2009 CHEVROLET TRAIL BLAZER 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 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.
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 seat position sensors which enables
the sensing system to monitor the position of the driver’s
and right front passenger’s seat. The sensors provide
information that is used to determine if the airbags
should deploy at a reduced level or at full deployment.
Your vehicle has roof-rail airbags. SeeAirbag System
on page 1-55. 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.
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.
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The passenger sensing system will turn off the right
front passenger frontal airbag under certain conditions.
The driver airbags and roof-rail airbags are not
affected by the passenger sensing system.
The passenger sensing system works with sensors that
are part of the right front passenger seat. 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.
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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 7-16.
{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, rearview mirror, front 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. 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.
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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 1-63.
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 5-77
for additional important information.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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;(Parking Lamps):Turns on the parking lamps,
as well as the following:
Sidemarker Lamps
Taillamps
License Plate Lamps
Instrument Panel Lights
2(Headlamps):Turns on the headlamps, as well as
the following:
Parking Lamps
Sidemarker Lamps
Taillamps
License Plate Lamps
Instrument Panel Lights
Headlamps on Reminder
A reminder tone sounds when the headlamps or parking
lamps are manually turned on, if the driver’s door is open
and the ignition is in LOCK/OFF or ACC/ACCESSORY.
To turn the tone off, turn the knob all the way
counterclockwise.
In the automatic mode, the headlamps turn off once the
ignition key is in LOCK/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 DRL are required on all vehicles rst
sold in Canada.
The DRL system makes the headlamps come on at
reduced brightness when the following conditions
are met:
The ignition is on.
The exterior lamps knob is in automatic
headlamp mode.
The light sensor detects daytime light.
The transmission is not in P (Park).
When the DRL are on, only the headlamps will be on.
The taillamps, sidemarker, instrument panel lights
and other lamps will not be on.
When it begins to get dark, the headlamps automatically
switch from DRL to the regular headlamps.
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Automatic Headlamp System
When it is dark enough outside, the Automatic
Headlamp System turns on the headlamps when the
vehicle is started and after the transmission has been
shifted out of the P (Park) position. The headlamps,
taillamps, sidemarker, and parking lamps will come on.
The instrument panel lights and radio lights will also turn
on at normal brightness. Once on, the system remains on
during these conditions even if the vehicle is shifted back
into P (Park).
The vehicle has a light sensor on the top of the
instrument panel. Do not cover the sensor or the
system may come on whenever the ignition is on
and the vehicle is shifted out of the P (Park) position.
The system could also turn on the lamps when driving
through a parking garage, heavy overcast weather
or a tunnel. This is normal.
There is a delay in the transition between the daytime
and nighttime operation of the Daytime Running Lamps
(DRL) and the automatic headlamp systems, so thatdriving under bridges or bright overhead street lights does
not affect the system. The DRL and automatic headlamp
system are only affected when the light sensor sees a
change in lighting lasting longer than the delay.
If the vehicle is started in a dark garage, the automatic
headlamp system comes on after the transmission
is shifted out of P (Park). Once the vehicle leaves the
garage, it takes about one minute for the automatic
headlamp system to change to DRL if it is light outside.
During that delay, the instrument panel cluster might
not be as bright as usual. Make sure the instrument
panel brightness control is in the full bright position.
If the vehicle is running and the automatic headlamp
system is already on, it can be turned off by turning
and releasing the headlamp control at the off position.
The automatic headlamp system stays off until you
turn and release the headlamp control at the off position
again. SeeHeadlamps on page 3-13.
3-15

Airbag Readiness Light
The system checks the airbag’s electrical system for
possible malfunctions. If the light stays on it indicates
there is an electrical problem. The system check includes
the airbag sensor, the pretensioners, the airbag modules,
the wiring and the crash sensing and diagnostic module.
For more information on the airbag system, seeAirbag
System on page 1-55.
The airbag readiness light
ashes for a few seconds
when the engine is started.
If the light does not come
on then, have it xed
immediately.{CAUTION:
If the airbag readiness light stays on after the
vehicle is started or comes on while driving,
it means the airbag system might not be working
properly. The airbags in the vehicle might not
inate in a crash, or they could even inate
without a crash. To help avoid injury, have
the vehicle serviced right away.
If there is a problem with the airbag system, an airbag
Driver Information Center (DIC) message can also come
on. SeeDIC Warnings and Messages on page 3-51
for more information.
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Electronically Controlled Air
Suspension System
With this feature, an electronically controlled air
suspension system automatically keeps the vehicle level
as it is loaded and unloaded. The system includes a
compressor, two height sensors and two air springs
supporting the rear axle.
The system also has an internal clock to prevent
overheating if the inator is used for prolonged periods.
If the system overheats, all leveling function stops
until the system cools down.
The ignition has to be on for the system to inate, in order
to raise the vehicle to the standard ride height after
loading. The system can lower the vehicle to the standard
ride height after unloading with the ignition on and also for
up to 30 minutes after the ignition has been turned off.
The compressor may be heard while it is operating when
the vehicle is being loaded, and periodically as the
system adjusts the vehicle to the standard ride height.
Load leveling will not function normally with the inator
hose attached to the inator outlet. Remove the inator
hose from the outlet during loading and unloading.
If the vehicle is parked for an extended period of time,
some bleed down of the suspension is normal. Upon
starting the vehicle, proper height will be achieved.
Overload Protection
The air suspension system is equipped with overload
protection. Overload protection is designed to protect
the air suspension system, and it is an indicator to the
driver that the vehicle is overloaded. When the overload
protection mode is on, it will not allow damage to the
air compressor. However, do not overload the vehicle.
SeeLoading the Vehicle on page 4-33.
If the suspension remains at a low height, the rear axle
load has exceeded GAWR (Gross Axle Weight Rating).
When the overload protection mode is activated, the
compressor operates for about 30 seconds to one minute
without raising the vehicle depending on the amount
of overload. This will continue each time the ignition
is turned on until the rear axle load is reduced
below GAWR.
Indicator Light
The indicator light on the inator switch in the rear
passenger compartment also serves as an indicator for
internal system error. If the indicator light is ashing
without the load leveling function or the inator being
active, turn off the ignition. The next day turn on the
ignition and check the indicator light. The vehicle can be
driven with the light ashing, but if it is, the vehicle should
be serviced as soon as possible.
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