service GMC YUKON DENALI 2003 Service Manual

Towing Loading Your Vehicle
Towing Your Vehicle
Consult your dealer or a professional towing service if
you need to have your disabled vehicle towed. See
Roadside Assistance Program on page
7-5.
If you want to tow your vehicle behind another vehicle
for recreational purposes (such as behind a motorhome),
see “Recreational Vehicle Towing” following.
Recreational Vehicle Towing
Recreational vehicle towing means towing your vehicle
behind another vehicle
- such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as “dinghy towing” (towing your vehicle
with all four wheels on the ground) and “dolly towing”
(towing your vehicle with two wheels
on the ground and
two wheels
up on a device known as a “dolly”).
Your vehicle was not designed
to be towed with any of
its wheels on the ground.
If your vehicle must be
towed, see Towing Your Vehicle on page
4-44.
Notices Towing an all-wheel-drive vehicle with all
four wheels on the ground, or even with only two
of
its wheels on the ground, will damage drivetrain
components. Don’t tow an all-wheel-drive vehicle
if
any of its wheels will be on the ground.
II II
GAWR FRT GAWR RR
!E mNERS MANUAL FOR ADDITIONAL INFORMATION[-]
The Certificationmire label is found on the rear edge of
the driver’s door.
The label shows the size of your original tires and the
inflation pressures needed
to obtain the gross weight
capacity of your vehicle. This is called the GVWR (Gross
Vehicle Weight Rating). The GVWR includes the
weight of the vehicle, all occupants, fuel and cargo.
The Certificationmire label also tells you the maximum
weights for the front and rear axles, called Gross
Axle Weight Rating (GAWR). To find out the actual loads
on your front and rear axles, you need to go
to a
4-44

Trailer Recommendations
You must subtract your hitch loads from the Cargo
Weight Rating (CWR). CWR is the maximum weight of
the load your vehicle can carry.
It doesn’t include
the weight of the people inside. But you can figure about
150 Ibs. (68 kg) for each seat. The total cargo load
must
not be more than your vehicle’s CWR.
Weigh your vehicle with the trailer attached,
so that you
won’t
go over the GVWR or GAWR. If you are using
a weight-distributing hitch, weigh the vehicle without the
spring bars in place.
You’ll get the best performance if you spread out the
weight of your load the right way, and
if you choose the
correct hitch and trailer brakes.
For more information, see
Towing a Trailer on
page 4-47.
Towing a Trailer
Is
IOU don’_ Ase e correct equipment anc-
drive properly, you can lose control when you
pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well
-- or even
at all.
You and your passengers could be
seriously injured. Pull a trailer only
if you have
followed all the steps
in this section. Ask your
dealer for advice and information about towing
a trailer with your vehicle.
Nofice: Pulling a trailer improperly can damage
your vehicle and result
in costly repairs not covered
by your warranty.
To pull a trailer correctly, follow
the advice
in this part, and see your dealer for
important information about towing a trailer with
your vehicle. Additional rear axle maintenance
is required for a vehicle used to tow a trailer. See
“Scheduled Maintenance Services” in the Index.
4-47

Parking on Hills
You really should not park your vehicle, with a
trailer attached, on a hill.
If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
2. Have someone place chocks under the trailer
3. When the wheel chocks are in place, release the
PARK
(P) yet.
wheels.
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
5. Release the regular brakes.
parking brake
and shift into PARK
(P).
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your 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
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don’t overfill),
engine
oil, axle lubricant, belts, cooling system and
brake system. Each
of these is covered in this manual,
and the Index will help you find them quickly. If
you’re trailering, it’s a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
4-55

Section 5 Service and Appearance Care
Service ............................................................ 5.3
Doing Your Own Service Work
......................... 5-3
Adding Equipment
to the Outside of Your
Vehicle
.................................................. 5-4
................................................................ Fuel 5.5
Gasoline Octane ............................................ 5.5
Gasoline Specifications ................................... 5-5
California Fuel ............................................... 5-6
Additives
....................................................... 5.6
Fuels in Foreign Countries
............................... 5-6
Filling Your Tank
............................................ 5-7
Filling a Portable Fuel Container ....................... 5.9
the Hood .................... , .................... 5.10
Hood Release ...................... ................ 5-10
Engine Compartment Overview ....... ......... 5-12
Engine Oil ....................................... ..... 5.13
Engine Air Cleaner/Filter ............................. 5.17
Automatic Transmission Fluid ......................... 5-20
Engine Coolant ......................................... 5-22
Checking Things Under
~~
Coolant Surge Tank Pressure Cap ............... 5-25
Engine Overheating ....................................... 5-25
Cooling System ............................................ 5.28
Engine Fan Noise ......................................... 5.33
Power Steering Fluid
..................................... 5-34
Windshield Washer Fluid
................................ 5.34
Brakes
........................................................ 5.36
Battery
........................................................ 5-39
Jump Starting
............................................... 5.40
All-Wheel Drive .............................................. 5.46
Rear Axle .................................. .......... 5-48
Bulb Replacement .......................................... 5-49
Halogen Bulbs .............................................. 5-49
Headlamps
.................................................. 5-49
Running Lamps
......................................... 5-50
Center High-Mounted Stoplamp (CHMSL) ......... 5-52
Taillamps ..................................................... 5-52
Replacement Bulbs ................................... 5.53
Front Turn Signal, Sidemarker and Daytime
5- 1

