2004 GMC ENVOY XL service

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-2
Rear Seats
............................................... 1-5
Safety Belts
.............................................. 1-8
Child Restraints
.......................................1-27
Air Bag Systems
......................................1-49
Restraint System Check
............................1-59
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
....................................... 2-8
Windows
.................................................2-15
Theft-Deterrent Systems
............................2-17
Starting and Operating Your Vehicle
...........2-19
Mirrors
....................................................2-36
OnStar
®System
......................................2-40
HomeLink®Transmitter
.............................2-42
Storage Areas
.........................................2-46
Sunroof
..................................................2-53
Vehicle Personalization
.............................2-53
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-22
Warning Lights, Gages, and Indicators
........3-35
Driver Information Center (DIC)
..................3-51
Audio System(s)
.......................................3-64Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-45
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-4
Checking Things Under the Hood
...............5-10
Rear Axle
...............................................5-48
Four-Wheel Drive
.....................................5-49
Front Axle
...............................................5-50
Bulb Replacement
....................................5-51
Windshield Wiper Blade Replacement
.........5-53
Tires
......................................................5-55
Appearance Care
.....................................5-88
Vehicle Identication
.................................5-95
Electrical System
......................................5-96
Capacities and Specications
...................5-109
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance and Information.............. 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-11
Index................................................................ 1
2004 GMC Envoy/Envoy XL Owner ManualM

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

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 7-12.
{CAUTION:
For up to 10 minutes after the ignition key is
turned off and the battery is disconnected,
an air bag can still inate during improper
service. You can be injured if you are close
to an air bag when it inates. 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 qualied 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

Remote Keyless Entry System
Your keyless entry system operates on a radio
frequency subject to Federal Communications
Commission (FCC) Rules and with Industry Canada.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
1. This device may not cause interference, and
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
This device complies with RSS-210 of Industry Canada.
Operation is subject to the following two conditions:
1. This device may not cause interference, and
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.At times you may notice a decrease in range. This is
normal for any remote keyless entry system. If the
transmitter does not work or if you have to stand closer
to your vehicle for the transmitter to work, try this:
Check the distance. You may be too far from your
vehicle. You may need to stand closer during
rainy or snowy weather.
Check the location. Other vehicles or objects may
be blocking the signal. Take a few steps to the
left or right, hold the transmitter higher, and
try again.
Check to determine if battery replacement is
necessary. See “Battery Replacement” under
Remote Keyless Entry System Operation on
page 2-6.
If you are still having trouble, see your dealer or
a qualied technician for service.
2-5

If a locked door is opened without the key or the
remote keyless entry transmitter, the alarm will go off.
The headlamps and parking lamps will ash for two
minutes, and the horn will sound for 30 seconds, then
will turn off to save the battery power.
Remember, the theft-deterrent system won’t activate
if you lock the doors with a key or use the manual door
lock. It activates only if you use a power door lock
switch with the door open, or with the remote keyless
entry transmitter. You should also remember that
you can start your vehicle with the correct ignition key
if the alarm has been set off.
Here’s how to avoid setting off the alarm by accident:
If you don’t want to activate the theft-deterrent
system, the vehicle should be locked with the
door keyafterthe doors are closed.
Always unlock a door with a key, or use the remote
keyless entry transmitter. Unlocking a door any
other way will set off the alarm.
If you set off the alarm by accident, unlock any door
with the key. You can also turn off the alarm by pressing
unlock on the remote keyless entry transmitter. The alarm
won’t stop if you try to unlock a door any other way.
Testing the Alarm
The alarm can be tested by following these steps:
1. From inside the vehicle, lower the driver’s window
and open the driver’s door.
2. Activate the system by locking the doors with
the power door lock switch while the door is
open, or with the remote keyless entry transmitter.
3. Get out of the vehicle, close the door and wait for
the security light to go out.
4. Then reach in through the window, unlock the
door with the manual door lock and open the
door. This should set off the alarm.
When the alarm is set the power door unlock switch
is not operational.
If the alarm does not sound when it should but the
headlamps ash, check to see if the horn works.
The horn fuse may be blown. To replace the fuse,
seeFuses and Circuit Breakers on page 5-97.
If the alarm does not sound or the headlamps do not
ash, the vehicle should be serviced by your dealer.
2-18

