2004 GMC ENVOY XL sensor

In many crashes severe enough to inate 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 inate only once. After
an air bag inates, 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 electronic frontal
sensors, which help 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 ination and driver’s safety belt
usage at deployment. The module also records
speed, engine rpm, brake and throttle data.
Let only qualied 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 air 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

Windshield Wipers
8
(Mist):For a single wiping cycle, turn the band to
mist. Hold it there until the wipers start. Then let go.
The wipers will stop after one wipe. If you want
more wipes, hold the band on mist longer.
9(Off):To stop the wipers, move the band to off.
N(Windshield Wipers):Turn the band to control the
windshield wipers.
You can set the wiper speed for a long or short delay
between wipes. This can be very useful in light rain
or snow. Turn the band to choose the delay time. The
closer to the top of the lever, the shorter the delay.
For steady wiping at low speed, turn the band away from
you to the rst solid band past the delay settings. For
high-speed wiping, turn the band further, to the second
solid band past the delay settings. To stop the wipers,
move the band to off.
Be sure to clear ice and snow from the wiper blades
before using them. If they’re frozen to the windshield,
carefully loosen or thaw them. If your blades do become
worn or damaged, get new blades or blade inserts.
Rainsense™ Wipers
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 ve delay settings on the multifunction
lever. Each of the ve 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:If you do not turn off the windshield wipers
when driving through an automatic car wash,
you could damage the wipers. Always turn off the
windshield wipers before entering an automatic
car wash.
3-10

Exterior Lamps
Your exterior lamps
knob is located on your
instrument panel to the
left of the steering wheel.
c(Off):Turn the knob to this symbol and release it
to turn off the Daytime Running Lamps (DRL) and
the automatic headlamps. An indicator will illuminate
when the position is selected. This position is not
available for vehicles rst sold in Canada.
i(Automatic DRL/AHS):Turning the knob to this
symbol puts the system into automatic headlamp mode.
An indicator will illuminate when the position is selected.
;(Parking Lamps):Turn the knob to this symbol to
manually turn on the following:
Parking Lamps
Sidemarker Lamps
Taillamps
License Plate Lamps
Instrument Panel Lights
2(Headlamps):Turn the knob to this symbol to turn
on all the lamps listed as well as the headlamps.
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.
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.
3-16

If you start your vehicle in a dark garage, the automatic
headlamp system will come on immediately. Once
you leave the garage, it will take about one minute for
the automatic headlamp system to change to DRL if it is
light outside. During that delay, your instrument panel
cluster may not be as bright as usual. Make sure
your instrument panel brightness control is in the full
bright position.
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,
shift out of park or turn the exterior lamp control to
the off position as described in “Exterior Lamps” listed
previously.
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 (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 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
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.
3-17

Safety Belt Reminder Light
When the key is turned to RUN, a chime will come on
for several seconds to remind people to fasten their
safety belts, unless the driver’s safety belt is already
buckled.
The safety belt light will
also come on and stay
on for several seconds,
then it will ash for
several more.
If the driver’s belt is already buckled, neither the chime
nor the light will come on.
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, seeAir Bag Systems on page 1-49.
This light will come on
when you start your
vehicle, and it will ash
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.
3-38

Electronically Controlled Air
Suspension System
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 inator system will be
ashing.
The ignition has to be on for the system to inate, 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 inator
hose attached to the inator outlet. Remove the inator
hose from the outlet during loading and unloading.
If the vehicle is parked for an extended period of time,
some bleed down of the suspension is normal. Upon
starting the vehicle, proper height will be achieved.
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. SeeLoading Your Vehicle on page 4-49.
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.
4-54

Fuses Usage
29 Oxygen Sensor
30 Air Conditioning
31 Truck Body Controller
32 Trailer
33 Anti-Lock Brakes (ABS)
34 Ignition A
35 Blower Motor
36 Ignition B
50 Passenger’s Side Trailer Turn
51 Driver’s Side Trailer Turn
52 Hazard Flashers
53 Electric Adjustable Pedal
54 A.I.R. Solenoid
56 A.I.R. PumpRelays Usage
37 Headlamp Washer
38 Rear Window Washer
39 Fog Lamps
40 Horn
41 Fuel Pump
42 Windshield Washer
43 High-Beam Headlamp
44 Air Conditioning
45 Cooling Fan
46 Headlamp Driver Module
47 Starter
49 Electric Adjustable Pedal
55 A.I.R. Solenoid
Miscellaneous Usage
48 Instrument Panel Battery
49 Blank
5-100

Fuses Usage
30 Air Conditioning
31 Truck Body Controller 1
32 Trailer
33 Anti-Lock Brakes (ABS)
34 Ignition A
35 Blower Motor
36 Ignition B
50 Passenger’s Side Trailer Turn
51 Driver’s Side Trailer Turn
52 Hazard Flashers
53 Oxygen Sensor Bank B
54 Oxygen Sensor Bank A
55 Injector Bank A
56 Injector Bank B
57 Electric Adjustable PedalRelays Usage
37 Headlamp Washer
38 Rear Window Washer
39 Fog Lamps
40 Horn
41 Fuel Pump
42 Windshield Washer
43 High-Beam Headlamp
44 Air Conditioning
45 Cooling Fan
46 Headlamp Driver Module
47 Starter
49 Electric Adjustable Pedal
58 Ignition 1
Miscellaneous Usage
48 Instrument Panel Battery
5-103