Parking on Hills
{WARNING:
Parking the vehicle on a hill with the trailer
attached can be dangerous. If something goes
wrong, the rig could start to move. People can be
injured, and both the vehicle and the trailer can be
damaged. When possible, always park the rig on a
flat surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift the
transmission into P (Park) yet. Turn the wheels into
the curb if facing downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
brake pedal until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking
brake and shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
•start the engine,
•shift into a gear, and
•release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual’s Maintenance Schedule
or Index for more information. Things that are especially
important in trailer operation are automatic transmission
fluid, engine oil, axle lubricant, belts, cooling system
and brake system. It is a good idea to inspect
these before and during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
5-41
Service............................................................6-3
Accessories and Modifications..........................6-3
California Proposition 65 Warning.....................6-4
California Perchlorate Materials Requirements.....6-4
Doing Your Own Service Work.........................6-4
Adding Equipment to the Outside of
the Vehicle.................................................6-5
Fuel................................................................6-5
Gasoline Octane............................................6-6
Gasoline Specifications....................................6-6
California Fuel...............................................6-6
Additives.......................................................6-7
Fuel E85 (85% Ethanol)..................................6-8
Fuels in Foreign Countries...............................6-9
Filling the Tank............................................6-10
Filling a Portable Fuel Container.....................6-12
Checking Things Under the Hood....................6-12
Hood Release..............................................6-13
Engine Compartment Overview.......................6-14
Engine Oil...................................................6-15
Engine Oil Life System..................................6-18
Engine Air Cleaner/Filter................................6-20
Automatic Transmission Fluid
(4-Speed Transmission)..............................6-21
Automatic Transmission Fluid
(6-Speed Transmission)..............................6-24Cooling System............................................6-28
Engine Coolant.............................................6-29
Engine Overheating.......................................6-35
Engine Fan Noise.........................................6-37
Power Steering Fluid.....................................6-38
Windshield Washer Fluid................................6-39
Brakes........................................................6-40
Battery........................................................6-43
Jump Starting...............................................6-44
All-Wheel Drive.............................................
.6-49
Rear Axle.......................................................6-50
Front Axle......................................................6-50
Noise Control System.....................................6-51
Tampering with Noise Control System
Prohibited.................................................6-51
Bulb Replacement..........................................6-53
Halogen Bulbs..............................................6-53
Headlamps..................................................6-53
Front Turn Signal, Sidemarker and
Parking Lamps..........................................6-55
Center High-Mounted Stoplamp (CHMSL).........6-56
Taillamps.....................................................6-56
License Plate Lamp......................................6-58
Replacement Bulbs.......................................6-58
Windshield Wiper Blade Replacement..............6-59
Section 6 Service and Appearance Care
6-1
Tires..............................................................6-60
Tire Sidewall Labeling...................................6-61
Tire Terminology and Definitions.....................6-65
Inflation - Tire Pressure.................................6-68
Dual Tire Operation.......................................6-70
Tire Pressure Monitor System.........................6-70
Tire Pressure Monitor Operation.....................6-72
Tire Inspection and Rotation...........................6-75
When It Is Time for New Tires.......................6-78
Buying New Tires.........................................6-79
Different Size Tires and Wheels......................6-80
Uniform Tire Quality Grading..........................6-81
Wheel Alignment and Tire Balance..................6-82
Wheel Replacement......................................6-82
Tire Chains..................................................6-84
If a Tire Goes Flat........................................6-85
Changing a Flat Tire.....................................6-86
Removing the Spare Tire and Tools................6-87
Removing the Flat Tire and Installing the
Spare Tire................................................6-90
Secondary Latch System...............................6-97
Storing a Flat or Spare Tire and Tools...........6-100
Spare Tire.................................................6-101
Appearance Care..........................................6-102
Interior Cleaning.........................................6-102
Fabric/Carpet..............................................6-103Instrument Panel, Vinyl, and Other Plastic
Surfaces.................................................6-104
Care of Safety Belts....................................6-104
Weatherstrips.............................................6-105
Washing Your Vehicle..................................6-105
Cleaning Exterior Lamps/Lenses....................6-105
Finish Care................................................6-106
Windshield and Wiper Blades.......................6-106
Aluminum Wheels.......................................6-107
Tires.........................................................6-107
Sheet Metal Damage...................................6-107
Finish Damage...........................................6-108
Underbody Maintenance...............................6-108
Chemical Paint Spotting...............................6-108
Vehicle Identi cation.....................................6-109
Vehicle Identification Number (VIN)................6-109
Service Parts Identification Label...................6-109
Electrical System..........................................6-109
Add-On Electrical Equipment.........................6-109
Headlamp Wiring........................................6-110
Windshield Wiper Fuses...............................6-110
Fuses and Circuit Breakers..........................6-110
Floor Console Fuse Block............................6-111
Engine Compartment Fuse Block...................6-112
Capacities and Speci cations........................6-116
Section 6 Service and Appearance Care
6-2
California Proposition 65 Warning
Most motor vehicles, including this one, contain and/or
emit chemicals known to the State of California to cause
cancer and birth defects or other reproductive harm.
Engine exhaust, many parts and systems, many fluids,
and some component wear by-products contain and/or
emit these chemicals.
