2005 GMC ENVOY XL octane

If the Light is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding steep uphill grades
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible
If the light stops ashing and remains on steady, see
“If the Light Is On Steady” following.
If the light continues to ash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see “If
the Light Is On Steady” following. If the light is still
ashing, follow the previous steps, and see your dealer
for service as soon as possible.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. SeeFilling the Tank on page 5-8. The
diagnostic system can determine if the fuel cap has
been left off or improperly installed. A loose or missing
fuel cap will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light off.
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-5. Poor fuel quality will
cause your engine not to run as efficiently as designed.
You may notice this as stalling after start-up, stalling
when you put the vehicle into gear, misring, hesitation
on acceleration, or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the
light to turn on.
3-42

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside
of Your Vehicle...........................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-19
Automatic Transmission Fluid.........................5-21
Engine Coolant.............................................5-23
Radiator Pressure Cap..................................5-26
Engine Overheating.......................................5-26
Cooling System............................................5-28
Engine Fan Noise.........................................5-33
Power Steering Fluid.....................................5-34Windshield Washer Fluid................................5-34
Brakes........................................................5-35
Battery........................................................5-38
Jump Starting...............................................5-39
Rear Axle.......................................................5-43
Four-Wheel Drive............................................5-44
Front Axle......................................................5-44
Bulb Replacement..........................................5-45
Halogen Bulbs..............................................5-45
Headlamps, Front Turn Signal, Sidemarker,
and Parking Lamps....................................5-46
Taillamps, Turn Signal, and Stoplamps............5-46
Back-Up Lamps............................................5-47
Replacement Bulbs.......................................5-47
Windshield Wiper Blade Replacement..............5-48
Tires..............................................................5-50
Tire Sidewall Labelling...................................5-51
Tire Terminology and Denitions.....................5-54
Ination - Tire Pressure.................................5-56
Tire Inspection and Rotation...........................5-57
When It Is Time for New Tires.......................5-59
Buying New Tires.........................................5-59
Uniform Tire Quality Grading..........................5-60
Wheel Alignment and Tire Balance..................5-61
Section 5 Service and Appearance Care
5-1

Adding Equipment to the Outside
of Your Vehicle
Things you might add to the outside of your vehicle
can affect the airow around it. This may cause
wind noise and affect windshield washer performance.
Check with your dealer before adding equipment to
the outside of your vehicle.
Fuel
Use of the recommended fuel is an important part of
the proper maintenance of your vehicle.
Gasoline Octane
Use regular unleaded gasoline with a posted octane
of 87 or higher. If the octane is less than 87, you may get
a heavy knocking noise when you drive. If this occurs,
use a gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you might damage your engine.
A little pinging noise when you accelerate or drive uphill is
considered normal. This does not indicate a problem
exists or that a higher-octane fuel is necessary. If you are
using 87 octane or higher-octane fuel and hear heavy
knocking, your engine needs service.
Gasoline Specications
It is recommended that gasoline meet specications
which were developed by automobile manufacturers
around the world and contained in the World-Wide Fuel
Charter which is available from the Alliance of Automobile
Manufacturers at www.autoalliance.org/fuel_charter.htm.
Gasoline meeting these specications could provide
improved driveability and emission control system
performance compared to other gasoline.
5-5

Notice:Your vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage would not be covered under
your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors does
not recommend the use of such gasolines. Fuels
containing MMT can reduce the life of spark plugs and
the performance of the emission control system may
be affected. The malfunction indicator lamp may turn on.
If this occurs, return to your authorized GM dealer for
service.Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
to nd. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not
be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you will be driving.
5-7