Passlock®
Your vehicle is equipped with the Passlock®
theft-deterrent system.
Passlock®is a passive theft-deterrent system that
enables fuel if the ignition lock cylinder is turned with
a valid key. If a correct key is not used or the ignition
lock cylinder is tampered with, the fuel system is
disabled and the vehicle will not start.
During normal operation, the security light will turn off
approximately ve seconds after the key is turned
to RUN.
If the engine stalls and the security light ashes, wait
about 10 minutes until the light stops ashing before
trying to restart the engine. Remember to release
the key from START as soon as the engine starts.
If the engine does not start after three tries, the vehicle
needs service.
If the engine is running and the security light comes on,
you will be able to restart the engine if you turn the engine
off. However, your Passlock
®system is not working
properly and must be serviced by your dealer. Your
vehicle is not protected by Passlock
®at this time. You
may also want to check the fuse. SeeFuses and Circuit
Breakers on page 5-97. See your dealer for service.
In an emergency, call the GM Roadside Assistance
Center. SeeRoadside Assistance Program on page 7-7.
Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not need an elaborate
“break-in.” But it will perform better in the long run
if you follow these guidelines:
Keep your speed at 55 mph (88 km/h) or less
for the rst 500 miles (805 km).
Do not drive at any one speed — fast or
slow — for the rst 500 miles (805 km).
Do not make full-throttle starts.
Avoid making hard stops for the rst 200 miles
(322 km) or so. During this time your new
brake linings are not yet broken in. Hard stops
with new linings can mean premature wear
and earlier replacement. Follow this breaking-in
guideline every time you get new brake
linings.
Do not tow a trailer during break-in. SeeTowing
a Trailer on page 4-55for more information.
2-19

Ignition Positions
Use the key to turn the ignition switch to four different
positions.
A (LOCK):This position locks the ignition and
transmission. It’s a theft-deterrent feature. You will only
be able to remove the key when the ignition is turned
to LOCK.Notice:If your key seems stuck in LOCK and you
can not turn it, be sure you are using the correct
key; if so, is it all the way in? Turn the key only with
your hand. Using a tool to force it could break the
key or the ignition switch. If none of these works,
then your vehicle needs service.
B (ACCESSORY):This position lets you use things
like the radio and the windshield wipers when the
engine is off.
Notice:Lengthy operation of features such as the
radio in the accessory ignition position may drain the
battery and prevent your vehicle from starting. Do not
operate your vehicle in the accessory ignition
position for a long period of time.
C (RUN):This is the position for driving.
D (START):This position starts the engine.
2-20

2HI (Two-Wheel High):This setting is for driving in
most street and highway situations. Your front axle is
not engaged in two-wheel drive. It also provides the best
fuel economy.
A4WD (Automatic Four-Wheel Drive):This setting is
ideal for use when road conditions are variable. When
driving your vehicle in A4WD, the front axle is engaged,
but the vehicle’s power is sent to the rear wheels. When
the vehicle senses a loss of traction, the system will
automatically engage four-wheel drive. Driving in this
mode results in slightly lower fuel economy than 2HI.
4HI (Four-Wheel High):Use 4HI when you need
extra traction, such as on snowy or icy roads or in
most off-road situations. This setting also engages
your front axle to help drive your vehicle.
4LO (Four-Wheel Low):This setting also engages
your front axle and delivers extra torque. It sends
maximum power to all four wheels. You might choose
4LO if you are driving off-road in deep sand, deep mud,
and climbing or descending steep hills.
{CAUTION:
Shifting the transfer case to NEUTRAL
can cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. SeeParking Brake on
page 2-29.
NEUTRAL:Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-45for more
information.
An indicator light in the knob will show you which position
the transfer case is in. The indicator lights will come on
briey when you turn on the ignition and one will stay on.
If the lights do not come on, you should take your vehicle
to your dealer for service. An indicator light will ash while
shifting the transfer case. It will remain illuminated when
the shift is complete. If for some reason the transfer case
cannot make a requested shift, it will return to the last
chosen setting.
2-27