California Perchlorate Materials
Requirements
Certain types of automotive applications, such as
airbag initiators, seat belt pretensioners, and lithium
batteries contained in remote keyless transmitters,
may contain perchlorate materials. Special handling
may be necessary. For additional information, see
www.dtsc.ca.gov/hazardouswaste/perchlorate.
Doing Your Own Service Work
{WARNING:
You can be injured and the vehicle could be
damaged if you try to do service work on a vehicle
without knowing enough about it.
•Be sure you have sufficient knowledge,
experience, the proper replacement parts,
and tools before attempting any vehicle
maintenance task.
•Be sure to use the proper nuts, bolts, and
other fasteners. English and metric fasteners
can be easily confused. If the wrong fasteners
are used, parts can later break or fall off.
You could be hurt.
If doing some of your own service work, use the proper
service manual. It tells you much more about how to
service the vehicle than this manual can. To order
the proper service manual, seeService Publications
Ordering Information on page 8-17.
This vehicle has an airbag system. Before attempting
to do your own service work, seeServicing Your
Airbag-Equipped Vehicle on page 2-78.
6-4
Keep a record with all parts receipts and list the
mileage and the date of any service work performed.
SeeMaintenance Record on page 7-16.
Adding Equipment to the Outside of
the Vehicle
Things added to the outside of the vehicle can affect the
airflow around it. This can cause wind noise and can
affect fuel economy and windshield washer performance.
Check with your dealer/retailer before adding equipment
to the outside of the vehicle.
Fuel
For diesel engine vehicles, see “Diesel Fuel
Requirements and Fuel System” in the DURAMAX®
Diesel manual.
For vehicles with gasoline engines, please read this.
Gasoline
Use of the recommended fuel is an important part of the
proper maintenance of this vehicle. To help keep the
engine clean and maintain optimum vehicle performance,
we recommend the use of gasoline advertised as
TOP TIER Detergent Gasoline.Look for the TOP TIER label on the fuel pump to
ensure gasoline meets enhanced detergency standards
developed by auto companies. A list of marketers
providing TOP TIER Detergent Gasoline can be found
at www.toptiergas.com.
The 8th digit of the Vehicle Identification Number (VIN)
shows the code letter or number that identifies the
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identi cation
Number (VIN) on page 6-109.
6-5
If the vehicle has the 4.8L V8 engine (VIN Code A),
the 5.3L V8 engine (VIN Code 4), or the 6.0L V8 engine
(VIN Code G) and the N15 flexible fuel option, you can
use either regular unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85). SeeFuel E85
(85% Ethanol) on page 6-8. For all other gasoline
engines, use only regular unleaded gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted octane
rating of 87 or higher. If the octane rating is less than 87,
an audible knocking noise, commonly referred to as spark
knock, might be heard when driving. If this occurs, use a
gasoline rated at 87 octane or higher as soon as possible.
If heavy knocking is heard when using gasoline rated at
87 octane or higher, the engine needs service.
Gasoline Speci cations
At a minimum, gasoline should meet ASTM specification
D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in
Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend against the use of
gasolines containing MMT. SeeAdditives on page 6-7
for additional information.
California Fuel
If the vehicle is certified to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specifications. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, the vehicle will operate
satisfactorily on fuels meeting federal specifications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and the
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 4-30. If this occurs, return to your
authorized dealer/retailer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs might not be covered by the vehicle warranty.
6-6
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, nothing should have to be added to the 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 the vehicle experiences
problems due to dirty injectors or valves, look for gasoline
that is advertised as TOP TIER Detergent Gasoline.
For customers who do not use TOP TIER Detergent
Gasoline regularly, one bottle of GM Fuel System
Treatment PLUS, added to the fuel tank at every engine
oil change, can help clean deposits from fuel injectors
and intake valves. GM Fuel System Treatment PLUS
is the only gasoline additive recommended by
General Motors.
Also, your dealer/retailer has additives that will help
correct and prevent most deposit-related problems.Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines might be available in
your area. We recommend that you use these gasolines,
if they comply with the specifications 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:This 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 the
vehicle warranty.
Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance
of the emission control system could be affected.
The malfunction indicator lamp might turn on. If this
occurs, return to your dealer/retailer for service.
6-7
Fuel E85 (85% Ethanol)
The 8th digit of the Vehicle Identification Number (VIN)
shows the code letter or number that identifies the
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identi cation Number
(VIN) on page 6-109.
If the vehicle has the 4.8L V8 engine (VIN Code A),
the 5.3L V8 engine (VIN Code 4), or the 6.0L V8 engine
(VIN Code G) and the N15 flexible fuel option, you can
use either unleaded gasoline or ethanol fuel containing
up to 85% ethanol (E85). SeeFuel on page 6-5. For all
other gasoline engines, use only the unleaded gasoline
described underGasoline Octane on page 6-6.
Only vehicles that have the 4.8L V8 engine (VIN Code A),
the 5.3L V8 engine (VIN Code 4) or the 6.0L V8 engine
(VIN Code G) and the N15 flexible fuel option 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 find
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 Specification
D 5798. By definition, 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 specifications 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 specification 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 0°C (32°F), the fuel mix in the fuel tank
should contain no more than 70% ethanol. It is best
not to alternate repeatedly between gasoline and E85.
6-8