octane GMC SONOMA 2004 Owner's Manual

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, misfiring, 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.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
your dealer can check the vehicle. Your dealer has
the proper test equipment and diagnostic tools to fix any
mechanical or electrical problems that may have
developed.Emissions Inspection and
Maintenance Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a vehicle
registration.
Here are some things you need to know to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the SERVICE
ENGINE SOON or CHECK ENGINE light is on or not
working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your
battery has run down. The diagnostic system is
designed to evaluate critical emission control systems
during normal driving. This may take several days
of routine driving. If you have done this and your vehicle
still does not pass the inspection for lack of OBD
system readiness, your GM dealer can prepare the
vehicle for inspection.
3-31

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 Specifications....................................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....................................................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Air Cleaner/Filter................................5-18
Automatic Transmission Fluid.........................5-19
Engine Coolant.............................................5-23
Radiator Pressure Cap..................................5-26
Engine Overheating.......................................5-26
Cooling System............................................5-28
Engine Fan Noise.........................................5-35
Power Steering Fluid.....................................5-35Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-40
Jump Starting...............................................5-41
Rear Axle.......................................................5-46
Four-Wheel Drive............................................5-46
Front Axle......................................................5-47
Bulb Replacement..........................................5-48
Halogen Bulbs..............................................5-48
Headlamps..................................................5-49
One-Piece Front Turn Signal Lamps................5-51
Two-Piece Front Turn Signal Lamps................5-51
Center High-Mounted Stoplamp (CHMSL).........5-52
Taillamps.....................................................5-53
Replacement Bulbs.......................................5-54
Windshield Wiper Blade Replacement..............5-54
Tires..............................................................5-57
Inflation - Tire Pressure.................................5-67
Tire Inspection and Rotation...........................5-68
When It Is Time for New Tires.......................5-69
Buying New Tires.........................................5-70
Uniform Tire Quality Grading..........................5-71
Wheel Alignment and Tire Balance..................5-72
Wheel Replacement......................................5-72
Section 5 Service and Appearance Care
5-1

CAUTION: (Continued)

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 airflow 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
The 8th digit of your vehicle identification number (VIN)
shows the code letter or number that identifies your
engine. You will find the VIN at the top left of the
instrument panel. SeeVehicle Identication
Number (VIN) on page 5-94.
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 specifications 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 find. 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 specified.
Using Your 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 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 genuine GM parts.
The proper fluids and lubricants to use are listed in
Part D. Make sure whoever services your vehicle uses
these. 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 find these limits on the tire and
loading information label. SeeLoading Your Vehicle
on page 4-45.
•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 4-14.
•use the recommended fuel. SeeGasoline Octane
on page 5-4.
6-4

F
Filter
Engine Air Cleaner......................................5-18
Finding a Program Type (PTY) Station...............3-52
Finding a Program Type (PTY) Station
(RDS and XM™).................................3-42, 3-63
Finding a Station....................3-37, 3-40, 3-50, 3-61
Finish Care....................................................5-90
Finish Damage...............................................5-92
Fixed Mast Antenna........................................3-76
Flash-to-Pass Feature....................................... 3-7
Flat Tire........................................................5-74
Flat Tire, Changing.........................................5-75
Fluid
Automatic Transmission................................5-19
Power Steering...........................................5-35
Windshield Washer......................................5-36
FM Stereo.....................................................3-74
Fog Lamps....................................................3-14
Following Distance..........................................4-61
Footnotes................................................6-7, 6-17
Four-Wheel Drive....................................2-22, 5-46
Front Axle......................................................5-47
Front Map Lamps...........................................3-15
Front Storage Area.........................................2-40Fuel............................................................... 5-4
Additives...................................................... 5-6
California Fuel.............................................. 5-5
Filling a Portable Fuel Container..................... 5-9
Filling Your Tank........................................... 5-7
Fuels in Foreign Countries.............................. 5-6
Gage.........................................................3-34
Gasoline Octane........................................... 5-4
Gasoline Specifications.................................. 5-5
Low Warning Light.......................................3-35
System Inspection.......................................6-30
Fuses
Fuses and Circuit Breakers...........................5-95
Windshield Wiper.........................................5-95
G
Gage
Check Gages Warning Light..........................3-34
Engine Coolant Temperature.........................3-28
Fuel..........................................................3-34
Oil Pressure...............................................3-32
Speedometer..............................................3-24
Tachometer.................................................3-24
Voltmeter Gage...........................................3-26
Garment Hooks..............................................2-40
6

Gasoline
Octane........................................................ 5-4
Specifications............................................... 5-5
Getting Familiar with Off-Road Driving................4-16
Glove Box.....................................................2-33
GM Mobility Program for Persons with
Disabilities.................................................... 7-5
H
Hazard Warning Flashers................................... 3-4
Head Restraints............................................... 1-6
Headlamp High/Low-Beam Changer.................... 3-7
Headlamps....................................................5-49
Bulb Replacement.......................................5-48
Electrical System.........................................5-95
Halogen Bulbs............................................5-48
One-Piece Front Turn Signal Lamps...............5-51
Two-Piece Front Turn Signal Lamps...............5-51
Heated Seats................................................... 1-4
Highway Hypnosis...........................................4-35
Hill and Mountain Roads..................................4-36
Hitches..........................................................4-59
Hood
Checking Things Under................................5-10
Release.....................................................5-10
Horn............................................................... 3-5
How to Add Automatic
Transmission Fluid.......................................5-22How to Add Coolant to the Coolant
Recovery Tank............................................5-30
How to Add Coolant to the Radiator..................5-32
How to Check................................................5-67
How to Check Lubricant..........................5-46, 5-47
How to Check Power Steering Fluid..................5-36
How to Check the Automatic
Transmission Fluid.......................................5-20
How to Inspect the Engine Air Cleaner/Filter.......5-18
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-13
Hydroplaning..................................................4-31
I
If No Steam Is Coming From Your Engine..........5-27
If Steam Is Coming From Your Engine...............5-26
If the Light Is Flashing.....................................3-30
If the Light Is On Steady.................................3-30
If You Are Caught in a Blizzard.........................4-40
If You Are Stuck in Sand, Mud, Ice or Snow.......4-42
If You Do Decide To Pull A Trailer.....................4-56
Ignition Positions.............................................2-17
Ignition Transmission Lock Check......................6-28
Infants and Young Children, Restraints...............1-29
Inflation - Tire Pressure...................................5-67
Inspection
Brake System.............................................6-31
Engine Cooling System................................6-30
7