2003 GMC SIERRA DENALI tires

If You Are Stuck: In Sand, Mud, Ice
or Snow
in order to free your vehicle when it is stuck, you will
need to spin the wheels, but you don’t want to spin your
wheels too fast. The method known as “rocking” can
help you aet out when you’re stuck, but you must
use cauti
.
If you let your tires spin at high speed, they
can explode, and you or others could be
injured.
And, the transmission or other parts of
the vehicle can overheat. That could cause an
CAUTION: (Continued) engine compartment fire or other
damage.
When you’re stuck, spin the wheels as little as
possible. Don’t spin the wheels above
25 mph
(55 km/h) as shown on the speedometer.
Nofice: Spinning your wheels can destroy parts of
your vehicle as well as the tires. If you spin the
wheels too fast while shifting your transmission back and forth, you can destroy your transmission.
For information about using tire chains on your
vehicle, see
Tire Chains on page 5-68.
4-42

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 4-45.
Notice: 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.
COLD TIRE PRESSURE
00
The Certificationflire 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.
4-45

Then, during the first 500 miles (800 km) that you
tow a trailer, don’t drive over
50 mph (80 km/h)
and don’t make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at
the heavier loads.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD
(3) or, if necessary, a
lower gear selection
if the transmission shifts
too often (e.g., under heavy loads and/or hilly
conditions).
Three important considerations have to do with weight:
the weight of the trailer,
the weight of the trailer tongue
and the weight on your vehicle’s tires.
Tow/HauI Mode
Tow/haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. The purpose
of the
tow/haul mode is to:
Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.
Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when
the vehicle is unloaded.
Improve control of vehicle speed while requiring
less throttle pedal activity when pulling a heavy
trailer or a large or heavy load.
Your vehicle may be equipped with a switch at the end
of the shift lever which when pressed enables
tow/haul. When the switch is pressed, a light on the
instrument panel will illuminate to indicate that tow/haul
has been selected. Tow/haul may be turned
off by
pressing the switch again, at which time the indicator
light on the instrument panel will turn
off. The vehicle will
automatically turn
off tow/haul every time it is started.
4-52

A B
If you’re using a weight-carrying or a weight-distributing
hitch, the trailer tongue weight
(A) should be 10 percent
to
15 percent of the total loaded trailer weight (B).
Do not exceed the maximum allowable tongue weight
for your vehicle.
After you’ve loaded your trailer, weigh the trailer and
then the tongue, separately, to see
if the weights
are proper. If they aren’t, you may be able to get them
right simply by moving some items around in the
trailer.
Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inflated to the upper limit
for cold tires. You’ll find these numbers on the
Certificationnire label at the rear edge of the driver’s
door or see
Loading Your Vehicle on page 4-45.
Then be sure you don’t go over the GVW or rear axle
limit for your vehicle, including the weight of the
trailer tongue.
If you use a weight distributing hitch,
make sure you don’t go over the rear axle limit before
you apply the weight distribution spring.
Hitches
It’s important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are
a few reasons why you’ll need the right hitch, Here
are some rules to follow:
0 If you’ll be pulling a trailer that, when loaded, will
weigh more than
5,000 lbs. (2 270 kg) be sure to
use a properly mounted, weight-distributing
hitch and sway control of the proper size. This
equipment is very important for proper vehicle
loading and good handling when you’re driving.
4-55

