stopping distance. Always
maintain a safe distance from the vehicle in front of you, espe cially in the
following situations:
● When driving on dirt, gravel or snow-covered roads
● When driving with tire chains
● When driving over bumps in the road
● When driving over roads with potholes or uneven surfaces
■ TRAC/VSC may not operate effectively when
Directional control and power may not be achievable while driving on slip-
pery road surfaces, even if the TRAC/VSC system is operating.
Drive the vehicle carefully in conditions where stability and p ower may be
lost.
■ Hill-start assist control does not operate effectively when
● Do not overly rely on hill-start assist control. Hill-start ass ist control may
not operate effectively on steep inclines and roads covered wit h ice.
● Unlike the parking brake, hill-st art assist control is not intended to hold the
vehicle stationary for an extended period of time. Do not attempt to use
hill-start assist control to hold the vehicle on an incline, as doing so may
lead to an accident.
■ When the TRAC/VSC/Trailer Sway Control are activated
The slip indicator light flashes. Always drive carefully. Reckless driving may
cause an accident. Exercise particular care when the indicator light flashes.

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)

3274-5. Using the driving support systems
4
Driving
Trailer brake controller
The trailer brakes can be controlled by the Trailer brake controller via
the 7-pin connector. By selecting the type of brakes that are being
used on the trailer (electric or electric-over-hydraulic) and s etting the
gain for the controller, the manual TRAILER BRAKE OUTPUT slider
is used to slow just the traile r. The vehicle brake pedal will also slow
down as well as stop the trailer when applied, also via the sam e con-
nector. Gain values, manual brake outputs, trailer brake types, and
the trailer connection status are displayed in the multi-information dis-
play.
Trailer connection indicator
When the trailer has been connected, the indicator comes on
green.
GAIN (+/-) selection button
Pressing the GAIN (+/-) buttons w ill adjust the amount of power
that can be outputted to the trailer brakes. The gain can be
adjusted from 0 (no trailer braking) to 10 (maximum output) in 0.5
increments. Each press of the bu tton will increase or decrease
the gain setting by one step. The gain value will appear in the
multi-information display.
: If equipped
Summary of functions
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3284-5. Using the driving support systems
Trailer brake type
Trailer brake type can be selected by using the multi-informati on. The
combination meter will show which trailer brake type is selected in the
multi-information display.
Manual TRAILER BRAKE OUTPUT slider
Adjusting this slider position will engage the trailer’s brakes only. If the
manual TRAILER BRAKE OUTPUT slider is used while the vehicle
brake is applied, the greater of the two outputs will be sent to the trailer
brakes.
The trailer brake type can be se lected on the multi-information display
as following:
Press “ ” or “” of meter control sw itches and select .
Press “ ” or “ ” of meter control switches and select “Vehicle Set-
tings”, and press .
Press “ ” or “ ” of meter control switches and select “TBC Trailer
Type”, and press to select the correct type of trailer brakes that
are equipped on the trailer.
Changing trailer brake type will cause the current gain setting to reset
to zero. Make sure to set the gain as described in the followin g sec-
tion.
Gain setting on trailer brake controller should be set for a sp ecific tow-
ing condition. Gain setting should be adjusted each time the ve hicle
load, trailer load, road conditions, or weather changes. Settin g the
gain value to 0 will disable the tra iler brake controller output.
Make sure the trailer brakes are in good working condition and
functioning normally. See trailer dealer if necessary.
Hook up the trailer and make p roper electrical connections.
Select the correct type of trailer brakes that are equipped on the
trailer by using the multi-information display.
Drive vehicle with trailer attached on a level road surface sim ilar to
towing condition and in traffic-free environment. Driving speed
should be approximately 20 - 25 mph [35 - 40 km/h].
Changing settings of the trailer brake type
Setting the Gain
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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.
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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.

4877-2. Steps to take in an emergency
7
When trouble arises
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such as• Natural causes ( P. 4 9 0 )
• Flat tire ( P. 506)
 Adjust the tire inflation pressure to the specified
level.
The light will turn off after a few minutes. In case
the light does not turn off even if the tire inflation
pressure is adjusted, have the system checked by
your Toyota dealer.
When the light comes on af ter blinking for 1 minute:
Malfunction in the tire p ressure warning system.
 Have the system checked by your Toyota dealer.
Slip indicator
Indicates a malfunction in:
• The VSC system;
• Trailer Sway Control system;
• The TRAC system;
• The hill-start assist control system; or
• The AUTO LSD system.
 Have the vehicle inspected by your Toyota dealer
immediately.
The light will flash when any of the above systems other
than the hill-start assist control are operating.
Warning lightWarning light/Details/Actions