CHEVROLET TRAIL BLAZER 2003 1.G Repair Manual

When Should an Air Bag In¯ate?
The driver's and right front passenger's frontal air bags
are designed to in¯ate in moderate to severe frontal
or near-frontal crashes. But they are designed to in¯ate
only if the impact speed is above the system's
designed ªthreshold level.º
In addition, your vehicle has ªdual stageº frontal air
bags, which adjust the amount of restraint according to
crash severity. For moderate frontal impacts, these
air bags in¯ate at a level less than full deployment.
For more severe frontal impacts, full deployment occurs.
If the front of your vehicle goes straight into a wall
that doesn't move or deform, the threshold level
for the reduced deployment is about 12 to 16 mph
(19 to 26 km/h), and the threshold level for a full
deployment is about 16 to 25 mph (26 to 40 km/h).
The threshold level can vary, however, with speci®c
vehicle design, so that it can be somewhat above
or below this range.
If your vehicle strikes something that will move or
deform, such as a parked car, the threshold level will be
higher. The driver's and right front passenger's frontal
air bags are not designed to in¯ate in rollovers, rear
impacts, or in many side impacts because in¯ation
would not help the occupant.Your vehicle may or may not have a side impact air
bag. See Air Bag Systems in the Index. Side impact air
bags are designed to in¯ate in moderate to severe
side crashes. A side impact air bag will in¯ate if
the crash severity is above the system's designed
ªthreshold level.º The threshold level can vary with
speci®c vehicle design. Side impact air bags are
not designed to in¯ate in frontal or near-frontal impacts,
rollovers or rear impacts, because in¯ation would not
help the occupant. A side impact air bag will only deploy
on the side of the vehicle that is struck.
In any particular crash, no one can say whether an air
bag should have in¯ated simply because of the damage
to a vehicle or because of what the repair costs were.
For frontal air bags, in¯ation is determined by the angle
of the impact and how quickly the vehicle slows down
in frontal and near-frontal impacts. For side impact
air bags, in¯ation is determined by the location
and severity of the impact.
The air bag system is designed to work properly under
a wide range of conditions, including off-road usage.
Observe safe driving speeds, especially on rough
terrain. As always, wear your safety belt. See
Off-Road
Driving with Your Four-Wheel-Drive Vehicle on
page 4-15
for tips on off-road driving.
1-55

What Makes an Air Bag In¯ate?
In an impact of sufficient severity, the air bag sensing
system detects that the vehicle is in a crash. For
both frontal and side impact air bags, the sensing
system triggers a release of gas from the in¯ator, which
in¯ates the air bag. The in¯ator, the air bag and
related hardware are all part of the air bag modules.
Frontal air bag modules are located inside the steering
wheel and instrument panel. For vehicles with side
impact air bags, the air bag modules are located in the
seatback closest to the driver's and/or right front
passenger's door.
How Does an Air Bag 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. The air bag supplements the protection
provided by safety belts. Air bags distribute the force of
the impact more evenly over the occupant's upper
body, stopping the occupant more gradually. But the
frontal air bags would not help you in many types
of collisions, including rollovers, rear impacts, and many
side impacts, primarily because an occupant's motion
is not toward the air bag. Side impact air bags would not
help you in many types of collisions, including frontal
or near frontal collisions, rollovers, and rear impacts,
primarily because an occupant's motion is not toward
those air bags. Air bags should never be regarded
as anything more than a supplement to safety belts, and
then only in moderate to severe frontal or near-frontal
collisions for the driver's and right front passenger's
frontal air bags, and only in moderate to severe
side collisions for vehicles with a driver's and right front
passenger's side impact air bag.
1-56

