2012 TOYOTA TUNDRA Owners Manual

249
2-4. Using other driving systems
2
When driving
Driving assist systems
To help enhance driving safety and performance, the following sys-
tems operate automatically in res ponse to various driving situations.
Be aware, however, that these systems are supplementary and
should not be relied upon too heavi ly when operating the vehicle.
■ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, 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 pedal is
depressed, when the system detects 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 engine torque when trailer
sway is detected.
Trailer Sway Control is part of the VSC system and will not operate if
VSC is turned off or experiences a malfunction.
■ TRAC (Traction Control) for 2WD models and 2WD mode on
4WD models
Maintains drive power and prevents the rear wheels from spinning
when starting the vehicle or accelerating on slippery roads.
■A-TRAC (Active Traction Control) for 4WD mode on 4WD
models
Maintains drive power and prevents all wheels from spinning when
starting the vehicle or accelerating on slippery roads.

250 2-4. Using other driving systems
When VSC/Trailer Sway Control/TRAC/A-TRAC are operatingVehicles with multi-information display If the vehicle is in danger of slip-
ping, or if the rear wheels (2WD
models and 2WD mode on 4WD
models) or all wheels (4WD
mode on 4WD models) spin, the
slip indicator flashes to indicate
that VSC/Trailer Sway Control/
TRAC/A-TRAC have been
engaged.
Vehicles without multi-information display

251
2-4. Using other
driving systems
2
When driving
To disable VSC, Trailer Sway Control and/or TRAC (2WD models
and 2WD mode on 4WD models)
If the vehicle gets stuck in fresh snow or mud, VSC, Trailer Sway
Control and TRAC may reduce power from the engine to the wheels.
You may need to turn the system off to enable you to rock the vehicle
in order to free it.
■ TRAC OFF mode
Press the VSC OFF switch
briefly.
The AUTO LSD indicator will
come on.
The system is in TRAC off, AUTO
LSD on and VSC, Trailer Sway
Control on mode.
Push the switch again to turn the
system back on.
■AUTO LSD mode
Stop the vehicle completely, and
press the VSC OFF switch for
more than 3 seconds, when the
system is in the TRAC OFF
mode.
The VSC OFF and AUTO LSD
indicators will come on.
The system is in TRAC off, AUTO
LSD on and VSC, Trailer Sway
Control off mode.

252 2-4. Using other driving systems
■VSC OFF mode
Stop the vehicle completely, and
press the VSC OFF switch for
more than 3 seconds, when the
system is in the AUTO LSD
mode.
The VSC OFF and TRAC OFF
indicators will come on.
The system is all off mode.
To disable VSC, Trailer Sway Control or A-TRAC (4H mode on 4WD models)
If the vehicle gets stuck in fresh snow or mud, VSC, Trailer Sway
Control or A-TRAC may reduce power from the engine to the wheels.
You may need to turn the system off to enable you to rock the vehicle
in order to free it.
■A-TRAC OFF mode
Press the VSC OFF switch
briefly.
The TRAC OFF indicator will
come on.
The system is in A-TRAC off and
VSC, Trailer Sway Control on
mode.
Push the switch again to turn the
system back on.

253
2-4. Using other
driving systems
2
When driving
■VSC OFF mode
Stop the vehicle completely, and
press the VSC OFF switch for
more than 3 seconds.
The VSC OFF and TRAC OFF
indicators will come on.
The system is all off mode.
Push the switch again to turn the
system back on.
To disable A-TRAC (4L mode on 4WD models)
If the vehicle gets stuck in fresh snow or mud, A-TRAC may reduce
power from the engine to the wheels. You may need to turn the sys-
tem off to enable you to rock the vehicle in order to free it. Stop the vehicle completely, and
press the VSC OFF switch for
more than 3 seconds.
The TRAC OFF indicators will
come on.
Push the switch again to turn the
system back on.

254 2-4. Using other driving systems
■When the TRAC OFF indicator light comes on even if the VSC OFF
switch has not been pressed
TRAC system cannot be operated. Contact your Toyota dealer.
■ Automatic reactivation of TRAC, A-TRAC, VSC and Trailer Sway Con-
trol
Turning the engine switch off after turning off the TRAC, A-TRAC, VSC and
Trailer Sway Control systems will automatically re-enable them.
■ Sounds and vibrations caused by the ABS, TRAC, A-TRAC, VSC,
Trailer Sway Control and Brake Assist system
● A sound may be heard from the engine compartment when the engine is
started and just after 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 systems are
operating. None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slightly after the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.
■ If the brake system overheats
TRAC or A-TRAC will cease operation, and the slip indicator will change
from 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.

255
2-4. Using other
driving systems
2
When driving
CAUTION
Any of the following conditions may result in an accident which could cause
death or serious injury.
■The ABS does not opera te effectively when
● The limits of the gripping performance have been exceeded.
● The vehicle hydroplanes while driving at high speed on the wet or slick
road.
■ 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 in the following situ-
ations.
● 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 pothol es or roads with uneven roads
■ When VSC and Trailer Sway Control are activated
The slip indicator flashes. Always drive carefully. Reckless driving may
cause an accident. Exercise particular care when the indicator flashes.
■ TRAC or A-TRAC may not operate effectively when
Directional control and power may not be achievable while driving on slip-
pery road surfaces, even if TRAC or A-TRAC is operating.
Do not drive the vehicle in conditions where stability and power may be lost.
■ Replacing tires
Make sure that all tires are of the same size, brand, tread pattern and total
load capacity. In addition, make sure that the tires are inflated to the appro-
priate tire pressure level.
The ABS, VSC and Trailer Sway Control will not function correctly if different
tires are fitted on the vehicle.
Contact your Toyota dealer for further information when replacing tires or
wheels.

256 2-4. Using other driving systems
CAUTION
■Handling of tires and suspension
Using tires with any kind of problem or modifying the suspension will affect
the driving assist systems, and may cause the system to malfunction.
■ 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 Sway Control sys-
tem may not be effective. Refer to your trailer owner’s manual for information
on how to tow your trailer properly.
■ If trailer sway occurs
Observe the following precautions.
Failing 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 wheel.
● Begin releasing the accelerator pedal immediately but very gradually 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. 290)