2012 TOYOTA TUNDRA engine

244 2-4. Using other driving systems
■If the 4LO indicator light blinks
●If the 4LO indicator continues to blink when shifting between 4H and 4L,
stop the vehicle completely, move the shift lever to N and operate the
switch again.
● If the shift lever is moved before the 4LO indicator turns on/off, the trans-
fer mode may not be shifted completely. The transfer mode disengages
both the front and rear driveshafts from the powertrain and allows the
vehicle to move regardless of the shift position. (At this time, the indicator
blinks and the buzzer sounds.)
Therefore, the vehicle is free to roll even if the automatic transmission is in
P. You or someone else could be seriously injured. You must complete the
shifting of the transfer mode.
To complete the shifting, stop the vehicle completely, return the shift lever
to N, and confirm that the shift was completed (The indicator turns on/off).
● If the engine coolant temperature is too low, the transfer mode may not
be able to be shifted. When the engine is warmer, operate the switch
again.
If the 4LO indicator light continues to blink even after attempting the above,
there may be a malfunction in the engine, the brake system or the four-
wheel drive system. In this case, you may not be able to shift between 4H
and 4L. Have the vehicle inspected by your Toyota dealer immediately.
■ Shifting to 4L
VSC is automatically turned off.
■ 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.

246
2-4. Using other driving systems
AUTO LSD system
The AUTO LSD system aids traction by using the traction control
system to control engine performance and braking when one of the
rear wheels begins to spin.
The system should be used only wh en one of the rear wheels spin-
ning occurs in a ditch or rough surface.
■ System operation
The system can be used on 2W D models and in 2WD mode on
4WD models.
The system is activated when dr iving at a speed under 62 mph
(100 km/h).
The AUTO LSD system will be ac tivated with the following two
procedures.
Press the VSC OFF switch
briefly.
At this time, the AUTO LSD
indicator will come on.
To turn off the system, push
the switch again.
Stop the vehicle completely,
and press the VSC OFF
switch for more than 3 sec-
onds.
At this time, the VSC OFF and
AUTO LSD indicators will
come on simultaneously.
To turn off the system, push
the switch again.

247
2-4. Using other
driving systems
2
When driving
When the AUTO LSD system is operating
Vehicles with multi-information display If the rear wheels spin, the slip
indicator flashes to indicate that
the AUTO LSD system has con-
trolled the spinning of the rear
wheels.
Vehicles without multi-information display
■ If the engine is turned off and restarted
The AUTO LSD system and the indicators are automatically turned off.
■ If the brake system overheats
The AUTO LSD system 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.)
The system will be automatically restored after a short time.

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.

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.