What Will You See After an Air Bag
In¯ates?
After the air bag in¯ates, it quickly de¯ates, so quickly
that some people may not even realize the air bag
in¯ated. Some components of the air bag module will be
hot for a short time. These components include the
steering wheel hub for the driver's frontal air bag and the
instrument panel for the right front passenger's frontal
air bag. For vehicles with side impact air bags, the side
of the seatback closest to the driver's and/or right
front passenger's door will be hot. The parts of the bag
that come into contact with you may be warm, but
not too hot to touch. There will be some smoke and dust
coming from the vents in the de¯ated air bags. Air
bag in¯ation doesn't prevent the driver from seeing or
being able to steer the vehicle, nor does it stop
people from leaving the vehicle.
{CAUTION:
When an air bag in¯ates, there is dust in the
air. This dust could cause breathing problems
for people with a history of asthma or other
breathing trouble. To avoid this, everyone in
the vehicle should get out as soon as it is safe
to do so. If you have breathing problems but
can't get out of the vehicle after an air bag
in¯ates, then get fresh air by opening a
window or a door. If you experience breathing
problems following an air bag deployment, you
should seek medical attention.
Your vehicle has a feature that will automatically unlock
the doors and turn the interior lamps on when the air
bags in¯ate (if battery power is available). You can lock
the doors again and turn the interior lamps off by
using the door lock and interior lamp controls.
1-57

In many crashes severe enough to in¯ate an air bag,
windshields are broken by vehicle deformation.
Additional windshield breakage may also occur from the
right front passenger air bag.
·Air bags are designed to in¯ate only once. After an
air bag in¯ates, you'll need some new parts for
your air bag system. If you don't get them, the air
bag system won't be there to help protect you
in another crash. A new system will include air bag
modules and possibly other parts. The service
manual for your vehicle covers the need to replace
other parts.
·Your vehicle is equipped with an electronic frontal
sensor, which helps the sensing system distinguish
between a moderate frontal impact and a more
severe frontal impact. Your vehicle is also equipped
with a crash sensing and diagnostic module,
which records information about the frontal air bag
system. The module records information about
the readiness of the system, when the system
commands air bag in¯ation and driver's safety belt
usage at deployment. The module also records
speed, engine rpm, brake and throttle data.
·Let only quali®ed technicians work on your air bag
systems. Improper service can mean that an air
bag system won't work properly. See your dealer for
service.
Notice:If you damage the covering for the driver's
or the right front passenger's air bag, or the air
bag covering on the driver's and right front
passenger's seatback, the bag may not work
properly. You may have to replace the air bag
module in the steering wheel, both the air bag
module and the instrument panel for the right front
passenger's air bag, or both the air bag module
and seatback for the driver's and right front
passenger's side impact air bag. Do not open or
break the air bag coverings.
1-58

