2008 HUMMER H3 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.
1-59

Your vehicle has roof-rail airbags. SeeAirbag System
on page 1-54. 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.
Roof-rail airbags are not intended to inate in frontal
impacts, near-frontal impacts, or 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.
Your vehicle has a seat position sensor which enables
the sensing system to monitor the position of the
driver’s seat. The sensor provides information that is
used to determine if the airbags should deploy at
a reduced level or at full deployment.
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.
How Does an Airbag Restrain?
In moderate to severe frontal or near frontal collisions,
even belted occupants can contact the steering wheel
or the instrument panel. In moderate to severe side
collisions, even belted occupants can contact the inside
of the vehicle.
Airbags supplement the protection provided by safety
belts. Frontal airbags distribute the force of the
impact more evenly over the occupant’s upper body,
stopping the occupant more gradually. Roof-rail airbags
distribute the force of the impact more evenly over
the occupant’s upper body.
1-60

The passenger sensing system will turn off the right
front passenger’s frontal airbag under certain conditions.
The driver’s airbags are not part of the passenger
sensing system.
The passenger sensing system works with sensors that
are part of the right front passenger’s seat and safety
belt. The sensors are designed to detect the presence of
a properly-seated occupant and determine if the right
front passenger’s frontal airbag should be enabled
(may inate) or not.
Accident statistics show that children are safer if they
are restrained in the rear rather than the front seat.
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 your 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’s airbag inates. This is because
the back of the rear-facing child restraint
would be very close to the inating airbag.
Even though the passenger sensing system is
designed to turn off the right front passenger’s
frontal airbag if the system detects a rear-facing
child restraint, no system is fail-safe, and no
one can guarantee that an airbag will not deploy
under some unusual circumstance, even
though it is turned off. We recommend that
rear-facing child restraints be secured 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.
1-63

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. 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, couldalso 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 1-62.
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 5-73
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.
1-68

Automatic Dimming Mirror Operation
The automatic dimming mirror comes on each time
the ignition is turned to start. To turn the automatic
dimming feature off or back on, press and hold
Yfor
nine seconds. The indicator light on the mirror is lit
when the automatic dimming feature is on.
Temperature Display
To adjust between Fahrenheit and Celsius:
PressYfor approximately four seconds to toggle
the display from F (Fahrenheit) to C (Celsius)
to OFF.
The temperature display will remain in its current
state each time the ignition goes through its cycle.
At start up, if the vehicle has been off for less
than two and a half hours, and the last stored
temperature was less than the current termperature,
the sensor will increase 1°F every two minutes
until the correct temperature is displayed.
If the vehicle has been off more than two and a
half hours, or the last stored temperature is
greater than the current temperature, the current
temperature immediately displays.
If the temperature is 37°F (3°C) or lower, ICE will
ash on the temperature display. This display will
ash every two seconds for a period of one minute.
If an abnormal temperature reading is displayed for
an extended period of time, see your dealer/retailer.
Under certain circumstances, a delay in updating
the temperature is normal.
Compass Display
Press theYbutton, located at the bottom of the mirror,
next to the OnStar®control buttons to turn the
compass/temperature display on or off.
If CAL is not displayed, press and hold
Yfor
15 seconds, or until CAL is displayed. The compass
is now in calibration mode. For more information,
see “Compass Calibration” following.
The mirror can be calibrated in one of two ways:
Drive the vehicle in circles at less than 5 mph
(8 km/h) until the CAL is no longer displayed in
the compass window. Then continue to drive
to make sure all eight directions are available.
Drive the vehicle under normal operating conditions.
2-39

Daytime Running Lamps (DRL)
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the
day. DRL can be helpful in many different driving
conditions, but they can be especially helpful in the short
periods after dawn and before sunset. 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 PARK (P) if you have an
automatic transmission.
The light sensor determines it is daytime.
When the DRL are on, no other lamps are on. The
instrument panel will not be lit up either. For vehicles rst
sold in Canada, if parking lamps are manually turned
on, DRL will stay on.
When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps.
As with any vehicle, you should turn on the regular
headlamp system when you need it.
To turn off the DRL, seeExterior Lamps on page 3-15.Vehicles rst sold in Canada cannot turn off DRL unless
certain conditions are met. SeeExterior Lamps on
page 3-15.
Automatic Headlamp System
When it is dark enough outside, the automatic headlamp
system will turn on after the transmission has been
shifted from PARK (P) to DRIVE (D). The headlamps,
taillamps, sidemarker, parking lamps, roof marker lamps,
and the instrument panel lights will turn on at normal
brightness. The radio lights will become more dim when
the headlights are off compared to when the headlights
are on.
Your vehicle has a light sensor located on the top of the
instrument panel. Be sure it is not covered, or the
system will be on whenever the ignition is on.
The system may also turn on the headlamps 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 system so
that driving under bridges or bright overhead street lights
does not affect the system. The DRL and automatic
headlamp system will only be affected when the
light sensor detects a change in lighting lasting longer
than the delay.
3-17

Airbag Readiness Light
There is an airbag readiness light on the instrument
panel cluster, which shows the airbag symbol. The
system checks the airbag’s electrical system for
malfunctions. The light tells you if 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 1-54.
This light will come on
when you start your
vehicle, and it will ash
for a few seconds.
The light should go out
and the system is ready.
If the airbag readiness light stays on after you start
the vehicle or comes on when you are driving,
your airbag system may not work properly. Have
your vehicle serviced right away.{CAUTION:
If the airbag readiness light stays on after you
start your vehicle, it means the airbag system
may not be working properly. The airbags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help
avoid injury to yourself or others, have your
vehicle serviced right away if the airbag
readiness light stays on after you start your
vehicle.
The airbag readiness light should ash for a few
seconds when you start the engine. If the light does not
come on then, have it xed immediately. If there is a
problem with the airbag system, an airbag Driver
Information Center (DIC) message may also come on.
SeeDIC Warnings and Messages on page 3-43for
more information.
3-29

How to Check
Use a good quality pocket-type gage to check
tire pressure. You cannot tell if your tires are
properly inated simply by looking at them. Radial
tires may look properly inated even when they
are underinated. Check the tire’s ination
pressure when the tires are cold. Cold means your
vehicle has been sitting for at least three hours
or driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage rmly onto the valve to
get a pressure measurement. If the cold tire
ination pressure matches the recommended
pressure on the Tire and Loading Information
label, no further adjustment is necessary. If the
ination pressure is low, add air until you reach the
recommended amount.
If you overll the tire, release air by pushing on
the metal stem in the center of the tire valve.
Recheck the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) uses radio
and sensor technology to check tire pressure levels.
The TPMS sensors monitor the air pressure in
your vehicle’s tires and transmit tire pressure readings
to a receiver located in the vehicle.
Each tire, including the spare (if provided), should be
checked monthly when cold and inated to the ination
pressure recommended by the vehicle manufacturer
on the vehicle placard or tire ination pressure label.
(If your vehicle has tires of a different size than the
size indicated on the vehicle placard or tire ination
pressure label, you should determine the proper
tire ination pressure for those tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system (TPMS)
that illuminates a low tire pressure telltale when one
or more of your tires is signicantly under-inated.
Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires as
soon as possible, and inate them to the proper
pressure. Driving on a signicantly under-inated tire
causes the tire to overheat and can lead to tire failure.
Under-ination also reduces fuel efficiency and tire
tread life, and may affect the vehicle’s handling
and stopping ability.
5-63