2005 GMC YUKON octane

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.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 x 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 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.
3-50

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuel E-85 (85% Ethanol).................................5-6
Fuels in Foreign Countries...............................5-8
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.............................................5-24
Coolant Surge Tank Pressure Cap..................5-26
Engine Overheating.......................................5-27Overheated Engine Protection Operating Mode . . .5-29
Cooling System............................................5-29
Engine Fan Noise.........................................5-34
Power Steering Fluid.....................................5-35
Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-40
Jump Starting...............................................5-41
All-Wheel Drive..............................................5-45
Rear Axle.......................................................5-46
Four-Wheel Drive............................................5-47
Front Axle......................................................5-48
Bulb Replacement..........................................5-49
Halogen Bulbs..............................................5-49
Headlamps..................................................5-50
Front Turn Signal, Sidemarker and Daytime
Running Lamps.........................................5-51
Side Identication Marker Lamps.....................5-52
Roof Marker Lamps......................................5-52
Taillamps.....................................................5-54
Replacement Bulbs.......................................5-56
Windshield Wiper Blade Replacement..............5-56
Section 5 Service and Appearance Care
5-1

Fuel
Gasoline
The 8th digit of your vehicle identication number (VIN)
shows the code letter or number that identies your
engine. You will nd the VIN at the top left of the
instrument panel. SeeVehicle Identication
Number (VIN) on page 5-104.
If your vehicle has the 5.3L V8 engine (VIN Code Z
only), you may use either regular unleaded gasoline or
ethanol fuel containing up to 85% ethanol (E-85);
also seeFuel E-85 (85% Ethanol) on page 5-6.Inall
other engines, use only regular unleaded gasoline.
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.
California Fuel
If your vehicle is certied to meet California Emission
Standards, it is designed to operate on fuels that
meet California specications. See the underhood
emission control label. If this fuel is not available
in states adopting California emissions standards, your
vehicle will operate satisfactorily on fuels meeting
federal specications, but emission control system
performance may be affected. The malfunction indicator
lamp may turn on and your vehicle may fail a
smog-check test. SeeMalfunction Indicator Lamp on
page 3-48. If this occurs, return to your authorized
GM dealer for diagnosis. If it is determined that
the condition is caused by the type of fuel used, repairs
may not be covered by your warranty.
5-5

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.
In most cases, 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. Also,
your GM dealer has additives that will help correct and
prevent most deposit-related problems.
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.
Fuel E-85 (85% Ethanol)
The 8th digit of your vehicle identication number (VIN)
shows the code letter or number that identies your
engine. You will nd the VIN at the top left of the
instrument panel. SeeVehicle Identication Number
(VIN) on page 5-104.
If your vehicle has the 5.3L V8 engine (VIN Code Z only),
you may use either regular unleaded gasoline or ethanol
fuel containing up to 85% ethanol (E-85); also seeFuel
on page 5-5. In all other engines, including the 5.3L V8
(VIN Code T), use only regular unleaded gasoline.
5-6

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 4-51.
are driven on reasonable road surfaces within legal
driving limits.
are driven off-road in the recommended manner.
SeeOff-Road Driving on page 4-21.
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.
Owner Checks and Services on page 6-9tells you what
should be checked, when to check it and what you
can easily do to help keep your vehicle in good
condition.
6-3

F
Filter
Engine Air Cleaner......................................5-19
Finish Damage.............................................5-102
Fixed Mast Antenna.......................................3-135
Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-76
Flat Tire, Changing.........................................5-76
Flat Tire, Storing.............................................5-91
Fluid
Automatic Transmission................................5-21
Power Steering...........................................5-35
Windshield Washer......................................5-36
Fog Lamps....................................................3-17
Four-Wheel Drive....................................2-27, 5-47
Four-Wheel-Drive Light....................................3-52
Front Axle......................................................5-48
Front Reading Lamps......................................3-19
Front Storage Area.........................................2-56
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-5
E-85 (85% Ethanol)....................................... 5-6
Filling a Portable Fuel Container....................5-10
Filling Your Tank........................................... 5-8Fuel (cont.)
Fuels in Foreign Countries.............................. 5-8
Gage.........................................................3-53
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-5
Low Warning Light.......................................3-53
Fuses
Center Instrument Panel Fuse Block.............5-108
Fuses and Circuit Breakers.........................5-105
Instrument Panel Fuse Block.......................5-106
Underhood Fuse Block...............................5-109
Windshield Wiper.......................................5-105
G
Gage
Engine Coolant Temperature.........................3-46
Fuel..........................................................3-53
Oil Pressure...............................................3-51
Speedometer..............................................3-38
Tachometer.................................................3-38
Transmission Temperature.............................3-46
Voltmeter Gage...........................................3-42
Garage Door Opener.......................................2-52
6

Gasoline
Octane........................................................ 5-5
Specications............................................... 5-5
Glove Box.....................................................2-56
GM Mobility Reimbursement Program.................. 7-5
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-7
Headlamps............................................3-14, 5-50
Automatic Headlamp System.........................3-16
Bulb Replacement.......................................5-49
Daytime Running Lamps...............................3-15
Flash-to-Pass............................................... 3-9
Front Turn Signal, Sidemarker and Daytime
Running Lamps........................................5-51
Halogen Bulbs............................................5-49
High/Low Beam Changer................................ 3-8
On Reminder..............................................3-15
Roof Marker Lamps.....................................5-52
Side Identication Marker Lamps...................5-52
Heated Seats................................................... 1-5
Heater...................................................3-21, 3-22
Heater...........................................................3-24Highbeam On Light.........................................3-52
Highway Hypnosis...........................................4-42
Hill and Mountain Roads..................................4-43
HomeLink
®Wireless Control System.................2-52
HomeLink®Wireless Control System Operation.....2-52
Hood
Checking Things Under................................5-10
Release.....................................................5-11
Horn............................................................... 3-6
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-27
I
Ignition Positions.............................................2-20
Infants and Young Children, Restraints...............1-45
Ination -- Tire Pressure..................................5-64
Instrument Panel
Overview..................................................... 3-4
Instrument Panel (I/P)
Brightness..................................................3-18
Cluster.......................................................3-37
7