
Thresholds can also vary with specific vehicle design.
Frontal airbags are not intended to inflate during vehicle
rollovers, rear impacts, or in many side impacts.
In any particular crash, no one can say whether an
airbag should have inflated simply because of the
damage to a vehicle or because of what the repair costs
were. For frontal airbags, inflation is determined by
what the vehicle hits, the angle of the impact, and how
quickly the vehicle slows down.
What Makes an Airbag Inflate?
In a deployment event, the sensing system sends an
electrical signal triggering a release of gas from the
inflator. Gas from the inflator fills the airbag causing the
bag to break out of the cover and deploy. The inflator, the
airbag, and related hardware are all part of the airbag
module.
Frontal airbag modules are located inside the steering
wheel and instrument panel.
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.
But airbags would not help in many types of collisions,
primarily because the occupant’s motion is not toward
those airbags. SeeWhen Should an Airbag Inflate? on
page 1-52for more information.
Airbags should never be regarded as anything more
than a supplement to safety belts.
1-53

Medical Condition.A passenger has a
medical condition which, according to his or
her physician:
•
Causes the passenger airbag to pose a special risk
for the passenger; and
•Makes the potential harm from the passenger
airbag in a crash greater than the potential
harm from turning off the airbag and allowing the
passenger, even if belted, to hit the dashboard
or windshield in a crash.
{CAUTION:
If the right front passenger’s airbag is turned off
for a person who is not in a risk group identified
by the national government, that person will not
have the extra protection of an airbag. In a crash,
the airbag will not be able to inflate and help
protect the person sitting there. Do not turn off the
passenger’s airbag unless the person sitting there
is in a risk group.To turn off the right front
passenger frontal airbag,
insert your ignition key into
the switch, push in, and
move the switch to the off
position.
The airbag off light will come on and stay on to let you
know that the right front passenger airbag is off.
SeeAirbag Off Light on page 3-28. The airbag off light
will stay on to remind you that the airbag is off. The
right front passenger’s airbag will remain off until
you turn it back on again.
1-56

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 7-10.
{CAUTION:
For up to 10 seconds after the ignition is turned off
and the battery is disconnected, an airbag can still
inflate during improper service. You can be injured
if you are close to an airbag when it inflates. 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 qualified 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, front sensors, or airbag wiring can affect
the operation of the airbag system.
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.
1-58

Q:Because I have a disability, I have to get my
vehicle modified. How can I find 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 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. See
Safety Belt Reminders on page 3-26for more
information.
Keep safety belts clean and dry. SeeCare of Safety
Belts on page 5-89.
Airbags
The airbag system does not need regularly scheduled
maintenance or replacement. Make sure the airbag
readiness light is working. SeeAirbag Readiness Light
on page 3-27for more information.
Notice:If an airbag covering is damaged, opened,
or broken, the airbag may not work properly. Do
not open or break the airbag coverings. If there are
any opened or broken airbag covers, have the
airbag covering and/or airbag module replaced. For
the location of the airbag modules, seeWhat
Makes an Airbag Inflate? on page 1-53. See your
dealer/retailer for service.
1-59

Replacing Restraint System Parts
After a Crash
{CAUTION:
A crash can damage the restraint systems in your
vehicle. A damaged restraint system may not
properly protect the person using it, resulting in
serious injury or even death in a crash. To help
make sure your restraint systems are working
properly after a crash, have them inspected and
any necessary replacements made as soon as
possible.If you have had a crash, do you need new belts?
After a very minor crash, nothing may be necessary.
But the belt assemblies that were used during any crash
may have been stressed or damaged. See your
dealer/retailer to have your safety belt assemblies
inspected or replaced.
New parts and repairs may be necessary even if the
belt was not being used at the time of the crash.
If an airbag inflates, if your vehicle has these, you will
need to replace airbag system parts. See the part on the
airbag system earlier in this section.
1-60

Doors and Locks
Door Locks
{CAUTION:
Unlocked doors can be dangerous.
•Passengers, especially children, can easily
open the doors and fall out of a moving
vehicle. When a door is locked, the handle
will not open it. You increase the chance of
being thrown out of the vehicle in a crash if
the doors are not locked. So, wear safety
belts properly and lock the doors whenever
you drive.
CAUTION: (Continued)
CAUTION: (Continued)
•
Young children who get into unlocked vehicles
may be unable to get out. A child can be
overcome by extreme heat and can suffer
permanent injuries or even death from heat
stroke. Always lock your vehicle whenever
you leave it.
•Outsiders can easily enter through an
unlocked door when you slow down or stop
your vehicle. Locking your doors can help
prevent this from happening.
There are several ways to lock and unlock your vehicle.
On a vehicle equipped with keyless entry, you can
use your transmitter to lock or unlock your vehicle. See
Remote Keyless Entry (RKE) System Operation on
page 2-4.
To lock or unlock the door from the outside, use the key.
2-6

Instrument Panel Overview...............................3-4
Hazard Warning Flashers................................3-6
Horn .............................................................3-6
Tilt Wheel.....................................................3-6
Turn Signal/Multifunction Lever.........................3-7
Turn and Lane-Change Signals........................3-7
Headlamp High/Low-Beam Changer..................3-8
Windshield Wipers..........................................3-8
Windshield Washer.........................................3-9
Cruise Control..............................................3-10
Exterior Lamps.............................................3-14
Headlamps on Reminder................................3-14
Daytime Running Lamps (DRL).......................3-15
Marker Lamps..............................................3-16
Instrument Panel Brightness...........................3-16
Dome Lamps ...............................................3-16
Entry Lighting...............................................3-17
Reading Lamps............................................3-17
Instrument Panel Switchbank..........................3-18
Accessory Power Outlet(s).............................3-19
Ashtray(s) and Cigarette Lighter......................3-19Climate Controls............................................3-20
Climate Control System.................................3-20
Outlet Adjustment.........................................3-22
Rear Heating System....................................3-23
Warning Lights, Gages, and Indicators............3-23
Instrument Panel Cluster................................3-24
Speedometer and Odometer...........................3-25
Trip Odometer..............................................3-25
Tachometer.................................................3-25
Engine Speed Limiter....................................3-25
Safety Belt Reminders...................................3-26
Airbag Readiness Light..................................3-27
Airbag Off Light............................................3-28
Charging System Light
..................................3-29
Voltmeter Gage............................................3-30
Service Transmission Warning Light................3-30
Range Inhibit Warning Indicator......................3-31
Brake System Warning Light..........................3-31
Antilock Brake System (ABS) Warning Light........3-33
Trailer Antilock Brake System Warning Light.......3-34
Engine Coolant Temperature Gage..................3-34
Section 3 Instrument Panel
3-1

Engine Road Speed Governor
This system controls maximum vehicle speed
automatically and reduces engine power until vehicle
speed gets down to maximum governed speed.
The default setting for C4500 and C5500 models up to
19,500 lbs GVWR is 80 to 85 mph (128 to 136 km/h).
Most other models have a default setting of 75 mph
(120 km/h), although some tire sizes and tread
patterns may limit maximum speed to 55 to 65 mph
(86 to 105 km/h). You may have a label on the headliner
of your vehicle with more information on your engine
road speed governor. See your GM dealer for assistance
with programming your engine limited speed.
Safety Belt Reminders
Safety Belt Reminder Light
When the engine is started, a light will come on for
several seconds to remind people to fasten their safety
belts.
The safety belt light will
also come on and stay on
for several seconds.
Safety Belt Reminder Tone
If your vehicle has this feature, when the engine is
started, a tone will sound for several seconds to remind
people to fasten their safety belts.
3-26