2009 CHEVROLET TAHOE sensor

When Should an Airbag Inate?
Frontal airbags are designed to inate in moderate to
severe frontal or near-frontal crashes to help reduce the
potential for severe injuries mainly to the driver’s or
right front passenger’s head and chest. However, they
are only designed to inate if the impact exceeds a
predetermined deployment threshold. Deployment
thresholds are used to predict how severe a crash is
likely to be in time for the airbags to inate and
help restrain the occupants.
Whether your frontal airbags will or should deploy is not
based on how fast your vehicle is traveling. It depends
largely on what you hit, the direction of the impact,
and how quickly your vehicle slows down.
Frontal airbags may inate at different crash speeds.
For example:
If the vehicle hits a stationary object, the airbags
could inate at a different crash speed than if the
vehicle hits a moving object.
If the vehicle hits an object that deforms, the
airbags could inate at a different crash speed than
if the vehicle hits an object does not deform.
If the vehicle hits a narrow object (like a pole), the
airbags could inate at a different crash speed
than if the vehicle hits a wide object (like a wall).
If the vehicle goes into an object at an angle, the
airbags could inate at a different crash speed
than if the vehicle goes straight into the object.
Thresholds can also vary with specic vehicle design.
Frontal airbags are not intended to inate during vehicle
rollovers, rear impacts, or in many side impacts.
In addition, your vehicle has dual-stage frontal airbags.
Dual-stage airbags adjust the restraint according to
crash severity. Your vehicle has electronic frontal
sensors, which help the sensing system distinguish
between a moderate frontal impact and a more severe
frontal impact. For moderate frontal impacts, dual-stage
airbags inate at a level less than full deployment.
For more severe frontal impacts, full deployment occurs.
Your vehicle has a seat position sensor which enables
the sensing system to monitor the position of the driver’s
seat. The seat position sensor provides information
that is used to determine if the airbags should deploy at
a reduced level or at full deployment.
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Passenger Sensing System
The vehicle has a passenger sensing system for the
right front passenger position. The passenger airbag
status indicator will be visible on the overhead console
when the vehicle is started.
The words ON and OFF, or the symbol for on and off,
will be visible during the system check. If you are
using remote start to start the vehicle from a distance, if
equipped, you may not see the system check. When
the system check is complete, either the word ON
or OFF, or the symbol for on or off, will be visible. See
Passenger Airbag Status Indicator on page 3-38.The passenger sensing system will turn off the right
front passenger frontal airbag under certain conditions.
The driver airbag and the roof-rail airbags (if equipped)
are not affected by the passenger sensing system.
The passenger sensing system works with sensors that
are part of the right front passenger seat and safety
belt. The sensors are designed to detect the presence
of a properly-seated occupant and determine if the
right front passenger frontal airbag should be enabled
(may inate) or not.
According to accident statistics, children are safer when
properly secured in a rear seat in the correct child
restraint for their weight and size.
We recommend that children be secured in a rear seat,
including: an infant or a child riding in a rear-facing
child restraint; a child riding in a forward-facing child
seat; an older child riding in a booster seat; and children,
who are large enough, using safety belts.
A label on the sun visor says, “Never put a rear-facing
child seat in the front.” This is because the risk to
the rear-facing child is so great, if the airbag deploys. United States
Canada
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Servicing Your Airbag-Equipped
Vehicle
Airbags affect how the vehicle should be serviced.
There are parts of the airbag system in several places
around the vehicle. Your dealer/retailer and the
service manual have information about servicing the
vehicle and the airbag system. To purchase a service
manual, seeService Publications Ordering Information
on page 7-15.
{CAUTION:
For up to 10 seconds after the ignition is turned off
and the battery is disconnected, an airbag can still
inate during improper service. You can be injured
if you are close to an airbag when it inates. Avoid
yellow connectors. They are probably part of the
airbag system. Be sure to follow proper service
procedures, and make sure the person performing
work for you is qualied to do so.
