2004 GMC SAFARI 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 Your Tank on page 5-7. 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 5-4. 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.
3-32

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under
the Hood......................................................5-9
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Cover...............................................5-18
Engine Air Cleaner/Filter................................5-22
Automatic Transmission Fluid.........................5-23
Engine Coolant.............................................5-26Radiator Pressure Cap..................................5-28
Engine Overheating.......................................5-29
Cooling System............................................5-31
Engine Fan Noise.........................................5-37
Power Steering Fluid.....................................5-38
Windshield Washer Fluid................................5-39
Brakes........................................................5-40
Battery........................................................5-44
Jump Starting...............................................5-45
All-Wheel Drive..............................................5-50
Rear Axle.......................................................5-51
Front Axle......................................................5-52
Bulb Replacement..........................................5-53
Halogen Bulbs..............................................5-53
Headlamps..................................................5-53
Front Turn Signal Lamps...............................5-57
Taillamps.....................................................5-58
Replacement Bulbs.......................................5-59
Windshield Wiper Blade Replacement..............5-60
Section 5 Service and Appearance Care
5-1

You should keep a record with all parts receipts and list
the mileage and the date of any service work you
perform. SeePart E: Maintenance Record on page 6-34.
{CAUTION:
You can be injured and your vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.
Be sure you have sufficient knowledge,
experience, the proper replacement parts
and tools before you attempt any vehicle
maintenance task.
Be sure to use the proper nuts, bolts and
other fasteners. “English” and “metric”
fasteners can be easily confused. If you
use the wrong fasteners, parts can later
break or fall off. You could be hurt.
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.
5-4

Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. You should not have to add anything to your
fuel. However, some gasolines contain only the
minimum amount of additive required to meet U.S.
Environmental Protection Agency regulations. General
Motors recommends that you buy gasolines that
are advertised to help keep fuel injectors and intake
valves clean. If your vehicle experiences problems due
to dirty injectors or valves, try a different brand of
gasoline.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines may be available in
your area to contribute to clean air. General Motors
recommends that you use these gasolines, particularly if
they comply with the specications described earlier.
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.
5-6

Part A: Scheduled Maintenance
Services
In this part are scheduled maintenance services which
are to be performed at the mileage intervals specied.
Using Your Maintenance Schedule
We at General Motors want to help you to keep
your vehicle in good working condition. But we do not
know exactly how you will drive it. You may drive
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 dealer.This part tells you the maintenance services you should
have done and when to schedule them.
When you go to your dealer for your service needs, you
will know that GM-trained and supported service
people will perform the work using GM parts.
The proper uids and lubricants to use are listed in
Part D. Make sure whoever services your vehicle uses
them. All parts should be replaced and all necessary
repairs done before you or anyone else drives the
vehicle.
These schedules are 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 4-29.
are driven on reasonable road surfaces within
driving limits.
use the recommended fuel. SeeGasoline Octane
on page 5-4.
6-4

Fuel (cont.)
Filling Your Tank........................................... 5-7
Fuels in Foreign Countries.............................. 5-6
Gage.........................................................3-36
Gasoline Octane........................................... 5-4
Gasoline Specications.................................. 5-5
Low Warning Light.......................................3-37
System Inspection.......................................6-30
Fuel Regulator................................................2-19
Fuses
Fuses and Circuit Breakers.........................5-102
Windshield Wiper.......................................5-102
G
Gage
Check Gages Warning Light..........................3-36
Engine Coolant Temperature.........................3-30
Fuel..........................................................3-36
Oil Pressure...............................................3-34
Speedometer..............................................3-25
Voltmeter Gage...........................................3-28
Gasoline
Octane........................................................ 5-4
Specications............................................... 5-5
Gate Operator and Canadian Programming........2-33
GM Mobility Program for Persons with
Disabilities.................................................... 7-6
H
Hatch Release................................................2-13
Hazard Warning Flashers................................... 3-4
Head Restraints............................................... 1-5
Headlamp High/Low-Beam Changer.................... 3-7
Headlamp Wiring...........................................5-102
Headlamps....................................................5-53
Bulb Replacement.......................................5-53
Front Turn Signal Lamps..............................5-57
Halogen Bulbs............................................5-53
Highway Hypnosis...........................................4-22
Hill and Mountain Roads..................................4-22
Hitches..........................................................4-39
HomeLink
®Transmitter, Programming................2-32
Hood
Checking Things Under.................................. 5-9
Release.....................................................5-10
Horn............................................................... 3-5
How to Add Coolant to the Coolant
Recovery Tank............................................5-32
How to Add Coolant to the Radiator..................5-35
How to Add Fluid............................................5-25
How to Check........................................5-24, 5-72
How to Check Lubricant...................................5-51
How to Check Power Steering Fluid..................5-38
How to Inspect the Engine Air Cleaner/Filter.......5-22
How to Use This Manual...................................... ii
6