Section 5 Service and Appearance Care
Windshield Wiper Blade Replacement .............. 5.54
Tires .............................................................. 5.55
Inflation .. Tire Pressure ............................... 5-55
Tire Inspection and Rotation ........................... 5.56
When It
Is Time for New Tires ....................... 5-58
Buying New Tires
......................................... 5.58
Uniform Tire Quality Grading
.......................... 5.59
Wheel Alignment and Tire Balance
.................. 5-61
Wheel Replacement
...................................... 5.61
Tire Chains
.................................................. 5-62
If a Tire Goes Flat ........................................ 5.63
Spare Tire
................................................... 5.77
Appearance Care ............................................ 5.78
Cleaning the Inside of Your Vehicle
................. 5-78
Care of Safety Belts
...................................... 5.80
Weatherstrips
............................................... 5.80
Changing a Flat Tire
..................................... 5-63 Cleaning the Outside
of Your Vehicle
.............. 5-81
Sheet Metal Damage
.................................... 25-83
Finish Damage
............................................ 5-83
Underbody Maintenance
............................... 5-84
Chemical Paint Spotting
................................ 5-84
GM Vehicle Care/Appearance Materials
........... 5-84
Vehicle Identification .................................... ,.5-86
Service Parts Identification Label
..................... 5-86
Electrical System ............................................ 5-87
Add-on Electrical Equipment .......................... 5-87
Windshield Wiper Fuses
............................... 25-87
Power Windows
and Other Power Options ....... 5-87
Fuses and Circuit Breakers
............................ 5-87
Capacities and Specifications .......................... 5-96
Capacities and Specifications ......................... 5-96
Vehicle
Identification Number (VIN)
................ 5-86
Normal Maintenance Replacement Parts ...... 5-98
5-2

Service
Your dealer knows your vehicle best and wants you to
be happy with it. We hope you’ll go to your dealer
for all your service needs. You’ll get genuine
GM parts
and GM-trained and supported service people.
We hope you’ll want to keep your GM vehicle all GM.
Genuine GM parts have one of these marks:
Doing Your Own Service Work
If you want to do some of your own service work, you’ll
want to use the proper service manual. It tells you
much more about how to service your vehicie
than this
manual can. To order the proper service manual,
see Service Publications Ordering Information
on
page 7-10.
Your vehicle has an air bag system. Before attempting
to do your own service work, see Servicing Your Air
Bag-Equipped Vehicle on page
1-85.
You should keep a record with all parts receipts and list
the mileage and the date of any service work you
perform. See Part
E: Maintenance Record on page 6-17.
5-3

You can be injured and your 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 you attempt any vehicle
maintenance task.
Be sure to use the proper nuts, bolts and
other fasteners. “English” and “metric”
fasteners can be easily confused.
If you
use the wrong fasteners, parts can later
break or fall
off. You could be hurt.
1
Adding Equipment to the Outside of
Your
Vehicle
Things you might add to the outside of your vehicle can
affect the airflow 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.
5-4

Fuel
Use of the recommended fuel is an important part of the
proper maintenance
of your vehicle.
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 Specifications
It is recommended that gasoline meet specifications
which were developed by the American Automobile
Manufacturers Association and endorsed
by the
Canadian Vehicle Manufacturers Association for better
vehicle performance and engine protection. Gasoline meeting these specifications could provide improved
driveability and emission control system performance
compared to other gasoline.
In Canada, look for the
"Auto Makers' Choice"
label on the pump.
Canada Only
5-5

California Fuel
If your vehicle is certified to meet California Emission
Standards (see the underhood emission control label), it
is designed
to operate on fuels that meet California
specifications.
If this fuel is not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be affected. The malfunction indicator lamp may
turn on (see Malfunction Indicator Lamp on page
3-38 )
and your vehicle may fail a smog-check test. 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. You should not have
to add anything to your
fuel. 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
specifications described earlier.
5-6
Notice: Your vehicle was not designed for fuel that
contains methanol. Don’t use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage wouldn’t 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.
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 find. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel wouldn’t 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’ll be driving.

What Kind of Engine Oil to Use
Oils recommended for your vehicle can be identified by
looking for the starburst symbol.
This symbol indicates that the oil has been certified by
the American Petroleum Institute (API).
Do not use
any oil which does not carry this starburst symbol.
1-1 If you choose to perform
i* Y
the engine oil change
service yourself, be sure
the oil you use has
the starburst symbol on
the front of the oil
container. If you have your
oil changed for you, be
sure the oil put into
your engine
is American
I I Petroleum Institute certified
for gasoline engines.
fou should also use the proper viscosity oil for your
vehicle, as shown in the viscosity chart.
RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS
HOT
WEATHER
-
"F
5.100
+ 80
+ 60
t 40
t 20
0
f
-
"C
- +3e
- t 2i
- + 1t
- t4
- -7
- - 16

I
I
i
I-
/
COLD
WEATHER
DO NOT USE SAE 1OW-40, SAE 2OW-50 OR ANY OTHER VISCOSITY GRADE OIL NOT RECOMMENDED
5-1 5