Adding Equipment to Your
Airbag-Equipped Vehicle
Q:Is there anything I might add to or change
about the vehicle that could keep the airbags
from working properly?
A:Yes. If you add things that change your vehicle’s
frame, bumper system, height, front end or side
sheet metal, they may keep the airbag system from
working properly. Changing or moving any parts
of the front seats, safety belts, the airbag sensing
and diagnostic module, steering wheel, instrument
panel, roof-rail airbag modules, ceiling headliner
or pillar garnish trim, overhead console, front
sensors, side impact sensors, rollover sensor
module, or airbag wiring can affect the operation of
the airbag system.
In addition, your vehicle has a passenger
sensing system for the right front passenger’s
position, which includes sensors that are part of
the passenger’s seat.
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The passenger sensing system may not operate
properly if the original seat trim is replaced
with non-GM covers, upholstery or trim, or with GM
covers, upholstery or trim designed for a different
vehicle. Any object, such as an aftermarket
seat heater or a comfort enhancing pad or device,
installed under or on top of the seat fabric, could
also interfere with the operation of the passenger
sensing system. This could either prevent
proper deployment of the passenger airbag(s) or
prevent the passenger sensing system from
properly turning off the passenger airbag(s). See
Passenger Sensing System on page 1-90.
If you have any questions about this, you should
contact Customer Assistance before you modify
your vehicle. The phone numbers and addresses for
Customer Assistance are in Step Two of the
Customer Satisfaction Procedure in this manual.
SeeCustomer Satisfaction Procedure on page 7-2.
If your vehicle has rollover roof-rail airbags, see
Different Size Tires and Wheels on page 5-80
for additional important information.Q:What if I added a snow plow? Will it keep the
airbags from working properly?
A:We have designed our airbag systems to work
properly under a wide range of conditions,
including snow plowing with vehicles that have the
optional Snow Plow Prep Package (RPO VYU).
But do not change or defeat the snow plow’s
“tripping mechanism.” If you do, it can damage your
snow plow and your vehicle, and it may cause an
airbag ination.
Q:Because I have a disability, I have to get my
vehicle modied. How can I nd out whether
this will affect my airbag system?
A:If you have questions, call Customer Assistance.
The phone numbers and addresses for Customer
Assistance are in Step Two of the Customer
Satisfaction Procedure in this manual. See
Customer Satisfaction Procedure on page 7-2.
In addition, your dealer/retailer and the service manual
have information about the location of the airbag
sensors, sensing and diagnostic module and airbag
wiring.
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The power liftgate may be temporarily disabled under
extreme temperatures, or under low battery conditions. If
this occurs, the liftgate can still be operated manually.
If you shift the transmission out of PARK (P) while
the power function is in progress, the liftgate power
function will continue to completion. If you shift the
transmission out of PARK (P) and accelerate before the
power liftgate latches closed, the liftgate may reverse
to the open position. Cargo could fall out of the vehicle.
Always make sure the power liftgate is closed and
latched before you drive away.
If you power open the liftgate and the liftgate support
struts have lost pressure, the lights will ash and a
chime will sound. The liftgate will stay open temporarily,
then slowly close. See your dealer/retailer for service
before using the liftgate.Obstacle Detection Features
If the liftgate encounters an obstacle during a power
open or close cycle, a warning chime will sound and the
liftgate will automatically reverse direction to the full
closed or open position. After removing the obstruction,
the power liftgate operation can be used again. If the
liftgate encounters multiple obstacles on the same power
cycle, the power function will deactivate, and you
must manually open or close the liftgate. The REAR
ACCESS OPEN warning message in the Driver
Information Center (DIC) will indicate that the liftgate is
open. After removing the obstructions, manually
open the liftgate to the full open position or close the
liftgate to the fully closed and latched position. The
liftgate will now resume normal power operation.
Your vehicle has pinch sensors located on the side
edges of the liftgate. If an object is caught between
the liftgate and the body and presses against this
sensor, the liftgate will reverse direction and open fully.
