maintenance GMC SIERRA DENALI 2003 User Guide

Towing a Trailer
If you don’t ,se the correct eq-., ...__. t and
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.
Notice: 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.
To identify the vehicle trailering capacity of your vehicle,
you should read the information in “Weight of the
Trailer” that appears later in this section.
If yours was built with trailering options, as many are,
it’s ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, durability and fuel economy.
Successful, safe trailering takes correct equipment, and it has to be used properly.
That’s the reason for this part. In it are many time-tested,
important trailering tips and safety rules. Many of
these are important for your safety and that of your
passengers.
So please read this section carefully before
you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
e
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live
but also where you’ll be driving.
A good source for
this information can be state or provincial police.
Consider using a sway control
if your trailer will
weigh
5,000 Ibs. (2 270 kg) or less. You should
always use a sway control
if your trailer will weigh
more than
5,000 Ibs. (2 270 kg). You can ask a
hitch dealer about sway controls.
Don’t tow a trailer at all during the first
500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
4-5 1

When You Are Ready to Leave After
Parking on a
Hill
1. Apply your regular brakes and hold the pedal down
while you:
0 start your engine,
shift into a gear, and
0 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, belt, 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.
4-59

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

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 vehicle than this
manual can.
To order the proper service manual,
see
Service Publications Ordering Information on
page
7- IO.
Your vehicle has an air bag system. Before attempting
to do your own service work, see
Servicing Your Air
Bag-Equipped Vehicle on page 1-72.
You should keep a record with all parts receipts and list
the mileage and the date
of any service work you
perform. See
Pat? E: Maintenance Record on page 6- 18.
.3u 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.
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 Gasoline Specifications
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. 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.
I I
Canada Only
5-5

To replace the engine air cleaner/filter do the following:
1. Loosen the screws on the cover of the housing
and lift up the cover.
2. Remove the air cleaner/filter from the housing.
Care should be taken
to dislodge as little dirt
as possible.
3. Clean the filter sealing surface and the housing.
4. Install the new engine air cleanedfilter.
5. Reinstall the cover and tighten the screws. Refer
to the Maintenance Schedule to determine when
to replace the engine air cleaner/filter. See
Part B: Owner Checks and Services on page 6-10.
Operating the engine with the air cleanedfilter
off can cause you or others to be burned. The
air cleaner not only cleans the air,
it stops
flame
if the engine backfires. If it isn’t there
and the engine backfires, you could be burned. Don’t drive with
it off, and be careful working
on the engine with the air cleaner/filter
off.
Notice: If the air cleaner/filter is off, a backfire
can cause a damaging engine fire. And, dirt
can easily get into your engine, which will damage
it. Always have the air cleanedfilter in place
when you’re driving.
5-20

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level
is when the engine oil is changed.
Change both the fluid and filter every
50,000 miles
(83
000 km) if the vehicle is mainly driven under one or
more
of these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
If you do not use your vehicle under any of these
conditions, change the fluid and filter every
100,000 miles (1 66 000 km).
See
Part A: Scheduled Maintenance Services on
page
6-4.
service.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice: Too much or too little fluid can damage
your transmission. Too much can mean that some
of the fluid could come out and fall on hot engine
part
or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to overheat. Be sure to get an accurate reading if you
check your transmission fluid.
Wait at least
30 minutes before checking the
transmission fluid level
if you have been driving:
0 When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic - especially in hot weather.
While pulling a trailer.
To get the right reading, the fluid should be at normal
operating temperature, which is 180°F
to 200°F
(82°C to 93°C).
5-2
1

~~ 3. Check
both sides of the dipstick, and read the lower
level. The fluid level must be in the
COLD area,
below the cross-hatched area, for a cold check or in
the HOT area or cross-hatched area for a hot check.
4. If the fluid level is in the acceptable range, push the
dipstick back in all the way; then flip the handle
down to lock the dipstick in place.
How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid
to use. See Part D:
Recommended Fluids and Lubricants on page
6-16.
Add fluid only after checking the transmission fluid while
it is hot.
(A cold check is used only as a reference.)
If the fluid level is
low, add only enough of the proper
fluid to bring the level up to the
HOT area for a hot
check. It doesn’t take much fluid, generally less than one
pint
(0.5 L). Don’t overfi//.
Notice: We recommend you use only fluid labeled
DEXRON@
111, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than DEXRON@
111 is
not covered by your new vehicle warranty.
@ After adding fluid, recheck the fluid level as
described under “How to Check”.
When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle
down
to lock the dipstick in place.
5-23

Brake Fluid
Your brake master cylinder reservoir is filled with DOT-3
brake fluid. See
Engine Compantment Overview on
page
5-12 for the location of the reservoir.
There are only two reasons why the brake fluid level
in the reservoir might go down. The first is that the brake
fluid goes down to an acceptable level during normal
brake lining wear. When new linings are put in, the fluid
level goes back
up. The other reason is that fluid is
leaking out of the brake system.
If it is, you should have
your brake system fixed, since a leak means that
sooner or later your brakes won’t work well, or won’t
work at all.
So, it isn’t a good idea to “top off your brake fluid.
Adding brake fluid won’t correct a leak.
If you add fluid
when your linings are worn, then you’ll have too much
fluid when you get new brake linings. You should add (or
remove) brake fluid, as necessary, only when work is
done
on the brake hydraulic system.
If yo, ..rave 1,- _._____ rake ---id, it ~~-1 spill on
the engine. The fluid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
fluid only when work is done on the brake
hydraulic system. See “Checking Brake Fluid”
in this section.
Refer to the Maintenance Schedule to determine when
to check your brake fluid. See
Part C: Periodic
Maintenance Inspections on page 6-14.
5-39

Brake Pedal Travel Battery
See your dealer if the brake pedal does not return to
normal height, or
if there is a rapid increase in
pedal travel. This could be a sign of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is complex. Its many
parts have to be of top quality and work well together
if
the vehicle is to have really good braking. Your vehicle
was designed and tested with top-quality
GM brake parts.
When you replace parts of your braking system -for
example, when your brake linings wear down and you
need new ones put in
- be sure you get new approved
GM replacement parts. If you don’t, your brakes may no
longer work properly. For example, if someone puts in
brake linings that are wrong for your vehicle, the balance
between your front and rear brakes can change
- for the
worse. The braking performance you’ve come to expect
can change in many other ways
if someone puts in the
wrong replacement brake parts. Your new
vehicle comes with a maintenance free
ACDelco@ battery. When it’s time for a new battery, get
one that has the replacement number shown on the
original battery’s label. We recommend an ACDelco@
battery. See
Engine Compartment Overview on
page
5-12 for battery location.
Warning: Battery posts, terminals and related
accessories contain lead and lead compounds,
chemicals known to the State of California to cause
cancer and reproductive harm. Wash hands after
handling.
5-42