2004 GMC SIERRA DENALI tow

The following instructions tell you how to change the
automatic door unlock mode. Choose one of the
four programming options listed above before entering
the program mode. To enter the program mode, do
the following:
1. Begin with the ignition off. Then pull the turn
signal/multifunction lever toward you and hold
it there while you perform the next step.
2. Turn the key to RUN and LOCK twice. Then,
with the key in LOCK, release the turn
signal/multifunction lever. Once you do this, the
doors will lock and unlock, the horn will chirp twice,
and a 30-second timer will begin. You are now
ready to program the automatic door unlock feature.3. Press the unlock side of the power lock switch
once. You will hear one, two, three, or four chimes.
The number of chimes tells you which unlock
mode is currently selected. Continue to press the
door unlock switch until the number of chimes
that you hear matches the number of the mode that
you want. If you take longer than 30 seconds,
the locks will automatically lock and unlock and the
horn will chirp twice to indicate that you have left
the program mode. If this occurs, you can repeat the
procedure beginning with Step 1 to re-enter the
programming mode.
You can exit the program mode any time by turning the
ignition to RUN (the doors will automatically lock and
unlock and the horn will chirp twice to indicate that you
are leaving the program mode). If the lock/unlock
switches are not pressed while in the programming
mode, the current automatic settings will not be
modi®ed.
See your dealer for more information.
2-10

Rear Doors
Your vehicle is equipped with rear access doors that
allow easier access to the rear area of the extended cab.
To open a rear access
door from the outside, ®rst
open the front door.
Then, use the handle
located on the front edge
of the rear access door
to open it.
You must fully close a rear access door before you can
close the front door.To open a rear access
door from the inside, the
front door must be opened
®rst. Then, use the
handle located on the
inside of the rear access
door to open it.
Tailgate
You can open the tailgate by lifting up on its handle
while pulling the tailgate toward you.
To shut the tailgate, ®rmly push it upward until it
latches.
After you put the tailgate back up, pull it back towards
you to be sure it latches securely.
2-11

Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not need an elaborate
ªbreak-in.º But it will perform better in the long run
if you follow these guidelines:
·Keep your speed at 55 mph (88 km/h) or less for
the ®rst 500 miles (805 km).
·Do not drive at any one speed Ð fast or
slow Ð for the ®rst 500 miles (805 km).
Do not make full-throttle starts.
·Avoid making hard stops for the ®rst 200 miles
(322 km) or so. During this time your new
brake linings are not yet broken in. Hard stops
with new linings can mean premature wear
and earlier replacement. Follow this breaking-in
guideline every time you get new brake
linings.
·Do not tow a trailer during break-in. SeeTowing
a Trailer on page 4-58
for more information.
Ignition Positions
With your key in the ignition switch you can turn it to
four different positions.
Notice:If your key seems stuck in LOCK and you
can not turn it, be sure you are using the correct
key; if so, is it all the way in? Turn the key only with
your hand. Using a tool to force it could break the
key or the ignition switch. If none of these works,
then your vehicle needs service.
2-18

Automatic Transmission Operation
Your vehicle is equipped with an automatic transmission
that features an electronic shift position indicator
located within the instrument panel cluster. This display
is powered anytime the shift lever is capable of being
moved out of PARK (P). See
Fuses and Circuit Breakers
on page 5-105.
There are several different positions for your shift lever.
PARK (P):This position locks your wheels. It's the
best position to use when you start your engine because
your vehicle can't move easily.
{CAUTION:
It is dangerous to get out of your vehicle if the
shift lever is not fully in PARK (P) with the
parking brake ®rmly set. Your vehicle can roll.
Do not leave your vehicle when the engine is
running unless you have to. If you have left
the engine running, the vehicle can move
suddenly. You or others could be injured.
CAUTION: (Continued)
CAUTION: (Continued)
To be sure your vehicle will not move, even
when you are on fairly level ground, always set
your parking brake and move the shift lever to
PARK (P). See
Shifting Into Park (P) on
page 2-26
. If you are pulling a trailer, see
Towing a Trailer on page 4-58.
REVERSE (R):Use this gear to back up.
Notice:Shifting to REVERSE (R) while your vehicle
is moving forward could damage the transmission.
The repairs would not be covered by your warranty.
Shift to REVERSE (R) only after your vehicle is
stopped.
To rock your vehicle back and forth to get out of snow,
ice or sand without damaging your transmission,
see If You Are Stuck: In Sand, Mud, Ice or Snow on
page 4-46.
2-22