Safety Chains
You should always attach safety chains between your
vehicle and your trailer. Cross the safety chains
under the tongue of the trailer to help prevent the tongue
from contacting the road
if it becomes separated from
the hitch.
You may attach the safety chains to the attaching point
on the hitch platform. Always leave just enough slack
so you can turn with your rig. Never allow safety chains
to drag on the ground.
Trailer Brakes
If your trailer weighs more than 2,000 Ibs. (900 kg)
loaded, then it needs its own brakes
- and they must be
adequate. Be sure to read and follow the instructions
for the trailer brakes
so you’ll be able to install,
adjust and maintain them properly.
Your trailer brake system can tap into the vehicle’s
hydraulic brake system only
if:
(20 650 kPa) of pressure.
The trailer parts can withstand 3,000 psi
The trailer’s brake system will use less than
0.02 cubic inch (0.3 cc) of fluid from your vehicle’s
master cylinder. Otherwise, both braking systems
won’t work well. You could even lose your brakes. If
everything checks out this far, make the brake tap at
the
port on the master cylinder that sends the fluid
to the rear brakes. But don’t use copper tubing for this.
If you do, it will bend and finally break off. Use steel
brake tubing.
Driving with a Trailer
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving and
then apply the trailer brake controller by hand to be
sure the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.
While towing a trailer or when exposed to long periods
of sunshine, the floor of the truck bed may become
very warm. Avoid putting items in the truck bed
that might be affected by high ambient temperatures.
4-56

Section 5 Service and Appearance Care
Tires .......................................................... 5-61
Inflation
.. Tire Pressure ................................ 5.62
Tire Inspection and Rotation
........................... 5.62
When It
Is Time for New Tires ....................... 5-64
Buying New Tires
......................................... 5-64
Uniform Tire Quality Grading
.......................... 5-65
Wheel Alignment and Tire Balance
.................. 5.67
Wheel Replacement
...................................... 5.67
Tire Chains
.................................................. 5-68
If a Tire Goes Flat ........................................ 5.68
Spare Tire
................................................... 5.85
Changing a
Flat Tire
.................. ............ 5.69
Appearance Care
............................................ 5.86
Cleaning the Inside of Your Vehicle
................. 5-86
Care of Safety Belts
...................................... 5-88
Weatherstrips
........................................... 5-88
Cleaning the Outside of Your Vehicle
.. .... 5-88
Sheet Metal Damage ..................................... 5-91
Underbody Maintenance
................................ 5-91
Chemical Paint Spotting
............................... -591
Vehicle Identification
...................................... 5-94
Vehicle Identification Number (VIN)
................. 5-94
Service Parts Identification Label
..................... 5-94
Electrical System
............................................ 5-95
Add-on Electrical Equipment
.......................... 5-95
Windshield Wiper Fuses
................................ 5-95
Fuses and Circuit Breakers
............................ 5-95
Capacities and Specifications
........................ 5-104
Normal Maintenance Replacement Parts
......... 5-105
Finish
Damage
............................................. 5-91
GM Vehicle Care/Appearance Materials
........... 5-92
Power Windows and Other Power Options
....... 5-95
5-2

Notice:
Using the wrong fluid can badly damage brake
system parts. For example, just a few drops of
mineral-based
oil, such as engine oil, in your
brake system can damage brake system
parts
so badly that they’ll have to be replaced.
Don’t let someone
put in the wrong kind of fluid.
If you spill brake fluid on your vehicle’s painted
surfaces, the paint finish can be damaged.
Be careful not to spill brake fluid on your
vehicle.
If you do, wash it off immediately.
See “Appearance Care” in the Index.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving (except when you are pushing on the
brake pedal firmly). The
brake wear warning sound means that soon
your brakes won’t work well. That could lead to
an accident. When you hear the brake wear
Notice: Continuing to drive with worn-out brake
pads could result
in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes are first applied or lightly applied.
This does not mean something is wrong with your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence
to GM torque specifications.
Brake linings should always be replaced as complete
axle sets.
See
Brake System Inspection on page 6- 15
5-41

I Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your
tire warranty and where to obtain service,
see your
GMC Warranty booklet for det+
Poorly maintained and improperly used tires
are dangerous.
0 Overloading your tires can cause
overheating as a result of too much
friction. You could have an air-out and a
serious accident. See "Loading Your
Vehicle" in the Index.
CAUTION: (Continued)
0 Underinflated tires pose the same danger
as overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.
0 Overinflated tires are more likely to be cut,
punctured or broken by a sudden impact
- such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn, old tires can cause accidents. If
your tread
is badly worn, or if your tires
have been damaged, replace them.
5-6 1