2004 GMC ENVOY XL maintenance schedule

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

Oil Pressure Gage
The oil pressure gage shows the engine oil pressure in
psi (pounds per square inch) when the engine is running.
Canadian vehicles indicate pressure in kPa (kilopascals).
{CAUTION:
Do not keep driving if the oil pressure is low.
If you do, your engine can become so hot that
it catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the
low pressure zone indicate the normal operating range.
A reading in the low pressure zone may be caused
by a dangerously low oil level or other problems causing
low oil pressure. United States
Canada
3-46

Change Engine Oil Light
When this light comes on, it means that service is
required for your vehicle. SeeScheduled Maintenance
on page 6-4andEngine Oil on page 5-16for more
information.
Once the engine oil has been changed, the change
engine oil light must be reset. Until it is reset, the light
will be displayed when the engine is on.
Security Light
This light will come on briey when you turn the key
toward START. The light will stay on until the engine
starts.
If the light ashes, the Passlock
®system has entered a
tamper mode. If the vehicle fails to start, seePasslock®
on page 2-19.
If the light comes on continuously while driving and
stays on, there may be a problem with the Passlock
®
system. Your vehicle will not be protected by Passlock®,
and you should see your dealer.
Also, seeContent Theft-Deterrent on page 2-17for
additional information regarding the SECURITY light. United States
CanadaUnited StatesCanada
3-47

If the water is not too deep, drive slowly through it.
At faster speeds, water splashes on your ignition
system and your vehicle can stall. Stalling can also
occur if you get your tailpipe under water. And, as long
as your tailpipe is under water, you will never be
able to start your engine. When you go through water,
remember that when your brakes get wet, it may
take you longer to stop.
{CAUTION:
Driving through rushing water can be
dangerous. Deep water can sweep your vehicle
downstream and you and your passengers
could drown. If it is only shallow water, it can
still wash away the ground from under your
tires, and you could lose traction and roll the
vehicle over. Do not drive through rushing
water.
SeeDriving in Rain and on Wet Roads on page 4-31for
more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust
system for damage. Also, check the fuel lines and
cooling system for any leakage.
Your vehicle will require more frequent service due to
off-road use. Refer to the Maintenance Schedule
for additional information.
4-29

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission uid (don’t overll),
engine oil, axle lubricant, belt(s), cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you nd them quickly. If you’re
trailering, it’s a good idea to review these sections before
you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
4-65

How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission uid to use. SeeRecommended
Fluids and Lubricants on page 6-13.
Add uid only after checking the transmission uid while
it is hot. (A cold check is used only as a reference.) If
the uid level is low, add only enough of the proper uid
to bring the level up to the HOT area for a hot check.
It doesn’t take much uid, generally less than one
pint (0.5 L).Don’t overll.
Notice:We recommend you use only uid labeled
DEXRON
®-III, because uid with that label is
made especially for your automatic transmission.
Damage caused by uid other than DEXRON
®-III
is not covered by your new vehicle warranty.
After adding uid, recheck the uid level as
described under “How to Check″.
When the correct uid level is obtained, push the
dipstick back in all the way; then ip the handle
down to lock the dipstick in place.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs rst, if you add
only DEX-COOL
®extended life coolant.
The following explains your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating
on page 5-28.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-24

Brakes
Brake Fluid
Your brake master cylinder reservoir is lled with DOT-3
brake uid. SeeEngine Compartment Overview on
page 5-12for the location of the reservoir.
There are only two reasons why the brake uid level
in the reservoir might go down. The rst is that the
brake uid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the uid level goes back up. The other reason is
that uid is leaking out of the brake system.If it is, you should have your brake system xed, since
a leak means that sooner or later your brakes will
not work well, or will not work at all.
So, it is not a good idea to “top off” your brake uid.
Adding brake uid will not correct a leak. If you add uid
when your linings are worn, then you will have too
much uid when you get new brake linings. You should
add (or remove) brake uid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can spill on
the engine. The uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
uid only when work is done on the brake
hydraulic system. See “Checking Brake Fluid”
in this section.
Refer to the Maintenance Schedule to determine when
to check your brake uid. SeeScheduled Maintenance
on page 6-4.
5-39

Remove the valve cap from the tire valve stem. Press
the tire gage rmly onto the valve to get a pressure
measurement. If the cold tire ination pressure matches
the recommended pressure on the tire and loading
information label, no further adjustment is necessary.
If the pressure is low, add air until you reach the
recommended amount.
If you overll the tire, release air by pushing on the
metal stem in the center of the tire valve. Recheck the
tire pressure with the tire gage.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km).
Any time you notice unusual wear, rotate your tires
as soon as possible and check wheel alignment.
Also check for damaged tires or wheels. SeeWhen
It Is Time for New Tires on page 5-66andWheel
Replacement on page 5-69for more information.Make sure the spare tire is stored securely. Push, pull,
and then try to rotate or turn the tire. If it moves, use the
wheel wrench to tighten the cable. For information on
storing or removing the spare tire, seeChanging a Flat
Tire on page 5-74.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The rst rotation
is the most important. SeeScheduled Maintenance
on page 6-4.
When rotating your tires, always use the correct rotation
pattern shown here.
5-65