2003 GMC SIERRA DENALI tire pressure

The anti-lock system can change the brake pressure
faster than any driver could. The computer is
programmed to make the most
of available tire and road
conditions. This can help you steer around the obstacle
while braking hard.
As you brake, your computer keeps receiving updates
on wheel speed and controls braking pressure
accordingly. Remember:
Anti-lock doesn’t change the time you need
to get your foot up
to the brake pedal or always
decrease stopping distance.
If you get too close to the
vehicle in front of you, you won’t have time to apply
your brakes
if that vehicle suddenly slows or stops.
Always leave enough room up ahead
to stop, even
though you have anti-lock brakes.
Using Anti-Lock
Don’t pump the brakes. Just hold the brake pedal down
firmly and let anti-lock work for you. You may feel
the brakes vibrate, or you may notice some noise, but
this is normal.
Braking in Emergencies
With anti-lock, you can steer and brake at the same
time. In many emergencies, steering can help you more
than even the very best braking.
Locking Rear Axle
If your vehicle has this feature, your locking rear axle
can give you additional traction on snow, mud, ice, sand
or gravel. It works like a standard axle most of the
time, but when one of the rear wheels has no traction
and the other does, this feature will allow the wheel with
traction to move the vehicle.
4-8

Hydroplaning
Hydroplaning is dangerous. So much water can build up
under your tires that they can actually ride on the
water. This can happen
if the road is wet enough and
you’re going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.
Hydroplaning doesn’t happen often. But it can
if
your tires do not have much tread or if the pressure in
one or more is low. It can happen
if a lot of water is
standing on the road. If you can see reflections
from trees, telephone poles or other vehicles, and
raindrops “dimple” the water’s surface, there could be
hydroplaning.
Hydroplaning usually happens at higher speeds. There
just isn’t a hard and fast rule about hydroplaning.
The best advice is to slow down when it is raining.
Driving Through Deep Standing Water
Notice: If you drive too quickly through deep
puddles or standing water, water can come in
through your engine’s air intake and badly damage your engine. Never drive through water that is
slightly lower than the underbody
of your vehicle. If
you can’t avoid deep puddles or standing water,
drive through them very slowly.
Driving Through Flowhg W=+er
--m
Flowing or rushing water creates strong forces.
If you try to drive through flowing water, as you
might at a low water crossing, your vehicle can
be carried away.
As little as six inches of
flowing water can carry away
a smaller vehicle.
If this happens, you and other vehicle
occupants could drown. Don’t ignore police
warning signs, and otherwise be very cautious
about trying to drive through flowing water.
Some Other Rainy Weather Tips
Turn on your low-beam headlamps - not just your
parking lamps
- to help make you more visible to
others.
Besides slowing down, allow some extra following
distance. And be especially careful when you
pass another vehicle. Allow yourself more clear
room ahead, and be prepared to have your
view restricted by road spray.
Have good tires with proper tread depth. See
Tires
on page 5-6 I.
4-33

Once you are moving on the freeway, make certain you
allow a reasonable following distance. Expect to
move slightly slower at night.
When you want
to leave the freeway, move to the
proper lane well in advance.
If you miss your exit, do
not, under any circumstances, stop and back up. Drive
on to the next exit.
The exit ramp can be curved, sometimes quite sharply.
The exit speed is usually posted.
Reduce your speed according to your speedometer, not
to your sense of motion. After driving for any distance
at higher speeds, you may tend
to think you are
going slower than you actually are.
Before Leaving on a Long Trip
Make sure you’re ready. Try to be well rested. If you
must start when you’re not fresh
- such as after a day’s
work
- don’t plan to make too many miles that first
part of the journey. Wear comfortable clothing and shoes
you can easily drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it’s ready to go. If it needs
service, have it done before starting out.
Of course,
you’ll find experienced and able service experts
in dealerships all across North America. They’ll be
ready and willing to help
if you need it.
Here are some things you can check before a trip:
e
e e
e
e
e
e
Windshield Washer Fluid: Is the reservior full? Are
all windows clean inside and outside?
Wiper Blades: Are they in good shape?
Fuel, Engine Oil, Other Fluids: Have you checked
all levels?
Lamps: Are they all working? Are the lenses clean?
Tires: They are vitally important to a safe,
trouble-free trip.
Is the tread good enough for
long-distance driving? Are the tires all inflated to the
recommended pressure?
Weather Forecasts: What’s the weather outlook
along your route? Should you delay your trip a
short time to avoid a major storm system?
Maps: Do you have up-to-date maps?
4-35

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

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

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

Inflation - Tire Pressure
The CertificationKire label, which is on the rear edge of
the driver’s door, shows the correct inflation pressures
for your tires when they’re cold. “Cold” means your
vehicle has been sitting for at least three hours or driven
no more than
1 mile (1.6 km).
Notice: Don’t let anyone tell you that underinflation
or overinflation is all right. It’s not. If your tires
don’t have enough air (underinflation), you can get
the following:
Too much flexing
Too much heat
Tire overloading
Bad wear
Bad handling
Bad fuel economy
If your tires have too much air (overinflation), you
can get the following:
Unusual wear
Bad handling
Rough ride
Needless damage from road hazards
5-62
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell
if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they’re underinflated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
Tire Inspection and Rotation
Tires should be rotated every 7,500 miles (12,500 km).
Any time you notice unusual wear, rotate your tires
as soon as possible and check wheel alignment.
Also
check for damaged tires or wheels. See When It Is Time
for New Tires on page 5-64 and Wheel Replacement
on page
5-67 for more information.
Make sure the spare tire
is stored securely. Push, pull,
and then try to rotate
or turn the tire. If it moves,
use the wheel wrench and jack handle extensions to
tighten the cable. See
Changing a Flat Tire on
page
5-69.