2009 GMC SIERRA 1500 sensor

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 4-34for 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.
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 1-72. 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.
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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.
{CAUTION:
A child in a rear-facing child restraint can be
seriously injured or killed if the right front passenger
airbag inates. This is because the back of the
rear-facing child restraint would be very close to the
inating airbag. A child in a forward-facing child
restraint can be seriously injured or killed if the right
front passenger airbag inates and the passenger
seat is in a forward position.
Even if the passenger sensing system has turned
off the right front passenger frontal airbag, no
system is fail-safe. No one can guarantee that an
airbag will not deploy under some unusual
circumstance, even though the airbag is turned off.
Secure rear-facing child restraints in a rear seat,
even if the airbag is off. If you secure a
forward-facing child restraint in the right front seat,
always move the front passenger seat as far back
as it will go. It is better to secure the child restraint in
a rear seat.
1-85

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 systemmay 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). SeePassenger Sensing
System on page 1-84.
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 5-88
for additional important information.
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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.
Restraint System Check
Checking the Restraint Systems
Safety Belts
Now and then, check that the safety belt reminder light,
safety belts, buckles, latch plates, retractors, and
anchorages are all working properly.
Look for any other loose or damaged safety belt system
parts that might keep a safety belt system from doing its
job. See your dealer/retailer to have it repaired. Torn or
frayed safety belts may not protect you in a crash. They
can rip apart under impact forces. If a belt is torn or
frayed, get a new one right away.
Make sure the safety belt reminder light is working.
SeeSafety Belt Reminders on page 3-36for more
information.
Keep safety belts clean and dry. SeeCare of Safety
Belts on page 5-118.
1-91

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.
CAUTION: (Continued)
CAUTION: (Continued)
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.
The display is located near
the passenger side rear
window and can be
seen by looking over your
right shoulder.
URPA uses three color-coded lights to provide distance
and system information.
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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, see
Washing 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.
2-63

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 5-66.
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.
3-11

;(Parking Lamps):Turns on the parking lamps
together with the following:
Instrument Panel Lights
Taillamps
License Plate Lamps
2(Headlamps):Turns on the headlamps together
with the following:
Parking Lamps
Instrument Panel Lights
Taillamps
License Plate Lamps
When the headlamps are turned on while the vehicle is
on, the headlamps turn off automatically 10 minutes after
the ignition is turned off. When the headlamps are turned
on while the vehicle is off, the headlamps will stay on for
10 minutes before automatically turning off to prevent the
battery from being drained. Turn the headlamp control to
off and then back to the headlamp on position to make
the headlamps stay on for an additional 10 minutes.
Push the turn signal/multifunction lever toward the
instrument panel to change the headlamps from low
beam to high beam.
Headlamps on Reminder
A reminder chime will sound when the headlamps or
parking lamps are manually turned on and the ignition
is off and a door is open. To disable the chime, turn the
light off.
Daytime Running Lamps (DRL)
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the day.
Fully functional daytime running lamps are required on
all vehicles rst sold in Canada.
The DRL system will come on when the following
conditions are met:
The ignition is on.
The exterior lamps control is in AUTO.
The transmission is not in P (Park).
The light sensor determines it is daytime.
When the DRL are on, only the DRL lamps will be on.
The taillamps, sidemarker, instrument panel lights,
and other lamps will not be on.
When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps.
To turn off the DRL lamps, turn the exterior lamps control
to the OFF position and then release. For vehicles rst
sold in Canada, the transmission must be in the P (Park)
position, before the DRL lamps can be turned off.
3-17