2004 GMC SIERRA DENALI tow

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-3
Rear Seats
............................................... 1-8
Safety Belts
.............................................. 1-8
Child Restraints
.......................................1-29
Air Bag Systems
......................................1-62
Restraint System Check
............................1-79
Features and Controls..................................... 2-1
Keys
........................................................ 2-2
Doors and Locks
....................................... 2-6
Windows
.................................................2-13
Theft-Deterrent Systems
............................2-15
Starting and Operating Your Vehicle
...........2-18
Mirrors
....................................................2-31
OnStar
žSystem
......................................2-36
HomeLinkžTransmitter
.............................2-38
Storage Areas
.........................................2-42
Vehicle Personalization
.............................2-45
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-2
Climate Controls
......................................3-19
Warning Lights, Gages and Indicators
.........3-27
Driver Information Center (DIC)
..................3-46
Audio System(s)
.......................................3-64Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-48
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-4
Checking Things Under the Hood
................. 5-8
All-Wheel Drive
........................................5-46
Rear Axle
...............................................5-47
Front Axle
...............................................5-48
Bulb Replacement
....................................5-49
Windshield Wiper Blade Replacement
.........5-58
Tires
......................................................5-59
Appearance Care
.....................................5-96
Vehicle Identi®cation
...............................5-104
Electrical System
....................................5-105
Capacities and Speci®cations
...................5-114
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance and Information.............. 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-10
Index................................................................ 1
2004 GMC Sierra Denali Owner ManualM

Front Seats
Power Seats
Horizontal Control:You can adjust your vehicle's front
seats with the horizontal control located on the
outboard edge of each front seat.
Raise or lower the front of the seat by raising or
lowering the forward edge of the control. Raise or lower
the rear of the seat by raising or lowering the rear
edge of the control.
Move the seat forward or rearward by moving the whole
control toward the front or toward the rear of the
vehicle.
Moving the whole control up or down raises or lowers
the entire seat cushion.
Vertical Control:See
Reclining Seatbacks on
page 1-5.
1-3

To heat only the seatback, press the vertical button with
the heated seatback symbol. An indicator light on the
seatback button will glow to designate that only the
seatback is being heated. Additional presses of
the seatback button will cycle through the heat levels for
the seatback only. Press the horizontal button again
to heat the whole seat.
The heated front seats will shut off automatically when
the ignition is turned off.Reclining Seatbacks
Your vehicles front seatbacks have a recline feature.
Vertical Control:You can use the vertical control to
adjust the angle of the seatback. Move the reclining front
seatback rearward or forward by moving the vertical
control toward the rear or toward the front of the vehicle.
1-5

{CAUTION:
Never do this.
Here two children are wearing the same belt.
The belt can't properly spread the impact
forces. In a crash, the two children can be
crushed together and seriously injured. A belt
must be used by only one person at a time.
Q:What if a child is wearing a lap-shoulder belt,
but the child is so small that the shoulder belt
is very close to the child's face or neck?
A:Move the child toward the center of the vehicle,
but be sure that the shoulder belt still is on the
child's shoulder, so that in a crash the child's upper
body would have the restraint the belts provide.
If the child is sitting in a rear seat outside position,
see
Rear Safety Belt Comfort Guides for Children
and Small Adults on page 1-27
.
If the child is so small that the shoulder belt is still
very close to the child's face or neck, you might
want to place the child in a seat that has a lap belt,
if your vehicle has one.
1-31

Child Restraint Systems
An infant car bed (A), a special bed made for use in a
motor vehicle, is an infant restraint system designed
to restrain or position a child on a continuous ¯at
surface. Make sure that the infant's head rests toward
the center of the vehicle.A rear-facing infant seat (B) provides restraint with the
seating surface against the back of the infant. The
harness system holds the infant in place and, in a crash,
acts to keep the infant positioned in the restraint.
1-36

Seat Position Sensors
Vehicle's with dual stage air bags are also equipped
with special sensors which enable the sensing system to
monitor the position of both the driver and passenger
front seats. The seat position sensor provides
information which is used to determine if the air bags
should deploy at a reduced level or at full depoyment.
What Makes an Air Bag In¯ate?
In an impact of sufficient severity, the air bag sensing
system detects that the vehicle is in a crash. The
sensing system triggers a release of gas from the
in¯ator, which in¯ates the air bag. The in¯ator, air bag,
and related hardware are all part of the air bag
modules inside the steering wheel and in the instrument
panel in front of the right front passenger.
How Does an Air Bag Restrain?
In moderate to severe frontal or near-frontal collisions,
even belted occupants can contact the steering wheel or
the instrument panel. Air bags supplement the
protection provided by safety belts. Air bags distribute
the force of the impact more evenly over the occupant's
upper body, stopping the occupant more gradually.But air bags would not help you in many types of
collisions, including rollovers, rear impacts and many
side impacts, primarily because an occupant's motion is
not toward those air bags. Air bags should never be
regarded as anything more than a supplement to safety
belts, and then only in moderate to severe frontal or
near-frontal collisions.
What Will You See After an Air Bag
In¯ates?
After an air bag in¯ates, it quickly de¯ates, so quickly
that some people may not even realize the air bag
in¯ated. Some components of the air bag module ± the
steering wheel hub for the driver's air bag, or the
instrument panel for the right front passenger's
bag ± will be hot for a short time. The parts of the bag
that come into contact with you may be warm, but
not too hot to touch. There will be some smoke and dust
coming from the vents in the de¯ated air bags. Air
bag in¯ation does not prevent the driver from seeing or
being able to steer the vehicle, nor does it stop
people from leaving the vehicle.
1-66

{CAUTION:
If the air bag readiness light in the instrument
panel cluster ever comes on and stays on, it
means that something may be wrong with the
air bag system. If this ever happens, have the
vehicle serviced promptly, because an
adult-size person sitting in the right front
passenger's seat may not have the protection
of the frontal air bag. See ªAir Bag Readiness
Lightº in the Index for more on this, including
important safety information.Aftermarket equipment, such as seat covers, can affect
how well the passenger sensing system operates.
You may want to consider not using seat covers or other
aftermarket equipment if your vehicle has the passenger
sensing system. SeeAdding Equipment to Your Air
Bag-Equipped Vehicle on page 1-78for more
information about modi®cations that can affect how the
system operates.
{CAUTION:
Stowing of articles under the passenger's seat
or between the passenger's seat cushion and
seatback may interfere with the proper
operation of the passenger sensing system.
1-77

The following instructions tell you how to change the
automatic door lock mode. Choose one of the three
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 then back to 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 lock feature.
3. Press the lock side of the power lock switch once.
You will hear one, two, or three chimes. The
number of chimes tells you which lock mode is
currently selected. Continue to press the door lock
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.
Programmable Unlocking Feature
The following is the list of available programming
options:
Mode 1:Driver's door unlocks when the transmission is
shifted into PARK (P).
Mode 2:All doors unlock when the transmission is
shifted into PARK (P). This is the mode that is
pre-programmed in the factory for your vehicle.
Mode 3:All doors unlock when the key is removed
from the ignition.
Mode 4:No automatic door unlock.
2-9