Using the Maintenance Schedule
We at General Motors want to help you keep your
vehicle in good working condition. But we do not know
exactly how you will drive it. You may drive very
short distances only a few times a week. Or you may
drive long distances all the time in very hot, dusty
weather. You may use your vehicle in making deliveries.
Or you may drive it to work, to do errands or in many
other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You may need more
frequent checks and replacements. So please read
the following and note how you drive. If you have any
questions on how to keep your vehicle in good condition,
see your GM Goodwrench
®dealer.
This schedule is for vehicles that:
carry passengers and cargo within recommended
limits. You will nd these limits on the tire and
loading information label. SeeLoading Your Vehicle
on page 4-43.
are driven on reasonable road surfaces within legal
driving limits.
are driven off-road in the recommended manner.
SeeOff-Road Driving with Your Four-Wheel-Drive
Vehicle on page 4-15.
use the recommended fuel. SeeGasoline Octane
on page 5-5.The services inScheduled Maintenance on page 6-4
should be performed when indicated. SeeAdditional
Required Services on page 6-6andMaintenance
Footnotes on page 6-7for further information.
{CAUTION:
Performing maintenance work on a vehicle
can be dangerous. In trying to do some jobs,
you can be seriously injured. Do your own
maintenance work only if you have the
required know-how and the proper tools and
equipment for the job. If you have any doubt,
see your GM Goodwrench
®dealer to have a
qualied technician do the work.
Some maintenance services can be complex. So,
unless you are technically qualied and have the
necessary equipment, you should have your
GM Goodwrench
®dealer do these jobs.
When you go to your GM Goodwrench
®dealer for your
service needs, you will know that GM-trained and
supported service technicians will perform the work
using genuine GM parts.
If you want to purchase service information, seeService
Publications Ordering Information on page 7-11.
6-3

Electrical System (cont.)
Rear Underseat Fuse Block..........................5-98
Windshield Wiper Fuses...............................5-91
Engine
Air Cleaner/Filter.........................................5-19
Battery.......................................................5-38
Change Engine Oil Light...............................3-45
Check and Service Engine Soon Light............3-41
Coolant......................................................5-23
Coolant Heater............................................2-23
Coolant Temperature Gage...........................3-40
Engine Compartment Overview......................5-12
Exhaust.....................................................2-35
Fan Noise..................................................5-33
Oil .............................................................5-15
Oil Life System...........................................5-18
Overheating................................................5-26
Reduced Power Light...................................3-46
Starting......................................................2-21
Entry Lighting.................................................3-18
Event Data Recorders (EDR)............................. 7-9
Exit Lighting...................................................3-18
Extender, Safety Belt.......................................1-30
F
Filter
Engine Air Cleaner......................................5-19
Finish Damage...............................................5-88Fixed Mast Antenna.......................................3-129
Flash-to-Pass................................................... 3-8
Flat Tire........................................................5-65
Flat Tire, Changing.........................................5-66
Flat Tire, Storing.............................................5-78
Fluid
Automatic Transmission................................5-21
Power Steering...........................................5-34
Windshield Washer......................................5-34
Fog Lamps....................................................3-17
Four-Wheel Drive....................................2-27, 5-44
Front Axle......................................................5-44
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-6
Check Gas Cap Light...................................3-48
Filling a Portable Fuel Container....................5-10
Filling Your Tank........................................... 5-8
Fuels in Foreign Countries.............................. 5-7
Gage.........................................................3-48
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-5
Low Warning Light.......................................3-48
Fuses
Engine Compartment Fuse Block...................5-92
Fuses and Circuit Breakers...........................5-91
Rear Underseat Fuse Block..........................5-98
Windshield Wiper.........................................5-91
5

G
Gage
Check Gages Warning Light..........................3-47
Engine Coolant Temperature.........................3-40
Fuel..........................................................3-48
Oil Pressure...............................................3-44
Speedometer..............................................3-33
Tachometer.................................................3-33
Voltmeter Gage...........................................3-38
Garage Door Opener.......................................2-49
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-5
Gate Ajar Light...............................................3-47
Glove Box.....................................................2-53
GM Mobility Reimbursement Program.................. 7-5
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-9
Headlamps....................................................3-14
Automatic Headlamp System.........................3-16
Bulb Replacement.......................................5-45
Daytime Running Lamps...............................3-15
Electrical System.........................................5-91
Flash-to-Pass............................................... 3-8Headlamps (cont.)
Halogen Bulbs............................................5-45
Headlamps, Front Turn Signal, Sidemarker,
and Parking Lamps..................................5-46
High/Low Beam Changer................................ 3-8
On Reminder..............................................3-15
Washer......................................................3-11
Heated Seats................................................... 1-6
Heater...........................................................3-20
Heater...........................................................3-23
Highbeam On Light.........................................3-46
Highway Hypnosis...........................................4-35
Hill and Mountain Roads..................................4-36
HomeLink
®Wireless Control System.................2-49
HomeLink®Wireless Control System
Operation...................................................2-50
Hood
Checking Things Under................................5-10
Release.....................................................5-11
Horn............................................................... 3-6
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-18
I
Ignition Positions.............................................2-20
Infants and Young Children, Restraints...............1-34
Ination -- Tire Pressure..................................5-56
6