2004 GMC SIERRA tow

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-3
Rear Seats
............................................... 1-9
Safety Belts
.............................................1-11
Child Restraints
.......................................1-33
Air Bag Systems
......................................1-70
Restraint System Check
............................1-87
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
....................................... 2-8
Windows
.................................................2-16
Theft-Deterrent Systems
............................2-19
Starting and Operating Your Vehicle
...........2-21
Mirrors
....................................................2-54
OnStar
žSystem
......................................2-64
Storage Areas
.........................................2-66
Vehicle Personalization
.............................2-69
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-21
Warning Lights, Gages and Indicators
.........3-33
Driver Information Center (DIC)
..................3-55
Audio System(s)
.......................................3-73Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-53
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-4
Checking Things Under the Hood
...............5-10
Rear Axle
...............................................5-59
Four-Wheel Drive
.....................................5-60
Noise Control System
...............................5-62
Bulb Replacement
....................................5-64
Windshield Wiper Blade Replacement
.........5-74
Tires
......................................................5-76
Appearance Care
...................................5-116
Vehicle Identi®cation
...............................5-125
Electrical System
....................................5-125
Capacities and Speci®cations
...................5-134
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance and Information.............. 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-11
Index................................................................ 1
2004 GMC Sierra Owner ManualM

Power SeatsIf your vehicle has a power seat, you can adjust it with
these controls located on the outboard sides of the
seats.
·Raise or lower the front of the seat cushion by
raising or lowering the forward edge of the
horizontal control.
·Move the seat forward or rearward by moving the
whole horizontal control forward or rearward.
·Raise or lower the rear of the seat cushion by
raising or lowering the rear edge of the horizontal
control.
·Moving the whole horizontal control up or down
raises or lowers the entire seat cushion.
If your vehicle has power reclining seats, you can use
the vertical control to adjust the angle of the seatback.
Move the reclining front seatback rearward or forward
by moving the control toward the rear or the front of the
vehicle. See
Reclining Seatbacks on page 1-6.
1-4

{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:If the child is sitting in a rear outside seat position,
move the child toward the center of the vehicle. See
Rear Safety Belt Comfort Guides for Children and
Small Adults on page 1-30
. If the child is sitting in
the center rear seat position of a crew cab, move
the child toward the safety belt buckle. In either
case 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 that belts provide.
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 a seat that has a lap belt, if your
vehicle has one.
1-34

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.
1-39

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 thede¯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.
{CAUTION:
When an air bag in¯ates, there is dust in the
air. This dust could cause breathing problems
for people with a history of asthma or other
breathing trouble. To avoid this, everyone in
the vehicle should get out as soon as it is safe
to do so. If you have breathing problems but
can't get out of the vehicle after an air bag
in¯ates, then get fresh air by opening a
window or a door. If you experience breathing
problems following an air bag deployment, you
should seek medical attention.
1-75

{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
CAUTION: (Continued)
CAUTION: (Continued)
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. See
Adding Equipment to Your Air
Bag-Equipped Vehicle on page 1-86for 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.
1-85

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 door 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), for automatic transmission
vehicles only.
Mode 2:All doors unlock when the transmission is
shifted into PARK (P), for automatic transmission
vehicles only. 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 This is the mode that is
pre-programmed in the factory for manual transmission
vehicles.
Mode 4:No automatic door unlock.
2-11

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 door unlock 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 thatyou 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.
Rear Door Security Locks
(Crew Cab)
With this feature, you can lock the rear side doors so
that they cannot be opened from the inside by
passengers.
2-12