octane CHEVROLET TAHOE 2007 3.G Owners Manual

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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 451.
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.
SeeGasoline Octane on page 447. 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.
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Service........................................................ 444
Accessories and Modications................... 444
California Proposition 65 Warning.............. 445
Doing Your Own Service Work.................. 445
Adding Equipment to the Outside of
Your Vehicle.......................................... 446
Fuel............................................................. 446
Gasoline Octane........................................ 447
Gasoline Specications.............................. 447
California Fuel........................................... 447
Additives................................................... 448
Fuel E85 (85% Ethanol)............................ 449
Fuels in Foreign Countries........................ 450
Filling the Tank......................................... 451
Filling a Portable Fuel Container............... 455
Checking Things Under the Hood.............. 456
Hood Release........................................... 457
Engine Compartment Overview.................. 458
Engine Oil................................................. 459
Engine Oil Life System.............................. 462
Engine Air Cleaner/Filter............................ 464
Automatic Transmission Fluid.................... 466
Engine Coolant.......................................... 470Coolant Surge Tank Pressure Cap............ 473
Engine Overheating................................... 473
Overheated Engine Protection
Operating Mode..................................... 476
Cooling System......................................... 477
Engine Fan Noise..................................... 483
Power Steering Fluid ................................. 484
Windshield Washer Fluid........................... 485
Brakes...................................................... 486
Battery...................................................... 490
Jump Starting............................................ 491
Rear Axle.................................................... 496
Four-Wheel Drive........................................ 497
Front Axle................................................... 498
Headlamp Aiming........................................ 499
Bulb Replacement....................................... 502
Halogen Bulbs........................................... 502
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps...................................... 502
License Plate Lamp................................... 504
Replacement Bulbs................................... 504
Section 5 Service and Appearance Care
441

Page 447 of 634

Gasoline Octane
Use regular unleaded gasoline with a posted
octane rating of 87 or higher. If the octane rating
is less than 87, you might 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, the engine
needs service.
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 448for 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 253. 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.
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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 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. 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 the fuel system and also damage
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 dealer for service.
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Fuel E85 (85% Ethanol)
The 8th digit of the Vehicle Identication Number
(VIN) shows the code letter or number that
identies your vehicle’s engine. The VIN is at the
top left of the instrument panel. SeeVehicle
Identication Number (VIN) on page 562.
If your vehicle has the 5.3L V8 engine (Code 0) or
the 5.3L V8 engine (Code 3), you can use
either regular unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85); also seeFuel
on page 446. In all other engines, use only the
unleaded gasoline described underGasoline
Octane on page 447.
Only vehicles that have the 5.3L V8 engine
(Code 0) or the 5.3L V8 engine (Code 3) can use
85% ethanol fuel (E85). We encourage the use
of E85 in vehicles that are designed to use it. The
ethanol in E85 is a “renewable” fuel, meaning it
is made from renewable sources such as corn and
other crops.Many service stations will not have an 85%
ethanol fuel (E85) pump available. The U. S.
Department of Energy has an alternative
fuels website (www.eere.energy.gov/afdc/
infrastructure/locator.html) that can help you
nd E85 fuel. Those stations that do have E85
should have a label indicating ethanol content. Do
not use the fuel if the ethanol content is greater
than 85%.
At a minimum, E85 should meet ASTM
Specication D 5798. By denition, this means
that fuel labeled E85 will have an ethanol content
between 70% and 85%. Filling the fuel tank
with fuel mixtures that do not meet ASTM
specications can affect driveability and could
cause the malfunction indicator lamp to come on.
To ensure quick starts in the wintertime, the
E85 fuel must be formulated properly for your
climate according to ASTM specication D 5798. If
you have trouble starting on E85, it could be
because the E85 fuel is not properly formulated
for your climate. If this happens, switching to
gasoline or adding gasoline to the fuel tank can
improve starting. For good starting and heater
efficiency below 32°F (0°C), the fuel mix in the fuel
tank should contain no more than 70% ethanol.
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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 407.
are driven on reasonable road surfaces within
legal driving limits.
are driven off-road in the recommended
manner. SeeOff-Road Driving on page 372.
use the recommended fuel. SeeGasoline
Octane on page 447.
The services inScheduled Maintenance on
page 579should be performed when indicated.
SeeAdditional Required Services on page 582and
Maintenance Footnotes on page 584for further
information.
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Engine (cont.)
Oil Life System........................................ 462
Overheated Protection Operating Mode...... 476
Overheating............................................. 473
Starting.................................................... 141
Entry Lighting.............................................. 220
Event Data Recorders (EDR)...................... 609
Exit Lighting................................................ 220
Extender, Safety Belt..................................... 60
Exterior Lamps............................................ 215
F
Filter
Engine Air Cleaner................................... 464
Finish Damage............................................ 560
Flashers, Hazard Warning........................... 204
Flash-to-Pass.............................................. 207
Flat Tire...................................................... 531
Flat Tire, Changing...................................... 532
Flat Tire, Storing......................................... 547
Fluid
Automatic Transmission............................ 466
Power Steering........................................ 484
Windshield Washer.................................. 485Fog Lamp
Fog .......................................................... 218
Fog Lamp Light........................................... 258
Four-Wheel Drive...............................150, 497
Front Axle................................................... 498
Fuel............................................................ 446
Additives.................................................. 448
California Fuel.......................................... 447
E85 (85% Ethanol)................................... 449
Filling a Portable Fuel Container.............. 455
Filling Your Tank...................................... 451
Fuels in Foreign Countries....................... 450
Gage....................................................... 259
Gasoline Octane...................................... 447
Gasoline Specications............................ 447
Low Warning Light................................... 260
Fuses
Center Instrument Panel Fuse Block........ 566
Fuses and Circuit Breakers...................... 564
Instrument Panel Fuse Block................... 565
Underhood Fuse Block............................. 567
Windshield Wiper..................................... 564
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G
Gage
Engine Coolant Temperature.................... 252
Fuel......................................................... 259
Oil Pressure............................................. 256
Speedometer........................................... 244
Tachometer.............................................. 244
Voltmeter Gage........................................ 249
Garage Door Opener................................... 178
Gasoline
Octane..................................................... 447
Specications........................................... 447
Glove Box................................................... 190
GM Mobility Reimbursement Program.......... 603
H
Hazard Warning Flashers............................ 204
Head Restraints............................................ 18
Headlamp
Aiming..................................................... 499
Headlamps
Bulb Replacement.................................... 502
Daytime Running Lamps.......................... 216
Flash-to-Pass........................................... 207
Halogen Bulbs......................................... 502Headlamps (cont.)
High/Low Beam Changer......................... 207
On Reminder........................................... 216
Heated Seats................................................ 12
Heater......................................................... 227
Heater......................................................... 231
Highbeam On Light..................................... 259
Highway Hypnosis....................................... 397
Hill and Mountain Roads............................. 398
Hood
Checking Things Under............................ 456
Release................................................... 457
Horn............................................................ 204
How to Use This Manual................................ 4
How to Wear Safety Belts Properly............... 43
I
Ignition Positions......................................... 140
Infants and Young Children, Restraints.......... 64
Ination - Tire Pressure............................... 515
Instrument Panel
Overview.................................................. 202
Instrument Panel (I/P)
Brightness................................................ 219
Cluster..................................................... 243
625