1999 GMC ENVOY steering wheel

yellowblue
1-23 How the Air Bag System Works
Where are the air bags?
The driver's air bag is in the middle of the
steering wheel.
The right front passenger's air bag is in the instrument
panel on the passenger's side.
ProCarManuals.com

yellowblue
1-24
CAUTION:
If something is between an occupant and an air
bag, the bag might not inflate properly or it
might force the object into that person. The path
of an inflating air bag must be kept clear. Don't
put anything between an occupant and an air
bag, and don't attach or put anything on the
steering wheel hub or on or near any other air
bag covering.
When should an air bag inflate?
An air bag is designed to inflate in a moderate to severe
frontal or near
-frontal crash. The air bag will inflate
only if the impact speed is above the system's designed
ªthreshold level.º If your vehicle goes straight into a
wall that doesn't move or deform, the threshold level is
about 14 to 18 mph (23 to 29 km/h). The threshold level can vary, however, with specific 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
air bag is not designed to inflate in rollovers, side
impacts or rear impacts, because inflation would not
help the occupant.
In any particular crash, no one can say whether an air
bag should have inflated simply because of the damage
to a vehicle or because of what the repair costs were.
Inflation is determined by the angle of the impact and
how quickly the vehicle slows down in frontal or
near
-frontal impacts.
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 ªOff
-Road
Drivingº in the Index for more tips on off
-road driving.
ProCarManuals.com

yellowblue
1-25
What makes an air bag inflate?
In an impact of sufficient severity, the air bag sensing
system detects that the vehicle is in a crash. The sensing
system triggers a release of gas from the inflator, which
inflates the air bag. The inflator, air bag and related
hardware are all part of the air bag modules inside the
steering wheel and in the instrument panel in front of the
right front passenger.
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. Air bags supplement 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 air bags
would not help you in many types of collisions,
including rollovers, rear impacts and side 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.What will you see after an air bag inflates?
After an air bag inflates, it quickly deflates, so quickly
that some people may not even realize the air bag
inflated. Some components of the air bag module
-- the
steering wheel hub for the driver's air bag, or the
instrument panel for the right front passenger's
bag
-- will be hot for a short time. 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 vents in the deflated air bags. Air bag
inflation doesn't prevent the driver from seeing or from
being able to steer the vehicle, nor does it stop people
from leaving the vehicle.
CAUTION:
When an air bag inflates, 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 inflates, then get
fresh air by opening a window or door.
ProCarManuals.com

yellowblue
1-26

Air bags are designed to inflate only once. After they
inflate, 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 a diagnostic module,
which records information about the air bag system.
The module records information about the readiness
of the system, when the sensors are activated and
driver's safety belt usage at deployment.

Let only qualified technicians work on your air bag
system. Improper service can mean that your 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, the bag may not
work properly. You may have to replace the air
bag module in the steering wheel or both the air
bag module and the instrument panel for the
right front passenger's air bag. Do not open or
break the air bag coverings.
If your vehicle ever gets into a lot of water -- such as
water up to the carpeting or higher
-- or if water enters
your vehicle and soaks the carpet, the air bag controller
can be soaked and ruined. If this ever happens, and then
you start your vehicle, the damage could make the air bags
inflate, even if there's no crash. You would have to replace
the air bags as well as the sensors and related parts. If your
vehicle is ever in a flood, or if it's exposed to water that
soaks the carpet, you can avoid needless repair costs by
turning off the vehicle immediately and disconnecting the
battery cables. Don't let anyone start the vehicle under any
circumstances. See your dealer for service.
ProCarManuals.com

yellowblue
2-11 Key in the Ignition
If you leave your vehicle with the keys inside, it's an
easy target for joy riders or professional thieves
-- so
don't do it.
When you park your vehicle and open the driver's door,
you'll hear a chime reminding you to remove your key
from the ignition and take it with you. Always do this.
Your steering wheel will be locked, and so will your
ignition and transmission. Also remember to lock
the doors.
Parking at Night
Park in a lighted spot, close all windows and lock your
vehicle. Remember to keep your valuables out of sight.
Put them in a storage area, or take them with you.
Parking Lots
If you park in a lot where someone will be watching
your vehicle, it's best to lock it up and take your keys.
But what if you have to leave your ignition key? What if
you have to leave something valuable in your vehicle?

Put your valuables in a storage area, like your
glove box.

Lock all the doors except the driver's.
Content Theft-Deterrent
Your vehicle is equipped with a Content Theft-Deterrent
alarm system.
With this system, the
SECURITY light will flash
as you open the door (if
your ignition is off).
This light reminds you to activate the theft
-deterrent
system. Here's how to do it:
1. Open the door.
2. Lock the door with the power door lock switch or the
remote keyless entry transmitter. The SECURITY
light should come on and stay on.
3. Close all doors. The SECURITY light should go off
after approximately 30 seconds. The alarm is not
armed until the SECURITY light goes off.
If a door is opened without the key or the remote keyless
entry transmitter, the alarm will go off. Your vehicle's
high
-beam headlamps will flash and the horn will sound
for 110 seconds, then will turn off to save the
battery power.
ProCarManuals.com

yellowblue
2-14
Ignition Positions
CAUTION:
Leaving children in a vehicle with the ignition
key is dangerous for many reasons. A child or
others could be injured or even killed. They could
operate power windows or other controls or even
make the vehicle move. Don't leave the keys in
the vehicle with children.
Use the key to turn the ignition switch to
five different positions.ACCESSORY (A): This position lets you use things
like the radio and the windshield wipers when the
engine is off. Push in the key and turn it toward you.
Your steering wheel will remain locked, just as it was
before you inserted the key.
ProCarManuals.com

yellowblue
2-15
NOTICE:
Don't operate accessories in the ACCESSORY
position for long periods of time. Prolonged
operation of accessories in the ACCESSORY
position could drain your battery and prevent
you from starting your vehicle.
LOCK (B): This position locks your ignition, steering
wheel and transmission. It's a theft
-deterrent feature.
You will only be able to remove your key when the
ignition is turned to LOCK.
OFF (C): This position lets you turn off the engine but
still turn the steering wheel. Use OFF if you must have
your vehicle in motion while the engine is off (for
example, if your vehicle is being towed).
RUN (D): This is the position for driving.
START (E): This position starts your engine.
NOTICE:
If your key seems stuck in LOCK and you can't
turn it, be sure you are using the correct key; if
so, is it all the way in? If it is, then turn the
steering wheel left and right while you turn the
key hard. But turn the key only with your hand.
Using a tool to force it could break the key or the
ignition switch. If none of this works, then your
vehicle needs service.
Retained Accessory Power
Your vehicle is equipped with a Retained Accessory
Power (RAP) feature which will allow certain features
on your vehicle to continue to work up to 20 minutes
after the ignition key is turned to OFF.
Your radio, power windows, sunroof and overhead
console will work when the ignition key is in RUN or
ACCESSORY. Once the key is turned from RUN to
OFF, these features will continue to work for up to
20 minutes or until a door is opened.
ProCarManuals.com

yellowblue
2-22 Automatic Transfer Case
The transfer case switches
are to the right of the
steering wheel on the
instrument panel. Use these
switches to shift into and
out of four
-wheel drive.
You can choose among four
driving settings:
2HI: This setting is for driving in most street and
highway situations. Your front axle is not engaged in
two
-wheel drive. This setting also provides the best
fuel economy.
ProCarManuals.com