NEUTRAL (N):In this position, your engine doesn't
connect with the wheels. To restart when you're already
moving, use NEUTRAL (N) only. Also, use
NEUTRAL (N) when your vehicle is being towed.
{CAUTION:
Shifting into a drive gear while your engine is
running at high speed is dangerous. Unless
your foot is ®rmly on the brake pedal, your
vehicle could move very rapidly. You could
lose control and hit people or objects. Do not
shift into a drive gear while your engine is
running at high speed.
Notice:Shifting out of PARK (P) or NEUTRAL (N)
with the engine running at high speed may damage
the transmission. The repairs would not be
covered by your warranty. Be sure the engine is not
running at high speed when shifting your vehicle.DRIVE (D):This position is for normal driving. If you
need more power for passing, and you're:
·Going less than about 35 mph (55 km/h), push your
accelerator pedal about halfway down.
·Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
You'll shift down to the next gear and have more power.
DRIVE (D) can be used when towing a trailer, carrying
a heavy load, driving on steep hills or for off-road driving.
You may want to shift the transmission to THIRD (3)
or, if necessary, a lower gear selection if the
transmission shifts too often.
THIRD (3):This position is also used for normal driving,
however it offers more power and lower fuel economy
than DRIVE (D).
SECOND (2):This position gives you more power but
lower fuel economy. You can use SECOND (2) on
hills. It can help control your speed as you go down
steep mountain roads, but then you would also want to
use your brakes occasionally.
If you manually select SECOND (2), the transmission
will drive in second gear. You may use this feature
for reducing the speed of the rear wheels when you are
trying to start your vehicle from a stop on slippery
road surfaces.
2-23

FIRST (1):This position gives you even more power
(but lower fuel economy) than SECOND (2). You
can use it on very steep hills, or in deep snow or mud.
If the shift lever is put in FIRST (1) while the vehicle
is moving forward, the transmission won't shift into ®rst
gear until the vehicle is going slowly enough.
Notice:Spinning the tires or holding the vehicle in
one place on a hill using only the accelerator
pedal may damage the transmission. If you are
stuck, do not spin the tires. When stopping on a hill,
use the brakes to hold the vehicle in place.
On cold days, approximately 32ÉF (0ÉC) or colder, your
transmission is designed to shift differently until the
engine reaches normal operating temperature. This is
intended to improve heater performance.
Tow/Haul Mode
Your vehicle may be equipped with a Tow/Haul mode.
The switch is located on the end of the column shift
lever. You can use this feature to assist when towing or
hauling a heavy load.
2-24

When Tow/Haul is
activated the Tow/Haul
symbol will illuminate
on the instrument panel
cluster. See
Tow/Haul
ModeunderTowing
a Trailer on page 4-58for
more information.
All-Wheel Drive
With this feature, engine power is sent to all four wheels
all the time.
This is like four-wheel drive, but there is no separate
lever or switch to engage or disengage the front axle.
It is fully automatic, and adjusts itself as needed for road
conditions.
Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking
brake pedal with your left foot.
A chime will activate and the warning light will ¯ash
when the parking brake is applied and the vehicle
is moving at least 3 mph (5 km/h) for at least
three seconds.To release the parking brake, hold the regular brake
pedal down. Pull the bottom edge of the lever, located
above the parking brake pedal, with the parking
brake symbol, to release the parking brake.
If the ignition is on when the parking brake is released,
the brake system warning light will go off.Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Verify that
the parking brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and are parking on any hill,
see
Towing a Trailer on page 4-58.
2-25

Shifting Into Park (P)
{CAUTION:
It can be dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P) with
the parking brake ®rmly set. Your vehicle can
roll. If you have left the engine running, the
vehicle can move suddenly. You or others
could be injured. To be sure your vehicle will
not move, even when you are on fairly level
ground, use the steps that follow. With
four-wheel drive, if your transfer case is in
NEUTRAL, your vehicle will be free to roll,
even if your shift lever is in PARK (P). So, be
sure the transfer case is in a drive gear Ð not
in NEUTRAL. If you are pulling a trailer, see
Towing a Trailer on page 4-58.
1. Hold the brake pedal down with your right foot and
set the parking brake.2. Move the shift lever into PARK (P) like this:
·Pull the shift lever toward you.
2-26