The liftgate will remain open until it is activated again
or closed manually. Do not force the liftgate open
or closed during a power cycle.
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Side Blind Zone Alert (SBZA)
If your vehicle has the Side Blind Zone Alert (SBZA)
system, seeSide Blind Zone Alert (SBZA) on page 2-58.
Object Detection Systems
Ultrasonic Rear Parking
Assist (URPA)
For vehicles with the Ultrasonic Rear Parking Assist
(URPA) system, it operates at speeds less than 5 mph
(8 km/h), and assists the driver with parking and
avoiding objects while in R (Reverse). The sensors on
the rear bumper are used to detect the distance to
an object up to 8 feet (2.5 m) behind the vehicle, and at
least 10 inches (25.4 cm) off the ground.
{CAUTION:
The Ultrasonic Rear Parking Assist (URPA)
system does not replace driver vision. It cannot
detect:
objects that are below the bumper,
underneath the vehicle, or if they are too
close or far from the vehicle
children, pedestrians, bicyclists, or pets.
If you do not use proper care before and while
backing; vehicle damage, injury, or death could
occur. Even with URPA, always check behind the
vehicle before backing up. While backing, be sure
to look for objects and check the vehicle’s mirrors.
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The system can be
disabled by pressing the
rear park aid disable button
located next to the radio.
The indicator light will come on and PARK ASSIST OFF
displays on the Driver Information Center (DIC) to
indicate that URPA is off, seeDIC Warnings and
Messages on page 3-64for information about clearing
the message.
When the System Does Not Seem to
Work Properly
If the URPA system will not activate due to a temporary
condition, the message PARK ASSIST OFF will be
displayed on the DIC and a red light will be shown on
the rear URPA display when the shift lever is moved into
R (Reverse). This occurs under the following conditions:
The driver disables the system.
The ultrasonic sensors are not clean. Keep the
vehicle’s rear bumper free of mud, dirt, snow,
ice and slush. For cleaning instructions, see
Washing Your Vehicle on page 5-109.
A trailer was attached to the vehicle, or a bicycle or
an object was hanging out of the liftgate during the
last drive cycle, the red light may illuminate in
the rear display. Once the attached object is
removed, URPA will return to normal operation.
A tow bar is attached to the vehicle.
The vehicle’s bumper is damaged. Take the vehicle
to your dealer/retailer to repair the system.
Other conditions may affect system performance,
such as vibrations from a jackhammer or the
compression of air brakes on a very large truck.
If the system is still disabled, after driving forward at
least 15 mph (25 km/h), take the vehicle to your
dealer/retailer.
Side Blind Zone Alert (SBZA)
The vehicle may have a Side Blind Zone Alert (SBZA)
system. Read this entire section before using the
system.
The SBZA system operates on a radio frequency
subject to Federal Communications Commission (FCC)
Rules and with Industry Canada.
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SBZA Detection Zones
The SBZA sensor covers a zone of approximately one
lane over from both sides of the vehicle, 11 ft. or
3.5 m. This zone starts at each side mirror and goes
back approximately 16 ft. (5.0 m). The height of the zone
is approximately between 1.5 ft. (0.5 m) and 6 ft. (2.0 m)
off the ground.
Use caution while changing lanes when towing a trailer,
as the SBZA detection zones do not change when a
trailer is towed.
How the System Works
When the vehicle is started, both outside mirror displays
will briey come on to indicate that the system is
operating. When the vehicle is moving forward, the left
or right side mirror SBZA display will light up if a
vehicle is detected in that blind zone. If the turn signal is
activated and a vehicle is also detected on the same
side, the SBZA display will ash to give you extra
warning not to change lanes.
SBZA displays do not come on while the vehicle is
approaching or passing other vehicles. At speeds
greater then 20 mph (32 km/h), SBZA displays may
come on when a vehicle you have passed remains in or
drops back into the detection zone.
Left Side Mirror DisplayRight Side Mirror
Display
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