2009 CHEVROLET SILVERADO 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 the 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 that 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.
If the GVWR (Gross Vehicle Weight Rating) of your
vehicle is 8,500 lb (3 855 kg) or above, your vehicle has
single stage airbags. If the GVWR is below 8,500 lb
(3 855 kg) then your vehicle has dual stage airbags. You
can nd the GVWR on the certication label on the
rear edge of the driver’s door. SeeLoading the Vehicle
on page 4-32for more information.
In addition, the vehicle may have dual-stage frontal
airbags. Dual-stage airbags adjust the restraint
according to crash severity. The 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.
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Vehicles with dual stage airbags also have seat position
sensors which enable the sensing system to monitor
the position of the driver seat (all models) and the right
front passenger seat (light-duty regular cab and
light-duty extended cab models only). The seat position
sensor provides information that is used to determine
if the airbags should deploy at a reduced level or at full
deployment.
The vehicle may or may not have roof-rail airbags. See
Airbag System on page 1-74. Roof-rail airbags are
intended to inate in moderate to severe side crashes.
In addition, these roof-rail airbags are intended to
inate during a rollover or in a severe frontal impact.
Roof-rail airbags will inate if the crash severity is above
the system’s designed threshold level. The threshold
level can vary with specic vehicle design.
Roof-rail airbags are not intended to inate in rear
impacts. Both roof-rail airbags will deploy when either
side of the vehicle is struck, or if the sensing system
predicts that the vehicle is about to roll over, or in
a severe frontal impact.In any particular crash, no one can say whether an
airbag should have inated simply because of the
damage to a vehicle or because of what the repair costs
were. For frontal airbags, ination is determined by
what the vehicle hits, the angle of the impact, and how
quickly the vehicle slows down. For roof-rail airbags,
deployment is determined by the location and severity of
the side impact. In a rollover event, roof-rail airbag
deployment is determined by the direction of the roll.
What Makes an Airbag Inate?
In a deployment event, the sensing system sends an
electrical signal triggering a release of gas from
the inator. Gas from the inator lls the airbag causing
the bag to break out of the cover and deploy. The
inator, the airbag, and related hardware are all part of
the airbag module.
Frontal airbag modules are located inside the
steering wheel and instrument panel. For vehicles
with roof-rail airbags, there are airbag modules in the
ceiling of the vehicle, near the side windows that
have occupant seating positions.
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Passenger Sensing System
If the vehicle has one of the indicators pictured in the
following illustrations, then the vehicle has a passenger
sensing system for the right front passenger position,
unless there is an airbag off switch located in the glove
box. If there is an airbag off switch, the vehicle does
not have a passenger sensing system. SeeAirbag Off
Switch on page 1-82for more information.
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 3-40.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.
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, rollover sensor module, or airbag wiring
can affect the operation of the airbag system.
In addition, your vehicle may have a passenger
sensing system for the right front passenger’s
position, which includes sensors that are part of the
passenger’s seat. 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
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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).
SeePassenger Sensing System on page 1-85.
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 5-86
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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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 3-66for information about clearing
the message.
Notice:If you use URPA while the tailgate is
lowered, it may not detect an object behind your
vehicle, and you might back into the object and
damage your vehicle. Always verify the tailgate is
closed when using URPA or turn off URPA when
driving with the tailgate lowered.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, seeWashing Your
Vehicle on page 5-118.
A trailer was attached to the vehicle, or a bicycle or
an object was hanging out of the tailgate 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.
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9(Off):Turns the wipers off.
6(Delay):Turn the band to adjust the delay time.
The delay between wiping cycles becomes shorter as
the band is moved to the top of the lever. This can
be very useful in light rain or snow.
6(Low Speed):For steady wiping at low speed.
?(High Speed):For high-speed wiping.
Clear ice and snow from the wiper blades before using
them. If they are frozen to the windshield, gently
loosen or thaw them. Damaged wiper blades may not
clear the windshield well, making it harder to see
and drive safely. If the blades do become damaged,
install new blades or blade inserts. For more information,
seeWindshield Wiper Blade Replacement on page 5-64.
Heavy snow or ice can overload the wiper motor.
A circuit breaker will stop the motor until it cools down.
Clear away snow or ice to prevent an overload.
Rainsense™ II Wipers
For vehicles with Rainsense™ II windshield wipers, the
moisture sensor is located next to the inside rearview
mirror and is mounted on the windshield. When active,
these sensors are able to detect moisture on the
windshield and automatically turn on the wipers.
To turn on the Rainsense feature, the wipers must be
set to one of the ve delay settings on the multifunction
lever. Each of the ve settings adjusts the sensitivity
of the sensor.
Since different drivers have different setting preferences,
it is recommended that the mid-range setting (position 3)
be used initially. For more wipes, select the higher
settings; for fewer wipes, select the lower settings located
closer to the off position on the multifunction lever.
The sensor will automatically control the frequency of the
wipes from the off setting to the high speed setting
according to the weather conditions. The wipers can be
left in a rainsense mode even when it is not raining.
When Rainsense is active, the headlamps will turn on
automatically if the exterior lamp control is in the AUTO
position and the wipers are active.
Notice:Going through an automatic car wash with
the wipers on can damage them. Turn the wipers
off when going through an automatic car wash.
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