Servicing Your Air Bag-Equipped
Vehicle
Air bags affect how your vehicle should be serviced.
There are parts of the air bag systems in several places
around your vehicle. Your dealer and the service
manual have information about servicing your vehicle
and the air bag systems. To purchase a service manual,
see
Service Publications Ordering Information on
page 7-9.
{CAUTION:
For up to 10 seconds after the ignition key is
turned off and the battery is disconnected, an
air bag can still in¯ate during improper
service. You can be injured if you are close to
an air bag when it in¯ates. Avoid yellow
connectors. They are probably part of the air
bag system. Be sure to follow proper service
procedures, and make sure the person
performing work for you is quali®ed to do so.
The air bag systems do not need regular maintenance.
Restraint System Check
Checking Your Restraint Systems
Now and then, make sure the safety belt reminder light
and all your belts, buckles, latch plates, retractors
and anchorages are working properly. Look for any other
loose or damaged safety belt system parts. If you see
anything that might keep a safety belt system from doing
its job, 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.
Also look for any opened or broken air bag covers, and
have them repaired or replaced. (The air bag system
does not need regular maintenance.)
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've had a crash, do you need new belts or LATCH
system parts?
After a very minor collision, nothing may be necessary.
But if the belts were stretched, as they would be if
worn during a more severe crash, then you need
new parts.
If the LATCH system was being used during a more
severe crash, you may need new LATCH system parts.
If belts are cut or damaged, replace them. Collision
damage also may mean you will need to have LATCH
system, safety belt or seat parts repaired or replaced.
New parts and repairs may be necessary even if the belt
or LATCH system wasn't being used at the time of
the collision.
If an air bag in¯ates, you'll need to replace air bag
system parts. See the part on the air bag system earlier
in this section.
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Keys...............................................................2-3
Remote Keyless Entry System.........................2-5
Remote Keyless Entry System Operation...........2-6
Doors and Locks.............................................2-8
Door Locks....................................................2-8
Power Door Locks..........................................2-9
Delayed Locking.............................................2-9
Programmable Automatic Door Locks..............2-10
Rear Door Security Locks..............................2-12
Lockout Protection........................................2-12
Leaving Your Vehicle....................................2-12
Liftgate/Liftglass............................................2-13
Windows........................................................2-14
Power Windows............................................2-15
Sun Visors...................................................2-15Theft-Deterrent Systems..................................2-16
Content Theft-Deterrent.................................2-16
Passlock
ž....................................................2-18
Starting and Operating Your Vehicle................2-18
New Vehicle Break-In....................................2-18
Ignition Positions..........................................2-19
Starting Your Engine.....................................2-20
Engine Coolant Heater..................................2-21
Automatic Transmission Operation...................2-22
Four-Wheel Drive..........................................2-24
Parking Brake..............................................2-28
Shifting Into Park (P).....................................2-29
Shifting Out of Park (P).................................2-31
Parking Over Things That Burn.......................2-31
Engine Exhaust............................................2-32
Running Your Engine While You Are
Parked.....................................................2-32
Section 2 Features and Controls
2-1

Mirrors...........................................................2-34
Automatic Dimming Rearview Mirror with
OnStar
žand Compass...............................2-34
Outside Manual Mirrors..................................2-36
Outside Power Mirrors...................................2-36
Outside Curb View Assist Mirror.....................2-36
Outside Convex Mirror...................................2-37
Outside Heated Mirrors..................................2-37
OnStar
žSystem.............................................2-38
HomeLinkžTransmitter...................................2-39
Programming the HomeLinkžTransmitter.........2-40Storage Areas................................................2-43
Glove Box...................................................2-43
Overhead Console........................................2-43
Front Storage Area.......................................2-44
Table..........................................................2-47
Luggage Carrier...........................................2-47
Rear Floor Storage Lid..................................2-48
Convenience Net..........................................2-49
Cargo Cover................................................2-49
Sunroof.........................................................2-50
Vehicle Personalization...................................2-50
Memory Seat...............................................2-50
Section 2 Features and Controls
2-2

Keys
{CAUTION:
Leaving children in a vehicle with the ignition
key is dangerous for many reasons. A child or
others could be badly injured or even killed.
They could operate the power windows or
other controls or even make the vehicle move.
Do not leave the keys in a vehicle with
children.
2-3

This vehicle has one
double-sided key for the
ignition and door lock.
It will ®t with either side up.
When a new vehicle is delivered, the dealer provides
the owner with a pair of identical keys and a key
code number.The key code number tells your dealer or a quali®ed
locksmith how to make extra keys. Keep this number in
a safe place. If you lose your keys, you'll be able to
have new ones made easily using this number.
Your selling dealer should also have this number.
Notice:If you ever lock your keys in your vehicle,
you may have to damage the vehicle to get in.
Be sure you have spare keys.
If you ever do get locked out of your vehicle, call the
GM Roadside Assistance Center. See
Roadside
Assistance Program on page 7-5.
If your vehicle is equipped with the OnStar
žsystem with
an active subscription and you lock your keys inside
the vehicle, OnStar
žmay be able to send a command to
unlock your vehicle. SeeOnStaržSystem on page 2-38for more information.
2-4