2012 TOYOTA SIENNA brake sensor

SIENNA_U (OM45477U)
27
Event data recorder
Your vehicle has computers that monitor and control certain aspects of your
vehicle. These computers assist in driving and maintaining optimal vehicle
performance.
Besides storing data useful for troubleshooting, there is an event data
recorder (EDR) that records data in a crash or near crash event.
The SRS airbag sensor assembly contains the EDR. In a crash or near crash
event, this device may record the following information:
• Engine speed
• Whether the brake pedal was depressed or not
• Vehicle speed
• To what extent the accelerator pedal was depressed
• The transaxle shift position
• Whether the driver and front passenger wore seat belts or not
• Driver’s seat position
• SRS airbag deployment data
• SRS airbag system diagnostic data
• Front passenger’s occupant classification
The information above is intended to be used for the purpose of improving
vehicle safety performance. Unlike general data recorders, the EDR does
not record sound data such as conversation between passengers.

81
1-2. Opening, closing and locking the doors
1
Before driving
SIENNA_U (OM45477U)
NOTICE
■
Sliding door
■ To prevent damage to your vehicle
● Vehicles with the power sliding door:
• Do not apply excessive force when the sliding door is operating.
• Do not place your hand or foot near door hinges or rollers when the
sliding door is operating.
• Avoid forcibly opening the left side sliding door fully when the fuel filler door is opened. Otherwise, the fuel filler door may be damaged.
• Take care not to damage the sensors (installed on the front edge of the power sliding door) with a knife or other sharp object.
● Make sure there is nothing in the doorway before closing.
● Do not close the sliding door by applying the brakes. Doing so could cause
the sliding door to be damaged.
Make sure magazines are not bent or
protruding from the sliding door pockets.
Do not insert anything too big so that the
shape of the sliding door pockets is dis-
torted. Such objects may obstruct the
opening/closing of the sliding doors, dam-
age the sliding door pockets or the vehi-
cle body, and may result in a malfunction.

270 2-3. Operating the lights and wipers
SIENNA_U (OM45477U)
■Daytime running light system (if equipped)
● To make your vehicle more visible to other drivers, the headlights turn on
automatically (at a reduced intensity) whenever the engine is started and
the parking brake is released. Daytime running lights are not designed for
use at night.
For the U.S.A.: Daytime running lights can be turned off by operating the
headlight switch.
● Compared to turning on the headlights, the daytime running light system
offers greater durability and consumes less electricity, so it can help
improve fuel economy.
■ Headlight control sensor (if equipped)
The sensor may not function properly if
an object is placed on the sensor, or any-
thing that blocks the sensor is affixed to
the windshield.
Doing so interferes with the sensor
detecting the level of ambient light and
may cause the automatic headlight sys-
tem to malfunction.

303
2-4. Using other
driving systems
2
When driving
SIENNA_U (OM45477U)
Driving in vehicle-to-vehicle distance control mode
This mode employs a radar sensor to detect the presence of vehicles
up to approximately 400 ft. (120 m) ahead, determines the current
vehicle-to-vehicle following distance, and operates to maintain a suit-
able following distance from the vehicle ahead.
Note that vehicle-to-vehicle distance will close in when traveling on long
downhill slopes.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-
vehicle distance can also be set by operating the vehicle-to-vehicle dis-
tance control.
Example of deceleration cruising
When the vehicle ahead is driving slower than the set speed
When a vehicle is detected running ahead of you, the system automati-
cally decelerates your vehicle. When a greater reduction in vehicle speed
is necessary, the system applies the brakes. A warning tone warns you
when the system cannot decelerate sufficiently to prevent your vehicle
from closing in on the vehicle ahead.

312 2-4. Using other driving systems
SIENNA_U (OM45477U)
CAUTION
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles
are in front of you.
As the sensor may not be able to correctly detect these types of vehicles,
the approach warning ( P. 304) will not be activated, and a fatal or serious
accident may result.
● Vehicles that cut in suddenly
● Vehicles traveling at low speeds
● Vehicles that are not moving
● Vehicles with small rear ends (trailers with no load on board etc.)
● Motorcycles traveling in the same lane
■ Conditions under which the vehicle -to-vehicle distance control may
not function correctly
Apply the brakes as necessary in the following conditions as the radar sen-
sor may not be able to correctly detect vehicles ahead, and a fatal or serious
accident may result:
● When water or snow thrown up by the surrounding vehicles hinders the
functioning of the sensor
● When your vehicle is pointing upwards (caused by a heavy load in the lug-
gage compartment, etc.)
● When the road curves or when the lanes are narrow
● When steering wheel operation or your position in the lane is unstable
● When the vehicle ahead of you decelerates suddenly

319
2-4. Using other
driving systems
2
When driving
SIENNA_U (OM45477U)
■Sensor detection information
● Certain vehicle conditions and the surrounding environment may affect
the ability of the sensor to correctly detect obstacles. Particular instances
where this may occur are listed below.
• There is dirt, snow or ice on the sensor.
• The sensor is frozen.
• The sensor is covered in any way.
• The vehicle is leaning considerably to one side.
• On an extremely bumpy road, on an incline, on gravel, or on grass
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle
engines, air brakes of large vehicles, or other loud noises producing
ultrasonic waves.
• There is another vehicle equipped with parking assist sensors in the vicinity.
• A sensor is coated with a sheet of spray or heavy rain.
• The vehicle is equipped with a fender pole or radio antenna.
• A bumper or sensor receives a strong impact.
• The vehicle is approaching a tall or right-angled curb.
• In harsh sunlight or intense cold weather
In addition to the examples above, there are instances in which, because of
their shapes, signs and other objects may be judged by the sensor to be
closer than they are.
● The shape of the obstacle may prevent the sensor from detecting it. Pay
particular attention to the following obstacles:
• Wires, fences, ropes etc.
• Cotton, snow and other materials that absorb sound waves
• Sharply-angled objects
• Low obstacles
• Tall obstacles with upper sections projecting outwards in the direction
of your vehicle

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.

339
2-4. Using other
driving systems
2
When driving
SIENNA_U (OM45477U)
■Conditions that may trigger the system even if there is no possibility of
a collision
● When there is an object by the roadside at the entrance to a curve
● When passing an oncoming vehicle on a curve
● When driving over a narrow iron bridge
● When there is a metal object on the road surface
● When driving on an uneven road surface
● When passing an oncoming vehicle on a left-turn
● When your vehicle rapidly closes on the vehicle in front
● When a grade separation/interchange, sign, billboard, or other structure
appears to be directly in the vehicle’s line of travel
● When climbing a steep hill causes an overhead billboard or other metallic
structure to appear directly in the vehicle’s line of travel
● When there is an overhead bridge, sign or billboard ahead
● When there are excessive changes in the vehicle height (when it tilts for-
wards or backwards)
● When there is an abnormality in the radar sensor
● When an overhead metal object can be seen at the top of an uphill road
● When passing through an electronic toll collection gate (only in countries
with electronic toll collection)
When the system is activated in the situations described above, there is also
a possibility that the seat belts will retract quickly and the brakes will be
applied with a force greater than normal. When the seat belt is locked in the
restricted position, stop the vehicle in a safe place, release the seat belt and
refasten it.
■ Obstacles not detected
The sensor cannot detect plastic obstacles such as traffic cones. There may
also be occasions when the radar sensor cannot detect pedestrians, ani-
mals, bicycles, motorcycles, trees, or snowdrifts.