2002 GMC ENVOY sensor

1-29
In many crashes severe enough to inflate 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 inflate only once. After an
air bag inflates, 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
inflation and driver's safety belt usage at deployment.
The module also records speed, engine rpm, brake
and throttle data.

Let only qualified 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.

2-41
Rainsense
Wipers (If Equipped)
Your vehicle may be equipped with Rainsense
windshield wipers. When active, these wipers are able to
detect moisture on the windshield and automatically turn
on the wipers.
The moisture sensor is located next to the inside
rearview mirror and is mounted on the windshield.
To turn on the Rainsense feature, the wipers must be set
to one of the five delay settings on the multifunction
lever. Each of the five settings adjusts the sensitivity
of the rainsensor. For more wipes, select the higher
settings; for fewer wipes, select the lower settings
located closer to off on the multifunction lever.
The rainsensor will automatically control the frequency
of the wipes from off to high speed according to the
weather conditions. The wipers can be left in a rainsense
mode even when it is not raining.
NOTICE:
Turn the windshield wiper band on the
multifunction lever to off to avoid wiper damage
when going through an automatic car wash.
Windshield Washer
There is a paddle marked with the windshield washer
symbol at the top of the multifunction lever. To spray
washer fluid on the windshield, push the paddle.
The wipers will clear the window and then either stop
or return to your preset speed.
CAUTION:
In freezing weather, don't use your washer until
the windshield is warmed. Otherwise the washer
fluid can form ice on the windshield, blocking
your vision.

2-46
Exterior Lamps
Your exterior lamps knob is
located on the driver's side
of your instrument panel.
Turn the knob clockwise to the parking lamps
symbol to manually turn on the following:

Parking Lamps

Sidemarker Lamps

Taillamps

License Plate Lamps

Instrument Panel Lights
Turn the knob clockwise to the master lamps
symbol to turn on all the lamps listed as well as
the headlamps.
Turn the knob all the way counterclockwise to this
symbol to turn off the lamps and put the system in
automatic headlamp mode.
Automatic Headlamp System
When it is dark enough outside, your automatic
headlamp system will turn on your headlamps at the
normal brightness along with other lamps such as the
taillamps, sidemarker, parking lamps and the instrument
panel lights. The radio lights will also be on.
Your vehicle is equipped with a light sensor 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 your lights when driving
through a parking garage, heavy overcast weather or a
tunnel. This is normal.

2-47
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 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 sees a change in lighting lasting longer than
the delay.
To idle your vehicle with the automatic headlamp
system off, set the parking brake while the ignition is
off. Then start your vehicle. The automatic headlamp
system will stay off until you release the parking brake,
or until you shift out of park.
You may be able to turn off your automatic headlamp
system. See ªDaytime Running Lamps (DRL)º later in
this section for more information.
As with any vehicle, you should turn on the regular
headlamp system when you need it.
Lamps On Reminder
A reminder tone will sound when your headlamps or
parking lamps are manually turned on, the driver's door
is open and your ignition is in LOCK or 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.
Daytime Running Lamps
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 first sold in Canada.
The DRL system will make your 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, and

the transmission is not in PARK (P).
When the DRL are on, only your headlamps will be on.
The taillamps, sidemarker and other lamps won't be on.
The instrument panel won't be lit up either.
When it begins to get dark, the headlamps
will automatically switch from DRL to the
regular headlamps.

2-77
Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows the air bag symbol. The system
checks the air bag's electrical system for malfunctions.
The light tells you if there is an electrical problem. The
system check includes the air bag sensors, the air bag
modules, the wiring and the crash sensing and
diagnostic module. For more information on the air bag
system, see ªAir Bagº in the Index.
This light will come on
when you start your vehicle,
and it will flash for a few
seconds. Then the light
should go out. This means
the system is ready.
If the air bag readiness light stays on after you start the
vehicle or comes on when you are driving, your air bag
system may not work properly. Have your vehicle
serviced right away.
CAUTION:
If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not inflate in a crash, or they
could even inflate without a crash. To help avoid
injury to yourself or others, have your vehicle
serviced right away if the air bag readiness light
stays on after you start your vehicle.
The air bag readiness light should flash for a few
seconds when you turn the ignition key to RUN. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.

