octane HUMMER H2 2007 Owners Manual

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 397.
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 394. 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........................................................ 392
Accessories and Modications................... 392
California Proposition 65 Warning.............. 393
Doing Your Own Service Work.................. 393
Adding Equipment to the Outside of
Your Vehicle.......................................... 394
Fuel............................................................. 394
Gasoline Octane........................................ 394
Gasoline Specications.............................. 394
California Fuel........................................... 395
Additives................................................... 395
Fuels in Foreign Countries........................ 396
Filling the Tank......................................... 397
Filling a Portable Fuel Container............... 399
Checking Things Under the Hood.............. 400
Hood Release........................................... 400
Engine Compartment Overview.................. 402
Engine Oil................................................. 404
Engine Oil Life System.............................. 407
Engine Air Cleaner/Filter............................ 409
Automatic Transmission Fluid.................... 412
Engine Coolant.......................................... 415Coolant Surge Tank Pressure Cap............ 418
Engine Overheating................................... 418
Overheated Engine Protection
Operating Mode..................................... 420
Cooling System......................................... 420
Power Steering Fluid ................................. 425
Windshield Washer Fluid........................... 426
Brakes...................................................... 427
Battery...................................................... 431
Jump Starting............................................ 432
Rear Axle.................................................... 437
Four-Wheel Drive........................................ 438
Front Axle................................................... 440
Bulb Replacement....................................... 441
Halogen Bulbs........................................... 441
Headlamps................................................ 441
Front Turn Signal and Parking Lamps.......... 442
Daytime Running Lamps (DRL)................. 443
Roof Marker Lamps................................... 443
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps...................................... 444
Replacement Bulbs................................... 446
Section 5 Service and Appearance Care
389

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.
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 395for additional information.
394

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 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.
396

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 362.
are driven on reasonable road surfaces within
legal driving limits.
are driven off-road in the recommended
manner. SeeOff-Road Driving on page 317.
use the recommended fuel. SeeGasoline
Octane on page 394.
The services inScheduled Maintenance on
page 517should be performed when indicated.
SeeAdditional Required Services on page 520and
Maintenance Footnotes on page 521for 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 393.
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.
516

Fuel (cont.)
Filling Your Tank...................................... 397
Fuels in Foreign Countries....................... 396
Gage....................................................... 221
Gasoline Octane...................................... 394
Gasoline Specications............................ 394
Low Warning Light................................... 221
Fuses
Center Instrument Panel Fuse Block........ 506
Fuses and Circuit Breakers...................... 504
Instrument Panel Fuse Block................... 504
Underhood Fuse Block............................. 507
Windshield Wiper..................................... 503
G
Gage
Engine Coolant Temperature.................... 213
Fuel......................................................... 221
Oil Pressure............................................. 218
Speedometer........................................... 206
Tachometer.............................................. 206
Transmission Temperature........................ 213
Voltmeter Gage........................................ 210Garage Door Opener..........................148, 149
Gasoline
Octane..................................................... 394
Specications........................................... 394
Glove Box................................................... 160
GM Mobility Reimbursement Program.......... 541
H
Hazard Warning Flashers............................ 176
Head Restraints............................................ 14
Headlamps.................................................. 441
Automatic Headlamp System.................... 189
Bulb Replacement.................................... 441
Daytime Running Lamps.................188, 443
Flash-to-Pass........................................... 180
Front Turn Signal and Parking Lamps......... 442
Halogen Bulbs......................................... 441
High/Low Beam Changer......................... 179
On Reminder........................................... 188
Roof Marker Lamps................................. 443
Heated Seats................................................ 10
Heater......................................................... 197
Highbeam On Light..................................... 220
561