2012 TOYOTA SIENNA brake light

328 2-4. Using other driving systems
SIENNA_U (OM45477U)
When the Enhanced VSC/TRAC systems are operatingIf the vehicle is in danger of slip-
ping or if any of the drive wheels
spins, the slip indicator light
flashes to indicate that the
Enhanced VSC/TRAC systems
are operating.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
■Active Torque Control 4WD (AWD models only)
Automatically switches from front-wheel drive to AWD (All-Wheel Drive)
according to driving conditions, helping to ensure reliable handling and
stability. Examples of conditions where the system will switch to AWD
are when cornering, going uphill, star ting off or accelerating, and when
the road surface is slippery due to snow or rain etc.
■ VDIM (Vehicle Dynamics In tegrated Management) (if
equipped)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-
start assist control, and EPS systems
Helps to maintain vehicle stability when swerving on slippery road sur-
faces by controlling the brakes and engine output
■ PCS (Pre-Collision System) (if equipped)
P. 336

330 2-4. Using other driving systems
SIENNA_U (OM45477U)
■When the “TRAC OFF” indicator light comes on even if the VSC OFF
switch has not been pressed
TRAC and hill-start assist control cannot be operated. Contact your Toyota
dealer.
■ Sounds and vibrations caused by ABS, brake assist, Enhanced VSC
and TRAC
● A sound may be heard from the engine compartment when the engine is
started or just after the vehicle begins to move. This sound does not indi-
cate 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 ABS is activated.
• The brake pedal may move down slightly after ABS is activated.
■ EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may
be heard. This does not indicate a malfunction.
■ Reactivation of the TRAC and VSC systems after turning off the engine
Turning off the engine after turning off the TRAC and VSC systems will auto-
matically reactivate them.
■ Reactivation of the TRAC system linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on
when vehicle speed increases. However, when both TRAC and VSC sys-
tems are turned off, the systems will not turn on even when vehicle speed
increases.

334 2-4. Using other driving systems
SIENNA_U (OM45477U)
■Hill-start assist control can be operated when
• The shift lever is in a position other than P.
• The parking brake is not applied.
• The accelerator pedal is not depressed.
■ Hill-start assist control
● While hill-start assist control is operating, the brakes remain automati-
cally applied after the driver releases the brake pedal. The stop lights and
the high mounted stoplight turn on.
● Hill-start assist control operates for about 2 seconds after the brake pedal
is released.
● If the slip indicator does not flash and the buzzer does not sound when
the brake pedal is further depressed, slightly reduce the pressure on the
brake pedal (do not allow the vehicl e to roll backward) and then firmly
depress it again. If the system still does not operate, check if the operat-
ing conditions explained above have been met.
■ Hill-start assist control buzzer
● When hill-start assist control is activated, the buzzer will sound once.
● In the following situations, hill-start assist control will be canceled and the
buzzer will sound twice.
• No attempt is made to drive the vehicle within approximately 2 seconds
of releasing the brake pedal.
• The shift lever is moved to P.
• The parking brake is applied.
• The brake pedal is depressed again.
• The brake pedal has been depressed for more than approximately 3 minutes.
■ If the slip indicator comes on...
It may indicate a malfunction in the system. Contact your Toyota dealer.

336
2-4. Using other driving systems
SIENNA_U (OM45477U)
PCS (Pre-Collision System)
: If equipped
When the radar sensor detects that a frontal collision is highly likely
or even unavoidable, the systems such as the brakes and seat
belts are automatically engaged to lessen impact to occupants as
well as vehicle damage.
■ Pre-collision seat belts (front seat belts only)
If the pre-collision s ensor detects that a co llision is unavoidable,
the pre-collision system will retract the seat belt before the colli-
sion occurs. The same will happen if the driver makes an emer-
gency braking or loses co ntrol of the vehicle. (P. 131)
However, when the VSC system is disabled, the system will not
operate in the event of skidding.
■ Pre-collision brake assist
When there is a high possibility of a frontal collision, the system
applies greater braking force in relation to how strongly the
brake pedal is depressed.
■ Pre-collision braking
When there is a high possibility of a frontal collision, the system
warns the driver using a warning light and buzzer. If the system
determines that a collision is un avoidable, the brakes are auto-
matically applied to reduce th e collision speed. Pre-collision
braking can be disabled usi ng the pre-collision braking off
switch.

375
2-5. Driving information
2
When driving
SIENNA_U (OM45477U)
CAUTION
■
When towing a trailer
Toyota recommends trailers with brak es that conform to any applicable fed-
eral and state/provincial regulations.
● If the gross trailer weight exceeds unbraked TWR, trailer brakes are
required. Toyota recommends trailers wi th brakes that conform to all appli-
cable federal and state/provincial regulations.
● Never tap into your vehicle’s hydraulic system, as this will lower the vehi-
cle’s braking effectiveness.
● Never tow a trailer without using a safety chain securely attached to both
the trailer and the vehicle. If damage occurs to the coupling unit or hitch
ball, there is danger of the trailer wandering into another lane.
NOTICE
■When installing a trailer hitch
Use only the position recommended by your Toyota dealer. Do not install the
trailer hitch on the bumper; this may cause body damage.
■ Do not directly splice trailer lights
Do not directly splice trailer lights. Directly splicing trailer lights may damage
your vehicle’s electrical system and cause a malfunction.

644 4-2. Maintenance
SIENNA_U (OM45477U)
ItemsCheck points
Indicators/buzzers • Do the indicators and buzzers
function properly?
Lights • Do all the lights come on?
• Are the headlights aimed cor-
rectly?
Parking brake • Does the parking brake lever or
pedal move smoothly?
• When parked on a slope with the parking brake on, is the vehicle
securely stopped?
Seat belts • Do the seat belts operate
smoothly?
• The seat belts should not be dam- aged.
Seats • Do the seat controls operate
properly?
Steering wheel • Does the steering wheel rotate
smoothly?
• Does the steering wheel have the correct amount of free play?
• There should not be any strange sounds coming from the steering
wheel.

666 4-3. Do-it-yourself maintenance
SIENNA_U (OM45477U)
■Brake fluid can absorb moisture from the air
Excess moisture in the brake fluid can cause a dangerous loss of braking
efficiency. Use only newly opened brake fluid.
CAUTION
■When filling the reservoir
Take care as brake fluid can harm your hands and eyes and damage painted
surfaces.
If fluid gets on your hands or in your eyes, flush the affected area with clean
water immediately.
If you still experience discomfort, see a doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads
wear out or when the fluid level in the accumulator is high.
If the reservoir needs frequent refilling, there may be a serious proble\
m.

5
When trouble arises
729
SIENNA_U (OM45477U)
5-2. Steps to take in an emergency
If a war ning light turns on or a war ning buzzer sounds...
Stop the vehicle immediately. Continuing to drive the vehicle
may be dangerous.The following warning indicates a possible problem in the brake sys-
tem. Immediately stop the vehicle in a safe place and contact your
Toyota dealer.
*: Parking brake engaged warning buzzer: A buzzer will sound if the vehicle is driven at a speed of approximately 3 mph (5 km/h) or more.
Warning lightWarning light/Details
(U.S.A.)
(Canada) Brake system warning light (warning buzzer)
*
• Low brake fluid
• Malfunction in the brake system
This light also comes on when the parking brake is not
released. If the light turns off after the parking brake is fully
released, the system is operating normally.
Calmly perform the following actio
ns if any of the warning lights
comes on or flashes. If a light comes on or flashes, but then goes
off, this does not necessarily indicate a malfunction in the system.
However, if this continues to o ccur, have the vehicle inspected by
your Toyota dealer.