2007 GMC YUKON DENALI octane

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.
SeeGasoline Octane on page 423. 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. 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.
239

Service........................................................ 420
Accessories and Modications................... 421
California Proposition 65 Warning.............. 421
Doing Your Own Service Work.................. 422
Adding Equipment to the Outside
of Your Vehicle...................................... 423
Fuel............................................................. 423
Gasoline Octane........................................ 423
Gasoline Specications.............................. 424
California Fuel........................................... 424
Additives................................................... 424
Fuels in Foreign Countries........................ 425
Filling the Tank......................................... 426
Filling a Portable Fuel Container............... 428
Checking Things Under the Hood.............. 428
Hood Release........................................... 429
Engine Compartment Overview.................. 430
Engine Oil................................................. 432
Engine Oil Life System.............................. 435Engine Air Cleaner/Filter............................ 437
Automatic Transmission Fluid.................... 440
Engine Coolant.......................................... 445
Coolant Surge Tank Pressure Cap............ 448
Engine Overheating................................... 448
Overheated Engine Protection
Operating Mode..................................... 450
Cooling System......................................... 451
Engine Fan Noise..................................... 456
Power Steering Fluid................................. 457
Windshield Washer Fluid........................... 458
Brakes...................................................... 459
Battery...................................................... 463
Jump Starting............................................ 464
All-Wheel Drive........................................... 469
Rear Axle.................................................... 470
Front Axle................................................... 471
Headlamp Aiming........................................ 473
Section 5 Service and Appearance Care
417

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.
To help keep your engine clean and maintain
optimum vehicle performance, GM recommends
the use of gasoline advertised as TOP TIER
Detergent Gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted
octane rating of 87 or higher. If the octane rating
is less than 87, you may notice an audible
knocking noise when you drive, commonly referred
to as spark knock. If this occurs, use a gasoline
rated at 87 octane or higher as soon as possible.
If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, your engine
needs service.
423

Gasoline Specications
At a minimum, gasoline should meet ASTM
specication D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines may
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl
(MMT). General Motors recommends against the
use of gasolines containing MMT. SeeAdditives
on page 424for additional information.
California Fuel
If your vehicle is certied to meet California
Emissions 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 237.
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.
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.
To help keep fuel injectors and intake valves clean,
or if your vehicle experiences problems due to
dirty injectors or valves, look for gasoline that is
advertised as TOP TIER Detergent Gasoline.
Also, your GM dealer has additives that will help
correct and prevent most deposit-related problems.
424

Gasolines containing oxygenates, such as ethers
and ethanol, and reformulated gasolines may
be available in your area. General Motors
recommends that you use these gasolines if they
comply with the specications described earlier.
However, E85 (85% ethanol) and other fuels
containing more than 10% ethanol must not
be used in vehicles that were not designed for
those fuels.
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 recommends against 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.
425

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 392.
are driven on reasonable road surfaces within
legal driving limits.
are driven off-road in the recommended
manner. SeeOff-Road Driving on page 359.
use the recommended fuel. SeeGasoline
Octane on page 423.
The services inScheduled Maintenance on
page 551should be performed when indicated.
SeeAdditional Required Services on page 554and
Maintenance Footnotes on page 555for 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. SeeDoing Your
Own Service Work on page 422.
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.
550

Engine
Air Cleaner/Filter...................................... 437
Battery..................................................... 463
Check and Service Engine Soon Light..... 237
Coolant.................................................... 445
Coolant Heater......................................... 144
Coolant Temperature Gage...................... 236
Drive Belt Routing.................................... 564
Engine Compartment Overview................ 430
Exhaust................................................... 156
Fan Noise................................................ 456
Oil ........................................................... 432
Oil Life System........................................ 435
Overheated Protection Operating Mode.... 450
Overheating............................................. 448
Starting.................................................... 141
Entry Lighting.............................................. 207
Event Data Recorders (EDR)...................... 582
Exit Lighting................................................ 207
Extender, Safety Belt..................................... 60
Exterior Lamps............................................ 203F
Filter
Engine Air Cleaner................................... 437
Finish Damage............................................ 534
Flashers, Hazard Warning........................... 192
Flash-to-Pass.............................................. 195
Flat Tire...................................................... 505
Flat Tire, Changing...................................... 506
Flat Tire, Storing......................................... 522
Fluid
Automatic Transmission............................ 440
Power Steering........................................ 457
Windshield Washer.................................. 458
Fog Lamp Light........................................... 242
Fog Lamps.................................................. 206
Front Axle................................................... 471
Front Reading Lamps.................................. 208
Fuel............................................................ 423
Additives.................................................. 424
California Fuel.......................................... 424
Filling a Portable Fuel Container.............. 428
Filling Your Tank...................................... 426
Fuels in Foreign Countries....................... 425
Gage....................................................... 243
Gasoline Octane...................................... 423
598

Fuel (cont.)
Gasoline Specications............................ 424
Low Warning Light................................... 244
Fuses
Center Instrument Panel Fuse Block........ 540
Fuses and Circuit Breakers...................... 538
Instrument Panel Fuse Block................... 538
Underhood Fuse Block............................. 541
Windshield Wiper..................................... 537
G
Gage
Engine Coolant Temperature.................... 236
Fuel......................................................... 243
Oil Pressure............................................. 240
Speedometer........................................... 227
Tachometer.............................................. 227
Voltmeter Gage........................................ 232
Garage Door Opener..........................166, 167
Gasoline
Octane..................................................... 423
Specications........................................... 424
Glove Box................................................... 178
GM Mobility Reimbursement Program.......... 575
H
Hazard Warning Flashers............................ 192
Head Restraints............................................ 16
Headlamp
Aiming..................................................... 473
Headlamps
Automatic Headlamp System.................... 205
Bulb Replacement.................................... 476
Daytime Running Lamps.......................... 205
Flash-to-Pass........................................... 195
Halogen Bulbs......................................... 476
High/Low Beam Changer......................... 195
On Reminder........................................... 205
Heated Seats................................................ 11
Heater......................................................... 214
Highbeam On Light..................................... 242
High-Speed Operation, Tires........................ 490
Highway Hypnosis....................................... 383
Hill and Mountain Roads............................. 384
Hood
Checking Things Under............................ 428
Release................................................... 429
Horn............................................................ 192
How to Use This Manual................................ 3
How to Wear Safety Belts Properly............... 43
599