3-6
To find your comfort setting, start with a 74
F (23
C)
temperature setting and allow about 20 minutes for the
system to regulate. Turn the driver's or passenger's side
temperature knob clockwise or counterclockwise to
adjust the temperature setting as necessary. If you
choose the temperature setting of 60
F (15
C), the
system will remain at the maximum cooling setting
and fan speed. If you choose the temperature setting of
90
F (32
C), the system will remain at the maximum
heat setting and fan speed. Choosing either maximum
setting will not cause the system to heat or cool any
faster.
Be careful not to cover the sensor located on the top of
the instrument panel near the windshield. This sensor
regulates air temperature based on sun load, and also
turns on your headlamps.
The EXT (exterior) temperature sensor is located in the
front of the vehicle behind the grille. The displayed
temperature is most accurate after the vehicle has been
moving for a few minutes. If the vehicle is stopped and
then restarted within 2 1/2 hours, the sensor will be hot
from the engine heat. In this case, the temperature first
displayed will continue to be the temperature that was
displayed before the vehicle was turned off. The display
will update after the vehicle has been moving for a few
minutes and the sensor has a chance to cool down to the
actual temperature.To avoid blowing cold air in cold weather, the system
will delay turning on the fan until warm air is available.
The length of delay depends on the engine coolant
temperature. Pushing the fan switch will override this
delay and change the fan to a selected speed.
Manual Operation
You may manually adjust the air delivery mode or fan
speed. Use the mode button to cycle through the
following four air delivery modes:
(Panel): This setting will deliver air to the
instrument panel outlets.
(Bi-Level): This setting will deliver warmer air to
the floor and cooler air to the instrument panel outlets.
(Floor): This setting will deliver air to the
floor outlets.
(Defog): This setting will deliver air to the floor
and windshield outlets.
OFF: Press this button to turn the system off. Some
fresh air will continue to flow through the vehicle from
the floor outlets. The system will try to maintain the
previously chosen temperature setting.

3-31
(CLEAN): If this message appears on the display, the
cassette tape player needs to be cleaned. It will still play
tapes, but you should clean it as soon as possible to
prevent damage to the tapes and player. See ªCare of
Your Cassette Tape Playerº in the Index. After you clean
the player, press and hold the cassette eject button for
five seconds to reset the CLEAN indicator. The radio
display will display CLEANED to show the indicator
was reset.
If any error occurs repeatedly or if an error can't be
corrected, please contact your dealer.
Tight/Loose Tape Sensor Defeat
With the radio off and the ignition on, press and hold the
TAPE CD button to disable the tight/loose tape sensing
feature to enable play of some tape head cleaners and
portable CD adapters. The radio will display READY
and flash the cassette icon. The tight/loose tape sensing
feature will then be disabled until the next time a
cassette is ejected.Playing a Compact Disc
Insert a disc partway into the slot, label side up. The
player will pull it in and the disc should begin playing.
The display will show the CD symbol. If you want to
insert a compact disc with the ignition off, first press
TUNE DISP or EJT.
If an error appears on the display, see ªRadio/Compact
Disc Messagesº later in this section.
1 PREV: Press this button or the left SEEK PSCAN
arrow to go to the previous track if the current selection
has been playing for less than eight seconds. If the
1 PREV button or the left SEEK PSCAN arrow is
pressed and the current selection has been playing for
more than eight seconds, it will go to the beginning of
the current selection. TRACK and the track number will
appear on the display. If you hold the 1 PREV button or
left SEEK PSCAN arrow or press it more than once, the
player will continue moving back through the disc. The
sound will mute while seeking.
2 NEXT: Press this button or the right SEEK PSCAN
arrow to go to the next track. TRACK and the track
number will appear on the display. If you hold the
2 NEXT button or the right SEEK PSCAN arrow
or press it more than once, the player will continue
moving forward through the disc. The sound will mute
while seeking.

4-49 Electronically Controlled Air Suspension
System (If Equipped)
Your vehicle may be equipped with an electronically
controlled air suspension system that automatically
keeps your vehicle level as you load and unload. 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 system overheats, all leveling
function stops until the system cools down. During
this time, the indicator light on the air inflator system
will be flashing.
The ignition has to be on for the system to inflate, 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.
You may hear the compressor operating when you load
your vehicle, and periodically as the system adjusts the
vehicle to the standard ride height.
Load leveling will not function normally with the
inflator hose attached to the inflator outlet. Remove
the inflator hose from the outlet during loading
and unloading.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.
See ªLoading Your Vehicleº earlier in this section.
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 inflator switch in the rear
passenger compartment also serves as an indicator for
internal system error. If the indicator light is flashing
without the load leveling function or the inflator 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 flashing, but if it is you should
have the vehicle serviced as soon as possible.